阅读说明：本技术 一种共享设备的co2布雷顿与热泵联合循环系统及运行方法 (CO of sharing equipment2Brayton and heat pump combined cycle system and operation method ) 是由 高炜 韩伟 杨玉 姚明宇 乔永强 吴帅帅 于 2021-10-15 设计创作，主要内容包括：本发明公开了一种共享设备的CO2布雷顿与热泵联合循环系统及运行方法,该系统包括了熔盐储热系统、CO-(2)布雷顿循环光热发电系统、热泵系统、低温发电系统、储冷系统、低温储热系统,其中共享CO-(2)高压透平、共享高温回热器、共享低温回热器、共享预冷器、共享主压缩机等几项主要设备为CO2布雷顿循环、热泵循环、低温发电循环所共有,这些设备的设计参数按照所用循环中的最高参数设计,由于采用了共享设备的设计,大大降低了设备投资成本,增加了系统经济性。(The invention discloses a CO2 Brayton and heat pump combined cycle system of shared equipment and an operation method thereof, wherein the system comprises a molten salt heat storage system and CO 2 Brayton cycle photo-thermal power generation system, heat pump system, low-temperature power generation system, cold storage system, and low-temperature heat storage system, wherein CO is shared 2 The main equipment of the high-pressure turbine, the shared high-temperature heat regenerator, the shared low-temperature heat regenerator, the shared precooler, the shared main compressor and the like is CO2The Brayton cycle, the heat pump cycle and the low-temperature power generation cycle are shared, the design parameters of the devices are designed according to the highest parameter in the used cycle, and the design of shared devices is adopted, so that the investment cost of the devices is greatly reduced, and the economical efficiency of the system is improved.)

1. A CO2 Brayton and heat pump combined cycle system for sharing equipment is characterized by comprising a molten salt heat storage system and CO₂The system comprises a Brayton cycle photo-thermal power generation system, a heat pump system, a low-temperature power generation system, a cold storage system and a low-temperature heat storage system;

the molten salt heat storage system comprises a heat collector (1-1), a high-temperature molten salt tank (1-2), a low-temperature molten salt tank (1-3) and a molten salt pump (1-4), wherein an outlet of the heat collector (1-1) is communicated with an inlet of the high-temperature molten salt tank (1-2), and an outlet of the high-temperature molten salt tank (1-2) is communicated with CO₂A fused salt side inlet of a fused salt heat exchanger (2-1) of the Brayton cycle photo-thermal power generation system is communicated, a fused salt side outlet of the fused salt heat exchanger (2-1) is communicated with an inlet of a low-temperature fused salt tank (1-3), an outlet of the low-temperature fused salt tank (1-3) is communicated with an inlet of a fused salt pump (1-4), and an outlet of the fused salt pump (1-4) is communicated with an inlet of a heat collector (1-1);

the CO is₂The Brayton cycle photo-thermal power generation system comprises a fused salt heat exchanger (2-1) and a shared CO₂The system comprises a high-pressure turbine (2-2), a first valve (2-3) of a photo-thermal power generation system, a shared high-temperature heat regenerator (2-4), a shared low-temperature heat regenerator (2-5), a second valve (2-6) of the photo-thermal power generation system, a recompressor (2-7), a shared precooler (2-8), a third valve (2-9) of the photo-thermal power generation system, a shared main compressor (2-10), a fourth valve (2-11) of the photo-thermal power generation system, a fifth valve (2-12) of the photo-thermal power generation system, a sixth valve (2-13) of the photo-thermal power generation system, and CO of a molten salt heat exchanger (2-1)₂Side export with shared CO₂The inlets of the high-pressure turbines (2-2) are connected and share CO₂An outlet of the high-pressure turbine (2-2) is communicated with an inlet of a first valve (2-3) of the photo-thermal power generation system, an outlet of the first valve (2-3) of the photo-thermal power generation system is communicated with a hot side inlet of a shared high-temperature heat regenerator (2-4), a hot side outlet of the shared high-temperature heat regenerator (2-4) is communicated with a hot side inlet of a shared low-temperature heat regenerator (2-5), a hot side outlet of the shared low-temperature heat regenerator (2-5) is divided into two paths, one path is communicated with an inlet of a second valve (2-6) of the photo-thermal power generation system, an outlet of the second valve (2-6) of the photo-thermal power generation system is communicated with an inlet of a recompressor (2-7), the other path is communicated with a hot side inlet of a shared precooler (2-8), and a hot side outlet of the shared precooler (2-8) is divided into three paths, one path of the air conditioner is communicated with an inlet of a third valve (2-9) of the photo-thermal power generation system, an outlet of the third valve (2-9) of the photo-thermal power generation system is communicated with an inlet of a shared main compressor (2-10), an outlet of the shared main compressor (2-10) is communicated with an inlet of a fourth valve (2-11) of the photo-thermal power generation system, and an outlet of the fourth valve (2-11) of the photo-thermal power generation systemAn outlet is communicated with a cooling inlet of the shared low-temperature heat regenerator (2-5), a cold side outlet of the shared low-temperature heat regenerator (2-5) is also divided into two paths, one path is communicated with an inlet of a fifth valve (2-12) of the photo-thermal power generation system, an outlet of the fifth valve (2-12) of the photo-thermal power generation system is converged with an outlet of a recompressor (2-7) and then communicated with a cooling inlet of the shared high-temperature heat regenerator (2-4), a cold side outlet of the shared high-temperature heat regenerator (2-4) is communicated with an inlet of a sixth valve (2-13) of the photo-thermal power generation system, and an inlet of the sixth valve (2-13) of the photo-thermal power generation system is communicated with a CO (carbon monoxide) of the molten salt heat exchanger (2-1)₂The side inlets are communicated;

the heat pump system comprises a low-pressure compressor (3-1), a shared main compressor (2-10), a first valve (3-2) of the heat pump system, a low-temperature heat source heater (3-3), a shared low-temperature heat regenerator (2-5), a second valve (3-4) of the heat pump system, a CO2 expander (3-5), a CO2 evaporator (3-6) and a third valve (3-7) of the heat pump system, wherein an outlet of the low-pressure compressor (3-1) is communicated with an inlet of the shared main compressor (2-10), the other path of an outlet of the shared main compressor (2-10) is communicated with an inlet of the first valve (3-2) of the heat pump system, an outlet of the first valve (3-2) of the heat pump system is communicated with a hot side inlet of the low-temperature heat source heater (3-3), the hot side outlet of the low-temperature heat source heater (3-3) is communicated with the cold side inlet of the shared low-temperature heat regenerator (2-5), the other path of the cold side outlet of the shared low-temperature heat regenerator (2-5) is communicated with the inlet of a second valve (3-4) of the heat pump system, the outlet of the second valve (3-4) of the heat pump system is communicated with the inlet of a CO2 expander (3-5), the outlet of the CO2 expander (3-5) is communicated with the inlet of the CO2 side of a CO2 evaporator (3-6), the outlet of the CO2 side of the CO2 evaporator (3-6) is communicated with the hot side inlet of the shared low-temperature heat regenerator (2-5), one path of the hot side outlets of the shared low-temperature heat regenerator (2-5) is communicated with the hot side inlet of the shared precooler (2-8), and one path of the hot side outlets of the shared cooler (2-8) is communicated with the inlet of a third valve (3-7) of the heat pump system The outlet of the third valve (3-7) of the heat pump system is communicated with the inlet of the low-pressure compressor (3-1);

the low-temperature power generation system comprises a liquid CO2 pump (4-1), a shared low-temperature heat regenerator (2-5), a valve (2-12), a shared high-temperature heat regenerator (2-4), a first valve (4-2) of the low-temperature power generation system, and heat conducting oil for heatingDevice (4-3), shared CO₂The high-pressure turbine (2-2), the second valve (4-4) of the low-temperature power generation system, the CO2 low-pressure turbine (4-5) and the third valve (4-6) of the low-temperature power generation system, the outlet of the liquid CO2 pump (4-1) is communicated with the low-temperature side inlet of the shared low-temperature heat regenerator (2-5), one path of the low-temperature side outlet of the shared low-temperature heat regenerator (2-5) is communicated with the inlet of the fifth valve (2-12) of the photo-thermal power generation system, the outlet of the fifth valve (2-12) of the photo-thermal power generation system is communicated with the cooling inlet of the shared high-temperature heat regenerator (2-4), the cold side outlet of the shared high-temperature heat regenerator (2-4) is communicated with the inlet of the first valve (4-2) of the low-temperature power generation system, the outlet of the first valve (4-2) of the low-temperature power generation system is communicated with the hot side of the heat-conducting oil heater (4-3), the hot side outlet of the heat conducting oil heater (4-3) shares CO₂The inlets of the high-pressure turbines (2-2) are connected and share CO₂An outlet of the high-pressure turbine (2-2) is communicated with an inlet of a second valve (4-4) of the low-temperature power generation system, an outlet of the second valve (4-4) of the low-temperature power generation system is communicated with an inlet of a CO2 low-pressure turbine (4-5), an outlet of a CO2 low-pressure turbine (4-5) is communicated with a hot side inlet of a shared high-temperature regenerator (2-4), one path of the hot side outlet of the shared precooler (2-8) is communicated with an inlet of a third valve (4-6) of the low-temperature power generation system, and an outlet of the third valve (4-6) of the low-temperature power generation system is communicated with an inlet of a liquid CO2 pump (4-1);

the cold storage system comprises a water pump (5-1), a CO2 evaporator (3-6), a low-temperature water storage tank (5-2), a cold storage system valve (5-3), a shared precooler (2-8) and a high-temperature water storage tank (5-4), wherein an outlet of the water pump (5-1) is communicated with a water side inlet of the CO2 evaporator (3-6), a water side outlet of the CO2 evaporator (3-6) is communicated with an inlet of the low-temperature water storage tank (5-2), an outlet of the low-temperature water storage tank (5-2) is communicated with an inlet of the cold storage system valve (5-3), an outlet of the valve (5-3) is communicated with a water side inlet of the shared precooler (2-8), a water side outlet of the shared precooler (2-8) is communicated with an inlet of the high-temperature water storage tank (5-4), the outlet of the high-temperature water storage tank (5-4) is communicated with the inlet of the water pump (5-1);

the low-temperature heat storage system comprises a heat conduction oil pump (6-1), a low-temperature heat source heater (3-3), a high-temperature heat conduction oil storage tank (6-2), a heat conduction oil heater (4-3) and a low-temperature heat conduction oil storage tank (6-3), an outlet of the heat conduction oil pump (6-1) is communicated with a heat conduction oil side inlet of the low-temperature heat source heater (3-3), a heat conduction oil side outlet of the low-temperature heat source heater (3-3) is communicated with an inlet of the high-temperature heat conduction oil storage tank (6-2), an outlet of the high-temperature heat conduction oil storage tank (6-2) is communicated with a heat conduction oil side inlet of the heat conduction oil heater (4-3), a heat conduction oil side outlet of the heat conduction oil heater (4-3) is communicated with an inlet of the low-temperature heat conduction oil storage tank (6-3), and an outlet of the low-temperature heat conduction oil storage tank (6-3) is communicated with an inlet of the heat conduction oil pump (6-1).

2. The CO2 brayton and heat pump combined cycle system for a shared device of claim 1, wherein the shared CO is₂The main equipment of the high-pressure turbine (2-2), the shared high-temperature heat regenerator (2-4), the shared low-temperature heat regenerator (2-5), the shared precooler (2-8) and the shared main compressor (2-10) is shared by a CO2 Brayton cycle, a heat pump cycle and a low-temperature power generation cycle, the design parameters of the equipment are designed according to the highest parameter in the used cycle, wherein the shared main compressor (2-10) is designed according to 25MPa and 350 ℃, and the shared CO is shared₂The high-pressure turbine (2-2) is designed according to 25MPa and 550 ℃, the shared high-temperature heat regenerator (2-4) is designed according to 25MPa and 350 ℃, the shared low-temperature heat regenerator (2-5) is designed according to 25MPa and 250 ℃, and the shared precooler (2-8) is designed according to 8MPa and 100 ℃.

3. A plant-shared CO2 brayton and heat pump combined cycle system according to claim 1, characterized in that the CO2 low pressure turbine (4-5) is designed at 8MPa, 350 ℃, the liquid CO2 pump (4-1) is designed at 25MPa, 25 ℃ and the low pressure compressor (3-1) is designed at 8MPa, 250 ℃.

4. A method of operating a CO2 brayton and heat pump combined cycle system sharing a plant as claimed in any one of claims 1 to 3, wherein: the system has the function of adjusting the load change of the power grid, and the operation of the system is divided into three working conditions:

(1) when the power of the power grid is surplus and cannot be consumed by users, the heat pump system operates, the system starts to store electric energy into heat energy, at the moment, the CO2 Brayton cycle photo-thermal power generation system and the low-temperature power generation system do not work, and part of equipment needing to be shared is used by the heat pump cycle; at the moment, a third valve (3-7) of the heat pump system, a second valve (3-4) of the heat pump system and a first valve (3-2) of the heat pump system are opened, and a first valve (2-3) of the photo-thermal power generation system, a second valve (2-6) of the photo-thermal power generation system, a third valve (2-9) of the photo-thermal power generation system, a fourth valve (2-11) of the photo-thermal power generation system, a fifth valve (2-12) of the photo-thermal power generation system, a sixth valve (2-13) of the photo-thermal power generation system, a first valve (4-2) of the low-temperature power generation system, a second valve (4-4) of the low-temperature power generation system, a third valve (4-6) of the low-temperature power generation system and a valve (5-3) of the cold storage system are all closed; firstly, surplus electric energy in a power grid drives a low-pressure compressor (3-1) and a shared main compressor (2-10) to operate, low-pressure CO2 is compressed to high-pressure high-temperature, high-pressure high-temperature CO2 enters a hot side of a low-temperature heat source heater (3-3) after passing through a first valve (3-2) of a heat pump system to release heat, then enters a cold side of a shared low-temperature heat regenerator (2-5) to continue releasing heat, then enters a CO2 expander (3-5) after passing through a second valve (3-4) of the heat pump system to do work through expansion, the expanded CO2 is in a low-pressure low-temperature state, the temperature of the expanded CO2 is lower than the ambient temperature, then enters a CO2 evaporator (3-6) to absorb heat, the heat-absorbed CO2 enters a cold side of the shared low-temperature heat regenerator (2-5) to continue absorbing heat, and then CO2 passes through a shared precooler (2-8) and a third valve (3-7) of the heat pump system, in the device, heat is not exchanged but flows through the device, and then returns to the inlet of the low-pressure compressor (3-1) to complete the whole cycle; meanwhile, the water pump (5-1) is operated to convey the hot water in the high-temperature water storage tank (5-4) to the water side in the CO2 evaporator (3-6) to release heat, and then the hot water returns to the low-temperature water storage tank (5-2) to be stored. Meanwhile, the heat conduction oil pump (6-1) operates, and low-temperature heat conduction oil in the low-temperature heat conduction oil storage tank (6-3) is conveyed to the low-temperature heat source heater (3-3) and then enters the high-temperature heat conduction oil storage tank (6-2) for storage;

(2) when the power of the power grid is insufficient and power generation is needed, the operation of the heat pump system is stopped, the low-temperature power generation circulating system is started at first, the CO2 Brayton cycle photo-thermal power generation system is not started temporarily, and at the moment, the fifth valve (2-12) of the photo-thermal power generation system, the first valve (4-2) of the low-temperature power generation system, the second valve (4-4) of the low-temperature power generation system and the third valve (4) of the low-temperature power generation system are connected with each other-6) and a cold storage system valve (5-3) are opened, a heat pump system third valve (3-7), a heat pump system second valve (3-4) and a heat pump system first valve (3-2) are opened, and a photo-thermal power generation system first valve (2-3), a photo-thermal power generation system second valve (2-6), a photo-thermal power generation system third valve (2-9), a photo-thermal power generation system fourth valve (2-11) and a photo-thermal power generation system sixth valve (2-13) are closed; firstly, a liquid CO2 pump (4-1) pressurizes and conveys low-temperature liquid CO2 to a cold side of a shared low-temperature heat regenerator (2-5) to absorb heat, then the low-temperature liquid CO2 is conveyed to the cold side of the shared high-temperature heat regenerator (2-4) through a fifth valve (2-12) of a photo-thermal power generation system to continuously absorb heat, then the low-temperature liquid CO2 is conveyed to a CO2 side of a heat-conducting oil heater (4-3) through a first valve (4-2) of the low-temperature power generation system to be heated, and then the high-temperature liquid CO2 enters the shared CO2 side of the shared high-temperature heat regenerator to be heated₂The high-pressure turbine (2-2) does work, enters the CO2 low-pressure turbine (4-5) to do work after passing through the second valve (4-4) of the low-temperature power generation system, then sequentially enters the hot side of the shared high-temperature heat regenerator (2-4), the hot side of the shared low-temperature heat regenerator (2-5) and the hot side of the shared precooler (2-8) to release heat, and finally returns to the inlet of the liquid CO2 pump (4-1) through the third valve (4-6) of the low-temperature power generation system. Meanwhile, low-temperature water in the low-temperature water storage tank (5-2) enters a cold side of the shared precooler (2-8) through a cold storage system valve (5-3) to cool working media, and then returns to the high-temperature water storage tank (5-4) to be stored; meanwhile, the high-temperature heat conduction oil in the high-temperature heat conduction oil storage tank (6-2) enters the hot side of the heat conduction oil heater (4-3) to release heat, and then returns to the low-temperature heat conduction oil storage tank (6-3) to be stored;

(3) when the consumption of the high-temperature heat conduction oil in the high-temperature heat conduction oil storage tank (6-2) reaches a preset value, the low-temperature power generation system is stopped, the CO2 Brayton cycle photo-thermal power generation system is started, and the heat pump system still keeps stopping; at the moment, a first valve (2-3) of the photo-thermal power generation system, a second valve (2-6) of the photo-thermal power generation system, a third valve (2-9) of the photo-thermal power generation system, a fourth valve (2-11) of the photo-thermal power generation system, a fifth valve (2-12) of the photo-thermal power generation system, a sixth valve (2-13) of the photo-thermal power generation system and a valve (5-3) of the cold storage system are opened, a third valve (3-7) of the heat pump system, a second valve (3-4) of the heat pump system, a first valve (3-2) of the heat pump system, a first valve (4-2) of the low-temperature power generation system, a second valve (4-4) of the low-temperature power generation system and a low-temperature power generation systemThe third valves (4-6) are all closed; firstly, CO2 enters a molten salt heat exchanger (2-1) to be heated to a high temperature, and then enters shared CO₂The high-pressure turbine (2-2) does work, then the high-pressure turbine enters a hot side of a shared high-temperature heat regenerator (2-4) in sequence through a first valve (2-3) of a photo-thermal power generation system, the hot side of the shared low-temperature heat regenerator (2-5) releases heat, then a part of CO2 enters a re-compressor (2-7) through a second valve (2-6) of the photo-thermal power generation system to be directly pressurized, the other part of CO2 enters a shared precooler (2-8) to be further cooled, then enters a shared main compressor (2-10) through a third valve (2-9) of the photo-thermal power generation system to be pressurized, then enters a cold side of the shared low-temperature heat regenerator (2-5) through a fourth valve (2-11) of the photo-thermal power generation system to absorb heat, then is converged with CO2 at an outlet of the recompressor (2-7), and then enters a cold side of the high-temperature heat regenerator (2-4) through a fifth valve (2-12) of the photo-thermal power generation system to absorb heat Finally, the heat returns to the inlet of the molten salt heat exchanger (2-1) after passing through a sixth valve (2-13) of the photo-thermal power generation system; meanwhile, low-temperature water in the low-temperature water storage tank (5-2) enters a cold side of the shared precooler (2-8) through a cold storage system valve (5-3) to cool working media, and then returns to the high-temperature water storage tank (5-4) to be stored; meanwhile, the high-temperature molten salt stored in the high-temperature molten salt tank (1-2) enters the molten salt side of the molten salt heat exchanger (2-1) to release heat, and then returns to the low-temperature molten salt tank (1-3) to be stored;

(4) the fused salt heat storage system is not shared with other systems and is independent in operation, only according to the sunshine condition, when the sunshine is sufficient and a storage space is arranged in the high-temperature fused salt tank (1-2), the fused salt heat storage system stores heat, low-temperature fused salt in the low-temperature fused salt tank (1-3) is conveyed to the heat collector (1-1) through the fused salt pump (1-4) to be heated, and then the low-temperature fused salt is stored in the high-temperature fused salt tank (1-2).

Technical Field

The invention relates to a power generation system, in particular to a CO2 Brayton and heat pump combined cycle system sharing equipment and an operation method.

Background

Under the large background of energy shortage and environmental crisis, increasing attention is paid to improving energy utilization rate. Solar energy is an inexhaustible clean energy, and in the current stage, the technology of solar photovoltaic is relatively mature, the application is photovoltaic, but the energy storage is difficult to solve. However, the photovoltaic power generation system is difficult to store energy, the current mature photovoltaic energy storage matching mode is still battery energy storage, but the manufacturing cost of the battery energy storage is always too high, meanwhile, accidents such as fire disasters are difficult to avoid, and for large-scale energy storage requirements of power plants at such power levels, various types of battery energy storage are difficult to popularize at present. Meanwhile, as the theoretical thermal efficiency of the solar photo-thermal power generation is high during high-temperature heat collection, and the problem of uneven solar time distribution can be solved by using cheaper heat storage and energy storage in theory, the photo-thermal power generation is also increasingly emphasized. Meanwhile, the electric heating energy storage is an energy storage mode with relatively high efficiency, and among the electric heating energy storage technologies, the CO2 heat pump electric heating energy storage technology is one of the technologies with relatively high efficiency.

However, solar thermal power generation has the difficulty that the cost is too high and the popularization is difficult, on the other hand, the price of photovoltaic power generation is reduced to be very low after years of development, and the state gradually reduces the price of electricity for the photovoltaic power generation. If photo-thermal power generation and other new energy resources can be combined, a photovoltaic power generation system and a wind power generation system which are low in price and relatively high in technical maturity are partially adopted, and a thermal energy storage and thermal power generation system is combined to serve as a regulation and supplementary power supply system for photovoltaic power generation, so that low investment cost of the power generation system can be maintained, and stability of power output can be realized. However, both photo-thermal power generation and electrothermal energy storage are relatively expensive, and cost reduction is a long-term goal of these technologies. Meanwhile, the CO2 Brayton cycle photothermal power generation system and the CO2 electrothermal energy storage system are required to be provided with corresponding CO2 regenerators, precoolers, compressors, turbines and the like. If the two can be combined together, part of equipment is shared, which can greatly reduce the investment cost.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention aims to realize energy storage of solar power generation on the premise of maintaining lower investment cost, and provides a CO2 Brayton and heat pump combined cycle system sharing equipment and an operation method.

In order to achieve the purpose, the invention adopts the following technical scheme:

a CO2 Brayton and heat pump combined cycle system for sharing equipment comprises a molten salt heat storage system and CO₂The system comprises a Brayton cycle photo-thermal power generation system, a heat pump system, a low-temperature power generation system, a cold storage system and a low-temperature heat storage system;

the molten salt heat storage system comprises a heat collector 1-1, a high-temperature molten salt tank 1-2, a low-temperature molten salt tank 1-3 and a molten salt pump 1-4, wherein an outlet of the heat collector 1-1 is communicated with an inlet of the high-temperature molten salt tank 1-2, and an outlet of the high-temperature molten salt tank 1-2 is communicated with CO₂A fused salt side inlet of a fused salt heat exchanger 2-1 of the Brayton cycle photo-thermal power generation system is communicated, a fused salt side outlet of the fused salt heat exchanger 2-1 is communicated with an inlet of a low-temperature fused salt tank 1-3, an outlet of the low-temperature fused salt tank 1-3 is communicated with an inlet of a fused salt pump 1-4, and an outlet of the fused salt pump 1-4 is communicated with an inlet of a heat collector 1-1;

the CO is₂The Brayton cycle photo-thermal power generation system comprises a fused salt heat exchanger 2-1 and shared CO₂2-2 parts of high-pressure turbine, 2-3 parts of first valve of photo-thermal power generation system, 2-4 parts of shared high-temperature heat regenerator, 2-5 parts of shared low-temperature heat regenerator, 2-6 parts of second valve of photo-thermal power generation system, 2-7 parts of recompressor, 2-8 parts of shared precooler, 2-9 parts of third valve of photo-thermal power generation system, 2-10 parts of shared main compressor, 2-11 parts of fourth valve of photo-thermal power generation system, 2-12 parts of fifth valve of photo-thermal power generation system, 2-13 parts of sixth valve of photo-thermal power generation system and 2-1 parts of molten salt heat exchangerCO₂Side export with shared CO₂The inlets of the high-pressure turbines 2-2 are communicated with each other and share CO₂An outlet of the high-pressure turbine 2-2 is communicated with an inlet of a first valve 2-3 of the photo-thermal power generation system, an outlet of the first valve 2-3 of the photo-thermal power generation system is communicated with a hot side inlet of a shared high-temperature heat regenerator 2-4, a hot side outlet of the shared high-temperature heat regenerator 2-4 is communicated with a hot side inlet of a shared low-temperature heat regenerator 2-5, the hot side outlet of the shared low-temperature heat regenerator 2-5 is divided into two paths, one path is communicated with an inlet of a second valve 2-6 of the photo-thermal power generation system, an outlet of the second valve 2-6 of the photo-thermal power generation system is communicated with an inlet of a recompressor 2-7, the other path is communicated with a hot side inlet of a shared precooler 2-8, a hot side outlet of the shared precooler 2-8 is divided into three paths, one path is communicated with an inlet of a third valve 2-9 of the photo-thermal power generation system, an outlet of a third valve 2-9 of the photo-thermal power generation system is communicated with an inlet of a shared main compressor 2-10, an outlet of the shared main compressor 2-10 is communicated with an inlet of a fourth valve 2-11 of the photo-thermal power generation system, an outlet of the fourth valve 2-11 of the photo-thermal power generation system is communicated with a cooling inlet of a shared low-temperature heat regenerator 2-5, an outlet of a cold side of the shared low-temperature heat regenerator 2-5 is also divided into two paths, one path is communicated with an inlet of a fifth valve 2-12 of the photo-thermal power generation system, an outlet of the fifth valve 2-12 of the photo-thermal power generation system is converged with an outlet of a recompressor 2-7 and then communicated with a cooling inlet of the shared high-temperature heat regenerator 2-4, and a cold side outlet of the shared high-temperature heat regenerator 2-4 is communicated with an inlet of a sixth valve 2-13 of the photo-thermal power generation system, an inlet of a sixth valve 2-13 of the photo-thermal power generation system and CO of the molten salt heat exchanger 2-1₂The side inlets are communicated;

the heat pump system comprises a low-pressure compressor 3-1, a shared main compressor 2-10, a first valve 3-2 of the heat pump system, a low-temperature heat source heater 3-3, a shared low-temperature heat regenerator 2-5, a second valve 3-4 of the heat pump system, a CO2 expander 3-5, a CO2 evaporator 3-6 and a third valve 3-7 of the heat pump system, wherein an outlet of the low-pressure compressor 3-1 is communicated with an inlet of the shared main compressor 2-10, the other path of an outlet of the shared main compressor 2-10 is communicated with an inlet of the first valve 3-2 of the heat pump system, an outlet of the first valve 3-2 of the heat pump system is communicated with a hot side inlet of the low-temperature heat source heater 3-3, a hot side outlet of the low-temperature heat source heater 3-3 is communicated with a cold side inlet of the shared low-temperature heat regenerator 2-5, the other path of the cold side outlet of the shared low-temperature regenerator 2-5 is communicated with the inlet of a second valve 3-4 of the heat pump system, the outlet of the second valve 3-4 of the heat pump system is communicated with the inlet of a CO2 expander 3-5, the outlet of the CO2 expander 3-5 is communicated with the inlet of the CO2 side of a CO2 evaporator 3-6, the outlet of the CO2 side of the CO2 evaporator 3-6 is communicated with the inlet of the hot side of the shared low-temperature regenerator 2-5, one path of the hot side outlet of the shared low-temperature regenerator 2-5 is communicated with the inlet of a shared precooler 2-8, one path of the hot side outlet of the shared precooler 2-8 is communicated with the inlet of a third valve 3-7 of the heat pump system, and the outlet of the third valve 3-7 of the heat pump system is communicated with the inlet of a low-pressure compressor 3-1;

the low-temperature power generation system comprises a liquid CO2 pump 4-1, a shared low-temperature heat regenerator 2-5, a valve 2-12, a shared high-temperature heat regenerator 2-4, a first valve 4-2 of the low-temperature power generation system, a heat conducting oil heater 4-3 and a shared CO₂A high-pressure turbine 2-2, a second valve 4-4 of a low-temperature power generation system, the system comprises a CO2 low-pressure turbine 4-5 and a third valve 4-6 of a low-temperature power generation system, wherein an outlet of a liquid CO2 pump 4-1 is communicated with a low-temperature side inlet of a shared low-temperature heat regenerator 2-5, one path of a low-temperature side outlet of the shared low-temperature heat regenerator 2-5 is communicated with an inlet of a fifth valve 2-12 of a photo-thermal power generation system, an outlet of the fifth valve 2-12 of the photo-thermal power generation system is communicated with a cooling inlet of the shared high-temperature heat regenerator 2-4, a cold side outlet of the shared high-temperature heat regenerator 2-4 is communicated with an inlet of a first valve 4-2 of the low-temperature power generation system, an outlet of the first valve 4-2 of the low-temperature power generation system is communicated with a hot side inlet of a heat-conducting oil heater 4-3, and a hot side outlet of the heat-conducting oil heater 4-3 is communicated with shared CO.₂The inlets of the high-pressure turbines 2-2 are communicated with each other and share CO₂An outlet of the high-pressure turbine 2-2 is communicated with an inlet of a second valve 4-4 of the low-temperature power generation system, an outlet of the second valve 4-4 of the low-temperature power generation system is communicated with an inlet of a CO2 low-pressure turbine 4-5, an outlet of a CO2 low-pressure turbine 4-5 is communicated with a hot side inlet of a shared high-temperature regenerator 2-4, one path of the hot side outlet of the shared precooler 2-8 is communicated with an inlet of a third valve 4-6 of the low-temperature power generation system, and an outlet of the third valve 4-6 of the low-temperature power generation system is communicated with an inlet of a liquid CO2 pump 4-1;

the cold storage system comprises a water pump 5-1, a CO2 evaporator 3-6, a low-temperature water storage tank 5-2, a cold storage system valve 5-3, a shared precooler 2-8 and a high-temperature water storage tank 5-4, an outlet of the water pump 5-1 is communicated with a water side inlet of a CO2 evaporator 3-6, a water side outlet of the CO2 evaporator 3-6 is communicated with an inlet of a low-temperature water storage tank 5-2, an outlet of the low-temperature water storage tank 5-2 is communicated with an inlet of a cold storage system valve 5-3, an outlet of the valve 5-3 is communicated with a water side inlet of a shared precooler 2-8, a water side outlet of the shared precooler 2-8 is communicated with an inlet of a high-temperature water storage tank 5-4, and an outlet of the high-temperature water storage tank 5-4 is communicated with an inlet of the water pump 5-1;

the low-temperature heat storage system comprises a heat conduction oil pump 6-1, a low-temperature heat source heater 3-3, a high-temperature heat conduction oil storage tank 6-2, a heat conduction oil heater 4-3 and a low-temperature heat conduction oil storage tank 6-3, wherein an outlet of the heat conduction oil pump 6-1 is communicated with a heat conduction oil side inlet of the low-temperature heat source heater 3-3, a heat conduction oil side outlet of the low-temperature heat source heater 3-3 is communicated with an inlet of the high-temperature heat conduction oil storage tank 6-2, an outlet of the high-temperature heat conduction oil storage tank 6-2 is communicated with a heat conduction oil side inlet of the heat conduction oil heater 4-3, a heat conduction oil side outlet of the heat conduction oil heater 4-3 is communicated with an inlet of the low-temperature heat conduction oil storage tank 6-3, and an outlet of the low-temperature heat conduction oil storage tank 6-3 is communicated with an inlet of the heat conduction oil pump 6-1.

The shared CO₂The main equipment of the high-pressure turbine 2-2, the shared high-temperature heat regenerator 2-4, the shared low-temperature heat regenerator 2-5, the shared precooler 2-8 and the shared main compressor 2-10 are shared by a CO2 Brayton cycle, a heat pump cycle and a low-temperature power generation cycle, the design parameters of the equipment are designed according to the highest parameter in the used cycle, wherein the shared main compressor 2-10 is designed according to 25MPa and 350 ℃, and shares CO₂The high-pressure turbine 2-2 is designed according to 25MPa at 550 ℃, the shared high-temperature heat regenerator 2-4 is designed according to 25MPa at 350 ℃, the shared low-temperature heat regenerator 2-5 is designed according to 25MPa at 250 ℃, and the shared precooler 2-8 is designed according to 8MPa at 100 ℃.

The CO2 low-pressure turbine 4-5 is designed according to 8MPa and 350 ℃, the liquid CO2 pump 4-1 is designed according to 25MPa and 25 ℃, and the low-pressure compressor 3-1 is designed according to 8MPa and 250 ℃. .

The operation method of the CO2 Brayton and heat pump combined cycle system of the shared equipment has the function of adjusting the load change of a power grid, and the operation of the system is divided into three working conditions:

1) when the power of the power grid is surplus and cannot be consumed by users, the heat pump system operates, the system starts to store electric energy into heat energy, at the moment, the CO2 Brayton cycle photo-thermal power generation system and the low-temperature power generation system do not work, and part of equipment needing to be shared is used by the heat pump cycle; at the moment, a third valve 3-7 of the heat pump system, a second valve 3-4 of the heat pump system and a first valve 3-2 of the heat pump system are opened, and a first valve 2-3 of the photo-thermal power generation system, a second valve 2-6 of the photo-thermal power generation system, a third valve 2-9 of the photo-thermal power generation system, a fourth valve 2-11 of the photo-thermal power generation system, a fifth valve 2-12 of the photo-thermal power generation system, a sixth valve 2-13 of the photo-thermal power generation system, a first valve 4-2 of the low-temperature power generation system, a second valve 4-4 of the low-temperature power generation system, a third valve 4-6 of the low-temperature power generation system and a valve 5-3 of the cold storage system are all closed; firstly, surplus electric energy of a power grid drives a low-pressure compressor 3-1 and a shared main compressor 2-10 to operate, low-pressure CO2 is compressed to high-pressure high-temperature, high-pressure high-temperature CO2 enters a hot side of a low-temperature heat source heater 3-3 to release heat after passing through a first valve 3-2 of a heat pump system, then enters a cold side of a shared low-temperature heat regenerator 2-5 to continue releasing heat, then enters a CO2 expander 3-5 to expand to do work after passing through a second valve 3-4 of the heat pump system, the expanded CO2 is in a low-pressure low-temperature state, the temperature of the expanded CO2 is lower than the ambient temperature, then enters a CO2 evaporator 3-6 to absorb heat, the heat-absorbed CO2 enters a cold side of the shared low-temperature heat regenerator 2-5 to continue absorbing heat, then CO2 passes through a shared precooler 2-8 and a third valve 3-7 of the heat pump system, and the heat pump system does not only flow through the heat exchanger, then returning to the inlet of the low-pressure compressor 3-1 to complete the whole cycle; meanwhile, the water pump 5-1 is operated to transfer the hot water in the high temperature water storage tank 5-4 to the water side of the CO2 evaporator 3-6 to release heat, and then returns to the low temperature water storage tank 5-2 to be stored. Meanwhile, the heat conduction oil pump 6-1 operates to convey the low-temperature heat conduction oil in the low-temperature heat conduction oil storage tank 6-3 to the low-temperature heat source heater 3-3, and then the low-temperature heat conduction oil enters the high-temperature heat conduction oil storage tank 6-2 to be stored;

2) when the power of the power grid is insufficient and power generation is needed, the heat is stoppedThe pump system operates, firstly, the low-temperature power generation circulating system is started, the CO2 Brayton cycle photo-thermal power generation system is not started for the moment, at the moment, the fifth valve 2-12 of the photo-thermal power generation system, the first valve 4-2 of the low-temperature power generation system, the second valve 4-4 of the low-temperature power generation system, the third valve 4-6 of the low-temperature power generation system and the valve 5-3 of the cold storage system are opened, the third valve 3-7 of the heat pump system, the second valve 3-4 of the heat pump system and the first valve 3-2 of the heat pump system are opened, and the first valve 2-3 of the photo-thermal power generation system, the second valve 2-6 of the photo-thermal power generation system, the third valve 2-9 of the photo-thermal power generation system, the fourth valve 2-11 of the photo-thermal power generation system and the sixth valve 2-13 of the photo-thermal power generation system are all closed; firstly, a liquid CO2 pump 4-1 pressurizes and conveys low-temperature liquid CO2 to a cold side of a shared low-temperature heat regenerator 2-5 to absorb heat, then the low-temperature liquid CO2 is conveyed to a cold side of the shared high-temperature heat regenerator 2-4 through a fifth valve 2-12 of a photo-thermal power generation system to continuously absorb heat, then the low-temperature liquid CO 3526 is conveyed to a CO2 side of a heat-conducting oil heater 4-3 through a first valve 4-2 of the low-temperature power generation system to be heated, and then the high-temperature liquid CO2 enters the shared CO2 side₂The high-pressure turbine 2-2 does work, enters the CO2 low-pressure turbine 4-5 to do work after passing through the second valve 4-4 of the low-temperature power generation system, then sequentially enters the hot side of the shared high-temperature heat regenerator 2-4, the hot side of the shared low-temperature heat regenerator 2-5 and the hot side of the shared precooler 2-8 to release heat, and finally returns to the inlet of the liquid CO2 pump 4-1 through the third valve 4-6 of the low-temperature power generation system. Meanwhile, low-temperature water in the low-temperature water storage tank 5-2 enters a cold side of the shared precooler 2-8 through a cold storage system valve 5-3 to cool a working medium, and then returns to the high-temperature water storage tank 5-4 to be stored; meanwhile, the high-temperature heat conducting oil in the high-temperature heat conducting oil storage tank 6-2 enters the hot side of the heat conducting oil heater 4-3 to release heat, and then returns to the low-temperature heat conducting oil storage tank 6-3 to be stored;

3) when the consumption of the high-temperature heat conduction oil in the high-temperature heat conduction oil storage tank 6-2 reaches a preset value, the low-temperature power generation system is stopped, the CO2 Brayton cycle photo-thermal power generation system is started, and the heat pump system still keeps stopping; at this time, the first valve 2-3 of the photo-thermal power generation system, the second valve 2-6 of the photo-thermal power generation system, the third valve 2-9 of the photo-thermal power generation system, the fourth valve 2-11 of the photo-thermal power generation system, the fifth valve 2-12 of the photo-thermal power generation system, the sixth valve 2-13 of the photo-thermal power generation system and the valve 5-3 of the cold storage system are opened, and heat is generatedA third valve 3-7 of the pump system, a second valve 3-4 of the heat pump system, a first valve 3-2 of the heat pump system, a first valve 4-2 of the low-temperature power generation system, a second valve 4-4 of the low-temperature power generation system and a third valve 4-6 of the low-temperature power generation system are all closed; firstly, CO2 enters a molten salt heat exchanger 2-1 to be heated to high temperature, and then enters shared CO₂The high-pressure turbine 2-2 does work, then sequentially enters a hot side of a shared high-temperature heat regenerator 2-4 through a first valve 2-3 of a photo-thermal power generation system, the hot side of the shared low-temperature heat regenerator 2-5 releases heat, then a part of CO2 enters a re-compressor 2-7 through a second valve 2-6 of the photo-thermal power generation system to be directly pressurized, the other part of CO2 enters a shared precooler 2-8 to be further cooled, then enters a shared main compressor 2-10 through a third valve 2-9 of the photo-thermal power generation system to be pressurized, then enters a cold side of the shared low-temperature heat regenerator 2-5 through a fourth valve 2-11 of the photo-thermal power generation system to absorb heat, then is converged with CO2 at an outlet of a recompressor 2-7 and then enters a cold side of the high-temperature heat regenerator 2-4 through a fifth valve 2-12 of the photo-thermal power generation system to absorb heat, finally, the molten salt returns to the inlet of the molten salt heat exchanger 2-1 after passing through a sixth valve 2-13 of the photo-thermal power generation system; meanwhile, low-temperature water in the low-temperature water storage tank 5-2 enters a cold side of the shared precooler 2-8 through a cold storage system valve 5-3 to cool a working medium, and then returns to the high-temperature water storage tank 5-4 to be stored; meanwhile, the high-temperature molten salt stored in the high-temperature molten salt tank 1-2 enters the molten salt side of the molten salt heat exchanger 2-1 to release heat, and then returns to the low-temperature molten salt tank 1-3 to be stored;

4) the molten salt heat storage system is not shared with other systems and operates independently, and only according to the sunshine condition, when the sunshine is sufficient and a storage space is still arranged in the high-temperature molten salt tank 1-2, the molten salt heat storage system stores heat, and low-temperature molten salt in the low-temperature molten salt tank 1-3 is conveyed to the heat collector 1-1 through the molten salt pump 1-4 to be heated and then is stored in the high-temperature molten salt tank 1-2.

Compared with the prior art, the invention has the following beneficial effects:

the supercritical CO2 Brayton and heat pump combined cycle of the shared equipment is a novel energy storage system, can balance new energy, including impact on a power grid caused by photovoltaic power generation, wind power generation and the like, and simultaneously, the CO2 Brayton cycle, the heat pump cycle and the low-temperature power generation cycle share part of equipment including a heat exchanger, a compressor and a turbine due to the adoption of the design of the shared equipment, so that the equipment investment cost is greatly saved, and the economy of the system is improved.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings:

as shown in FIG. 1, the CO2 Brayton and heat pump combined cycle system of the shared equipment comprises a molten salt heat storage system and CO₂The system comprises a Brayton cycle photo-thermal power generation system, a heat pump system, a low-temperature power generation system, a cold storage system and a low-temperature heat storage system;

the molten salt heat storage system comprises a heat collector 1-1, a high-temperature molten salt tank 1-2, a low-temperature molten salt tank 1-3 and a molten salt pump 1-4, wherein an outlet of the heat collector 1-1 is communicated with an inlet of the high-temperature molten salt tank 1-2, and an outlet of the high-temperature molten salt tank 1-2 is communicated with CO₂A fused salt side inlet of a fused salt heat exchanger 2-1 of the Brayton cycle photo-thermal power generation system is communicated, a fused salt side outlet of the fused salt heat exchanger 2-1 is communicated with an inlet of a low-temperature fused salt tank 1-3, an outlet of the low-temperature fused salt tank 1-3 is communicated with an inlet of a fused salt pump 1-4, and an outlet of the fused salt pump 1-4 is communicated with an inlet of a heat collector 1-1;

the CO is₂The Brayton cycle photo-thermal power generation system comprises a fused salt heat exchanger 2-1 and shared CO₂2-2 parts of high-pressure turbine, 2-3 parts of first valve of photo-thermal power generation system, 2-4 parts of shared high-temperature heat regenerator, 2-5 parts of shared low-temperature heat regenerator, 2-6 parts of second valve of photo-thermal power generation system, 2-7 parts of recompressor, 2-8 parts of shared precooler, 2-9 parts of third valve of photo-thermal power generation system, 2-10 parts of shared main compressor, 2-11 parts of fourth valve of photo-thermal power generation system, 2-12 parts of fifth valve of photo-thermal power generation system, 2-13 parts of sixth valve of photo-thermal power generation system and 2-1 part of CO of fused salt heat exchanger₂Side export with shared CO₂The inlets of the high-pressure turbines 2-2 are communicated with each other and share CO₂The outlet of the high-pressure turbine 2-2 is communicated with the inlet of the first valve 2-3 of the photo-thermal power generation system, and the outlet of the first valve 2-3 of the photo-thermal power generation system and the shared high temperatureThe hot side inlet of the heat regenerator 2-4 is communicated, the hot side outlet of the shared high-temperature heat regenerator 2-4 is communicated with the hot side inlet of the shared low-temperature heat regenerator 2-5, the hot side outlet of the shared low-temperature heat regenerator 2-5 is divided into two paths, one path is communicated with the inlet of a second valve 2-6 of the photo-thermal power generation system, the outlet of the second valve 2-6 of the photo-thermal power generation system is communicated with the inlet of a recompressor 2-7, the other path is communicated with the hot side inlet of a shared precooler 2-8, the hot side outlet of the shared precooler 2-8 is divided into three paths, one path is communicated with the inlet of a third valve 2-9 of the photo-thermal power generation system, the outlet of the third valve 2-9 of the photo-thermal power generation system is communicated with the inlet of a shared main compressor 2-10, and the outlet of the shared main compressor 2-10 is communicated with the inlet of a fourth valve 2-11 of the photo-thermal power generation system, an outlet of a fourth valve 2-11 of the photo-thermal power generation system is communicated with a cooling inlet of a shared low-temperature heat regenerator 2-5, a cold side outlet of the shared low-temperature heat regenerator 2-5 is also divided into two paths, one path of the outlet is communicated with an inlet of a fifth valve 2-12 of the photo-thermal power generation system, an outlet of the fifth valve 2-12 of the photo-thermal power generation system is communicated with a cooling inlet of a shared high-temperature heat regenerator 2-4 after being converged with an outlet of a recompressor 2-7, a cold side outlet of the shared high-temperature heat regenerator 2-4 is communicated with an inlet of a sixth valve 2-13 of the photo-thermal power generation system, and an inlet of the sixth valve 2-13 of the photo-thermal power generation system is communicated with CO of a molten salt heat exchanger 2-1₂The side inlets are communicated;

the heat pump system comprises a low-pressure compressor 3-1, a shared main compressor 2-10, a first valve 3-2 of the heat pump system, a low-temperature heat source heater 3-3, a shared low-temperature heat regenerator 2-5, a second valve 3-4 of the heat pump system, a CO2 expander 3-5, a CO2 evaporator 3-6 and a third valve 3-7 of the heat pump system, wherein an outlet of the low-pressure compressor 3-1 is communicated with an inlet of the shared main compressor 2-10, the other path of an outlet of the shared main compressor 2-10 is communicated with an inlet of the first valve 3-2 of the heat pump system, an outlet of the first valve 3-2 of the heat pump system is communicated with a hot side inlet of the low-temperature heat source heater 3-3, a hot side outlet of the low-temperature heat source heater 3-3 is communicated with a cold side inlet of the shared low-temperature heat regenerator 2-5, the other path of the cold side outlet of the shared low-temperature regenerator 2-5 is communicated with the inlet of a second valve 3-4 of the heat pump system, the outlet of the second valve 3-4 of the heat pump system is communicated with the inlet of a CO2 expander 3-5, the outlet of the CO2 expander 3-5 is communicated with the inlet of the CO2 side of a CO2 evaporator 3-6, the outlet of the CO2 side of the CO2 evaporator 3-6 is communicated with the inlet of the hot side of the shared low-temperature regenerator 2-5, one path of the hot side outlet of the shared low-temperature regenerator 2-5 is communicated with the inlet of a shared precooler 2-8, one path of the hot side outlet of the shared precooler 2-8 is communicated with the inlet of a third valve 3-7 of the heat pump system, and the outlet of the third valve 3-7 of the heat pump system is communicated with the inlet of a low-pressure compressor 3-1;

the low-temperature power generation system comprises a liquid CO2 pump 4-1, a shared low-temperature heat regenerator 2-5, a valve 2-12, a shared high-temperature heat regenerator 2-4, a first valve 4-2 of the low-temperature power generation system, a heat conducting oil heater 4-3 and a shared CO₂A high-pressure turbine 2-2, a second valve 4-4 of a low-temperature power generation system, the system comprises a CO2 low-pressure turbine 4-5 and a third valve 4-6 of a low-temperature power generation system, wherein an outlet of a liquid CO2 pump 4-1 is communicated with a low-temperature side inlet of a shared low-temperature heat regenerator 2-5, one path of a low-temperature side outlet of the shared low-temperature heat regenerator 2-5 is communicated with an inlet of a fifth valve 2-12 of a photo-thermal power generation system, an outlet of the fifth valve 2-12 of the photo-thermal power generation system is communicated with a cooling inlet of the shared high-temperature heat regenerator 2-4, a cold side outlet of the shared high-temperature heat regenerator 2-4 is communicated with an inlet of a first valve 4-2 of the low-temperature power generation system, an outlet of the first valve 4-2 of the low-temperature power generation system is communicated with a hot side inlet of a heat-conducting oil heater 4-3, and a hot side outlet of the heat-conducting oil heater 4-3 is communicated with shared CO.₂The inlets of the high-pressure turbines 2-2 are communicated with each other and share CO₂An outlet of the high-pressure turbine 2-2 is communicated with an inlet of a second valve 4-4 of the low-temperature power generation system, an outlet of the second valve 4-4 of the low-temperature power generation system is communicated with an inlet of a CO2 low-pressure turbine 4-5, an outlet of a CO2 low-pressure turbine 4-5 is communicated with a hot side inlet of a shared high-temperature regenerator 2-4, one path of the hot side outlet of the shared precooler 2-8 is communicated with an inlet of a third valve 4-6 of the low-temperature power generation system, and an outlet of the third valve 4-6 of the low-temperature power generation system is communicated with an inlet of a liquid CO2 pump 4-1;

the cold storage system comprises a water pump 5-1, a CO2 evaporator 3-6, a low-temperature water storage tank 5-2, a cold storage system valve 5-3, a shared precooler 2-8 and a high-temperature water storage tank 5-4, an outlet of the water pump 5-1 is communicated with a water side inlet of a CO2 evaporator 3-6, a water side outlet of the CO2 evaporator 3-6 is communicated with an inlet of a low-temperature water storage tank 5-2, an outlet of the low-temperature water storage tank 5-2 is communicated with an inlet of a cold storage system valve 5-3, an outlet of the valve 5-3 is communicated with a water side inlet of a shared precooler 2-8, a water side outlet of the shared precooler 2-8 is communicated with an inlet of a high-temperature water storage tank 5-4, and an outlet of the high-temperature water storage tank 5-4 is communicated with an inlet of the water pump 5-1;

the low-temperature heat storage system comprises a heat conduction oil pump 6-1, a low-temperature heat source heater 3-3, a high-temperature heat conduction oil storage tank 6-2, a heat conduction oil heater 4-3 and a low-temperature heat conduction oil storage tank 6-3, wherein an outlet of the heat conduction oil pump 6-1 is communicated with a heat conduction oil side inlet of the low-temperature heat source heater 3-3, a heat conduction oil side outlet of the low-temperature heat source heater 3-3 is communicated with an inlet of the high-temperature heat conduction oil storage tank 6-2, an outlet of the high-temperature heat conduction oil storage tank 6-2 is communicated with a heat conduction oil side inlet of the heat conduction oil heater 4-3, a heat conduction oil side outlet of the heat conduction oil heater 4-3 is communicated with an inlet of the low-temperature heat conduction oil storage tank 6-3, and an outlet of the low-temperature heat conduction oil storage tank 6-3 is communicated with an inlet of the heat conduction oil pump 6-1.

The shared CO₂The main equipment of the high-pressure turbine 2-2, the shared high-temperature heat regenerator 2-4, the shared low-temperature heat regenerator 2-5, the shared precooler 2-8 and the shared main compressor 2-10 are shared by a CO2 Brayton cycle, a heat pump cycle and a low-temperature power generation cycle, the design parameters of the equipment are designed according to the highest parameter in the used cycle, wherein the shared main compressor 2-10 is designed according to 25MPa and 350 ℃, and shares CO₂The high-pressure turbine 2-2 is designed according to 25MPa at 550 ℃, the shared high-temperature heat regenerator 2-4 is designed according to 25MPa at 350 ℃, the shared low-temperature heat regenerator 2-5 is designed according to 25MPa at 250 ℃, and the shared precooler 2-8 is designed according to 8MPa at 100 ℃.

The invention relates to an operation method of a CO2 Brayton and heat pump combined cycle system of shared equipment, which has the function of adjusting the load change of a power grid and has the following operation conditions:

1) when the power of the power grid is surplus and cannot be consumed by users, the heat pump system operates, the system starts to store electric energy into heat energy, at the moment, the CO2 Brayton cycle photo-thermal power generation system and the low-temperature power generation system do not work, and part of equipment needing to be shared is used by the heat pump cycle; at the moment, a third valve 3-7 of the heat pump system, a second valve 3-4 of the heat pump system and a first valve 3-2 of the heat pump system are opened, and a first valve 2-3 of the photo-thermal power generation system, a second valve 2-6 of the photo-thermal power generation system, a third valve 2-9 of the photo-thermal power generation system, a fourth valve 2-11 of the photo-thermal power generation system, a fifth valve 2-12 of the photo-thermal power generation system, a sixth valve 2-13 of the photo-thermal power generation system, a first valve 4-2 of the low-temperature power generation system, a second valve 4-4 of the low-temperature power generation system, a third valve 4-6 of the low-temperature power generation system and a valve 5-3 of the cold storage system are all closed; firstly, surplus electric energy of a power grid drives a low-pressure compressor 3-1 and a shared main compressor 2-10 to operate, low-pressure CO2 is compressed to high-pressure high-temperature, high-pressure high-temperature CO2 enters a hot side of a low-temperature heat source heater 3-3 to release heat after passing through a first valve 3-2 of a heat pump system, then enters a cold side of a shared low-temperature heat regenerator 2-5 to continue releasing heat, then enters a CO2 expander 3-5 to expand to do work after passing through a second valve 3-4 of the heat pump system, the expanded CO2 is in a low-pressure low-temperature state, the temperature of the expanded CO2 is lower than the ambient temperature, then enters a CO2 evaporator 3-6 to absorb heat, the heat-absorbed CO2 enters a cold side of the shared low-temperature heat regenerator 2-5 to continue absorbing heat, then CO2 passes through a shared precooler 2-8 and a third valve 3-7 of the heat pump system, and the heat pump system does not only flow through the heat exchanger, then returning to the inlet of the low-pressure compressor 3-1 to complete the whole cycle; meanwhile, the water pump 5-1 is operated to transfer the hot water in the high temperature water storage tank 5-4 to the water side of the CO2 evaporator 3-6 to release heat, and then returns to the low temperature water storage tank 5-2 to be stored. Meanwhile, the heat conduction oil pump 6-1 operates to convey the low-temperature heat conduction oil in the low-temperature heat conduction oil storage tank 6-3 to the low-temperature heat source heater 3-3, and then the low-temperature heat conduction oil enters the high-temperature heat conduction oil storage tank 6-2 to be stored;

2) when the power of a power grid is insufficient and power generation is needed, the operation of the heat pump system is stopped, the low-temperature power generation circulating system is started at first, the CO2 Brayton cycle photo-thermal power generation system is not started temporarily, at the moment, the fifth valve 2-12 of the photo-thermal power generation system, the first valve 4-2 of the low-temperature power generation system, the second valve 4-4 of the low-temperature power generation system, the third valve 4-6 of the low-temperature power generation system and the valve 5-3 of the cold storage system are opened, the third valve 3-7 of the heat pump system, the second valve 3-4 of the heat pump system and the first valve 3-2 of the heat pump system are opened, and the first valve 3-2 of the photo-thermal power generation system is openedClosing the valve 2-3, the second valve 2-6 of the photo-thermal power generation system, the third valve 2-9 of the photo-thermal power generation system, the fourth valve 2-11 of the photo-thermal power generation system and the sixth valve 2-13 of the photo-thermal power generation system; firstly, a liquid CO2 pump 4-1 pressurizes and conveys low-temperature liquid CO2 to a cold side of a shared low-temperature heat regenerator 2-5 to absorb heat, then the low-temperature liquid CO2 is conveyed to a cold side of the shared high-temperature heat regenerator 2-4 through a fifth valve 2-12 of a photo-thermal power generation system to continuously absorb heat, then the low-temperature liquid CO 3526 is conveyed to a CO2 side of a heat-conducting oil heater 4-3 through a first valve 4-2 of the low-temperature power generation system to be heated, and then the high-temperature liquid CO2 enters the shared CO2 side₂The high-pressure turbine 2-2 does work, enters the CO2 low-pressure turbine 4-5 to do work after passing through the second valve 4-4 of the low-temperature power generation system, then sequentially enters the hot side of the shared high-temperature heat regenerator 2-4, the hot side of the shared low-temperature heat regenerator 2-5 and the hot side of the shared precooler 2-8 to release heat, and finally returns to the inlet of the liquid CO2 pump 4-1 through the third valve 4-6 of the low-temperature power generation system. Meanwhile, low-temperature water in the low-temperature water storage tank 5-2 enters a cold side of the shared precooler 2-8 through a cold storage system valve 5-3 to cool a working medium, and then returns to the high-temperature water storage tank 5-4 to be stored; meanwhile, the high-temperature heat conducting oil in the high-temperature heat conducting oil storage tank 6-2 enters the hot side of the heat conducting oil heater 4-3 to release heat, and then returns to the low-temperature heat conducting oil storage tank 6-3 to be stored;

3) when the consumption of the high-temperature heat conduction oil in the high-temperature heat conduction oil storage tank 6-2 reaches a preset value, the low-temperature power generation system is stopped, the CO2 Brayton cycle photo-thermal power generation system is started, and the heat pump system still keeps stopping; at the moment, a first valve 2-3 of the photo-thermal power generation system, a second valve 2-6 of the photo-thermal power generation system, a third valve 2-9 of the photo-thermal power generation system, a fourth valve 2-11 of the photo-thermal power generation system, a fifth valve 2-12 of the photo-thermal power generation system, a sixth valve 2-13 of the photo-thermal power generation system and a valve 5-3 of the cold storage system are opened, and a third valve 3-7 of the heat pump system, a second valve 3-4 of the heat pump system, a first valve 3-2 of the heat pump system, a first valve 4-2 of the low-temperature power generation system, a second valve 4-4 of the low-temperature power generation system and a third valve 4-6 of the low-temperature power generation system are all closed; firstly, CO2 enters a molten salt heat exchanger 2-1 to be heated to high temperature, and then enters shared CO₂The high-pressure turbine 2-2 does work, then enters the hot side of the shared high-temperature heat regenerator 2-4 in sequence through a first valve 2-3 of the photo-thermal power generation system, and is sharedThe hot side of the low-temperature heat regenerator 2-5 releases heat, then a part of CO2 enters a re-compressor 2-7 through a second valve 2-6 of the photo-thermal power generation system to be directly pressurized, the other part of CO2 enters a shared precooler 2-8 to be further cooled, then enters a shared main compressor 2-10 through a third valve 2-9 of the photo-thermal power generation system to be pressurized, then enters a shared low-temperature heat regenerator 2-5 through a fourth valve 2-11 of the photo-thermal power generation system to absorb heat, then is converged with CO2 at the outlet of a recompressor 2-7, then enters a cold side of a high-temperature heat regenerator 2-4 through a fifth valve 2-12 of the photo-thermal power generation system to absorb heat, and finally returns to the inlet of a molten salt heat exchanger 2-1 through a sixth valve 2-13 of the photo-thermal power generation system; meanwhile, low-temperature water in the low-temperature water storage tank 5-2 enters a cold side of the shared precooler 2-8 through a cold storage system valve 5-3 to cool a working medium, and then returns to the high-temperature water storage tank 5-4 to be stored; meanwhile, the high-temperature molten salt stored in the high-temperature molten salt tank 1-2 enters the molten salt side of the molten salt heat exchanger 2-1 to release heat, and then returns to the low-temperature molten salt tank 1-3 to be stored;

4) the molten salt heat storage system is not shared with other systems and operates independently, and only according to the sunshine condition, when the sunshine is sufficient and a storage space is still arranged in the high-temperature molten salt tank 1-2, the molten salt heat storage system stores heat, and low-temperature molten salt in the low-temperature molten salt tank 1-3 is conveyed to the heat collector 1-1 through the molten salt pump 1-4 to be heated and then is stored in the high-temperature molten salt tank 1-2.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.