阅读说明：本技术 分级蒸发联合循环动力装置 (Staged evaporation combined cycle power device ) 是由 李鸿瑞 李华玉 于 2019-09-28 设计创作，主要内容包括：本发明提供分级蒸发联合循环动力装置,属于能源与动力工程领域。扩压管有循环介质通道经高温热交换器与膨胀机连通,膨胀机还有循环介质通道经中温蒸发器和低温蒸发器与扩压管连通,冷凝器有冷凝液管路经循环泵与中温蒸发器连通之后中温蒸发器再有蒸汽通道与第二膨胀机连通,第二膨胀机还有蒸汽通道与冷凝器连通,冷凝器还有冷凝液管路经第二循环泵与低温蒸发器连通之后低温蒸发器再有蒸汽通道与第三膨胀机连通,第三膨胀机还有蒸汽通道与冷凝器连通；高温热交换器、中温蒸发器和低温蒸发器还分别有热源介质通道与外部连通,冷凝器还有冷却介质通道与外部连通,膨胀机、第二膨胀机和第三膨胀机连接外部并输出动力,形成分级蒸发联合循环动力装置。(The invention provides a graded evaporation combined cycle power device, belonging to the field of energy and power engineering. The pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through the second circulating pump, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the third; the high-temperature heat exchanger, the medium-temperature evaporator and the low-temperature evaporator are respectively communicated with the outside through a heat source medium channel, the condenser is also communicated with the outside through a cooling medium channel, and the expander, the second expander and the third expander are connected with the outside and output power to form the graded evaporation combined cycle power device.)

1. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator and a condenser; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is further provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with a third expander (4), and the third expander (4) is further provided with; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

2. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator and a condenser; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is further provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with a third expander (4), and the third expander (4) is further provided with; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) or the low-temperature evaporator (9) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the staged evaporation combined cycle power device is formed.

3. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator and a condenser; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is further provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with a third expander (4), and the third expander (4) is further provided with; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) and the low-temperature evaporator (9) are also respectively provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

4. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the diffuser pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5), then the medium-temperature evaporator (8) is provided with a steam channel which is communicated with the second expander (3), the second expander (3) is also provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the heat regenerator (12) through a second circulating pump (6), the third expander (4) or the second expander (3) is provided with a steam extraction channel which is communicated with the heat regenerator (12), the heat regenerator (12) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a third circulating pump (11), the third expander (4) is also provided with a steam channel which is communicated with the condenser (10); the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

5. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the diffuser pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5), then the medium-temperature evaporator (8) is provided with a steam channel which is communicated with the second expander (3), the second expander (3) is also provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the heat regenerator (12) through a second circulating pump (6), the third expander (4) or the second expander (3) is provided with a steam extraction channel which is communicated with the heat regenerator (12), the heat regenerator (12) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a third circulating pump (11), the third expander (4) is also provided with a steam channel which is communicated with the condenser (10); the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) or the low-temperature evaporator (9) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the staged evaporation combined cycle power device is formed.

6. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the diffuser pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5), then the medium-temperature evaporator (8) is provided with a steam channel which is communicated with the second expander (3), the second expander (3) is also provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the heat regenerator (12) through a second circulating pump (6), the third expander (4) or the second expander (3) is provided with a steam extraction channel which is communicated with the heat regenerator (12), the heat regenerator (12) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a third circulating pump (11), the third expander (4) is also provided with a steam channel which is communicated with the condenser (10); the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) and the low-temperature evaporator (9) are also respectively provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

7. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the diffuser pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with a heat regenerator (12) through a circulating pump (5), the second expander (3) or the third expander (4) is provided with a steam extraction channel which is communicated with the heat regenerator (12), the heat regenerator (12) is also provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a third circulating pump (11), the medium-temperature evaporator (8) is also provided with a steam channel which is communicated with the second expander (3), the second expander (3) is also provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6), and the low-temperature evaporator (9) is also provided with a steam, the third expander (4) is also provided with a steam channel which is communicated with the condenser (10); the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

8. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the diffuser pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with a heat regenerator (12) through a circulating pump (5), the second expander (3) or the third expander (4) is provided with a steam extraction channel which is communicated with the heat regenerator (12), the heat regenerator (12) is also provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a third circulating pump (11), the medium-temperature evaporator (8) is also provided with a steam channel which is communicated with the second expander (3), the second expander (3) is also provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6), and the low-temperature evaporator (9) is also provided with a steam, the third expander (4) is also provided with a steam channel which is communicated with the condenser (10); the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) or the low-temperature evaporator (9) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the staged evaporation combined cycle power device is formed.

9. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the diffuser pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with a heat regenerator (12) through a circulating pump (5), the second expander (3) or the third expander (4) is provided with a steam extraction channel which is communicated with the heat regenerator (12), the heat regenerator (12) is also provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a third circulating pump (11), the medium-temperature evaporator (8) is also provided with a steam channel which is communicated with the second expander (3), the second expander (3) is also provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6), and the low-temperature evaporator (9) is also provided with a steam, the third expander (4) is also provided with a steam channel which is communicated with the condenser (10); the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) and the low-temperature evaporator (9) are also respectively provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

10. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump, a heat regenerator, a fourth circulating pump and a second heat regenerator; the diffuser pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the heat regenerator (12) through a circulating pump (5), the second expander (3) or the third expander (4) is provided with a steam extraction channel which is communicated with the heat regenerator (12), the heat regenerator (12) is also provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a third circulating pump (11), the medium-temperature evaporator (8) is also provided with a steam channel which is communicated with the second expander (3), the second expander (3) is also provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the second heat regenerator (14) through a second circulating pump (6), and the third expander (4) or the second expander (3) is provided with a steam extraction channel which is communicated with the second, the second heat regenerator (14) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a fourth circulating pump (13), then a steam channel of the low-temperature evaporator (9) is communicated with a third expander (4), and the third expander (4) is also provided with a steam channel which is communicated with the condenser (10); the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

11. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump, a heat regenerator, a fourth circulating pump and a second heat regenerator; the diffuser pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the heat regenerator (12) through a circulating pump (5), the second expander (3) or the third expander (4) is provided with a steam extraction channel which is communicated with the heat regenerator (12), the heat regenerator (12) is also provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a third circulating pump (11), the medium-temperature evaporator (8) is also provided with a steam channel which is communicated with the second expander (3), the second expander (3) is also provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the second heat regenerator (14) through a second circulating pump (6), and the third expander (4) or the second expander (3) is provided with a steam extraction channel which is communicated with the second, the second heat regenerator (14) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a fourth circulating pump (13), then a steam channel of the low-temperature evaporator (9) is communicated with a third expander (4), and the third expander (4) is also provided with a steam channel which is communicated with the condenser (10); the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) or the low-temperature evaporator (9) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the staged evaporation combined cycle power device is formed.

12. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump, a heat regenerator, a fourth circulating pump and a second heat regenerator; the diffuser pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the heat regenerator (12) through a circulating pump (5), the second expander (3) or the third expander (4) is provided with a steam extraction channel which is communicated with the heat regenerator (12), the heat regenerator (12) is also provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a third circulating pump (11), the medium-temperature evaporator (8) is also provided with a steam channel which is communicated with the second expander (3), the second expander (3) is also provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the second heat regenerator (14) through a second circulating pump (6), and the third expander (4) or the second expander (3) is provided with a steam extraction channel which is communicated with the second, the second heat regenerator (14) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a fourth circulating pump (13), then a steam channel of the low-temperature evaporator (9) is communicated with a third expander (4), and the third expander (4) is also provided with a steam channel which is communicated with the condenser (10); the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) and the low-temperature evaporator (9) are also respectively provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

13. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6) and a preheater (15), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with a third expander (4), and the third expander (4) is further provided; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, the preheater (15) is also provided with a heat source medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that a graded evaporation combined cycle power device is formed.

14. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6) and a preheater (15), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with a third expander (4), and the third expander (4) is further provided; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) or the low-temperature evaporator (9) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, the preheater (15) is also provided with a heat source medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power to form a staged evaporation combined cycle power device.

15. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6) and a preheater (15), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with a third expander (4), and the third expander (4) is further provided; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) and the low-temperature evaporator (9) are also respectively provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, the preheater (15) is also provided with a heat source medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power to form a staged evaporation combined cycle power device.

16. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5) and a preheater (15), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is further provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with the third expander (4), and the third expander (4) is further provided; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, the preheater (15) is also provided with a heat source medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that a graded evaporation combined cycle power device is formed.

17. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5) and a preheater (15), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is further provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with the third expander (4), and the third expander (4) is further provided; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) or the low-temperature evaporator (9) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, the preheater (15) is also provided with a heat source medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power to form a staged evaporation combined cycle power device.

18. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5) and a preheater (15), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is further provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with the third expander (4), and the third expander (4) is further provided; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) and the low-temperature evaporator (9) are also respectively provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, the preheater (15) is also provided with a heat source medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power to form a staged evaporation combined cycle power device.

19. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a preheater and a second preheater; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5) and a preheater (15), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is further provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6) and a second preheater (16), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with the third expander (4), and the third expander (4) is further provided; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, the preheater (15) and the second preheater (16) are also respectively provided with a heat source medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that a graded evaporation combined cycle power device is formed.

20. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a preheater and a second preheater; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5) and a preheater (15), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is further provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6) and a second preheater (16), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with the third expander (4), and the third expander (4) is further provided; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) or the low-temperature evaporator (9) is also provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, the preheater (15) and the second preheater (16) are also respectively provided with a heat source medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

21. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a preheater and a second preheater; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5) and a preheater (15), then the medium-temperature evaporator (8) is further provided with a steam channel which is communicated with the second expander (3), the second expander (3) is further provided with a steam channel which is communicated with the condenser (10), the condenser (10) is further provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6) and a second preheater (16), then the low-temperature evaporator (9) is further provided with a steam channel which is communicated with the third expander (4), and the third expander (4) is further provided; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) and the low-temperature evaporator (9) are also respectively provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, the preheater (15) and the second preheater (16) are also respectively provided with a heat source medium channel communicated with the outside, and the expander (2), the second expander (3) and the third expander (4) are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

22. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a preheater and a second preheater; the pressure-expanding pipe (1) is provided with a circulating medium channel which is communicated with the expander (2) through a high-temperature heat exchanger (7), the expander (2) is also provided with a circulating medium channel which is communicated with the pressure-expanding pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9), the condenser (10) is provided with a condensate pipeline which is communicated with the medium-temperature evaporator (8) through a circulating pump (5) and a preheater (15), then the medium-temperature evaporator (8) is provided with a steam channel which is communicated with the second expander (3), the condenser (10) is also provided with a condensate pipeline which is communicated with the low-temperature evaporator (9) through a second circulating pump (6) and a second preheater (16), then the low-temperature evaporator (9) is provided with a middle steam inlet channel which is communicated with the second expander (3), and the second expander (3) is also provided with a steam channel which is communicated; the high-temperature heat exchanger (7) is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator (8) and the low-temperature evaporator (9) are also respectively provided with a heat source medium channel communicated with the outside, the condenser (10) is also provided with a cooling medium channel communicated with the outside, the preheater (15) and the second preheater (16) are also respectively provided with a heat source medium channel communicated with the outside, and the expander (2) and the second expander (3) are connected with the outside and output power to form a graded evaporation combined cycle power device.

23. A staged evaporation combined cycle power plant, which is characterized in that in any staged evaporation combined cycle power plant of claims 1 to 21, an intermediate reheater is added, a medium temperature evaporator (8) is provided with a steam passage to be communicated with a second expander (3), the second expander (3) is provided with a steam passage to be communicated with a condenser (10), the medium temperature evaporator (8) is provided with a steam passage to be communicated with the second expander (3), the second expander (3) and an intermediate reheated steam passage are communicated with the second expander (3) through an intermediate reheater (19), the second expander (3) and a steam passage are communicated with the condenser (10), and the intermediate reheater (19) and a heat source medium passage are communicated with the outside to form the staged evaporation combined cycle power plant.

24. A staged evaporation combined cycle power plant, which is characterized in that in any staged evaporation combined cycle power plant of claims 1-21 and 23, a second expander (3) is communicated with a condenser (10) through a steam channel, and the second expander (3) is communicated with a third expander (4) through a steam channel, so that the staged evaporation combined cycle power plant is formed.

25. A staged evaporation combined cycle power plant, which is characterized in that in any staged evaporation combined cycle power plant of claims 19-21, a second condenser is added, a second expander (3) is communicated with the condenser (10) through a steam channel, the second expander (3) is communicated with the second condenser (18) through a steam channel, the condenser (10) is communicated with a medium temperature evaporator (8) through a circulating pump (5) and a preheater (15) through a condensate pipeline, the second condenser (18) is communicated with the medium temperature evaporator (8) through the circulating pump (5) and the preheater (15) through a condensate pipeline, and the second condenser (18) is also communicated with the outside through a cooling medium channel to form the staged evaporation combined cycle power plant.

26. A staged evaporation combined cycle power device is characterized in that in any staged evaporation combined cycle power device of claims 19-21, a condenser (10) is provided with a condensate pipeline which is communicated with a medium temperature evaporator (8) through a circulating pump (5) and a preheater (15), the condenser (10) is provided with a condensate pipeline which is communicated with a low temperature evaporator (9) through a second circulating pump (6) and a second preheater (16), the two pipelines are adjusted together to be that the condenser (10) is provided with a condensate pipeline which is communicated with the low temperature evaporator (9) directly after passing through the second circulating pump (6) and the second preheater (16), and the first pipeline is communicated with the medium temperature evaporator (8) through the circulating pump (5) and the preheater (15), so that the staged evaporation combined cycle power device is formed.

27. A staged evaporation combined cycle power device is characterized in that a newly-added compressor and a newly-added high-temperature heat exchanger are added in any staged evaporation combined cycle power device according to claims 1-26, a circulating medium channel of a diffuser pipe (1) is communicated with an expander (2) through the high-temperature heat exchanger (7) and adjusted to be communicated with a circulating medium channel of the diffuser pipe (1) and the newly-added compressor (A) through the high-temperature heat exchanger (7), a steam channel of the newly-added compressor (A) is communicated with the expander (2) through the newly-added high-temperature heat exchanger (C), a heat source medium channel of the newly-added high-temperature heat exchanger (C) is communicated with the outside, and the expander (2) is connected with the newly-added compressor (A) and transmits power to form the staged evaporation combined cycle power device.

28. A staged evaporation combined cycle power device is characterized in that in any staged evaporation combined cycle power device of claims 1-26, a high-temperature heat regenerator is added, a circulation medium channel of a diffuser pipe (1) is communicated with an expander (2) through a high-temperature heat exchanger (7) and adjusted to be communicated with the expander (2) through a high-temperature heat regenerator (17) and the high-temperature heat exchanger (7), a circulation medium channel of the expander (2) is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9) and adjusted to be communicated with the expander (2) through a circulation medium channel of the expander (2) and the high-temperature heat regenerator (17), the medium-temperature evaporator (8) and the low-temperature evaporator (9), and a staged evaporation combined cycle power device is formed.

29. A staged evaporation combined cycle power device is characterized in that in any staged evaporation combined cycle power device of claims 1-26, a high-temperature heat regenerator, a newly-added compressor and a newly-added high-temperature heat exchanger are added, a circulation medium channel of a diffuser pipe (1) is communicated with an expander (2) through the high-temperature heat exchanger (7) and adjusted to be communicated with the newly-added compressor (A) through a high-temperature heat regenerator (17) and the high-temperature heat exchanger (7), a circulation medium channel of the newly-added compressor (A) is communicated with the expander (2) through the newly-added high-temperature heat exchanger (C), a circulation medium channel of the expander (2) is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9) and adjusted to be communicated with the expander (2) through the high-temperature heat regenerator (17), the medium-temperature evaporator (8) and the low-temperature evaporator (9) and communicated with the diffuser pipe (1), the newly-added high-temperature heat exchanger (C) is also provided with a heat source medium channel communicated with the outside, and the expander (2) is connected with the newly-added compressor (A) and transmits power to form a graded evaporation combined cycle power device.

30. A staged evaporation combined cycle power device is characterized in that a new expansion machine and a new high-temperature heat exchanger are added in any staged evaporation combined cycle power device according to claims 1-26, a circulation medium channel of a pressure expansion pipe (1) is communicated with an expansion machine (2) through the high-temperature heat exchanger (7) and adjusted to be communicated with a circulation medium channel of the pressure expansion pipe (1) through the high-temperature heat exchanger (7) and a new expansion machine (B), a steam channel of the new expansion machine (B) is communicated with the expansion machine (2) through the new high-temperature heat exchanger (C), the new high-temperature heat exchanger (C) is also communicated with the outside through a heat source medium channel, and the new expansion machine (B) is connected with the outside and outputs power to form the staged evaporation combined cycle power device.

31. A staged evaporation combined cycle power device is characterized in that in any staged evaporation combined cycle power device of claims 1-26, a high-temperature heat regenerator, a new expansion machine and a new increased high-temperature heat exchanger are added, a circulation medium channel of a diffuser pipe (1) is communicated with an expansion machine (2) through a high-temperature heat exchanger (7) and adjusted to be communicated with the new expansion machine (B) through a high-temperature heat regenerator (17) and the high-temperature heat exchanger (7), a circulation medium channel of the new expansion machine (B) is communicated with the expansion machine (2) through a new increased high-temperature heat exchanger (C), a circulation medium channel of the expansion machine (2) is communicated with the expansion pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9) and adjusted to be communicated with the expansion machine (2) through the high-temperature heat regenerator (17), the medium-temperature evaporator (8) and the low-temperature evaporator (9) and communicated with the diffuser pipe (1), the newly-increased high-temperature heat exchanger (C) is also provided with a heat source medium channel communicated with the outside, and the newly-increased expansion machine (B) is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

32. A staged evaporation combined cycle power device is characterized in that any staged evaporation combined cycle power device of claims 1-26 is additionally provided with a newly-added diffuser pipe and a newly-added high-temperature heat exchanger, the diffuser pipe (1) is communicated with an expander (2) through a high-temperature heat exchanger (7) and adjusted to be communicated with the newly-added diffuser pipe (D) through the high-temperature heat exchanger (7) and a circulating medium channel of the diffuser pipe (1), a steam channel of the newly-added diffuser pipe (D) is communicated with the expander (2) through the newly-added high-temperature heat exchanger (C), and the newly-added high-temperature heat exchanger (C) and a heat source medium channel are communicated with the outside to form the staged evaporation combined cycle power device.

33. A staged evaporation combined cycle power device is characterized in that in any staged evaporation combined cycle power device of claims 1-26, a high-temperature heat regenerator, a newly-increased diffuser pipe and a newly-increased high-temperature heat exchanger are added, a circulation medium channel of the diffuser pipe (1) is communicated with an expander (2) through the high-temperature heat exchanger (7) and adjusted to be communicated with the newly-increased diffuser pipe (D) through a high-temperature heat regenerator (17) and the high-temperature heat exchanger (7), a circulation medium channel of the newly-increased diffuser pipe (D) is communicated with the expander (2) through a newly-increased high-temperature heat exchanger (C), a circulation medium channel of the expander (2) is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9) and adjusted to be communicated with the expander (2) through a circulation medium channel of the high-temperature heat regenerator (17), the medium-temperature evaporator (8) and the low-temperature evaporator (9) and communicated with the diffuser pipe (1), the newly-added high-temperature heat exchanger (C) is also provided with a heat source medium channel which is communicated with the outside to form a staged evaporation combined cycle power device.

34. A staged evaporation combined cycle power device is characterized in that any staged evaporation combined cycle power device of claims 1-26 is additionally provided with a newly-added spray pipe and a newly-added high-temperature heat exchanger, a circulating medium channel of a diffuser pipe (1) is communicated with an expander (2) through the high-temperature heat exchanger (7) and is adjusted to be communicated with the newly-added spray pipe (E) through the high-temperature heat exchanger (7) and the circulating medium channel of the diffuser pipe (1), a steam channel of the newly-added spray pipe (E) is communicated with the expander (2) through the newly-added high-temperature heat exchanger (C), and the newly-added high-temperature heat exchanger (C) is also communicated with the outside through a heat source medium channel to form the staged evaporation combined cycle power device.

35. A staged evaporation combined cycle power device is characterized in that in any staged evaporation combined cycle power device of claims 1-26, a high-temperature heat regenerator, a newly-added spray pipe and a newly-added high-temperature heat exchanger are added, a circulation medium channel of a diffuser pipe (1) is communicated with an expander (2) through the high-temperature heat exchanger (7) and adjusted to be communicated with the newly-added spray pipe (E) through a high-temperature heat regenerator (17) and the high-temperature heat exchanger (7), a circulation medium channel of the newly-added spray pipe (E) is communicated with the expander (2) through the newly-added high-temperature heat exchanger (C), a circulation medium channel of the expander (2) is communicated with the diffuser pipe (1) through a medium-temperature evaporator (8) and a low-temperature evaporator (9) and adjusted to be communicated with the expander (2) through a circulation medium channel of the high-temperature heat regenerator (17), the medium-temperature evaporator (8) and the low-temperature evaporator (9) and communicated with the diffuser pipe (1), the newly-added high-temperature heat exchanger (C) is also provided with a heat source medium channel which is communicated with the outside to form a staged evaporation combined cycle power device.

36. A staged evaporation combined cycle power device is characterized in that a new expansion machine, a new intermediate temperature evaporator and a new circulating pump are added in any staged evaporation combined cycle power device of claims 1-27, 32 and 34, a condensate pipeline is additionally arranged on a condenser (10) and is communicated with the new intermediate temperature evaporator (F) through the new circulating pump (G), then a steam channel of the new intermediate temperature evaporator (F) is communicated with a new expansion machine (B), the new expansion machine (B) is also communicated with the condenser (10) through a steam channel, the expansion machine (2) is communicated with a diffuser pipe (1) through the intermediate temperature evaporator (8) and a low temperature evaporator (9) and is adjusted to be that the expansion machine (2) is provided with a circulating medium channel which is communicated with the diffuser pipe (1) through the new intermediate temperature evaporator (F), the intermediate temperature evaporator (8) and the low temperature evaporator (9), the new intermediate temperature evaporator (F) or a heat source medium channel is also communicated with the outside, the new expansion machine (B) is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

37. A staged evaporation combined cycle power plant, which is characterized in that a new expansion machine, a new intermediate temperature evaporator, a new circulating pump and a new preheater are added in any staged evaporation combined cycle power plant of claims 1-27, 32 and 34, a condensate pipeline is additionally arranged on a condenser (10) and is communicated with the new intermediate temperature evaporator (F) through the new circulating pump (G) and the new preheater (H), then a steam channel of the new intermediate temperature evaporator (F) is communicated with a new expansion machine (B), the new expansion machine (B) is also communicated with the condenser (10), a circulating medium channel of an expansion machine (2) is communicated with a pressure expansion pipe (1) through the intermediate temperature evaporator (8) and the low temperature evaporator (9) and is adjusted to be communicated with the pressure expansion pipe (1) through the new intermediate temperature evaporator (F), the intermediate temperature evaporator (8) and the low temperature evaporator (9), the newly added preheater (H) is also provided with a heat source medium channel communicated with the outside, the newly added intermediate temperature evaporator (F) or the heat source medium channel is also communicated with the outside, and the newly added expansion machine (B) is connected with the outside and outputs power, thereby forming a graded evaporation combined cycle power device.

38. A staged evaporation combined cycle power plant, which is characterized in that a new expansion machine, a new intermediate temperature evaporator, a new circulating pump, a new second circulating pump and a new heat regenerator are added in any staged evaporation combined cycle power plant of claims 1-27, 32 and 34, a condensate pipeline is additionally arranged on a condenser (10) and is communicated with the new heat regenerator through a new circulating pump (G), a new expansion machine (B) or a second expansion machine (3) is also communicated with the new heat regenerator through an extraction channel, the new intermediate temperature evaporator (F) is communicated with the new intermediate temperature evaporator (F) through a new second circulating pump, a steam channel is communicated with the new expansion machine (B), the new expansion machine (B) is also communicated with the condenser (10) through a steam channel, the expansion machine (2) is communicated with a diffusion pipe (1) through the intermediate temperature evaporator (8) and the low temperature evaporator (9) to adjust that the expansion machine (2) is provided with a circulating pump (1) The mass channel is communicated with the diffuser pipe (1) through a newly-added medium temperature evaporator (F), a medium temperature evaporator (8) and a low temperature evaporator (9), the newly-added medium temperature evaporator (F) or a heat source medium channel is communicated with the outside, and a newly-added expansion machine (B) is connected with the outside and outputs power, so that the graded evaporation combined cycle power device is formed.

39. A staged evaporation combined cycle power device is characterized in that a new expansion machine, a new intermediate temperature evaporator and a new circulating pump are added in any staged evaporation combined cycle power device of claims 28-29, 33 and 35, a condensate pipeline is additionally arranged on a condenser (10) and is communicated with the new intermediate temperature evaporator (F) through the new circulating pump (G), then the new intermediate temperature evaporator (F) is communicated with a new expansion machine (B) through a steam channel, the new expansion machine (B) is also communicated with the condenser (10) through a steam channel, the expansion machine (2) is communicated with a diffuser pipe (1) through a circulating medium channel, a high temperature regenerator (17), an intermediate temperature evaporator (8) and a low temperature evaporator (9) are adjusted to be communicated with the diffuser pipe (1) through the circulating medium channel of the expansion machine (2) and the high temperature regenerator (17), the new intermediate temperature evaporator (F), the intermediate temperature evaporator (8) and the low temperature evaporator (9), the newly added medium temperature evaporator (F) or a heat source medium channel is communicated with the outside, and the newly added expansion machine (B) is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

40. A staged evaporation combined cycle power plant, which is characterized in that a new expansion machine, a new intermediate temperature evaporator, a new circulating pump and a new preheater are added in any staged evaporation combined cycle power plant of claims 28-29, 33 and 35, a condensate liquid pipeline is additionally arranged on a condenser (10) and is communicated with the new intermediate temperature evaporator (F) through the new circulating pump (G) and the new preheater (H), then the new intermediate temperature evaporator (F) is communicated with the new expansion machine (B) through a steam channel, the new expansion machine (B) is also communicated with the condenser (10) through a steam channel, the expansion machine (2) is adjusted to be provided with a circulating medium channel which is communicated with a diffuser pipe (1) through a high temperature regenerator (17), an intermediate temperature evaporator (8) and a low temperature evaporator (9), and is adjusted to be provided with the expansion machine (2) which is provided with a circulating medium channel which is communicated with the expansion pipe (1) through the high temperature regenerator (17), the intermediate temperature evaporator, The medium-temperature evaporator (8) and the low-temperature evaporator (9) are communicated with the diffuser pipe (1), the newly-added preheater (H) is also communicated with the outside through a heat source medium channel, the newly-added medium-temperature evaporator (F) or the heat source medium channel is communicated with the outside, and the newly-added expansion machine (B) is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

41. A combined-cycle power plant for fractional evaporation is prepared as adding new expansion unit, new intermediate-temperature evaporator, new circulating pump, new second circulating pump and new heat regenerator to any one of said power plants of claims 28-29, 33 and 35, connecting condensate pipeline to new heat regenerator through new circulating pump (G) by condenser (10), connecting new expansion unit (B) or second expansion unit (3) to new heat regenerator through steam extraction channel, connecting new intermediate-temperature evaporator (F) to new intermediate-temperature evaporator (F) through steam channel to new expansion unit (B) and connecting new expansion unit (B) to condenser (10) through steam channel, connecting expansion unit (2) to circulating medium channel through high-temperature heat regenerator (17), The medium temperature evaporator (8) and the low temperature evaporator (9) are communicated with the diffuser pipe (1) and adjusted to be that the expander (2) is provided with a circulating medium channel which is communicated with the diffuser pipe (1) through the high temperature heat regenerator (17), the newly-increased medium temperature evaporator (F), the medium temperature evaporator (8) and the low temperature evaporator (9), the newly-increased medium temperature evaporator (F) or a heat source medium channel is communicated with the outside, and the newly-increased expander (B) is connected with the outside and outputs power to form a graded evaporation combined circulating power device.

42. A staged evaporation combined cycle power plant, which is characterized in that in any staged evaporation combined cycle power plant of claim 30, a newly added second expander, a newly added intermediate temperature evaporator and a newly added circulating pump are added, a condenser (10) is additionally provided with a condensate liquid pipeline which is communicated with the newly added intermediate temperature evaporator (F) through the newly added circulating pump (G), then a steam channel of the newly added intermediate temperature evaporator (F) is communicated with the newly added second expander (I), the newly added second expander (I) is also communicated with the condenser (10) through a steam channel, the expander (2) is communicated with a diffuser pipe (1) through the intermediate temperature evaporator (8) and the low temperature evaporator (9) and is adjusted to be that the expander (2) is provided with a circulating medium channel which is communicated with the diffuser pipe (1) through the newly added intermediate temperature evaporator (F), the intermediate temperature evaporator (8) and the low temperature evaporator (9), and the newly added intermediate temperature evaporator (F) or a heat source medium channel is also communicated with the outside, and a second expansion machine (I) is added to be connected with the outside and output power, so that a graded evaporation combined cycle power device is formed.

43. A staged evaporation combined cycle power plant, which is characterized in that in any staged evaporation combined cycle power plant of claim 30, a newly added second expander, a newly added intermediate temperature evaporator, a newly added circulating pump and a newly added preheater are added, a condensate pipeline is additionally arranged on a condenser (10) and is communicated with the newly added intermediate temperature evaporator (F) through a newly added circulating pump (G) and a newly added preheater (H), then a steam channel of the newly added intermediate temperature evaporator (F) is communicated with the newly added second expander (I), the newly added second expander (I) is also communicated with the condenser (10), the expander (2) is provided with a circulating medium channel which is communicated with a diffuser pipe (1) through the intermediate temperature evaporator (8) and a low temperature evaporator (9), and is adjusted to be communicated with the diffuser pipe (1) through a circulating medium channel which is communicated with the newly added intermediate temperature evaporator (F), the intermediate temperature evaporator (8) and the low temperature evaporator (9), the newly added preheater (H) is also provided with a heat source medium channel communicated with the outside, the newly added intermediate temperature evaporator (F) or the heat source medium channel is also communicated with the outside, and the newly added second expander (I) is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

44. A staged evaporation combined cycle power plant, which is characterized in that in any one of the staged evaporation combined cycle power plants of claim 30, a newly added second expander, a newly added intermediate temperature evaporator, a newly added circulating pump, a newly added second circulating pump and a newly added heat regenerator are added, a condensate liquid pipeline is additionally arranged on a condenser (10) and is communicated with the newly added heat regenerator through the newly added circulating pump (G), the newly added second expander (I) or the second expander (3) is also communicated with the newly added heat regenerator through a steam extraction channel, the newly added heat regenerator is also communicated with the newly added intermediate temperature evaporator (F) through the newly added second circulating pump, then the newly added intermediate temperature evaporator (F) is communicated with the newly added intermediate temperature evaporator (F) through a steam extraction channel, the newly added second expander (I) is also communicated with the condenser (10) through a steam channel, the expander (2) is communicated with a pressure expansion pipe (1) through the intermediate temperature evaporator (8) and the low temperature evaporator (9) to adjust that the expander (2) has a circulating medium channel The mass channel is communicated with the diffuser pipe (1) through a newly-added medium temperature evaporator (F), a medium temperature evaporator (8) and a low temperature evaporator (9), the newly-added medium temperature evaporator (F) or a heat source medium channel is communicated with the outside, and a newly-added second expander (I) is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

45. A staged evaporation combined cycle power plant, which is characterized in that in any staged evaporation combined cycle power plant of claim 31, a newly added second expander, a newly added intermediate temperature evaporator and a newly added circulating pump are added, a condensate pipeline is additionally arranged on a condenser (10) and is communicated with the newly added intermediate temperature evaporator (F) through the newly added circulating pump (G), then a steam channel of the newly added intermediate temperature evaporator (F) is communicated with the newly added second expander (I), the newly added second expander (I) is also communicated with the condenser (10) through a steam channel, the expander (2) is provided with a circulating medium channel which is communicated with a diffuser pipe (1) through a high temperature regenerator (17), an intermediate temperature evaporator (8) and a low temperature evaporator (9), and the expander (2) is adjusted to be provided with a circulating medium channel which is communicated with the diffuser pipe (1) through the high temperature regenerator (17), the newly added intermediate temperature evaporator (F), the intermediate temperature evaporator (8) and the low temperature evaporator (9), the newly-added intermediate temperature evaporator (F) or a heat source medium channel is communicated with the outside, and the newly-added second expander (I) is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

46. A combined-cycle power plant for fractional evaporation is characterized by that in any one of the power plants of claim 31, a newly-added second expander, a newly-added intermediate-temperature evaporator, a newly-added circulating pump and a newly-added preheater are added, the condenser (10) is additionally provided with a condensed liquid pipeline which is communicated with the newly-added intermediate-temperature evaporator (F) through a newly-added circulating pump (G) and a newly-added preheater (H), then the newly-added intermediate-temperature evaporator (F) is communicated with a newly-added second expander (I) through a steam channel, the newly-added second expander (I) is also communicated with the condenser (10), the expander (2) is provided with a circulating medium channel which is communicated with the diffuser pipe (1) through a high-temperature regenerator (17), an intermediate-temperature evaporator (8) and a low-temperature evaporator (9), and is adjusted to be that the expander (2) is provided with a circulating medium channel which is communicated with the high-temperature regenerator (17, The medium-temperature evaporator (8) and the low-temperature evaporator (9) are communicated with the diffuser pipe (1), the newly-added preheater (H) is also communicated with the outside through a heat source medium channel, the newly-added medium-temperature evaporator (F) or the heat source medium channel is communicated with the outside, and the newly-added second expander (I) is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

47. A combined-cycle power plant for fractional evaporation is characterized by that in any one of the power plants of claim 31, a new second expander, a new intermediate-temperature evaporator, a new circulating pump, a new second circulating pump and a new heat regenerator are added, the condenser (10) is additionally provided with a condensate liquid pipeline which is communicated with the new heat regenerator through the new circulating pump (G), the new second expander (I) or the second expander (3) is also provided with a steam extraction channel which is communicated with the new heat regenerator, the new heat regenerator is also provided with a condensate liquid pipeline which is communicated with the new intermediate-temperature evaporator (F) through the new second circulating pump, then the new intermediate-temperature evaporator (F) is provided with a steam channel which is communicated with the new second expander (I), the new second expander (I) is also provided with a steam channel which is communicated with the condenser (10), and the expander (2) is provided with a circulating medium channel which is communicated with the high-temperature heat regenerator (17), The medium temperature evaporator (8) and the low temperature evaporator (9) are communicated with the diffuser pipe (1) and adjusted to be that the expander (2) is provided with a circulating medium channel which is communicated with the diffuser pipe (1) through the high temperature heat regenerator (17), the newly-increased medium temperature evaporator (F), the medium temperature evaporator (8) and the low temperature evaporator (9), the newly-increased medium temperature evaporator (F) or a heat source medium channel is communicated with the outside, and the newly-increased second expander (I) is connected with the outside and outputs power to form a graded evaporation combined circulating power device.

The technical field is as follows:

the invention belongs to the technical field of energy and power.

Background art:

the heat energy is converted into mechanical energy which is needed by human life and production; the staged evaporation combined cycle power device adopting the combined cycle principle to work has important significance in the field of heat power variation. The expander, the compressor and the heat exchanger are essential basic components and core components from the viewpoint of components constituting the staged evaporation combined cycle power plant; the two core components of the compressor and the expander are difficult to manufacture, high in requirements on materials and high in manufacturing cost, and the application of the two core components is adversely affected. Therefore, the number of compressors or expanders should be reduced or replaced by simple components, which significantly reduces the manufacturing difficulty and cost of the staged evaporation combined cycle power plant, and facilitates the popularization and application thereof.

The invention provides a graded evaporation combined cycle power device which utilizes a diffuser pipe to replace a compressor, and mainly aims to reduce the manufacturing difficulty and the manufacturing cost of the graded evaporation combined cycle power device, and takes the basic premise of keeping or effectively improving the thermal efficiency of the graded evaporation combined cycle power device; wherein, also proposed and utilized the technical scheme of the nozzle to replace the non-main expander.

The invention content is as follows:

the invention mainly aims to provide a staged evaporation combined cycle power device adopting a diffuser pipe to replace a compressor, and the specific invention contents are set forth in the following items:

1. the graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator and a condenser; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through the second circulating pump, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the third; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power to form a graded evaporation combined cycle power device.

2. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator and a condenser; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through the second circulating pump, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the third; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator or the low-temperature evaporator is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

3. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator and a condenser; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through the second circulating pump, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the third; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator and the low-temperature evaporator are also respectively provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

4. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the heat regenerator is also provided with a condensate pipeline which is communicated with the heat regenerator through a second circulating pump, a steam extraction channel which is communicated with the heat regenerator after the third expander or the second expander is provided with a steam extraction channel, the heat regenerator is also provided with a steam channel which is communicated with the heat regenerator after the condensate pipeline is communicated with the low-temperature evaporator through a third circulating pump, and the low-temperature evaporator is also provided with a steam channel which is communicated with the third expander; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power to form a graded evaporation combined cycle power device.

5. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the heat regenerator is also provided with a condensate pipeline which is communicated with the heat regenerator through a second circulating pump, a steam extraction channel which is communicated with the heat regenerator after the third expander or the second expander is provided with a steam extraction channel, the heat regenerator is also provided with a steam channel which is communicated with the heat regenerator after the condensate pipeline is communicated with the low-temperature evaporator through a third circulating pump, and the low-temperature evaporator is also provided with a steam channel which is communicated with the third expander; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator or the low-temperature evaporator is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

6. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the heat regenerator is also provided with a condensate pipeline which is communicated with the heat regenerator through a second circulating pump, a steam extraction channel which is communicated with the heat regenerator after the third expander or the second expander is provided with a steam extraction channel, the heat regenerator is also provided with a steam channel which is communicated with the heat regenerator after the condensate pipeline is communicated with the low-temperature evaporator through a third circulating pump, and the low-temperature evaporator is also provided with a steam channel which is communicated with the third expander; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator and the low-temperature evaporator are also respectively provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

7. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the pressure-expanding tube is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-expanding tube through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the heat regenerator through a circulating pump, the second expander or a third expander is provided with a steam extraction channel which is communicated with the heat regenerator, the heat regenerator is also provided with a steam channel which is communicated with the medium-temperature evaporator after the condensate pipeline is communicated with the medium-temperature evaporator through a third circulating pump, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a steam channel which is communicated with the third expander after the condensate pipeline is communicated with the low-temperature evaporator through the second circulating pump, and the third expander is also provided with a; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power to form a graded evaporation combined cycle power device.

8. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the pressure-expanding tube is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-expanding tube through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the heat regenerator through a circulating pump, the second expander or a third expander is provided with a steam extraction channel which is communicated with the heat regenerator, the heat regenerator is also provided with a steam channel which is communicated with the medium-temperature evaporator after the condensate pipeline is communicated with the medium-temperature evaporator through a third circulating pump, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a steam channel which is communicated with the third expander after the condensate pipeline is communicated with the low-temperature evaporator through the second circulating pump, and the third expander is also provided with a; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator or the low-temperature evaporator is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

9. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the pressure-expanding tube is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-expanding tube through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the heat regenerator through a circulating pump, the second expander or a third expander is provided with a steam extraction channel which is communicated with the heat regenerator, the heat regenerator is also provided with a steam channel which is communicated with the medium-temperature evaporator after the condensate pipeline is communicated with the medium-temperature evaporator through a third circulating pump, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a steam channel which is communicated with the third expander after the condensate pipeline is communicated with the low-temperature evaporator through the second circulating pump, and the third expander is also provided with a; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator and the low-temperature evaporator are also respectively provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

10. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump, a heat regenerator, a fourth circulating pump and a second heat regenerator; the diffuser pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the diffuser pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the heat regenerator through a circulating pump, the second expander or the third expander is provided with a steam extraction channel which is communicated with the heat regenerator, the heat regenerator is also provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a third circulating pump, the medium-temperature evaporator is further provided with a steam channel which is communicated with the second expander, the second expander is further provided with a steam channel which is communicated with the condenser, the condenser is further provided with a condensate pipeline which is communicated with the second heat regenerator through a second circulating pump, the third expander or the second expander is provided with a steam extraction channel which is communicated with the second heat regenerator, the second heat regenerator is further provided with a condensate pipeline which is communicated with the low-temperature evaporator, the third expander is also provided with a steam channel communicated with the condenser; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power to form a graded evaporation combined cycle power device.

11. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump, a heat regenerator, a fourth circulating pump and a second heat regenerator; the diffuser pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the diffuser pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the heat regenerator through a circulating pump, the second expander or the third expander is provided with a steam extraction channel which is communicated with the heat regenerator, the heat regenerator is also provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a third circulating pump, the medium-temperature evaporator is further provided with a steam channel which is communicated with the second expander, the second expander is further provided with a steam channel which is communicated with the condenser, the condenser is further provided with a condensate pipeline which is communicated with the second heat regenerator through a second circulating pump, the third expander or the second expander is provided with a steam extraction channel which is communicated with the second heat regenerator, the second heat regenerator is further provided with a condensate pipeline which is communicated with the low-temperature evaporator, the third expander is also provided with a steam channel communicated with the condenser; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator or the low-temperature evaporator is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

12. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump, a heat regenerator, a fourth circulating pump and a second heat regenerator; the diffuser pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the diffuser pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the heat regenerator through a circulating pump, the second expander or the third expander is provided with a steam extraction channel which is communicated with the heat regenerator, the heat regenerator is also provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a third circulating pump, the medium-temperature evaporator is further provided with a steam channel which is communicated with the second expander, the second expander is further provided with a steam channel which is communicated with the condenser, the condenser is further provided with a condensate pipeline which is communicated with the second heat regenerator through a second circulating pump, the third expander or the second expander is provided with a steam extraction channel which is communicated with the second heat regenerator, the second heat regenerator is further provided with a condensate pipeline which is communicated with the low-temperature evaporator, the third expander is also provided with a steam channel communicated with the condenser; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator and the low-temperature evaporator are also respectively provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

13. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through a second circulating pump and a preheater, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, the preheater is also provided with a heat source medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

14. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through a second circulating pump and a preheater, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator or the low-temperature evaporator is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, the preheater is also provided with a heat source medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power to form the graded evaporation combined cycle power device.

15. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through a second circulating pump and a preheater, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator and the low-temperature evaporator are also respectively provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, the preheater is also provided with a heat source medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power to form a graded evaporation combined cycle power device.

16. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump and a preheater, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through the second circulating pump, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, the preheater is also provided with a heat source medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

17. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump and a preheater, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through the second circulating pump, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator or the low-temperature evaporator is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, the preheater is also provided with a heat source medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power to form the graded evaporation combined cycle power device.

18. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser and a preheater; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump and a preheater, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through the second circulating pump, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator and the low-temperature evaporator are also respectively provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, the preheater is also provided with a heat source medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power to form a graded evaporation combined cycle power device.

19. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a preheater and a second preheater; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump and a preheater, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through the second circulating pump and the second preheater, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, the preheater and the second preheater are also respectively provided with a heat source medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

20. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a preheater and a second preheater; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump and a preheater, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through the second circulating pump and the second preheater, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator or the low-temperature evaporator is also provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, the preheater and the second preheater are also respectively provided with a heat source medium channel communicated with the outside, and the expander, the second expander and the third expander are connected with the outside and output power, so that the graded evaporation combined cycle power device is formed.

21. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a preheater and a second preheater; the pressure-diffusing pipe is provided with a circulating medium channel which is communicated with the expander through a high-temperature heat exchanger, the expander is also provided with a circulating medium channel which is communicated with the pressure-diffusing pipe through a medium-temperature evaporator and a low-temperature evaporator, the condenser is provided with a condensate pipeline which is communicated with the medium-temperature evaporator through a circulating pump and a preheater, then the medium-temperature evaporator is provided with a steam channel which is communicated with a second expander, the second expander is also provided with a steam channel which is communicated with the condenser, the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through the second circulating pump and the second preheater, then the low-temperature evaporator is provided with a steam channel which is communicated with a third expander, and the; the high-temperature heat exchanger is also communicated with the outside through a heat source medium channel, the medium-temperature evaporator and the low-temperature evaporator are also respectively communicated with the outside through a heat source medium channel, the condenser is also communicated with the outside through a cooling medium channel, the preheater and the second preheater are also respectively communicated with the outside through a heat source medium channel, and the expander, the second expander and the third expander are connected with the outside and output power to form the graded evaporation combined cycle power device.

22. The graded evaporation combined cycle power device mainly comprises a diffuser pipe, an expander, a second expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a preheater and a second preheater; the condenser is also provided with a condensate pipeline which is communicated with the low-temperature evaporator through a second circulating pump and a second preheater, then the low-temperature evaporator is communicated with a second expander through a middle steam inlet channel, and the second expander is also provided with a steam channel communicated with the condenser; the high-temperature heat exchanger is also provided with a heat source medium channel communicated with the outside, the medium-temperature evaporator and the low-temperature evaporator are also respectively provided with a heat source medium channel communicated with the outside, the condenser is also provided with a cooling medium channel communicated with the outside, the preheater and the second preheater are also respectively provided with a heat source medium channel communicated with the outside, and the expander and the second expander are connected with the outside and output power to form a graded evaporation combined cycle power device.

23. A staged evaporation combined cycle power plant, which is characterized in that in any staged evaporation combined cycle power plant of items 1 to 21, an intermediate reheater is added, a medium temperature evaporator is communicated with a second expander through a steam channel, a second expander is communicated with a condenser through a steam channel, the medium temperature evaporator is communicated with the second expander through a steam channel, the second expander is also communicated with the condenser through an intermediate reheater and a steam channel, and the intermediate reheater is also communicated with the outside through a heat source medium channel, so that the staged evaporation combined cycle power plant is formed.

24. A staged evaporation combined cycle power plant, which is characterized in that in any staged evaporation combined cycle power plant of items 1 to 21 and 23, a second expander is communicated with a condenser through a steam channel, and the second expander is communicated with a third expander through a steam channel, so that the staged evaporation combined cycle power plant is formed.

25. A staged evaporation combined cycle power plant, wherein a second condenser is added in any one of the staged evaporation combined cycle power plants of items 19-21, a second expander is communicated with the condenser through a steam channel, the second expander is communicated with the second condenser through a steam channel, the condenser is communicated with a medium temperature evaporator through a circulating pump and a preheater, the condenser is communicated with the medium temperature evaporator through a condensate pipeline, the second condenser is communicated with the medium temperature evaporator through the circulating pump and the preheater, and the second condenser is also communicated with the outside through a cooling medium channel, so that the staged evaporation combined cycle power plant is formed.

26. A staged evaporation combined cycle power plant, which is characterized in that in any one of the staged evaporation combined cycle power plants described in items 19-21, a condenser is provided with a condensate pipeline which is communicated with a medium temperature evaporator through a circulating pump and a preheater, and the condenser is provided with a condensate pipeline which is communicated with a low temperature evaporator through a second circulating pump and a second preheater, and the condensate pipeline is adjusted into two paths after passing through the second circulating pump and the second preheater, wherein the first path is directly communicated with the low temperature evaporator, and the second path is communicated with the medium temperature evaporator through the circulating pump and the preheater, so that the staged evaporation combined cycle power plant is formed.

27. A staged evaporation combined cycle power device, which is characterized in that a newly-added compressor and a newly-added high-temperature heat exchanger are added in any staged evaporation combined cycle power device of items 1 to 26, a circulation medium channel arranged on a diffuser pipe is communicated with an expander through the high-temperature heat exchanger, the circulation medium channel arranged on the diffuser pipe is communicated with the newly-added compressor through the high-temperature heat exchanger, a steam channel arranged on the newly-added compressor is communicated with the expander through the newly-added high-temperature heat exchanger, the newly-added high-temperature heat exchanger is also communicated with the outside through a heat source medium channel, and the expander is connected with the newly-added compressor and transmits power, so that the staged evaporation combined cycle power.

28. A staged evaporation combined cycle power device is characterized in that in any staged evaporation combined cycle power device of items 1-26, a high-temperature heat regenerator is added, a circulation medium channel arranged on a diffuser pipe is communicated with an expander through a high-temperature heat exchanger and adjusted to be communicated with the expander through the high-temperature heat regenerator and the high-temperature heat exchanger, a circulation medium channel arranged on the expander is communicated with the diffuser pipe through a medium-temperature evaporator and a low-temperature evaporator and adjusted to be communicated with the expander through the circulation medium channel arranged on the expander and the high-temperature heat regenerator, the medium-temperature evaporator and the low-temperature evaporator, and the staged evaporation combined cycle power device is formed.

29. A staged evaporation combined cycle power plant, which is characterized in that in any staged evaporation combined cycle power plant of items 1-26, a high-temperature heat regenerator, a newly-added compressor and a newly-added high-temperature heat exchanger are added, a circulation medium channel arranged on a diffuser pipe is communicated with an expander through the high-temperature heat exchanger and is adjusted to be communicated with the newly-added compressor through the high-temperature heat regenerator and the high-temperature heat exchanger, a circulation medium channel arranged on the newly-added compressor is communicated with the expander through the newly-added high-temperature heat exchanger, a circulation medium channel arranged on the expander is communicated with the diffuser pipe through a medium-temperature evaporator and a low-temperature evaporator, the expansion machine is adjusted to be communicated with the diffuser pipe through the high-temperature heat regenerator, the medium-temperature evaporator and the low-temperature evaporator, the newly-added high-temperature heat exchanger is also communicated with the outside through a heat source medium channel, forming a staged evaporation combined cycle power plant.

30. A staged evaporation combined cycle power device, which is characterized in that a new expansion machine and a new increased high-temperature heat exchanger are added in any staged evaporation combined cycle power device of items 1 to 26, a circulation medium channel of a pressure expansion pipe is communicated with an expansion machine through the high-temperature heat exchanger and is adjusted to be communicated with the new expansion machine through the high-temperature heat exchanger, a steam channel of the new expansion machine is communicated with the expansion machine through the new increased high-temperature heat exchanger, the new increased high-temperature heat exchanger is also communicated with the outside through a heat source medium channel, and the new expansion machine is connected with the outside and outputs power to form the staged evaporation combined cycle power device.

31. A staged evaporation combined cycle power plant, which is characterized in that in any staged evaporation combined cycle power plant of items 1 to 26, a high-temperature heat regenerator, a new expansion machine and a new increased high-temperature heat exchanger are added, a circulation medium channel arranged on a diffuser pipe is communicated with the expansion machine through the high-temperature heat exchanger and adjusted to be communicated with the new expansion machine through the high-temperature heat regenerator and the high-temperature heat exchanger, a circulation medium channel arranged on the new expansion machine is communicated with the expansion machine through the new increased high-temperature heat exchanger, a circulation medium channel arranged on the expansion machine is communicated with the diffuser pipe through a medium-temperature evaporator and a low-temperature evaporator, adjusted to be communicated with the diffuser pipe through the high-temperature heat regenerator, the medium-temperature evaporator and the low-temperature evaporator, the new increased high-temperature heat exchanger is also communicated with the outside through a heat source medium channel, and the new expansion machine is connected with the outside, forming a staged evaporation combined cycle power plant.

32. A staged evaporation combined cycle power plant, which is characterized in that in any one of the staged evaporation combined cycle power plants described in items 1-26, a newly added diffuser pipe and a newly added high temperature heat exchanger are added, the diffuser pipe is communicated with an expander through the high temperature heat exchanger and adjusted to be communicated with the expander through the high temperature heat exchanger and the circulating medium channel, the diffuser pipe is communicated with the newly added diffuser pipe through the high temperature heat exchanger, the newly added diffuser pipe is communicated with the expander through a steam channel, and the newly added high temperature heat exchanger is communicated with the outside through a heat source medium channel, so that the staged evaporation combined cycle power plant is formed.

33. A staged evaporative combined cycle power plant, in any of the staged evaporative combined cycle power plants described in items 1-26, a high-temperature heat regenerator, a newly-increased diffuser pipe and a newly-increased high-temperature heat exchanger are added, a circulating medium channel arranged on the diffuser pipe is communicated with an expander through the high-temperature heat exchanger and is adjusted to be communicated with the newly-increased diffuser pipe through the high-temperature heat exchanger and the high-temperature heat exchanger, a circulating medium channel arranged on the newly-increased diffuser pipe is communicated with the expander through the newly-increased high-temperature heat exchanger, a circulating medium channel arranged on the expander is communicated with the diffuser pipe through a medium-temperature evaporator and a low-temperature evaporator, is adjusted to be communicated with the expander through a circulating medium channel arranged on the expander and is communicated with the diffuser pipe through the high-temperature heat regenerator, the medium-temperature evaporator and the low-temperature evaporator, and the newly-increased high-temperature.

34. A staged evaporation combined cycle power plant, which is characterized in that in any one of the staged evaporation combined cycle power plants described in items 1-26, a newly added spray pipe and a newly added high-temperature heat exchanger are added, a circulating medium channel arranged on a diffuser pipe is communicated with an expander through the high-temperature heat exchanger, the circulating medium channel arranged on the diffuser pipe is communicated with the newly added spray pipe through the high-temperature heat exchanger, a steam channel arranged on the newly added spray pipe is communicated with the expander through the newly added high-temperature heat exchanger, and a heat source medium channel arranged on the newly added high-temperature heat exchanger is communicated with the outside, so that the staged evaporation combined cycle power.

35. A staged evaporation combined cycle power plant, which is characterized in that a high-temperature heat regenerator, a newly-added spray pipe and a newly-added high-temperature heat exchanger are added in any staged evaporation combined cycle power plant of items 1 to 26, a circulation medium channel arranged on a diffuser pipe is communicated with an expander through the high-temperature heat exchanger and the expander, and is adjusted to be communicated with the newly-added spray pipe through the high-temperature heat exchanger and the high-temperature heat exchanger, a circulation medium channel arranged on the newly-added spray pipe is communicated with the expander through the newly-added high-temperature heat exchanger, a circulation medium channel arranged on the expander is communicated with the diffuser pipe through a medium-temperature evaporator and a low-temperature evaporator, and is adjusted to be communicated with the expander through the circulation medium channel arranged on the expander through the high-temperature heat regenerator, the medium-temperature evaporator and the low-temperature evaporator, and the newly-added high.

36. A staged evaporative combined cycle power plant, in any of the staged evaporative combined cycle power plants described in items 1-27, 32, 34, a new expansion machine, a new intermediate temperature evaporator and a new circulating pump are added, a condensate pipeline is additionally arranged on a condenser and is communicated with the new intermediate temperature evaporator through the new circulating pump, then the new intermediate temperature evaporator is communicated with the new expansion machine through a steam channel, the new expansion machine is also communicated with the condenser through the steam channel, the expansion machine is communicated with a diffuser pipe through the intermediate temperature evaporator and the low temperature evaporator, the expansion machine is adjusted to be communicated with the diffuser pipe through the new intermediate temperature evaporator, the intermediate temperature evaporator and the low temperature evaporator, the new intermediate temperature evaporator or a heat source medium channel is communicated with the outside, the new expansion machine is connected with the outside and outputs power, and a graded evaporation combined circulating power device is formed.

37. A combined circulating power unit for fractional evaporation is prepared as adding new expansion unit, new middle-temp evaporator, new circulating pump and new preheater to any one of said power units 1-27, 32 and 34, connecting condenser with condensate pipeline via new circulating pump and new preheater to new middle-temp evaporator, connecting steam channel to new expansion unit, connecting steam channel to condenser, connecting said expansion unit with circulating medium channel via middle-temp evaporator and low-temp evaporator to diffuser pipe, connecting said expansion unit with heat source medium channel to outside, connecting new middle-temp evaporator or heat source medium channel to outside, the new expansion machine is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

38. A step evaporation combined cycle power device is characterized in that a new expansion machine, a new intermediate temperature evaporator, a new circulating pump, a new second circulating pump and a new heat regenerator are added in any step evaporation combined cycle power device of items 1-27, 32 and 34, a condensate pipeline additionally arranged in a condenser is communicated with the new heat regenerator through the new circulating pump, the new expansion machine or the second expansion machine is further provided with a steam extraction channel communicated with the new heat regenerator, the new heat regenerator is also provided with a condensate pipeline communicated with the new intermediate temperature evaporator through the new second circulating pump, then the new intermediate temperature evaporator is further provided with a steam channel communicated with the new expansion machine, the new expansion machine is further provided with a steam channel communicated with the condenser, the expansion machine is provided with a circulating medium channel communicated with an expansion pipe through the intermediate temperature evaporator and the low temperature evaporator, and the expansion pipe are adjusted to be provided with the expansion machine through the intermediate temperature evaporator, the circulating medium channel is communicated with the new intermediate, The medium temperature evaporator and the low temperature evaporator are communicated with a diffuser pipe, the newly added medium temperature evaporator or a heat source medium channel is communicated with the outside, and the newly added expansion machine is connected with the outside and outputs power, so that the graded evaporation combined cycle power device is formed.

39. A staged evaporation combined cycle power plant, which is provided in any one of the staged evaporation combined cycle power plants 28 to 29, 33 and 35, a new expansion machine, a new intermediate temperature evaporator and a new circulating pump are added, a condensate pipeline is additionally arranged on a condenser and is communicated with the new intermediate temperature evaporator through the new circulating pump, then the new intermediate temperature evaporator is communicated with the new expansion machine through a steam channel, the new expansion machine is also communicated with the condenser through the steam channel, the expansion machine is communicated with a diffuser pipe through a high temperature heat regenerator, the intermediate temperature evaporator and a low temperature evaporator, the expansion machine is adjusted to be communicated with the diffuser pipe through the high temperature heat regenerator, the new intermediate temperature evaporator, the intermediate temperature evaporator and the low temperature evaporator, the new intermediate temperature evaporator or a heat source medium channel is communicated with the outside, the new expansion machine is connected with the outside and outputs power, and the graded evaporation combined cycle power device is formed.

40. A staged evaporation combined cycle power plant, which is characterized in that a new expansion machine, a new intermediate temperature evaporator, a new circulating pump and a new preheater are added in any one of the staged evaporation combined cycle power plants of items 28-29, 33 and 35, a condensate pipeline is additionally arranged on a condenser, the new intermediate temperature evaporator is communicated with the new intermediate temperature evaporator through the new circulating pump and the new preheater, then a steam channel is communicated with the new expansion machine, the steam channel is also communicated with the condenser, the circulation medium channel of the expansion machine is communicated with a diffuser pipe through a high temperature evaporator, the intermediate temperature evaporator and a low temperature evaporator, the expansion machine is adjusted to be provided with a circulation medium channel, the circulation medium channel is communicated with the diffuser pipe through the high temperature regenerator, the new intermediate temperature evaporator, the intermediate temperature evaporator and the low temperature evaporator, the new preheater is also provided with a heat source medium channel communicated with the outside, and the new intermediate temperature evaporator or the heat source medium channel is also communicated with, the new expansion machine is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

41. A step evaporation combined cycle power device is characterized in that a new expansion machine, a new intermediate temperature evaporator, a new circulating pump, a new second circulating pump and a new heat regenerator are added in any step evaporation combined cycle power device of items 28-29, 33 and 35, a condensate pipeline additionally arranged in a condenser is communicated with the new heat regenerator through the new circulating pump, a steam extraction channel of the new expansion machine or the second expansion machine is communicated with the new heat regenerator, the new heat regenerator is also communicated with the new intermediate temperature evaporator through the new second circulating pump, a steam channel of the new intermediate temperature evaporator is communicated with the new expansion machine, a steam channel of the new expansion machine is communicated with the condenser, a circulating medium channel of the expansion machine is communicated with a pressure expansion pipe through the high temperature heat regenerator, the intermediate temperature evaporator and the low temperature evaporator, and is adjusted to be a circulating medium channel of the expansion machine through the high temperature heat regenerator, The newly added intermediate temperature evaporator, the intermediate temperature evaporator and the low temperature evaporator are communicated with a diffuser pipe, the newly added intermediate temperature evaporator or a heat source medium channel is communicated with the outside, and the newly added expansion machine is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

42. A staged evaporative combined cycle power plant as in any of the staged evaporative combined cycle power plants of claim 30, and a newly-added second expander, a newly-added intermediate-temperature evaporator and a newly-added circulating pump are added, a condensate pipeline is additionally arranged on the condenser and is communicated with the newly-added intermediate-temperature evaporator through the newly-added circulating pump, then the newly-added intermediate-temperature evaporator is communicated with the newly-added second expander through a steam channel, the newly-added second expander is communicated with the condenser through a steam channel, the expander is communicated with a diffuser pipe through the intermediate-temperature evaporator and the low-temperature evaporator, the expander is adjusted to be communicated with the diffuser pipe through the intermediate-temperature evaporator and the low-temperature evaporator, the newly-added intermediate-temperature evaporator or a heat source medium channel is communicated with the outside, and the newly-added second expander is connected with the outside and outputs power to form a graded evaporation combined circulating power device.

43. A combined-cycle power plant for fractional evaporation, wherein a new second expander, a new intermediate-temperature evaporator, a new circulating pump and a new preheater are added to any of the combined-cycle power plants for fractional evaporation described in item 30, a condensate line additionally provided in a condenser is communicated with the new intermediate-temperature evaporator via the new circulating pump and the new preheater, then a steam channel of the new intermediate-temperature evaporator is communicated with the new second expander, a steam channel of the new second expander is communicated with the condenser, the expander is adjusted to have a circulating medium channel communicated with a diffuser pipe via the intermediate-temperature evaporator and the low-temperature evaporator, the expander has a circulating medium channel communicated with the outside via the new intermediate-temperature evaporator, the intermediate-temperature evaporator and the low-temperature evaporator, the new preheater also has a heat source medium channel communicated with the outside, and the new intermediate-temperature evaporator or the heat source medium channel is communicated with the outside, and a second expansion machine is added to be connected with the outside and output power, so that a graded evaporation combined cycle power device is formed.

44. A combined-cycle power plant for fractional evaporation, which is characterized in that in any of the combined-cycle power plants for fractional evaporation described in item 30, a newly added second expander, a newly added intermediate-temperature evaporator, a newly added circulating pump, a newly added second circulating pump and a newly added heat regenerator are added, a condenser is additionally provided with a condensate pipeline which is communicated with the newly added heat regenerator through the newly added circulating pump, the newly added second expander or the second expander is also provided with a steam extraction channel which is communicated with the newly added heat regenerator, the newly added heat regenerator is also provided with a condensate pipeline which is communicated with the newly added intermediate-temperature evaporator through the newly added second circulating pump, the newly added intermediate-temperature evaporator is further provided with a steam channel which is communicated with the newly added second expander, the newly added second expander is further provided with a steam channel which is communicated with the condenser, the expander is provided with a circulating medium channel which is communicated with a diffuser pipe through the intermediate-temperature evaporator, The medium-temperature evaporator and the low-temperature evaporator are communicated with a diffuser pipe, the newly-added medium-temperature evaporator or a heat source medium channel is communicated with the outside, and the newly-added second expander is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

45. A staged evaporative combined cycle power plant as in any of the staged evaporative combined cycle power plants of item 31, and a newly-added second expander, a newly-added intermediate-temperature evaporator and a newly-added circulating pump are added, a condensate pipeline is additionally arranged on the condenser and is communicated with the newly-added intermediate-temperature evaporator through the newly-added circulating pump, then the newly-added intermediate-temperature evaporator is communicated with the newly-added second expander through a steam channel, the newly-added second expander is also communicated with the condenser through a steam channel, the expander is communicated with a diffuser pipe through a high-temperature heat regenerator, an intermediate-temperature evaporator and a low-temperature evaporator and is adjusted to be communicated with the expander through the high-temperature heat regenerator, the newly-added intermediate-temperature evaporator, the intermediate-temperature evaporator and the low-temperature evaporator, the newly-added intermediate-temperature evaporator or a heat source medium channel is communicated with the outside, and the newly-added second expander is connected with the outside and outputs.

46. A combined circulating power plant for fractional evaporation is characterized by that in any one of the said power plants, a newly-added second expander, a newly-added intermediate-temperature evaporator, a newly-added circulating pump and a newly-added preheater are added, after the condenser is added with condensate pipeline, said condenser is communicated with said newly-added intermediate-temperature evaporator by means of said newly-added circulating pump and said newly-added preheater, said newly-added intermediate-temperature evaporator is communicated with said newly-added second expander by means of steam channel, said newly-added second expander also has steam channel communicated with condenser, and the communication of said expander with circulating medium channel, said high-temperature regenerator, intermediate-temperature evaporator and low-temperature evaporator and diffuser pipe is regulated to make said expander have circulating medium channel communicated with diffuser pipe by means of high-temperature regenerator, newly-added intermediate-temperature evaporator, intermediate-temperature evaporator and low-temperature evaporator, said newly-added preheater also has heat source medium channel communicated with exterior, and said newly-added, and a second expansion machine is added to be connected with the outside and output power, so that a graded evaporation combined cycle power device is formed.

47. A combined-cycle power plant for fractional evaporation is characterized by that in any one of the said power plants, a newly-added second expander, a newly-added intermediate-temperature evaporator, a newly-added circulating pump, a newly-added second circulating pump and a newly-added heat regenerator are added, the condenser is additionally provided with a condensed liquid pipeline communicated with the newly-added heat regenerator via the newly-added circulating pump, the newly-added second expander or second expander also has a steam-pumping channel communicated with the newly-added heat regenerator, the newly-added heat regenerator also has a condensed liquid pipeline communicated with the newly-added intermediate-temperature evaporator via the newly-added second circulating pump, then the newly-added intermediate-temperature evaporator has a steam channel communicated with the newly-added second expander, the newly-added second expander also has a steam channel communicated with the condenser, the expander has a circulating medium channel communicated with the expansion pipe via the high-temperature heat regenerator, the intermediate-temperature evaporator and the low-temperature evaporator, and the expansion pipe, The newly-added intermediate-temperature evaporator, the intermediate-temperature evaporator and the low-temperature evaporator are communicated with a diffuser pipe, the newly-added intermediate-temperature evaporator or a heat source medium channel is communicated with the outside, and the newly-added second expander is connected with the outside and outputs power to form a graded evaporation combined cycle power device.

Description of the drawings:

FIG. 1 is a schematic 1 st principal thermodynamic system diagram of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 2 is a schematic thermodynamic system diagram of a 2 nd principle of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 3 is a schematic diagram of a 3 rd principle thermodynamic system of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 4 is a diagram of a 4 th principal thermodynamic system of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 5 is a diagram of a 5 th principal thermodynamic system of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 6 is a 6 th principal thermodynamic system diagram of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 7 is a 7 th principal thermodynamic system diagram of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 8 is a diagram of an 8 th principle thermodynamic system of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 9 is a diagram of a 9 th principal thermodynamic system of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 10 is a 10 th principal thermodynamic system diagram of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 11 is a schematic diagram of the 11 th principal thermodynamic system of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 12 is a 12 th principal thermodynamic system diagram of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 13 is a 13 th principal thermodynamic system diagram of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 14 is a 14 th principal thermodynamic system diagram of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 15 is a diagram of a 15 th principal thermodynamic system of a staged evaporative combined cycle power plant provided in accordance with the present invention.

FIG. 16 is a 16 th principle thermodynamic system diagram of a staged evaporative combined cycle power plant provided in accordance with the present invention.

In the figure, 1-compressor, 2-expander, 3-second expander, 4-third expander, 5-circulating pump, 6-second circulating pump, 7-high temperature heat exchanger, 8-medium temperature evaporator, 9-low temperature evaporator, 10-condenser, 11-third circulating pump, 12-heat regenerator, 13-fourth circulating pump, 14-second heat regenerator, 15-preheater, 16-second preheater, 17-high temperature heat regenerator, 18-second condenser, 19-intermediate reheater; a-a newly-added compressor, B-a newly-added expansion machine, C-a newly-added high-temperature heat exchanger, D-a newly-added expansion pipe, E-a newly-added spray pipe, F-a newly-added medium-temperature heat exchanger, G-a newly-added circulating pump, H-a newly-added preheater and I-a newly-added second expansion machine.

The specific implementation mode is as follows:

it is to be noted that, in the description of the structure and the flow, the repetition is not necessary; obvious flow is not described. The invention is described in detail below with reference to the figures and examples.

The staged evaporative combined cycle power plant shown in FIG. 1 is implemented as follows:

(1) structurally, the system mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator and a condenser; the diffuser pipe 1 is provided with a circulating medium channel which is communicated with the expander 2 through a high-temperature heat exchanger 7, the expander 2 is also provided with a circulating medium channel which is communicated with the diffuser pipe 1 through a medium-temperature evaporator 8 and a low-temperature evaporator 9, the condenser 10 is provided with a condensate pipeline which is communicated with the medium-temperature evaporator 8 through a circulating pump 5, then the medium-temperature evaporator 8 is provided with a steam channel which is communicated with the second expander 3, the second expander 3 is also provided with a steam channel which is communicated with the condenser 10, the condenser 10 is also provided with a condensate pipeline which is communicated with the low-temperature evaporator 9 through a second circulating pump 6, then the low-temperature evaporator 9 is provided with a steam channel which is communicated with the third expander 4, and the third expander 4 is also provided with; the high-temperature heat exchanger 7 is also communicated with the outside through a heat source medium channel, the condenser 10 is also communicated with the outside through a cooling medium channel, and the expander 2, the second expander 3 and the third expander 4 are connected with the outside and output power.

(2) In the process, the circulating medium discharged by the diffuser pipe 1 flows through the high-temperature heat exchanger 7 and absorbs heat, and then enters the expansion machine 2 to reduce the pressure and do work; circulating media discharged by the expander 2 flow through the medium-temperature evaporator 8 and the low-temperature evaporator 9 and gradually release heat, and then enter the diffuser pipe 1 to increase pressure, raise temperature and reduce speed; the first path of condensate of the condenser 10 is pressurized by flowing through a circulating pump 5, absorbed and vaporized by flowing through a medium-temperature evaporator 8, depressurized and worked by flowing through a second expansion machine 3, and then enters the condenser 10 to release heat and be condensed; the other path of condensate of the condenser 10 flows through a second circulating pump 6 to be pressurized, flows through a low-temperature evaporator 9 to absorb heat and be vaporized, flows through a third expansion machine 4 to reduce pressure and do work, and then enters the condenser 10 to release heat and be condensed; the heat source medium provides driving heat load through the high-temperature heat exchanger 7, the cooling medium takes away low-temperature heat load through the condenser 10, and the expander 2, the second expander 3 and the third expander 4 provide power (such as driving a working machine or a generator) to the outside together to form a graded evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 2 is implemented as follows:

(1) structurally, the system mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator and a condenser; the diffuser pipe 1 is provided with a circulating medium channel which is communicated with the expander 2 through a high-temperature heat exchanger 7, the expander 2 is also provided with a circulating medium channel which is communicated with the diffuser pipe 1 through a medium-temperature evaporator 8 and a low-temperature evaporator 9, the condenser 10 is provided with a condensate pipeline which is communicated with the medium-temperature evaporator 8 through a circulating pump 5, then the medium-temperature evaporator 8 is provided with a steam channel which is communicated with the second expander 3, the second expander 3 is also provided with a steam channel which is communicated with the condenser 10, the condenser 10 is also provided with a condensate pipeline which is communicated with the low-temperature evaporator 9 through a second circulating pump 6, then the low-temperature evaporator 9 is provided with a steam channel which is communicated with the third expander 4, and the third expander 4 is also provided with; the high-temperature heat exchanger 7 is also communicated with the outside through a heat source medium channel, the medium-temperature evaporator 8 and the low-temperature evaporator 9 are also respectively communicated with the outside through a heat source medium channel, the condenser 10 is also communicated with the outside through a cooling medium channel, and the expander 2, the second expander 3 and the third expander 4 are connected with the outside and output power.

(2) In the process, the circulating medium discharged by the diffuser pipe 1 flows through the high-temperature heat exchanger 7 and absorbs heat, and then enters the expansion machine 2 to reduce the pressure and do work; circulating media discharged by the expander 2 flow through the medium-temperature evaporator 8 and the low-temperature evaporator 9 and gradually release heat, and then enter the diffuser pipe 1 to increase pressure, raise temperature and reduce speed; the first path of condensate of the condenser 10 is pressurized by flowing through a circulating pump 5, absorbed and vaporized by flowing through a medium-temperature evaporator 8, depressurized and worked by flowing through a second expansion machine 3, and then enters the condenser 10 to release heat and be condensed; the other path of condensate of the condenser 10 flows through a second circulating pump 6 to be pressurized, flows through a low-temperature evaporator 9 to absorb heat and be vaporized, flows through a third expansion machine 4 to reduce pressure and do work, and then enters the condenser 10 to release heat and be condensed; the heat source medium provides driving heat load through the high-temperature heat exchanger 7, the medium-temperature evaporator 8 and the low-temperature evaporator 9 respectively, the cooling medium takes away the low-temperature heat load through the condenser 10, and the expander 2, the second expander 3 and the third expander 4 provide power outwards together to form a graded evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 3 is implemented as follows:

(1) structurally, the system mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump and a heat regenerator; the diffuser pipe 1 is provided with a circulating medium channel which is communicated with the expander 2 through a high-temperature heat exchanger 7, the expander 2 is also provided with a circulating medium channel which is communicated with the diffuser pipe 1 through a medium-temperature evaporator 8 and a low-temperature evaporator 9, the condenser 10 is provided with a condensate pipeline which is communicated with the medium-temperature evaporator 8 through a circulating pump 5, then the medium-temperature evaporator 8 is provided with a steam channel which is communicated with the second expander 3, the second expander 3 is also provided with a steam channel which is communicated with the condenser 10, the condenser 10 is also provided with a condensate pipeline which is communicated with a heat regenerator 12 through a second circulating pump 6, the third expander 4 is provided with a steam extraction channel which is communicated with the heat regenerator 12, the heat regenerator 12 is also provided with a condensate pipeline which is communicated with the low-temperature evaporator 9 through a third circulating pump 11, then the low-temperature evaporator 9 is provided with a steam channel which is communicated with the third; the high-temperature heat exchanger 7 is also communicated with the outside through a heat source medium channel, the medium-temperature evaporator 8 and the low-temperature evaporator 9 are also respectively communicated with the outside through a heat source medium channel, the condenser 10 is also communicated with the outside through a cooling medium channel, and the expander 2, the second expander 3 and the third expander 4 are connected with the outside and output power.

(2) In the process, the circulating medium discharged by the diffuser pipe 1 flows through the high-temperature heat exchanger 7 and absorbs heat, and then enters the expansion machine 2 to reduce the pressure and do work; circulating media discharged by the expander 2 flow through the medium-temperature evaporator 8 and the low-temperature evaporator 9 and gradually release heat, and then enter the diffuser pipe 1 to increase pressure, raise temperature and reduce speed; the first path of condensate of the condenser 10 is pressurized by flowing through a circulating pump 5, absorbed and vaporized by flowing through a medium-temperature evaporator 8, depressurized and worked by flowing through a second expansion machine 3, and then enters the condenser 10 to release heat and be condensed; the other path of condensate of the condenser 10 is pressurized by the second circulating pump 6 and enters the heat regenerator 12, the steam extracted by the third expansion machine 4 enters the heat regenerator 12 to release heat and condense, the condensate of the heat regenerator 12 is pressurized by the third circulating pump 11 and enters the low-temperature evaporator 9 to absorb heat and vaporize, the steam enters the third expansion machine 4 to complete partial work and then is divided into two paths, the first path enters the heat regenerator 12, the second path continues to reduce the pressure and work and then enters the condenser 10 to release heat and condense; the heat source medium provides driving heat load through the high-temperature heat exchanger 7, the medium-temperature evaporator 8 and the low-temperature evaporator 9 respectively, the cooling medium takes away the low-temperature heat load through the condenser 10, and the expander 2, the second expander 3 and the third expander 4 provide power outwards together to form a graded evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 4 is implemented as follows:

(1) structurally, the system mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a third circulating pump, a heat regenerator, a fourth circulating pump and a second heat regenerator; the diffuser pipe 1 is provided with a circulating medium channel which is communicated with the expander 2 through a high-temperature heat exchanger 7, the expander 2 is also provided with a circulating medium channel which is communicated with the diffuser pipe 1 through a medium-temperature evaporator 8 and a low-temperature evaporator 9, a condenser 10 is provided with a condensate pipeline which is communicated with a heat regenerator 12 through a circulating pump 5, a second expander 3 is provided with a steam extraction channel which is communicated with the heat regenerator 12, the heat regenerator 12 is also provided with a condensate pipeline which is communicated with the medium-temperature evaporator 8 through a third circulating pump 11, then the medium-temperature evaporator 8 is provided with a steam channel which is communicated with a second expander 3, the second expander 3 is also provided with a steam channel which is communicated with the condenser 10, the condenser 10 is also provided with a condensate pipeline which is communicated with the second heat regenerator 14 through a second circulating pump 6, the third expander 4 is provided with a steam extraction channel which is communicated with the second heat regenerator 14, the second heat regenerator 14 is also provided with a condensate pipeline which is communicated with the low-temperature evaporator 9 through a fourth, the third expander 4 is also communicated with a condenser 10 through a steam channel; the high-temperature heat exchanger 7 is also communicated with the outside through a heat source medium channel, the medium-temperature evaporator 8 and the low-temperature evaporator 9 are also respectively communicated with the outside through a heat source medium channel, the condenser 10 is also communicated with the outside through a cooling medium channel, and the expander 2, the second expander 3 and the third expander 4 are connected with the outside and output power.

(2) In the process, the circulating medium discharged by the diffuser pipe 1 flows through the high-temperature heat exchanger 7 and absorbs heat, and then enters the expansion machine 2 to reduce the pressure and do work; circulating media discharged by the expander 2 flow through the medium-temperature evaporator 8 and the low-temperature evaporator 9 and gradually release heat, and then enter the diffuser pipe 1 to be boosted and heated; the first path of condensate of the condenser 10 enters the heat regenerator 12 after flowing through the circulating pump 5 for pressurization, the steam extracted by the second expander 3 enters the heat regenerator 12 for heat release and condensation, the condensate of the heat regenerator 12 enters the medium temperature evaporator 8 for heat absorption and vaporization after being pressurized by the third circulating pump 11, the steam enters the second expander 3 to complete partial pressure reduction work, and then the steam is divided into two paths, namely the first path enters the heat regenerator 12, and the second path enters the condenser 10 for heat release and condensation after continuing the pressure reduction work; the other path of condensate of the condenser 10 enters a second heat regenerator 14 after being pressurized by a second circulating pump 6, the extracted steam of the third expander 4 enters the second heat regenerator 14 to release heat and condense, the condensate of the second heat regenerator 14 enters a low-temperature evaporator 9 to absorb heat and vaporize after being pressurized by a fourth circulating pump 13, the steam enters the third expander 4 to finish partial work, and then the steam is divided into two paths, namely the first path enters the second heat regenerator 14, and the second path enters the condenser 10 to release heat and condense after being continuously depressurized and worked; the heat source medium provides driving heat load through the high-temperature heat exchanger 7, the medium-temperature evaporator 8 and the low-temperature evaporator 9 respectively, the cooling medium takes away the low-temperature heat load through the condenser 10, and the expander 2, the second expander 3 and the third expander 4 provide power outwards together to form a graded evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 5 is implemented as follows:

(1) structurally, the system mainly comprises a diffuser pipe, an expander, a second expander, a third expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a preheater and a second preheater; the diffuser pipe 1 is provided with a circulating medium channel which is communicated with the expander 2 through a high-temperature heat exchanger 7, the expander 2 is also provided with a circulating medium channel which is communicated with the diffuser pipe 1 through a medium-temperature evaporator 8 and a low-temperature evaporator 9, the condenser 10 is provided with a condensate pipeline which is communicated with the medium-temperature evaporator 8 through a circulating pump 5 and a preheater 15, then the medium-temperature evaporator 8 is provided with a steam channel which is communicated with the second expander 3, the second expander 3 is also provided with a steam channel which is communicated with the condenser 10, the condenser 10 is also provided with a condensate pipeline which is communicated with the low-temperature evaporator 9 through a second circulating pump 6 and a second preheater 16, then the low-temperature evaporator 9 is provided with a steam channel which is communicated with the third expander 4, and the third expander 4 is also provided; the high-temperature heat exchanger 7 is also communicated with the outside through a heat source medium channel, the medium-temperature evaporator 8 and the low-temperature evaporator 9 are also respectively communicated with the outside through a heat source medium channel, the condenser 10 is also communicated with the outside through a cooling medium channel, the preheater 15 and the second preheater 16 are also respectively communicated with the outside through a heat source medium channel, and the expander 2, the second expander 3 and the third expander 4 are connected with the outside and output power.

(2) In the process, the circulating medium discharged by the diffuser pipe 1 flows through the high-temperature heat exchanger 7 and absorbs heat, and then enters the expansion machine 2 to reduce the pressure and do work; circulating media discharged by the expander 2 flow through the medium-temperature evaporator 8 and the low-temperature evaporator 9 and gradually release heat, and then enter the diffuser pipe 1 to increase pressure, raise temperature and reduce speed; the first path of condensate of the condenser 10 is pressurized by flowing through a circulating pump 5, flows through a preheater 15, absorbs heat and heats up, flows through a medium-temperature evaporator 8, absorbs heat and vaporizes, flows through a second expander 3, reduces pressure and does work, and then enters the condenser 10 to release heat and condense; the other path of condensate of the condenser 10 flows through a second circulating pump 6 to be pressurized, flows through a second preheater 16 to absorb heat and raise the temperature, flows through a low-temperature evaporator 9 to absorb heat and vaporize, flows through a third expander 4 to reduce the pressure and do work, and then enters the condenser 10 to release heat and condense; the heat source medium provides driving heat load through a high-temperature heat exchanger 7, a medium-temperature evaporator 8, a low-temperature evaporator 9, a preheater 15 and a second preheater 16 respectively, the cooling medium takes away the low-temperature heat load through a condenser 10, and the expander 2, the second expander 3 and the third expander 4 provide power outwards together to form a staged evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 6 is implemented as follows:

(1) structurally, the system mainly comprises a diffuser pipe, an expander, a second expander, a circulating pump, a second circulating pump, a high-temperature heat exchanger, a medium-temperature evaporator, a low-temperature evaporator, a condenser, a preheater and a second preheater; the diffuser pipe 1 is provided with a circulating medium channel which is communicated with the expander 2 through a high-temperature heat exchanger 7, the expander 2 is also provided with a circulating medium channel which is communicated with the diffuser pipe 1 through a medium-temperature evaporator 8 and a low-temperature evaporator 9, the condenser 10 is provided with a condensate pipeline which is communicated with the medium-temperature evaporator 8 through a circulating pump 5 and a preheater 15, then the medium-temperature evaporator 8 is provided with a steam channel which is communicated with the second expander 3, the condenser 10 is also provided with a condensate pipeline which is communicated with the low-temperature evaporator 9 through a second circulating pump 6 and a second preheater 16, then the low-temperature evaporator 9 is provided with a middle steam inlet channel which is communicated with the second expander 3, and the second expander 3 is also provided with a steam channel which; the high-temperature heat exchanger 7 is also communicated with the outside through a heat source medium channel, the medium-temperature evaporator 8 and the low-temperature evaporator 9 are also respectively communicated with the outside through a heat source medium channel, the condenser 10 is also communicated with the outside through a cooling medium channel, the preheater 15 and the second preheater 16 are respectively communicated with the outside through a heat source medium channel, and the expander 2 and the second expander 3 are connected with the outside and output power.

(2) In the process, the circulating medium discharged by the diffuser pipe 1 flows through the high-temperature heat exchanger 7 and absorbs heat, and then enters the expansion machine 2 to reduce the pressure and do work; circulating media discharged by the expander 2 flow through the medium-temperature evaporator 8 and the low-temperature evaporator 9 and gradually release heat, and then enter the diffuser pipe 1 to increase pressure, raise temperature and reduce speed; the first path of condensate of the condenser 10 is pressurized by flowing through a circulating pump 5, flows through a preheater 15, absorbs heat and heats up, flows through a medium-temperature evaporator 8, absorbs heat and vaporizes, flows through a second expander 3, reduces pressure and does work, and then enters the condenser 10 to release heat and condense; the other path of condensate of the condenser 10 is pressurized by flowing through a second circulating pump 6, flows through a second preheater 16, absorbs heat and heats, flows through a low-temperature evaporator 9, absorbs heat and vaporizes, and the steam enters a second expander 3 through a middle steam inlet channel, is decompressed and does work, and then enters the condenser 10 to release heat and condense; the heat source medium provides driving heat load through a high-temperature heat exchanger 7, a medium-temperature evaporator 8, a low-temperature evaporator 9, a preheater 15 and a second preheater 16 respectively, the cooling medium takes away the low-temperature heat load through a condenser 10, and the expander 2 and the second expander 3 provide power outwards together to form a staged evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 7 is implemented as follows:

in the step-evaporation combined-cycle power plant shown in fig. 2, an intermediate reheater is added, and the intermediate temperature evaporator 8 having a steam passage communicating with the second expander 3 and the second expander 3 having a steam passage communicating with the condenser 10 are adjusted such that the intermediate temperature evaporator 8 having a steam passage communicating with the second expander 3, the second expander 3 having an intermediate reheater steam passage communicating with the second expander 3 via the intermediate reheater 19 and the second expander 3 having a steam passage communicating with the condenser 10, and the intermediate reheater 19 having a heat source medium passage communicating with the outside; the steam output by the medium temperature evaporator 8 enters the second expansion machine 3 to reduce the pressure and do work, is led out when reaching a certain intermediate pressure, enters the intermediate reheater 19 through the intermediate reheated steam channel to absorb heat and raise the temperature, then enters the second expansion machine 3 through the intermediate reheated steam channel to continue to finish the pressure reduction and do work, and then enters the condenser 10 to release heat and condense, thereby forming the graded evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 8 is implemented as follows:

in the step-evaporation combined cycle power plant shown in fig. 5, the second expander 3 having a vapor passage communicating with the condenser 10 is adjusted so that the second expander 3 having a vapor passage communicating with the third expander 4; the steam entering the second expansion machine 3 completes partial decompression work, enters the third expansion machine 4 to continue decompression work, and then enters the condenser 10 to release heat and condense, thus forming the graded evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 9 is implemented as follows:

(1) structurally, in the fractional evaporation combined cycle power plant shown in fig. 5, a second condenser is added, the second expander 3 is adjusted to have a steam passage to communicate with the condenser 10, the second expander 3 has a steam passage to communicate with the second condenser 18, the condenser 10 has a condensate pipeline to communicate with the medium temperature evaporator 8 through the circulating pump 5 and the preheater 15, the condenser 18 has a condensate pipeline to communicate with the medium temperature evaporator 8 through the circulating pump 5 and the preheater 15, and the second condenser 18 also has a cooling medium passage to communicate with the outside.

(2) Compared with the staged evaporation combined cycle power device shown in fig. 5, the difference in the flow is that the steam discharged from the second expander 3 enters the second condenser 18 to release heat to the cooling medium and condense, the condensate of the second condenser 18 flows through the circulating pump 5 to increase the pressure, flows through the preheater 15 to absorb heat to increase the temperature, flows through the medium temperature evaporator 8 to absorb heat and vaporize, and then flows through the second expander 3 to reduce the pressure and do work, thereby forming the staged evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 10 is implemented as follows:

(1) structurally, in the staged evaporation combined cycle power plant shown in fig. 5, the condenser 10 is adjusted to have a condensate pipeline communicated with the intermediate temperature evaporator 8 through the circulating pump 5 and the preheater 15 and a condensate pipeline communicated with the low temperature evaporator 9 through the second circulating pump 6 and the second preheater 16, and the condenser 10 is divided into two paths after having a condensate pipeline communicated with the low temperature evaporator 9 through the second circulating pump 6 and the second preheater 16, wherein the first path is directly communicated with the low temperature evaporator 9, and the second path is communicated with the intermediate temperature evaporator 8 through the circulating pump 5 and the preheater 15.

(2) In the process, compared with the staged evaporation combined cycle power device shown in fig. 5, the difference is that the condensate of the condenser 10 is divided into two paths after flowing through the second circulating pump 6 for pressure increase and flowing through the second preheater 16 for heat absorption and temperature increase, the first path flows through the low-temperature evaporator 9 for heat absorption and vaporization and then is supplied to the third expander 4, the second path flows through the circulating pump 5 for pressure increase, flows through the preheater 15 for heat absorption and temperature increase and flows through the medium-temperature evaporator 8 for heat absorption and vaporization and then is supplied to the second expander 3, and the staged evaporation combined cycle power device is formed.

The staged evaporative combined cycle power plant shown in FIG. 11 is implemented as follows:

(1) structurally, in the staged evaporation combined cycle power plant shown in fig. 5, a newly added compressor and a newly added high-temperature heat exchanger are added, a circulation medium channel of a diffuser pipe 1 is communicated with an expander 2 through the high-temperature heat exchanger 7, the circulation medium channel of the diffuser pipe 1 is communicated with a newly added compressor a through the high-temperature heat exchanger 7, a steam channel of the newly added compressor a is communicated with the expander 2 through a newly added high-temperature heat exchanger C, the newly added high-temperature heat exchanger C is also communicated with the outside through a heat source medium channel, and the expander 2 is connected with the newly added compressor a and transmits power.

(2) Compared with the staged evaporation combined cycle power plant shown in fig. 5, the difference in the flow is that the circulating medium discharged from the diffuser pipe 1 flows through the high-temperature heat exchanger 7 and absorbs heat, and then enters the newly-added compressor a to increase the pressure and temperature; circulating medium discharged by the newly-added compressor A flows through the newly-added high-temperature heat exchanger C and absorbs heat, and then enters the expander 2 to reduce pressure and do work; the expander 2 provides power for the newly-added compressor A, and the heat source medium provides driving heat load through the high-temperature heat exchanger 7, the newly-added high-temperature heat exchanger C, the medium-temperature evaporator 8, the low-temperature evaporator 9, the preheater 15 and the second preheater 16 respectively, so that the graded evaporation combined cycle power device is formed.

The staged evaporative combined cycle power plant shown in FIG. 12 is implemented as follows:

(1) structurally, in the staged evaporation combined cycle power plant shown in fig. 2, a high-temperature heat regenerator is added, a circulation medium channel of the diffuser pipe 1 is communicated with the expander 2 through a high-temperature heat exchanger 7 and adjusted to be communicated with the diffuser pipe 1 through a circulation medium channel of the diffuser pipe 1 and the high-temperature heat exchanger 17 and the high-temperature heat exchanger 7, and a circulation medium channel of the expander 2 is communicated with the diffuser pipe 1 through a medium-temperature evaporator 8 and a low-temperature evaporator 9 and adjusted to be communicated with the expander 2 through a circulation medium channel of the expander 2 and the diffuser pipe 1 through the high-temperature heat regenerator 17, the medium-temperature evaporator 8 and the low-temperature evaporator 9.

(2) Compared with the staged evaporation combined cycle power device shown in fig. 2, the difference in the flow is that the circulating medium discharged from the diffuser pipe 1 flows through the high-temperature heat regenerator 17 and the high-temperature heat exchanger 7 and absorbs heat gradually, and the circulating medium discharged from the expander 2 flows through the high-temperature heat regenerator 17, the medium-temperature evaporator 8 and the low-temperature evaporator 9 and releases heat gradually, so as to form the staged evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 13 is implemented as follows:

(1) structurally, in the staged evaporation combined cycle power plant shown in fig. 5, a high temperature heat regenerator, a newly-added diffuser pipe and a newly-added high temperature heat exchanger are added, a circulation medium channel of the diffuser pipe 1 is communicated with the expander 2 through the high temperature heat exchanger 7 and adjusted to be communicated with a newly-added diffuser pipe D through the high temperature heat regenerator 17 and the high temperature heat exchanger 7, a circulation medium channel of the newly-added diffuser pipe D is communicated with the expander 2 through a newly-added high temperature heat exchanger C, a circulation medium channel of the expander 2 is communicated with the diffuser pipe 1 through the medium temperature evaporator 8 and the low temperature evaporator 9 and adjusted to be communicated with a circulation medium channel of the expander 2 through the high temperature heat regenerator 17, the medium temperature evaporator 8 and the low temperature evaporator 9, and the newly-added high temperature heat exchanger C is also communicated with the outside through a heat source medium channel.

(2) Compared with the staged evaporation combined cycle power plant shown in fig. 5, the difference in the process is that the circulating medium discharged from the diffuser pipe 1 flows through the high-temperature heat regenerator 17 and the high-temperature heat exchanger 7 and gradually absorbs heat, and then enters the newly added diffuser pipe D to increase pressure, raise temperature and reduce speed; circulating media discharged by the newly added diffuser pipe D flow through the newly added high-temperature heat exchanger C and absorb heat, and then enter the expander 2 to reduce the pressure and do work; the circulating medium discharged by the expander 2 flows through the high-temperature heat regenerator 17, the medium-temperature evaporator 8 and the low-temperature evaporator 9 and gradually releases heat, and the heat source medium provides driving heat load through the high-temperature heat exchanger 7, the newly-added high-temperature heat exchanger C, the medium-temperature evaporator 8, the low-temperature evaporator 9, the preheater 15 and the second preheater 16 respectively to form a graded evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 14 is implemented as follows:

(1) structurally, in the staged evaporation combined cycle power plant shown in fig. 5, a newly added spray pipe and a newly added high-temperature heat exchanger are added, the connection between the diffuser pipe 1 with a circulation medium channel and the expander 2 through the high-temperature heat exchanger 7 is adjusted to be that the diffuser pipe 1 with a circulation medium channel is connected with the newly added spray pipe E through the high-temperature heat exchanger 7, the newly added spray pipe E with a steam channel is connected with the expander 2 through the newly added high-temperature heat exchanger C, and the newly added high-temperature heat exchanger C with a heat source medium channel is connected with the outside.

(2) Compared with the staged evaporation combined cycle power device shown in fig. 5, the difference in the process is that the circulating medium discharged from the diffuser pipe 1 flows through the high-temperature heat exchanger 7 and absorbs heat, and then enters the newly added spray pipe E to reduce the pressure, reduce the temperature and increase the speed; circulating medium discharged by the newly added spray pipe E flows through the newly added high-temperature heat exchanger C and absorbs heat, and then enters the expansion machine 2 to reduce pressure and do work; the heat source medium provides driving heat load through a high-temperature heat exchanger 7, a newly-added high-temperature heat exchanger C, a medium-temperature evaporator 8, a low-temperature evaporator 9, a preheater 15 and a second preheater 16 respectively to form a graded evaporation combined cycle power device.

The staged evaporative combined cycle power plant shown in FIG. 15 is implemented as follows:

(1) structurally, in the staged evaporation combined cycle power plant shown in fig. 5, a new expansion machine, a new intermediate temperature evaporator, a new circulating pump and a new preheater are added, a condenser 10 is additionally provided with a condensate pipeline which is communicated with the new intermediate temperature evaporator F through a new circulating pump G and a new preheater H, then the new intermediate temperature evaporator F is communicated with a new expansion machine B through a steam channel, the new expansion machine B is communicated with the condenser 10 through a steam channel, the expansion machine 2 is communicated with a diffuser pipe 1 through an intermediate temperature evaporator 8 and a low temperature evaporator 9, the expansion machine 2 is adjusted to be communicated with the diffuser pipe 1 through a circulating medium channel, the new intermediate temperature evaporator F, the intermediate temperature evaporator 8 and the low temperature evaporator 9, the new preheater H is communicated with the outside through a heat source medium channel, and the new intermediate temperature evaporator F is communicated with the outside through a heat source medium channel, the new expansion machine B is connected with the outside and outputs power.

(2) Compared with the step evaporation combined cycle power device shown in fig. 5, the difference in the process is that the circulating medium discharged by the expander 2 flows through the newly added intermediate temperature evaporator F, the intermediate temperature evaporator 8 and the low temperature evaporator 9 and gradually releases heat, and then enters the diffuser pipe 1 to increase pressure, raise temperature and reduce speed; part of condensate of the condenser 10 flows through a newly-added circulating pump G to be boosted, flows through a newly-added preheater H to absorb heat and be boosted, flows through a newly-added intermediate temperature evaporator F to absorb heat and be vaporized, then is supplied to a newly-added expansion machine B to be decompressed and work, and steam discharged by the newly-added expansion machine B enters the condenser 10 to release heat and is condensed; the heat source medium provides driving heat load through the high-temperature heat exchanger 7, the newly-added middle-temperature evaporator F, the middle-temperature evaporator 8, the low-temperature evaporator 9, the newly-added preheater H, the preheater 15 and the second preheater 16, and the expander 2, the second expander 3, the third expander 4 and the newly-added expander B output power outwards (such as driving a generator), so that the graded evaporation combined cycle power device is formed.

The staged evaporative combined cycle power plant shown in FIG. 16 is implemented as follows:

(1) structurally, in the staged evaporation combined cycle power plant shown in fig. 14, a new expansion machine, a new intermediate temperature evaporator, a new circulating pump and a new preheater are added, a condenser 10 is additionally provided with a condensate pipeline which is communicated with the new intermediate temperature evaporator F through a new circulating pump G and a new preheater H, then the new intermediate temperature evaporator F is communicated with a new expansion machine B through a steam channel, the new expansion machine B is communicated with the condenser 10 through a steam channel, the expansion machine 2 is communicated with a diffuser pipe 1 through an intermediate temperature evaporator 8 and a low temperature evaporator 9, the expansion machine 2 is adjusted to be communicated with the diffuser pipe 1 through a circulating medium channel, the new intermediate temperature evaporator F, the intermediate temperature evaporator 8 and the low temperature evaporator 9, the new preheater H is communicated with the outside through a heat source medium channel, and the new intermediate temperature evaporator F is communicated with the outside through a heat source medium channel, the new expansion machine B is connected with the outside and outputs power.

(2) In the process, compared with the step evaporation combined cycle power plant shown in fig. 14, the difference lies in that the circulating medium discharged by the expander 2 flows through the newly added intermediate temperature evaporator F, the intermediate temperature evaporator 8 and the low temperature evaporator 9 and gradually releases heat, and then enters the diffuser pipe 1 to increase pressure, raise temperature and reduce speed; part of condensate of the condenser 10 flows through a newly-added circulating pump G to be boosted, flows through a newly-added preheater H to absorb heat and be boosted, flows through a newly-added intermediate temperature evaporator F to absorb heat and be vaporized, then is supplied to a newly-added expansion machine B to be decompressed and work, and steam discharged by the newly-added expansion machine B enters the condenser 10 to release heat and is condensed; the heat source medium provides driving heat load through the high-temperature heat exchanger 7, the newly-added high-temperature heat exchanger C, the newly-added medium-temperature evaporator F, the medium-temperature evaporator 8, the low-temperature evaporator 9, the newly-added preheater H, the preheater 15 and the second preheater 16, and the expander 2, the second expander 3, the third expander 4 and the newly-added expander B output power outwards to form a graded evaporation combined cycle power device.

The effect that the technology of the invention can realize-the grading evaporation combined cycle power device provided by the invention has the following effects and advantages:

(1) the diffuser pipe replaces a compressor, and the manufacturing difficulty and the manufacturing cost of the graded evaporation combined cycle power device are greatly reduced.

(2) The spray pipe replaces a non-main expansion machine, and the manufacturing difficulty and the manufacturing cost of the staged evaporation combined cycle power device are reduced.

(3) The load of the main expander (i.e., the expander 2) can be indirectly reduced, and the manufacturing difficulty and cost of the main expander are reduced.

(4) The simple components replace complex components, which is beneficial to maintaining or improving the thermal efficiency of the staged evaporation combined cycle power plant.

(5) A plurality of specific technical schemes are provided, and the device can be used for coping with a plurality of different actual conditions and has a wider application range.

(6) The technology of the graded evaporation combined cycle power device is expanded, the types of the graded evaporation combined cycle power device are enriched, the conversion of heat energy into mechanical energy is favorably realized, and the application range of the device is expanded.