阅读说明：本技术 一种间接空冷系统余热利用方法及装置 (Waste heat utilization method and device for indirect air cooling system ) 是由 冯海波 王军 袁汉川 袁志先 谭茹 吴俊杰 许祥训 季薇 潘翠翠 王雪平 张尚云 于 2020-06-29 设计创作，主要内容包括：本发明属于电厂余热回收技术领域,尤其涉及一种间接空冷系统余热利用方法及装置。该方法所使用的装置包括汽轮机、间接空冷系统、吸收式热泵和热压机。其中,汽轮机的排汽进入间接空冷系统,通过间接空冷系统内的循环水对排汽进行冷却,热压机驱动吸收式热泵回收对排汽进行冷却后的循环水中的部分余热后,吸收式热泵将热网用户端的热网水加热,且吸收式热泵将加热后的热网水输送至热网用户端。由此,该方法将间接空冷系统对汽轮机的排汽进行冷却后的间接空冷系统内的循环水的余热进行回收利用,提供一种高品位热源。(The invention belongs to the technical field of waste heat recovery of power plants, and particularly relates to a waste heat utilization method and device of an indirect air cooling system. The device used by the method comprises a steam turbine, an indirect air cooling system, an absorption heat pump and a hot press. The exhaust steam of the steam turbine enters the indirect air cooling system, the exhaust steam is cooled through circulating water in the indirect air cooling system, the absorption heat pump is driven by the hot press to recover part of waste heat in the circulating water after the exhaust steam is cooled, the absorption heat pump heats the heat supply network water at the heat supply network user side, and the absorption heat pump conveys the heated heat supply network water to the heat supply network user side. Therefore, the method recycles the waste heat of the circulating water in the indirect air cooling system after the indirect air cooling system cools the exhaust steam of the steam turbine, and provides a high-grade heat source.)

1. The method for utilizing the waste heat of the indirect air cooling system is characterized in that the used device comprises a steam turbine, the indirect air cooling system, an absorption heat pump (11) and a hot press (26); wherein the content of the first and second substances,

the exhaust steam of the steam turbine enters the indirect air cooling system, and the exhaust steam is cooled by circulating water in the indirect air cooling system;

after the hot press (26) drives the absorption heat pump (11) to recover part of waste heat in the circulating water after the exhaust steam is cooled, the absorption heat pump (11) heats the heat supply network water at the heat supply network user side, and the absorption heat pump (11) conveys the heated heat supply network water to the heat supply network user side.

2. The method for utilizing the waste heat of the indirect air cooling system according to claim 1, wherein the used device further comprises a peak heater (24), and partial extraction steam of the steam turbine enters the peak heater (24);

when the heating load of the heated heat supply network water does not meet the heat load requirement of the heat supply network user side, the peak heater (24) heats the heated heat supply network water;

when the heating load of the heated heat supply network water meets the heat load requirement of the heat supply network user end, the peak heater (24) does not operate.

3. The method for utilizing the waste heat of the indirect air cooling system according to claim 2,

one part of the heat source of the hot press is the exhaust steam of the low pressure cylinder (1) of the steam turbine, and the other part of the heat source of the hot press is the extraction steam of the medium pressure cylinder (2) of the steam turbine.

4. The waste heat utilization device of the indirect air cooling system is characterized by comprising a steam turbine, the indirect air cooling system, an absorption heat pump (11) and a hot press (26); wherein the content of the first and second substances,

the steam exhaust outlet of the steam turbine is communicated with the steam side inlet of the indirect air cooling system;

a first water side inlet and a first water side outlet of the absorption heat pump (11) are selectively communicated with a water side outlet and a water side inlet of the indirect air cooling system respectively;

the second water side inlet and the second water side outlet of the absorption heat pump (11) are selectively communicated with a heat supply network user side;

the hot press (26) comprises a controller for controlling the steam inlet and outlet of the hot press (26), wherein the steam side outlet of the hot press (26) is connected with the steam side inlet of the absorption heat pump (11).

5. The waste heat utilization device of the indirect air cooling system of claim 4,

further comprising a spike heater (24);

the steam turbine comprises a low pressure cylinder (1) and a medium pressure cylinder (2);

the steam side outlet of the intermediate pressure cylinder (2) is selectively communicated with the steam side inlet of the spike heater (24) in a flow-adjustable mode.

6. The waste heat utilization device of the indirect air cooling system of claim 5,

the indirect air cooling system comprises an indirect air cooling tower (6), a low-temperature circulating water pipeline (7), a high-temperature circulating water pipeline (5) and a host condenser (4);

a steam side outlet of the low pressure cylinder (1) is communicated with a steam side inlet of the host condenser (4);

a water side inlet of the low-temperature circulating water pipeline (7) is communicated with a water side outlet of the indirect air cooling tower (6), and a water side outlet of the low-temperature circulating water pipeline (7) is communicated with a water side inlet of the host condenser (4);

and a water side inlet of the high-temperature circulating water pipeline (5) is communicated with a water side outlet of the main machine condenser (4), and a water side outlet of the high-temperature circulating water pipeline (5) is communicated with a water side inlet of the indirect air cooling tower (6).

7. The waste heat utilization device of the indirect air cooling system of claim 6,

also comprises a waste hot water supply pipeline (10) and a waste hot water return pipeline (12);

a water side inlet of the waste hot water supply pipeline (10) is selectively communicated with the high-temperature circulating water pipeline (5), and a water side outlet of the waste hot water supply pipeline (10) is selectively communicated with a first water side inlet of the absorption heat pump (11);

and a water side inlet of the residual hot water return pipeline (12) is selectively communicated with a first water side outlet of the absorption heat pump (11), and a water side outlet of the residual hot water return pipeline (12) is selectively communicated with the low-temperature circulating water pipeline (7).

8. The waste heat utilization device of the indirect air cooling system of claim 6,

a first steam inlet of the hot press (26) is selectively communicated with a steam side outlet of the main machine condenser (4);

the second steam inlet of the hot press (26) is selectively communicated with the steam side outlet of the intermediate pressure cylinder (2) in a flow-adjustable mode.

9. The waste heat utilization device of the indirect air cooling system of claim 4,

the system also comprises a heat supply network low-temperature water return pipeline (14) and a heat supply network high-temperature water supply pipeline (18);

a water side inlet of the heat supply network low-temperature water return pipeline (14) is selectively communicated with a heat supply network user side, and a water side outlet of the heat supply network low-temperature water return pipeline (14) is selectively communicated with a second water side inlet of the absorption heat pump (11);

the water side inlet of the heat supply network high-temperature water supply pipeline (18) is selectively communicated with the second water side outlet of the absorption heat pump (11), and the water side outlet of the heat supply network high-temperature water supply pipeline (18) is selectively communicated with the heat supply network user side.

10. The waste heat utilization device of the indirect air cooling system of claim 4,

also comprises an iron removal device (20);

the iron removal device (20) is communicated with a condensed water outlet of the absorption heat pump (11).

Technical Field

The invention belongs to the technical field of waste heat recovery of power plants, and particularly relates to a waste heat utilization method and device of an indirect air cooling system.

Background

The air cooling technology of the power plant is roughly divided into two forms, namely direct air cooling and indirect air cooling. The direct air cooling is that the exhaust steam of a steam turbine is directly cooled by air, and the air and steam exchange heat. The indirect air cooling is that water is used as an intermediate cooling medium, the low-temperature circulating water brings out the heat of steam exhausted by the steam turbine, the heated circulating water is cooled by the air, the secondary cooling process is a closed system, and the circulating water is not in direct contact with the air, so the indirect air cooling is called.

The indirect air cooling is similar to wet cooling in system, circulating water is used as an intermediate cooling medium, but a secondary circulating system is a closed system, and the heat exchange efficiency is lower than that of a wet cooling system, so that the power plant adopting the indirect air cooling system has the advantages of high unit backpressure, high unit exhaust enthalpy value and large residual heat development potential.

In the heating area in the north of China, the waste heat of the cooling system of the power plant is recovered and used for urban heating, so that the utilization efficiency of energy is improved, the heating capacity of a unit is increased, and the economic and environmental benefits are high. The temperature of waste heat water of an indirect air cooling system is usually about 50 ℃, and the indirect air cooling system belongs to a low-grade heat source and has high difficulty in waste heat recovery.

Disclosure of Invention

Technical problem to be solved

In order to solve the problems in the prior art, the invention provides a method and a device for utilizing waste heat of an indirect air cooling system, which can provide a high-grade heat source.

(II) technical scheme

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

the invention provides a waste heat utilization method of an indirect air cooling system, and the used device comprises a steam turbine, the indirect air cooling system, an absorption heat pump and a hot press; the exhaust steam of the steam turbine enters an indirect air cooling system, and the exhaust steam is cooled by circulating water in the indirect air cooling system; after the hot press drives the absorption heat pump to recover part of waste heat in the circulating water after cooling the exhaust steam, the absorption heat pump heats the heat supply network water at the user end of the heat supply network, and the absorption heat pump conveys the heated heat supply network water to the user end of the heat supply network.

Preferably, the apparatus used also comprises a spike heater into which part of the steam extracted by the turbine enters; when the heating load of the heated heat supply network water does not meet the heat load requirement of a heat supply network user side, the peak heater heats the heated heat supply network water; when the heating load of the heated heat supply network water meets the heat load requirement of the user end of the heat supply network, the peak heater does not operate.

Preferably, one part of the heat source of the hot press is the exhaust steam of the low pressure cylinder of the steam turbine, and the other part of the heat source of the hot press is the extracted steam of the medium pressure cylinder of the steam turbine.

The invention also provides a waste heat utilization device of the indirect air cooling system, which comprises a steam turbine, the indirect air cooling system, an absorption heat pump and a hot press; wherein, the steam exhaust outlet of the steam turbine is communicated with the steam side inlet of the indirect air cooling system; a first water side inlet and a first water side outlet of the absorption heat pump are selectively communicated with a water side outlet and a water side inlet of the indirect air cooling system respectively; the second water side inlet and the second water side outlet of the absorption heat pump are used for being selectively communicated with a heat supply network user side; the hot press comprises a controller, wherein the controller is used for controlling the steam inlet quantity and the steam outlet quantity of the hot press, and a steam side outlet of the hot press is connected with a steam side inlet of the absorption heat pump.

Preferably, the waste heat utilization device of the indirect air cooling system further comprises a spike heater; the steam turbine comprises a low-pressure cylinder and an intermediate-pressure cylinder; the steam side outlet of the intermediate pressure cylinder is selectively and adjustably communicated with the steam side inlet of the spike heater.

Preferably, the indirect air cooling system comprises an indirect air cooling tower, a low-temperature circulating water pipeline, a high-temperature circulating water pipeline and a host condenser; a steam side outlet of the low pressure cylinder is communicated with a steam side inlet of the main machine condenser; a water side inlet of the low-temperature circulating water pipeline is communicated with a water side outlet of the indirect air cooling tower, and a water side outlet of the low-temperature circulating water pipeline is communicated with a water side inlet of the main machine condenser; the water side inlet of the high-temperature circulating water pipeline is communicated with the water side outlet of the main machine condenser, and the water side outlet of the high-temperature circulating water pipeline is communicated with the water side inlet of the indirect air cooling tower.

Preferably, the waste heat utilization device of the indirect air cooling system further comprises a waste heat water supply pipeline and a waste heat water return pipeline; the water side inlet of the waste heat water supply pipeline is selectively communicated with the high-temperature circulating water pipeline, and the water side outlet of the waste heat water supply pipeline is selectively communicated with the first water side inlet of the absorption heat pump; and a water side inlet of the residual hot water return pipeline is selectively communicated with a first water side outlet of the absorption heat pump, and a water side outlet of the residual hot water return pipeline is selectively communicated with the low-temperature circulating water pipeline.

Preferably, a first steam inlet of the hot press is selectively communicated with a steam side outlet of the main machine condenser; and a second steam inlet of the hot press is selectively communicated with a steam side outlet of the intermediate pressure cylinder in a flow-adjustable manner.

Preferably, the waste heat utilization device of the indirect air cooling system further comprises a heat supply network low-temperature water return pipeline and a heat supply network high-temperature water supply pipeline; a water side inlet of the heat supply network low-temperature water return pipeline is selectively communicated with a heat supply network user side, and a water side outlet of the heat supply network low-temperature water return pipeline is selectively communicated with a second water side inlet of the absorption heat pump; the water side inlet of the high-temperature water supply pipeline of the heat supply network is selectively communicated with the second water side outlet of the absorption heat pump, and the water side outlet of the high-temperature water supply pipeline of the heat supply network is selectively communicated with the user end of the heat supply network.

Preferably, the waste heat utilization device of the indirect air cooling system further comprises an iron removal device; the deironing device is communicated with a condensed water outlet of the absorption heat pump.

(III) advantageous effects

The invention has the beneficial effects that:

according to the method for utilizing the waste heat of the indirect air cooling system, the absorption heat pump is used for recovering part of the waste heat in the circulating water after cooling the exhaust steam of the steam turbine, so that the heat load of the indirect air cooling system is reduced, the economical efficiency of the operation of the steam turbine is improved, the intermediate medium in the absorption heat pump is driven by the driving steam in the hot press, the intermediate medium can further absorb the low-grade heat energy of the waste heat water, and the heat network water is heated and warmed, so that a high-grade heat source is provided, and the utilization of the heat network water is facilitated.

According to the waste heat utilization device for the indirect air cooling system, the absorption heat pump is arranged to recover part of waste heat in circulating water after cooling exhaust steam of the steam turbine, so that the heat load of the indirect air cooling system is reduced, the running economy of the steam turbine is improved, the intermediate medium in the absorption heat pump is driven by driving steam in the hot press, the intermediate medium can further absorb low-grade heat energy of the waste heat water, and heat net water is heated and heated, so that a high-grade heat source is provided, and the utilization of the net water is facilitated.

Drawings

Fig. 1 is a schematic structural diagram of a waste heat utilization device of an indirect air cooling system in an embodiment of the invention.

[ description of reference ]

1: a low pressure cylinder; 2: an intermediate pressure cylinder; 3: a generator; 4: a host condenser; 5: a high-temperature circulating water pipeline; 6: an indirect air cooling tower; 7: a low-temperature circulating water pipeline; 8: a main machine circulating water pump; 9: a first isolation valve; 10: a waste heat water supply pipeline; 11: an absorption heat pump; 12: residual hot water return pipeline; 13: a second isolation valve; 14: a heat supply network low-temperature water return pipeline; 15: a heat supply network water circulating pump; 16: a fourth isolation valve; 17: a fifth isolation valve; 18: a heat supply network high temperature water supply pipeline; 19: a bypass valve; 20: a deironing device; 21: a second condensate pump; 22: a seventh isolation valve; 23: an eighth isolation valve; 24: a spike heater; 25: a first condensate pump; 26: a hot press; 27: a third isolation valve; 28: a sixth isolation valve; 29: a safety valve; 30: a quick check valve; 31: a quick-closing valve; 32: an electric steam extraction regulating valve; 33: and a seventh isolation valve.

Detailed Description

For the purpose of better explaining the present invention and to facilitate understanding, the present invention will be described in detail by way of specific embodiments with reference to the accompanying drawings.

As shown in fig. 1, the present embodiment provides a method for utilizing waste heat of an indirect air cooling system, and the devices used in the method include a steam turbine, an indirect air cooling system, an absorption heat pump 11 and a hot press 26. The exhaust steam of the steam turbine enters the indirect air cooling system, the exhaust steam is cooled by circulating water in the indirect air cooling system, the hot press 26 drives the absorption heat pump 11 to recover part of waste heat in the circulating water after cooling the exhaust steam, the absorption heat pump 11 heats the heat supply network water at the user end of the heat supply network, and the absorption heat pump 11 conveys the heated heat supply network water to the user end of the heat supply network.

According to the method for utilizing the waste heat of the indirect air cooling system, the absorption heat pump 11 is used for recovering part of the waste heat in the circulating water after cooling the exhaust steam of the steam turbine, so that the heat load of the indirect air cooling system is reduced, the economical efficiency of the operation of the steam turbine is improved, the intermediate medium in the absorption heat pump is driven by the driving steam in the hot press 26, the intermediate medium can further absorb the low-grade heat energy of the waste heat water, and the heat network water is heated and warmed, so that a high-grade heat source is provided, and the utilization of the heat network water is facilitated. It should be noted that the high-grade heat source and the low-grade heat source are a pair of relative concepts, wherein the temperature of the low-grade heat source is generally lower than about 50 ℃, and is difficult to be directly used for heating, heating and the like, and the temperature of the high-grade heat source is higher (generally can reach more than 80 ℃) and can be directly used for heating and heating.

In this embodiment, a part of the heat source of the hot press 26 is the exhaust steam of the low pressure cylinder 1 of the steam turbine, another part of the heat source of the hot press 26 is the extraction steam of the intermediate pressure cylinder 2 of the steam turbine, and the flow rate of the exhaust steam in the heat source of the hot press 26 is greater than the flow rate of the extraction steam, wherein the hot press 26 utilizes the exhaust steam of the low pressure cylinder 1, thereby reducing the environmental pollution and further improving the economy of the operation of the steam turbine.

Specifically, the used device further comprises a peak heater 24, partial extracted steam of the steam turbine enters the peak heater 24, when the heating load of the heated heat supply network water does not meet the heat load requirement of the heat supply network user side, the peak heater 24 heats the heated heat supply network water, the stability and the reliability of heat used by the heat supply network user side are improved, the heat source of the peak heater 24 is provided for the intermediate pressure cylinder 2 of the steam turbine, and the economical efficiency of unit operation is improved. When the heating load of the heated heat supply network water meets the heat load requirement of the user end of the heat supply network, the peak heater 24 does not operate.

The embodiment also provides a waste heat utilization device of the indirect air cooling system, and the waste heat utilization device of the indirect air cooling system comprises a steam turbine, the indirect air cooling system, an absorption heat pump 11 and a hot press 26. The steam turbine is connected with the generator 3, a steam exhaust outlet of the steam turbine is communicated with a steam side inlet of the indirect air cooling system, a first water side inlet and a first water side outlet of the absorption heat pump 11 are respectively and selectively communicated with a water side outlet and a water side inlet of the indirect air cooling system, a second water side inlet and a second water side outlet of the absorption heat pump 11 are used for being selectively communicated with a heat supply network user side, the hot press 26 comprises a controller, the controller is used for controlling steam inlet and steam outlet of the hot press 26, and the steam side outlet of the hot press 26 is connected with a steam side inlet of the absorption heat pump 11. In this embodiment, the stepless adjustable hot press 26 is preferably used as the hot press 26, and the hot press 26 can achieve design parameters by doping a small amount of high-quality heat source into a large amount of low-quality steam (such as exhaust steam of the low-pressure cylinder 1 of the steam turbine), thereby reducing energy waste.

Wherein the steam turbine comprises a low pressure cylinder 1 and a medium pressure cylinder 2. The indirect air cooling system comprises an indirect air cooling tower 6, a low-temperature circulating water pipeline 7, a high-temperature circulating water pipeline 5 and a host condenser 4. The steam side export of low pressure jar 1 and the steam side entry intercommunication of host computer condenser 4, the water side entry of low temperature circulating water pipeline 7 and the water side export intercommunication of indirect air cooling tower 6, the water side export of low temperature circulating water pipeline 7 and the water side entry intercommunication of host computer condenser 4, the water side entry and the 4 water side export intercommunication of host computer condenser of high temperature circulating water pipeline 5, the water side export of high temperature circulating water pipeline 5 and the water side entry intercommunication of indirect air cooling tower 6. After the circulating water in the low-temperature circulating water pipeline 7 exchanges heat with the unit exhaust steam of the turbine low-pressure cylinder 1 in the main machine condenser 4, the high-temperature circulating water enters the indirect air cooling tower 6, and the high-temperature circulating water in the high-temperature circulating water pipeline 5 is cooled through air. Wherein, a main machine circulating water pump 8 is also arranged on the low-temperature circulating water pipeline 7. It should be noted that in the present embodiment, the high-temperature water and the low-temperature water are a pair of opposite concepts, and the low-temperature water becomes the high-temperature water after being heated by the heat source, but the specific temperatures of the two are not limited.

The waste heat utilization device of the indirect air cooling system further comprises a waste heat water supply pipeline 10 and a waste heat water return pipeline 12. The water side inlet of the waste heat water supply pipeline 10 is selectively communicated with the high-temperature circulating water pipeline 5, and the water side outlet of the waste heat water supply pipeline 10 is selectively communicated with the first water side inlet of the absorption heat pump 11. The water side inlet of the residual hot water return pipeline 12 is selectively communicated with the first water side outlet of the absorption heat pump 11, and the water side outlet of the residual hot water return pipeline 12 is selectively communicated with the low-temperature circulating water pipeline 7. Wherein, be equipped with first isolating valve 9 on surplus hot water supply pipe 10, be equipped with second isolating valve 13 on surplus hot water return pipe 12, be convenient for the isolation and the maintenance of pipeline through setting up first isolating valve 9 and second isolating valve 13.

When the first isolation valve 9 and the second isolation valve 13 are opened, according to the heat load requirement of a user side of a heat supply network, part of circulating water in the high-temperature circulating water pipeline 5 of the indirect air cooling system enters the absorption heat pump 11 through the waste heat water supply pipeline 10, after heat recovery is carried out on the circulating water in the waste heat water supply pipeline 10 through the absorption heat pump 11, return water can directly return to the low-temperature circulating water pipeline 7 through the waste heat water return pipeline 12 and then enters the host condenser 4 after mixing, and the cooling fan section is properly closed by the indirect air cooling tower 6 according to the reduction of the heat load in the host condenser 4. When the first and second isolation valves 9, 13 are closed, the indirect air cooling tower 6 cools the entire heat load within the main machine condenser 4.

Specifically, a first steam inlet of the thermocompressor 26 is selectively communicated with a steam side outlet of the host condenser 4, and a second steam inlet of the thermocompressor 26 is selectively and adjustably communicated with a steam side outlet of the intermediate pressure cylinder 2. And a seventh isolating valve 33 is arranged on a pipeline for communicating the hot press 26 with the host condenser 4, and a third isolating valve 27 is also arranged on a pipeline for communicating the hot press 26 with the intermediate pressure cylinder 2, so that the device is convenient to isolate and overhaul. Wherein, the first steam inlet lets in the exhaust steam of low pressure cylinder 1, and the second steam inlet lets in the extraction steam of intermediate pressure cylinder 2, and the flow that gets into exhaust steam in hot press 26 is greater than the flow of extraction steam, and wherein hot press 26 utilizes the exhaust steam of low pressure cylinder 1, reduces environmental pollution and has further improved the economic nature of steam turbine operation.

It should be noted that a safety valve 29, a quick check valve 30, a quick-closing valve 31, and an electric steam extraction regulating valve 32 are provided at the steam side outlet of the intermediate pressure cylinder 2, and the steam extraction in the intermediate pressure cylinder 2 is sequentially passed through the safety valve 29, the quick check valve 30, the quick-closing valve 31, and the electric steam extraction regulating valve 32.

Specifically, the waste heat utilization device of the indirect air cooling system further comprises a heat supply network low-temperature water return pipeline 14 and a heat supply network high-temperature water supply pipeline 18. The water side inlet of the heat supply network low-temperature water return pipeline 14 is selectively communicated with a heat supply network user side, and the water side outlet of the heat supply network low-temperature water return pipeline 14 is selectively communicated with the second water side inlet of the absorption heat pump 11. The water side inlet of the heat supply network high-temperature water supply pipeline 18 is selectively communicated with the second water side outlet of the absorption heat pump 11, and the water side outlet of the heat supply network high-temperature water supply pipeline 18 is selectively communicated with a heat supply network user side. A heat supply network water circulating water pump 15 and a fourth isolating valve 16 are arranged on the heat supply network low-temperature water return pipeline 14, and a fifth isolating valve 17 is arranged on the heat supply network high-temperature water supply pipeline 18. The fourth isolation valve 16 and the fifth isolation valve 17 are arranged to facilitate the isolation and maintenance of the pipeline.

The heat supply network water entering the heat supply network low-temperature water return pipeline 14 of the absorption heat pump 11 absorbs heat through the absorption heat pump 11, the hot press 26 can utilize a small amount of high-temperature steam and part of low-temperature exhaust steam to be mixed into driving steam meeting parameter requirements, after the intermediate medium in the absorption heat pump 11 is driven, the intermediate medium can efficiently absorb low-grade heat energy of waste heat water, the heat supply network water is heated, and the return water can be directly conveyed to a heat supply network user side through the heat supply network high-temperature water supply pipeline 18.

In practical application, the waste heat utilization device of the indirect air cooling system further comprises a spike heater 24. The steam side outlet of the intermediate pressure cylinder 2 is selectively communicated with the steam side inlet of the peak heater 24 in a flow-adjustable manner, a sixth isolation valve 28 is arranged on a pipeline for communicating the steam side outlet of the intermediate pressure cylinder 2 with the steam side inlet of the peak heater 24, and the pipeline is conveniently isolated and overhauled by arranging the sixth isolation valve 28.

The high-temperature water supply pipeline 18 of the heat supply network is provided with a bypass valve 19, the spike heater 24 is connected with the bypass valve 19 in parallel, and the pipeline of the spike heater 24 connected with the bypass valve 19 in parallel is provided with a seventh isolation valve 22 and an eighth isolation valve 23.

When the heat supply amount of the heat supply network water output from the second water side outlet of the absorption heat pump 11 meets the heat load requirement, the sixth isolation valve 28, the seventh isolation valve 22 and the eighth isolation valve 23 are closed, the bypass valve 19 is opened, the spike heater 24 does not operate at this time, and the water supply in the heat supply network high-temperature water supply pipeline 18 directly enters a heat supply network user end. When the heat supply amount of the heat supply network water output from the second water side outlet of the absorption heat pump 11 does not meet the heat load requirement, the sixth isolation valve 28, the seventh isolation valve 22 and the eighth isolation valve 23 are opened, the bypass valve 19 is closed, the peak heater 24 is connected in series with the heat supply network high-temperature water supply pipeline 18, the peak heater 24 heats the heat supply network water output from the second water side outlet of the absorption heat pump 11, the stability and reliability of heat used by a heat network user end are improved, the heat source of the peak heater 24 is provided for the intermediate pressure cylinder 2 of the steam turbine, and the running economy of the unit is improved. And the peak heater 24 output condensate is recycled to the condensate system by a first condensate pump 25, it being noted that the condensate system is part of the plant thermodynamic system.

As shown in fig. 1, the waste heat utilization device of the indirect air cooling system further includes an iron removal device 20, the iron removal device 20 is communicated with the condensed water outlet of the absorption heat pump 11, and the condensed water output by the condensed water outlet of the absorption heat pump 11 is recovered to the condensed water system through a second condensed water pump 21 after passing through the iron removal device 20. According to the characteristics of the generator set and the water temperature, the iron removal device 20 is arranged for the subcritical generator set, so that the water quality of the condensed water after waste heat recovery after being treated by the iron removal device 20 reaches the standard.