Source and storage integrated low-carbon power generation system and operation method

Abstract

The invention discloses a source and storage integrated low-carbon power generation system and an operation method. The system comprises a coal-fired power generation subsystem, a decarburization subsystem and a pump heat energy storage subsystem. In order to improve the operation flexibility and the energy efficiency level of the system, the system is optimized as follows: (1) in a low ebb of electricity consumption, electric energy is output to drive a compressor to pressurize and heat steam extracted by an intermediate-pressure cylinder, then molten salt is heated, and then the steam enters a reboiler after acting through an expansion machine; and finally, redundant electric energy is converted into heat energy of the fused salt to be stored. And (2) in the peak period of power utilization, the feed water from the deaerator is heated by the high-temperature fused salt stored in the fused salt storage tank and then enters the expansion machine to do work, so that the output of the decarburization coal-fired power generation unit is improved. And the extracted steam of the intermediate-pressure cylinder acts through the expansion machine and then enters the reboiler. And (3) normal-temperature water serves as a heat absorption working medium, waste heat in the decarburization process is sequentially absorbed according to the heat grade, and part of medium-pressure cylinder extraction steam is replaced under the action of the ejector to provide heat for the reboiler. According to the system, the carbon capture energy efficiency punishment is effectively reduced, and the operation flexibility is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal-fired power generation, and particularly relates to a low-carbon power generation system integrating source and storage and an operation method thereof. Background Art

[0002] As a major carbon dioxide emission source, the power industry urgently needs to take measures to reduce carbon emissions. Post-combustion carbon capture and storage technology (CCS) is an effective solution to reduce carbon emissions from coal-fired power plants. Among them, the carbon capture technology using monoethanolamine (MEA) solvent has the advantages of mature process, high capture efficiency and low cost, and has been widely used.

[0003] However, the decarbonization process based on the chemical absorption method of MEA requires a large amount of thermal energy and releases a large amount of low-grade waste heat. Generally, the heat required for the decarbonization unit is supplied by the extraction steam from the intermediate and low-pressure cylinders of the steam turbine, resulting in a significant decrease in the power generation efficiency of the coal-fired power plant and affecting the operation safety of the low-pressure cylinder. In addition, with the rapid increase in the proportion of renewable energy sources with strong time-varying characteristics such as wind energy and solar energy, it is urgent to improve the operation flexibility of coal-fired power plants. Summary of the Invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a low-carbon power generation system integrating source and storage and an operation method thereof. The system is a carbon capture coal-fired power generation system integrating pump heat energy storage and waste heat recovery, which effectively reduces the energy efficiency penalty of carbon capture, further expands the peak shaving range of the unit, and improves the operation flexibility of the system.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A low-carbon power generation system integrating source and storage, the system includes a coal-fired power generation subsystem, a decarbonization subsystem and a pump heat energy storage subsystem,

[0007] The pump thermal energy storage subsystem includes a charging compressor 25, a molten salt heat exchanger 26, a charging expander 27, an ejector 28, a low-temperature molten salt storage tank 29, a high-temperature molten salt storage tank 30, a discharging expander 31, a No. 2 feed water pump 32, an evaporator 33, a superheater 34, a discharging high-pressure cylinder 35, a flow dividing valve 36, a reheater 37, and a discharging low-pressure cylinder 38; on the charging side, the charging compressor 25 is connected in series with the steam side of the molten salt heat exchanger 26, the charging expander 27, and the ejector 28 in sequence; the inlet and outlet of the molten salt side of the molten salt heat exchanger 26 are respectively connected to the molten salt outlet of the low-temperature molten salt storage tank 29 and the molten salt inlet of the high-temperature molten salt storage tank 30; on the discharging side, the molten salt at the outlet of the high-temperature molten salt storage tank 30 on the molten salt side is divided into two paths by the flow dividing valve 36, one path is connected to the molten salt side of the superheater 34, and the other path is connected to the molten salt side of the reheater 37, and then is mixed by the flow collecting valve 22 and is connected in series with the molten salt side of the evaporator 33 and the inlet of the low-temperature molten salt storage tank 29 to form a loop; the No. 2 feed water pump 32 on the working fluid side is connected in series with the working fluid side of the evaporator 33, the working fluid side of the superheater 34, and the discharging high-pressure cylinder 35 in sequence; the exhaust steam at the outlet of the discharging high-pressure cylinder 35 is divided into two paths by the flow dividing valve 36, one path passes through the reheater 37 and is connected to the inlet of the discharging low-pressure cylinder 38, and the other path is mixed with the exhaust steam of the discharging low-pressure cylinder 38 by the flow collecting valve 22 and is connected to the ejecting steam inlet of the ejector 28; the jet inlet of the ejector 28 is connected to the outlet of the discharging expander 31;

[0008] The pump thermal energy storage subsystem is interconnected with the coal-fired power generation subsystem and the decarbonization subsystem. The working fluid at the inlet of the charging compressor 25 and the working fluid at the inlet of the discharging expander 31 in the pump thermal energy storage subsystem both come from the extraction steam of the No. 3 extraction of the middle-pressure cylinder in the coal-fired power generation subsystem; the feed water of the No. 2 feed water pump 32 comes from the deaerator 9 in the coal-fired power generation subsystem; the waste heat steam entering the ejector 28 in the pump thermal energy storage subsystem comes from the steam-water separator 24 in the decarbonization subsystem; the outlet of the ejector 28 is connected to the inlet of the reboiler 19 in the decarbonization subsystem.

[0009] In the coal-fired power generation subsystem, the main steam outlet of the boiler 1 is connected to the inlet of the high-pressure cylinder 2; the high-pressure cylinder 2, the middle-pressure cylinder 3, the low-pressure cylinder 4, and the generator 5 are connected in series in sequence; the exhaust steam of the middle-pressure cylinder 3 is divided into two paths, one path enters the pump thermal energy storage subsystem, and the other path is connected to the steam inlet of the low-pressure cylinder 4 through the throttle valve 13 in sequence; the exhaust steam of the low-pressure cylinder 4 is connected to the inlet of the condenser 6, and the condenser 6, the condensate pump 7, the low-pressure heater group 8, the deaerator 9, the No. 1 feed water pump 10, and the high-pressure heater group 11 are connected in series in sequence; among them, part of the extraction steam of the high-pressure cylinder 2 and the middle-pressure cylinder 3 is connected to the high-pressure heater group 11 through the extraction steam pipeline, part of the extraction steam of the middle-pressure cylinder 3 is introduced into the deaerator 9, and part of the extraction steam of the middle-pressure cylinder 3 and the low-pressure cylinder 4 is transported to the low-pressure heater group 8 to heat the return water; the flue gas outlet of the boiler 1 is connected to the inlet of the flue gas cooler 14 in the decarbonization subsystem.

[0010] In the decarbonization subsystem, the flue gas at the outlet of boiler 1 is connected to the flue gas cooler 14 and the flue gas inlet of the absorption tower 15; the bottom of the absorption tower 15 is connected in series with the rich liquid pump 16, the rich and lean liquid heat exchanger 17, and the desorption tower 18 in sequence; the bottom of the desorption tower 18 is connected in series with the reboiler 19, the rich and lean liquid heat exchanger 17, the lean liquid cooler 21, the manifold valve 22, and the absorption tower 15 in sequence; the top of the desorption tower 18 is connected to the condenser 20 and the steam-water separator 24, and the steam-water separator 24 is connected in series with the absorption tower exhaust cooler 23, the flue gas cooler 14, and the lean liquid cooler 21 in sequence; the inlet of the reboiler 19 is connected to the outlet of the ejector 28 of the pump heat energy storage subsystem, and the outlet of the reboiler 19 is connected to the inlet of the condenser 6 of the coal-fired power generation subsystem.

[0011] Both the rich and lean liquid heat exchanger 17 and the molten salt heat exchanger 26 adopt shell-and-tube heat exchangers.

[0012] The lean liquid cooler 21 is connected in series with the flue gas cooler 14, the absorption tower exhaust cooler 23, and the steam-water separator 24 in sequence, and heats an industrial water at 25°C through the waste heat of carbon capture to form a saturated steam.

[0013] The heat transfer terminal difference of the heat exchanger at the reboiler 19 is 10°C.

[0014] Both the high-temperature molten salt storage tank 30 and the low-temperature molten salt storage tank 29 use solar salt with a mass fraction of 60% Na2CO3 + 40% KNO3 as the heat storage medium, and the operating temperature range is 250 - 550°C.

[0015] The primary flow fluid of the ejector 28 is steam with a pressure greater than 0.3 MPa, and the ejector of the waste heat steam makes the pressure of the mixed gas flow 0.3 MPa.

[0016] The charging compressor 25 adopts a centrifugal compressor, and the pressure ratio at the inlet and outlet reaches 5.94.

[0017] For the operation method of the low-carbon power generation system integrating source and storage, 1) When in the low electricity consumption period, a part of the electric energy output by the coal-fired generator set through the generator 5 is used to drive the charging compressor 25 to compress a part of the exhaust steam from the intermediate pressure cylinder 3, heat the molten salt through the molten salt heat exchanger 26, and then enter the charging expander 27 to do work, and then enter the ejector 28 to eject the waste heat steam and supply it to the reboiler 19; the pump heat energy storage subsystem is used to convert the excess electric energy into the heat energy of the molten salt, and finally store it in the high-temperature molten salt storage tank 30.

[0018] 2) During peak power consumption, part of the exhaust steam from the intermediate pressure cylinder 3 does work through the discharge expansion machine 31 and then mixes with the waste heat steam, etc.; the molten salt in the high-temperature molten salt storage tank 30 is divided into two streams. One stream enters the superheater 34 to heat the superheated steam, and the other stream enters the reheater 37 to heat the reheated steam; then these two streams of molten salt are mixed and enter the evaporator 33 to heat the feed water from the deaerator 9. The temperature of the molten salt further decreases and enters the low-temperature molten salt storage tank 29; during the process, the heated superheated steam and reheated steam enter the discharge high-pressure cylinder 35 and the discharge low-pressure cylinder 38 to do work respectively, and at the same time, the feed water volume entering the boiler 1 remains unchanged, significantly increasing the power generation of the system's steam turbine.

[0019] The beneficial effects of the present invention are as follows:

[0020] (1) By integrating the waste heat recovery system into the decarbonized coal-fired unit, the present invention can effectively recover the waste heat of the MEA carbon capture system and replace part of the decarbonization steam to provide heat for the reboiler.

[0021] (2) By coupling the pumped heat energy storage system into the decarbonized coal-fired unit, the present invention can store the excess electric energy in the molten salt during off-peak power consumption, further absorb the output load of the unit, avoid the safety problems of low-load operation of each component of the unit, expand the peak shaving range of the unit, and improve the peak shaving depth.

[0022] (3) The present invention uses an ejector in the pumped heat energy storage system to adjust the pressure of the steam entering the reboiler, and injects the low-pressure waste heat steam through the high-pressure jet to ensure the stable pressure of the steam entering the reboiler.

[0023] The pumped heat energy storage system is a large-scale power storage system based on heat storage, which can realize the value-added heating of electric energy and the efficient conversion of heat and electricity. It has the characteristics of high energy storage density and easy realization of multi-energy combined supply, and is a large-scale high-efficiency heat energy storage technology with great potential. Combining the pumped heat energy storage technology with the carbon capture system and effectively recovering the low-grade waste heat of carbon capture is expected to reduce the energy efficiency penalty while achieving CO2 emissions reduction and realize the efficient and flexible operation of coal-fired power generation units. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of a low-carbon power generation system integrating source and storage of the present invention.

[0025] In the figure: 1. Boiler, 2. High-pressure cylinder, 3. Intermediate pressure cylinder, 4. Low-pressure cylinder, 5. Generator, 6. Condenser, 7.

[0026] Condensate pump, 8. Low-pressure heater group, 9. Deaerator, 10. 1# feed water pump, 11. High-pressure heater group, 12.

[0027] Small steam turbine, 13. Throttle valve, 14. Flue gas cooler, 15. Absorption tower, 16. Rich liquid pump, 17. Rich and lean liquid heat exchanger, 18. Desorption tower, 19. Reboiler, 20. Condenser, 21. Lean liquid cooler, 22. Manifold valve, 23.

[0028] Absorption tower exhaust cooler, 24. Steam-water separator, 25. Charging compressor, 26. Molten salt heat exchanger, 27. Charging expander, 28. Ejector, 29. Low-temperature molten salt storage tank, 30. High-temperature molten salt storage tank, 31. Discharging expander,

[0029] 32. Feed water pump 2#, 33. Evaporator, 34. Superheater, 35. Discharging high-pressure cylinder, 36. Shunt valve, 37. Reheater,

[0030] 38. Discharging low-pressure cylinder. Specific implementation mode

[0031] The present invention provides a low-carbon power generation system integrating source and storage. The present invention will be further described in detail below with reference to the accompanying drawings.

[0032] As Figure 1 shown, the present invention is a low-carbon power generation system integrating source and storage, and the system includes a coal-fired power generation subsystem, a decarbonization subsystem and a pumped heat energy storage subsystem; wherein,

[0033] In the coal-fired power generation subsystem and the decarbonization subsystem, the working processes of each component are as follows: Feed water enters the boiler 1, and after generating main steam, it enters the high-pressure cylinder 2. Part of the intermediate extraction steam of the high-pressure cylinder 2 is used to heat part of the feed water of the high-pressure heater group 11. The exhaust steam of the high-pressure cylinder 2 returns to the boiler 1 for reheating. After generating reheated steam, it enters the intermediate-pressure cylinder 3. Part of the intermediate extraction steam of the intermediate-pressure cylinder 3 is respectively used to heat part of the feed water of the high-pressure heater group 11 and the condensate water in the deaerator 9. Another part of the intermediate extraction steam enters the small steam turbine 12. The exhaust steam of the intermediate-pressure cylinder 3 is divided into three parts. One part is used to heat part of the feed water of the low-pressure heater group 8, one part enters the pump heat energy storage subsystem, and the last part enters the low-pressure cylinder 4 through the throttle valve 13. Part of the intermediate extraction steam of the low-pressure cylinder 4 is used to heat part of the feed water of the low-pressure heater group 8; The high-pressure cylinder 2, the intermediate-pressure cylinder 3, and the low-pressure cylinder 4 are coaxially connected to transfer the generated mechanical energy to the generator 5 to generate electric energy and output it to the outside; The flue gas generated by the boiler 1 is cooled after treatment and then enters the flue gas cooler 14 to be cooled down, and then enters the absorption tower 15 to be absorbed by the MEA solvent to form rich liquid. The rich liquid enters the rich and lean liquid heat exchanger 17 through the rich liquid pump 16, is heated up and then enters the desorption tower 18, and forms a mixed gas of carbon dioxide and water vapor under the action of the reboiler 19, and successively passes through the condenser 20 and the steam-water separator 24; The lean liquid at the bottom of the desorption tower 18 successively passes through the rich and lean liquid heat exchanger 17 and the lean liquid cooler 21, and the temperature decreases. Then, it enters the absorption tower 15 together with the supplemented MEA and water through the manifold valve 22 to complete the cycle; Among them, the waste heat recovery process is that a stream of feed water at 25°C successively passes through the lean liquid cooler 21, the flue gas cooler 14, the absorption tower exhaust cooler 23, and the steam-water separator 24 for heat exchange, and finally forms a stream of saturated steam; The condensate water of the reboiler 19, the exhaust steam of the small steam turbine 12, the exhaust steam of the low-pressure cylinder 4, and the drain water of the low-pressure heater group 8 are all converged into the condenser 6, condensed to generate condensate water, enter the low-pressure heater group 8 through the condensate pump 7, and the condensate water at the outlet of the low-pressure heater group 8 and the drain water from the high-pressure heater group 11 are all converged into the deaerator 9. After the deaerator 9 generates saturated feed water, part of it enters the pump heat energy storage system, and part of it enters the high-pressure heater group 11 through the feed water pump 10, and then enters the boiler 1. After generating new steam in the boiler 1, it enters the high-pressure cylinder 2, and this process is repeated.

[0034] In the pump thermal energy storage subsystem, during charging, the externally input electric energy drives the charging compressor 25 to compress part of the exhaust steam from the intermediate pressure cylinder 3 to generate high-temperature and high-pressure steam. Then, the steam enters the molten salt heat exchanger 26, where its temperature decreases, and it continues to do work in the charging expander 27. After that, it enters the ejector 28 as the main jet to eject the waste heat steam into the reboiler 19. At the same time, the low-temperature molten salt from the low-temperature molten salt storage tank 29 is heated to high-temperature molten salt and enters the high-temperature molten salt storage tank 30. During discharging, the molten salt in the high-temperature molten salt storage tank 30 is divided into two streams by the flow dividing valve 36. One stream enters the superheater 34 to heat the steam, and the other stream enters the reheater 37 to heat the steam. Then, these two streams of molten salt are mixed by the collecting valve 22 and enter the evaporator 33 to heat the feed water from the deaerator 9. Finally, the temperature decreases and it enters the low-temperature molten salt storage tank 29, and the cycle ends. During this process, the feed water from the deaerator 9 is boosted in pressure by the 2# feed water pump 32. The heated superheated steam and reheated steam enter the discharging high-pressure cylinder 35 and the discharging low-pressure cylinder 38 to do work respectively. Then, the exhaust steam is mixed by the collecting valve 22 and enters the ejector 28 together with the waste heat steam, and is ejected by the steam from the discharging expander 31 and supplied to the reboiler 19.

[0035] Further, the high-temperature molten salt storage tank 30 and the low-temperature molten salt storage tank 29 use solar salt with a mass fraction of 60% Na2CO3 + 40% KNO3 as the heat storage medium, and the operating temperature range is 250 - 550 °C. This realizes a better temperature range matching between the steam and the molten salt and ensures the high efficiency of energy storage.

[0036] Further, both the lean-rich liquid heat exchanger 17 and the molten salt heat exchanger 26 adopt shell-and-tube heat exchangers. This ensures the high efficiency of the heat exchange process and is convenient for maintenance.

[0037] Further, the primary flow fluid of the ejector 28 is steam with a pressure greater than 0.3 MPa, and it ejects gases such as waste heat steam to make the pressure of the mixed gas flow 0.3 MPa. This ensures the stable pressure of the heating steam entering the reboiler 19 and improves the safety and economy of the system.

[0038] Further, the charging compressor 25 adopts a centrifugal compressor, and the pressure ratio at the inlet and outlet can reach 5.94.

[0039] Further, the lean liquid cooler 21 is connected in series with the flue gas cooler 14, the absorber exhaust cooler 23, and the steam-water separator 24 in sequence, and heats an industrial water at 25 °C through the waste heat of carbon capture to form a saturated steam. This reduces the extraction steam of the intermediate pressure cylinder 3 and effectively reduces the energy efficiency penalty.

[0040] Further, the heat transfer end difference of the heat exchanger at the reboiler 19 is 10 °C. This can ensure that the lean MEA solution does not degrade and corrode the equipment at an appropriate heating temperature.

[0041] The operating method of a low-carbon power generation system integrating source and storage as described above

[0042] 1) When in the low electricity consumption period, part of the electric energy output by the coal-fired generator set through the generator 5 is used to drive the charging compressor 25 to compress part of the exhaust steam of the intermediate pressure cylinder 3. After being heated by the molten salt heat exchanger 26, the molten salt enters the charging expander 27 to do work, and then enters the ejector 28 to eject the waste heat steam and supply it to the reboiler 19. The pump heat energy storage subsystem is used to convert the excess electric energy into the heat energy of the molten salt, and finally store it in the high-temperature molten salt storage tank 30.

[0043] 2) When in the high electricity consumption period, part of the exhaust steam of the intermediate pressure cylinder 3 does work through the discharging expander 31 and then is mixed with the waste heat steam and the like. The molten salt in the high-temperature molten salt storage tank 30 is divided into two streams. One stream enters the superheater 34 to heat the superheated steam, and the other stream enters the reheater 37 to heat the reheated steam. Then the two streams of molten salt are mixed and enter the evaporator 33 to heat the feed water from the deaerator 9. The temperature of the molten salt further decreases and enters the low-temperature molten salt storage tank 29. During this process, the heated superheated steam and reheated steam enter the discharging high-pressure cylinder 35 and the discharging low-pressure cylinder 38 to do work respectively, and at the same time, the feed water flow rate into the boiler 1 remains unchanged, significantly increasing the power generation of the system steam turbine.

Claims

1. A low-carbon power generation system integrating power generation and energy storage, which system comprises a coal-fired power generation subsystem, a decarbonization subsystem and a pumped heat energy storage subsystem. The pumped heat energy storage subsystem includes a charging compressor (25), a molten salt heat exchanger (26), a charging expander (27), an ejector (28), a low-temperature molten salt storage tank (29), a high-temperature molten salt storage tank (30), a discharging expander (31), a No. 2 feed water pump (32), an evaporator (33), a superheater (34), a discharging high-pressure cylinder (35), a shunt valve (36), a reheater (37) and a discharging low-pressure cylinder (38); on the charging side, the charging compressor (25) is successively connected in series with the steam side of the molten salt heat exchanger (26), the charging expander (27) and the ejector (28); the inlet and outlet of the molten salt side of the molten salt heat exchanger (26) are respectively connected to the molten salt outlet of the low-temperature molten salt storage tank (29) and the molten salt inlet of the high-temperature molten salt storage tank (30); on the discharging side, the molten salt outlet of the high-temperature molten salt storage tank (30) on the molten salt side is divided into two paths by the shunt valve (36), one path is connected to the molten salt side of the superheater (34), and the other path is connected to the molten salt side of the reheater (37), and then after being mixed by a manifold valve (22), it is connected in series with the molten salt side of the evaporator (33) and the inlet of the low-temperature molten salt storage tank (29) to form a loop; the No. 2 feed water pump (32) on the working fluid side is successively connected in series with the working fluid side of the evaporator (33), the working fluid side of the superheater (34) and the discharging high-pressure cylinder (35); the exhaust steam at the outlet of the discharging high-pressure cylinder (35) is divided into two paths by the shunt valve (36), one path passes through the reheater (37) and is connected to the inlet of the discharging low-pressure cylinder (38), and the other path is mixed with the exhaust steam of the discharging low-pressure cylinder (38) by the manifold valve (22) and then connected to the ejecting steam inlet of the ejector (28); the jet inlet of the ejector (28) is connected to the outlet of the discharging expander (31). The pumped heat energy storage subsystem is interconnected with the coal-fired power generation subsystem and the decarbonization subsystem. The working fluid at the inlet of the charging compressor (25) and the working fluid at the inlet of the discharging expander (31) in the pumped heat energy storage subsystem both come from the extraction steam of the intermediate-pressure cylinder (3) of the coal-fired power generation subsystem; the feed water of the No. 2 feed water pump (32) comes from the deaerator (9) of the coal-fired power generation subsystem; the waste heat steam entering the ejector (28) in the pumped heat energy storage subsystem comes from the steam-water separator (24) of the decarbonization subsystem; the outlet of the ejector (28) is connected to the inlet of the reboiler (19) in the decarbonization subsystem.

2. The integrated source and storage low-carbon power generation system according to claim 1, wherein: For the coal-fired power generation subsystem, the main steam outlet of the boiler (1) is connected to the inlet of the high-pressure cylinder (2); the high-pressure cylinder (2), intermediate-pressure cylinder (3), low-pressure cylinder (4), and generator (5) are connected in series in sequence; the exhaust steam of the intermediate-pressure cylinder (3) is divided into two paths, one path enters the pump thermal energy storage subsystem, and the other path is connected to the steam inlet of the low-pressure cylinder (4) through a throttle valve (13) in sequence; the exhaust steam of the low-pressure cylinder (4) is connected to the inlet of the condenser (6), and the condenser (6), condensate pump (7), low-pressure heater bank (8), deaerator (9), 1# feed water pump (10), and high-pressure heater bank (11) are connected in series in sequence; among them, part of the extraction steam of the high-pressure cylinder (2) and intermediate-pressure cylinder (3) is connected to the high-pressure heater bank (11) through an extraction steam pipeline, part of the extraction steam of the intermediate-pressure cylinder (3) is introduced into the deaerator (9), and part of the extraction steam of the intermediate-pressure cylinder (3) and low-pressure cylinder (4) is transported to the low-pressure heater bank (8) to heat the return water; the flue gas outlet of the boiler (1) is connected to the inlet of the flue gas cooler (14) of the carbon capture subsystem.

3. The integrated source and storage low-carbon power generation system according to claim 1, characterized in that: For the carbon capture subsystem, the flue gas at the outlet of the boiler (1) is connected to the flue gas cooler (14) and the flue gas inlet of the absorption tower (15); the bottom of the absorption tower (15) is connected in series with a rich liquid pump (16), a rich / lean liquid heat exchanger (17), and a desorption tower (18) in sequence; the bottom of the desorption tower (18) is connected in series with a reboiler (19), a rich / lean liquid heat exchanger (17), a lean liquid cooler (21), a manifold valve (22), and the absorption tower (15) in sequence; the top of the desorption tower (18) is connected to a condenser (20) and a steam-water separator (24), and the steam-water separator (24) is connected in series with an absorption tower exhaust cooler (23), a flue gas cooler (14), and a lean liquid cooler (21) in sequence; the inlet of the reboiler (19) is connected to the outlet of the ejector (28) of the pump thermal energy storage subsystem, and the outlet of the reboiler (19) is connected to the inlet of the condenser (6) of the coal-fired power generation subsystem.

4. A low-carbon power generation system integrating source and storage according to claim 3, characterized in that: Both the rich / lean liquid heat exchanger (17) and the molten salt heat exchanger (26) adopt shell-and-tube heat exchangers.

5. The integrated source-storage low-carbon power generation system according to claim 3, wherein: The lean liquid cooler (21) is connected in series with the flue gas cooler (14), the absorption tower exhaust cooler (23), and the steam-water separator (24) in sequence, and heats an industrial water at 25°C to form a saturated steam by using the waste heat from carbon capture.

6. The integrated source and storage low-carbon power generation system according to claim 3, wherein: The heat transfer terminal difference of the heat exchanger at the reboiler (19) is 10°C.

7. The integrated source-storage low-carbon power generation system according to claim 1, wherein: The high-temperature molten salt storage tank (30) and the low-temperature molten salt storage tank (29) use solar salt with a mass fraction of 60% Na2CO3 + 40% KNO3 as the heat storage medium, and the operating temperature range is 250 - 550°C.

8. The integrated source and storage low-carbon power generation system according to claim 1, characterized in that: The primary flow fluid of the ejector (28) is steam with a pressure greater than 0.3 MPa, and the ejector uses the waste heat steam to make the pressure of the mixed gas flow 0.3 MPa.

9. The integrated source and storage low-carbon power generation system according to claim 1, characterized in that: The charging compressor (25) adopts a centrifugal compressor, and the inlet and outlet pressure ratio reaches 5.

94.

10. The operation method of a low-carbon power generation system integrating source and storage according to any one of claims 1 to 9, characterized in that: 1) When in the low electricity consumption period, part of the electric energy output by the coal-fired generator set drives the charging compressor (25) through the generator (5), compresses part of the exhaust steam of the intermediate-pressure cylinder (3), heats the molten salt through the molten salt heat exchanger (26), then enters the charging expander (27) to do work, and then enters the ejector (28) to eject the waste heat steam and supply it to the reboiler (19); the pump heat energy storage subsystem is used to convert the excess electric energy into the heat energy of the molten salt, and finally store it in the high-temperature molten salt storage tank (30). 2) When in the high electricity consumption period, part of the exhaust steam of the intermediate-pressure cylinder (3) does work through the discharging expander (31), and then is mixed with the waste heat steam, etc.; the molten salt in the high-temperature molten salt storage tank (30) is divided into two streams, one stream enters the superheater (34) to heat the superheated steam, and the other stream enters the reheater (37) to heat the reheated steam; then these two streams of molten salt are mixed and enter the evaporator (33) to heat the feed water from the deaerator (9), and the temperature of the molten salt is further reduced and enters the low-temperature molten salt storage tank (29); during the process, the heated superheated steam and reheated steam enter the discharging high-pressure cylinder (35) and the discharging low-pressure cylinder (38) to do work respectively, and at the same time, the feed water volume entering the boiler (1) remains unchanged, significantly increasing the power generation of the system steam turbine.

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