A deep peak shaving system configured with a steam ejector and a heat storage device and an operation method thereof

Abstract

The application discloses a deep peak regulation system configured with a steam ejector and a heat storage device and an operation method, which comprises a coal-fired power generation system, a heat storage loop and a steam ejector loop. When the load is increased and the wet state is converted to the dry state, the recirculated water separated from the boiler water separator is heated by the molten salt and mixed with the main steam, and the high-pressure feed water is bypassed, the steam turbine extraction flow is reduced, the steam turbine work capacity is rapidly increased, the recirculated water and the high-pressure extraction steam are reduced to cause the feed water temperature to be reduced, the heat storage loop and the steam ejector loop are used to store energy, the feed water is heated, the water-cooled wall inlet enthalpy deficit is reduced, and the rapid state conversion is realized; when the load is reduced and the dry state is converted to the wet state, the reheated steam is bypassed to heat the molten salt and the steam is recovered in the steam storage tank, and the unit output power is rapidly reduced. The application realizes the dry and wet rapid state conversion of the coal-fired unit at an ultra-low load through the reconstruction of the steam-water working fluid flow path, the multi-medium energy storage across time and space control of the molten salt / steam and the like, and improves the deep peak regulation capacity of the unit.

Description

Technical Field

[0001] This invention belongs to the field of coal-fired power generation technology, specifically relating to a deep peak-shaving system and its operation method that is equipped with a steam ejector and a thermal storage device. Background Technology

[0002] With the rapid increase in installed capacity of renewable energy sources such as solar and wind power, their volatility, intermittency, and unpredictability pose significant challenges to the stable and safe operation of the power grid. As a development trend in coal-fired power generation technology, ultra-supercritical (UF) supercritical units are the mainstay of my country's coal-fired power generation, accounting for approximately 60% of the total installed coal-fired power capacity. They are also the primary type of unit used in my country for absorbing renewable energy and for peak and frequency regulation. However, under deep peak-shaving conditions, UF units inevitably experience wet-state operation, with long transition times and high control difficulty, severely limiting the unit's deep peak-shaving capability.

[0003] A steam ejector is a device that uses a high-pressure energy flow to eject a low-pressure energy flow, increasing the pressure of the low-pressure steam, improving the dryness of the working fluid, and exhibiting high ejection efficiency and low energy loss. External thermal storage devices can be used for the intertemporal and spatial storage and release of energy within coal-fired power units, storing energy from load reduction processes for rapid load increases. This overcomes the constraints of large boiler delays and inertia, breaks through the limitations of peak shaving and frequency regulation in coal-fired power units, and further improves the deep peak shaving capability of the units. Configuring steam ejectors and thermal storage devices in the thermal system of coal-fired power generation is a highly promising technical route for achieving wide-range flexible peak shaving in supercritical units. Summary of the Invention

[0004] To address the lack of flexibility in deep peak-shaving operation of supercritical coal-fired power generating units, this invention aims to provide a deep peak-shaving system and operation method equipped with a steam ejector and a thermal storage device. By configuring the steam ejector and thermal storage device, and through thermal system configuration design, switching of the storage / release circuit, and steam ejection, a rapid transition between dry and wet conditions at ultra-low loads is achieved: During the transition from wet to dry conditions at increased load, molten salt releases heat to heat the boiler recirculation working fluid, increasing the main steam flow rate. Simultaneously, the bypass feedwater reduces the extraction steam flow rate, further increasing the turbine's work capacity and achieving a rapid power increase. Simultaneously, molten salt / steam energy is stored in stages to heat the feedwater, reducing the underenthalpy at the water-cooled wall inlet, thus achieving a rapid transition. During the transition from dry to wet conditions at decreased load, bypass reheat steam heats the molten salt. Part of the heated steam is stored in a steam storage tank, and part is used to eject exhaust steam from the intermediate-pressure cylinder to reduce the humidity of the final stage of the low-pressure cylinder. This rapidly reduces the unit's output power while achieving efficient storage of molten salt / steam energy.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A deep peak-shaving system configured with a steam ejector and a thermal storage device includes a coal-fired power generation system, a thermal storage circuit, and a steam ejector circuit;

[0007] The coal-fired power generation system includes a boiler 1, a high-pressure turbine cylinder 7, a medium-pressure turbine cylinder 8, a low-pressure turbine cylinder 9, a generator 10, a condenser 11, a condensate pump 12, a low-pressure heater 13, a deaerator 14, a feedwater pump 15, a high-pressure heater 16, a feedwater bypass regulating valve 17, a feedwater bypass pump 18, a feedwater bypass heater 19, and a medium-pressure cylinder outlet regulating valve 33. The main steam outlet of the boiler 1 is connected to the steam inlet of the high-pressure turbine cylinder 7 via a pipeline, and the extraction steam outlet of the high-pressure turbine cylinder 7 is connected to the steam inlet of the high-pressure heater 16 via a pipeline. The reheat steam from cylinder 7 enters boiler 1 and connects to the steam inlet of intermediate-pressure cylinder 8 of the turbine. The extraction steam from intermediate-pressure cylinder 8 is connected to the steam inlet of deaerator 14 via a pipeline. The steam outlet of intermediate-pressure cylinder 8 is connected to the steam inlet of low-pressure cylinder 9 via intermediate-pressure cylinder outlet regulating valve 33. The extraction steam outlet of low-pressure cylinder 9 is connected to the steam inlet of low-pressure heater 13 via a pipeline. The steam outlet of low-pressure cylinder 9 is connected to condenser 11. The condensate outlet of condenser 11 is connected to the condensate inlet of low-pressure heater 13 via condensate pump 12. The condensate outlet of the low-pressure heater 13 is connected to the feedwater inlet of the deaerator 14. The feedwater outlet of the deaerator 14 is connected to the feedwater inlet of the high-pressure heater 16 via a feedwater pump 15. The feedwater outlet of the high-pressure heater 16 is connected to the boiler 1 via the molten salt-feedwater heat exchanger 26 in the heat storage circuit. The bypass feedwater outlet of the deaerator 14 flows through the feedwater bypass regulating valve 17, the feedwater bypass pump 18, and the feedwater bypass heater 19 before mixing with the feedwater from the high-pressure heater 16. The boiler 1 is equipped with a recirculation system, which includes... The steam-water separator 2, separator water tank 3, recirculation pump 4, recirculation water first regulating valve 5, and recirculation water second regulating valve 6 are included. The saturated water separated by the steam-water separator 2 enters the separator water tank 3. The recirculation water from the outlet of the separator water tank 3 is divided into two paths after passing through the recirculation pump 4. One path passes through the recirculation regulating valve 5 and mixes with the turbine feedwater before entering the boiler 1. The other path passes through the recirculation water second regulating valve 6 and enters the molten salt-recirculation water heat exchanger 25 in the heat storage circuit. The high-pressure cylinder 7, intermediate-pressure cylinder 8, and low-pressure cylinder 9 of the turbine are coaxial and connected to the power grid through the generator 10.

[0008] The heat storage circuit includes a steam-molten salt heat exchanger 20, a hot tank 21, a hot tank outlet regulating valve 22, a hot tank outlet pump 23, a molten salt-recirculating water heat exchanger 25, a molten salt-feedwater heat exchanger 26, a cold tank 27, a cold tank outlet regulating valve 28, a cold tank outlet pump 29, and pipelines connecting various equipment. The molten salt at the outlet of the hot tank 21 is connected to the molten salt inlet of the molten salt-recirculating water heat exchanger 25 through the hot tank outlet regulating valve 22 and the hot tank outlet pump 23. The boiler recirculating water is connected to the molten salt through the second recirculating water regulating valve 6. The working fluid inlet of the recirculating water heat exchanger 25 is connected to the steam inlet of the high-pressure cylinder 7 of the steam turbine. The molten salt outlet of the molten salt recirculating water heat exchanger 25 flows through the molten salt feedwater heat exchanger 26 and is connected to the molten salt inlet of the cold tank 27. The molten salt outlet of the cold tank 27 is connected to the molten salt inlet of the steam-molten salt heat exchanger 20 through the cold tank outlet regulating valve 28 and the cold tank outlet pump 29. The molten salt outlet of the steam-molten salt heat exchanger 20 is connected to the molten salt inlet of the hot tank 21.

[0009] The steam ejector circuit includes a reheat steam bypass regulating valve 24, a first steam ejector 31, a first steam ejector first regulating valve 30, a first steam ejector second regulating valve 32, a low-pressure steam tank extraction valve 34, a high-pressure steam tank 35, a high-pressure steam tank regulating valve 36, a low-pressure steam tank 37, a low-pressure steam tank regulating valve 38, and a second steam ejector 39. The bypass reheat steam flows through a steam-molten salt heat exchanger 20 and collects in the high-pressure steam tank 35. A portion of the bypass reheat steam flows through the first steam ejector first regulating valve 30 and enters the first steam ejector 39. 1. The exhaust steam from the outlet of the intermediate-pressure cylinder 8 of the steam ejector turbine flows through the second regulating valve 32 of the first steam ejector and enters the first steam ejector 31. The working fluid from the outlet of the first steam ejector 31 enters the low-pressure cylinder 9 of the steam turbine. The extracted steam from the low-pressure cylinder 9 flows through the extraction valve 34 of the low-pressure steam storage tank and is stored in the low-pressure steam storage tank 37. The steam from the outlet of the high-pressure steam storage tank 35 flows through the regulating valve 36 of the high-pressure steam storage tank and ejects the low-pressure steam from the low-pressure steam storage tank 37 through the regulating valve 38 of the low-pressure steam storage tank. The working fluid from the outlet of the second steam ejector 39 heats the feedwater in the feedwater bypass heater 19 and then returns to the deaerator 14.

[0010] The operation method of the deep peak-shaving system with steam ejector and thermal storage device described above, when the coal-fired power generation system is transitioning from a wet to a dry state during load increase, closes the first regulating valve 5 of the recirculating water, opens the second regulating valve 6 of the recirculating water, closes the reheat steam bypass regulating valve 24, the first regulating valve 30 of the first steam ejector, and the second regulating valve 32 of the first steam ejector, opens the hot tank outlet regulating valve 22, and closes the cold tank outlet regulating valve 28. The hot molten salt flows through the molten salt-recirculating water heat exchanger 25 to heat the recirculating water and then flows into the main steam, increasing the steam flow at the inlet of the high-pressure cylinder 7 of the turbine and improving the work capacity. Closes the low-pressure steam storage tank extraction valve 34, opens the high-pressure steam storage tank regulating valve 36 and the low-pressure steam storage tank regulating valve 38, and opens the feedwater bypass regulating valve 17. After the feedwater bypass, the steam extraction flow of the turbine high-pressure heater decreases, and the working fluid flow increases, improving the work capacity. After the feedwater bypass, the temperature decreases and is heated by the working fluid at the outlet of the steam ejector in the feedwater bypass heater 19. The heat flows into the main feedwater line and is further heated in the molten salt-feedwater heat exchanger 26, reducing the under-enthalpy of the working fluid at the water-cooled wall inlet and achieving a rapid transition from wet to dry state. When the coal-fired power generation system is operating at reduced load and transitioning from dry to wet state, the second recirculation water regulating valve 6 is closed, the first recirculation water regulating valve 5 is opened, and the recirculation water separated by the steam-water separator 2 enters the boiler 1. The hot tank outlet regulating valve 22 is closed, the cold tank outlet regulating valve 28 is opened, and the reheat steam bypass regulating valve 2 is opened. 4. Bypass reheat steam heats the molten salt, while reducing the working fluid flow rate of the intermediate and low-pressure cylinders of the turbine to achieve rapid load reduction. Open the first regulating valve 30 of the first steam ejector, the second regulating valve 32 of the first steam ejector, and the regulating valve 33 of the intermediate-pressure cylinder outlet. The heated reheat steam ejects the exhaust steam from the intermediate-pressure cylinder 8 of the turbine. Adjust the second regulating valve 32 of the first steam ejector and the regulating valve 33 of the intermediate-pressure cylinder outlet to increase the inlet pressure of the low-pressure cylinder 9 of the turbine and reduce the final stage humidity of the low-pressure cylinder 9 of the turbine.

[0011] Compared with the prior art, the present invention has the following advantages:

[0012] 1. The present invention provides a deep peak shaving system with a steam ejector and a thermal storage device. When the load changes from wet to dry state: the molten salt releases heat to heat the boiler recirculation working fluid, increasing the main steam flow rate. At the same time, the bypass feedwater reduces the extraction steam flow rate, further increasing the turbine's work capacity and achieving a rapid increase in power. Simultaneously, the molten salt / steam energy storage is used in stages to heat the feedwater, reducing the underenthalpy at the water-cooled wall inlet, thus achieving a rapid transition.

[0013] 2. The present invention provides a deep peak shaving system with a steam ejector and a thermal storage device. When the load is reduced from dry to wet state, the bypass reheat steam heats the molten salt. The heated steam is partially stored in a steam storage tank and partially used to eject the exhaust steam from the intermediate pressure cylinder to reduce the humidity of the final stage of the low pressure cylinder. This rapidly reduces the output power of the coal-fired power generation system while achieving efficient storage of molten salt / steam energy.

[0014] 3. This invention configures a steam ejector and a thermal storage device in coal-fired power generation. Based on the thermal system configuration design, the switching of the storage / release circuit, and the steam ejector, it provides a method for operating the coupled system. Through the reconstruction of the steam-water working fluid flow path, the time-lapse air conditioning control of multi-media energy storage such as molten salt / steam, and the multi-grade energy cascade utilization, it achieves rapid dry-wet transition at ultra-low loads, overcomes the constraints of large delay and large inertia of boilers, and improves the deep peak-shaving capability of the unit. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a deep peak shaving system configured with a steam ejector and a thermal storage device. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] like Figure 1 As shown, a deep peak-shaving system configured with a steam ejector and a thermal storage device includes a coal-fired power generation system, a thermal storage circuit, and a steam ejector circuit.

[0018] Figure 1 The coal-fired power generation system includes: a boiler 1, a high-pressure turbine cylinder 7, an intermediate-pressure turbine cylinder 8, a low-pressure turbine cylinder 9, a generator 10, a condenser 11, a condensate pump 12, a low-pressure heater 13, a deaerator 14, a feedwater pump 15, a high-pressure heater 16, a feedwater bypass regulating valve 17, a feedwater bypass pump 18, a feedwater bypass heater 19, and an intermediate-pressure cylinder outlet regulating valve 33. The boiler is equipped with a steam-water separator 2, a separator water storage tank 3, a recirculation pump 4, a first recirculation water regulating valve 5, and a second recirculation water regulating valve 6. The thermal storage circuit includes: a steam-molten salt heat exchanger 20, a heat tank 21, and a heat tank outlet... The system includes: outlet regulating valve 22, hot tank outlet pump 23, molten salt-recirculating water heat exchanger 25, molten salt-feed water heat exchanger 26, cold tank 27, cold tank outlet regulating valve 28, cold tank outlet pump 29, and pipelines connecting various equipment; the steam ejector circuit includes: reheat steam bypass regulating valve 24, first steam ejector 31, first steam ejector first regulating valve 30, first steam ejector second regulating valve 32, low-pressure steam tank extraction valve 34, high-pressure steam tank 35, high-pressure steam tank regulating valve 36, low-pressure steam tank 37, low-pressure steam tank regulating valve 38, and second steam ejector 39.

[0019] like Figure 1As shown, the main steam outlet of boiler 1 is connected to the steam inlet of the high-pressure cylinder 7 of the steam turbine via a pipeline. The extraction steam outlet of the high-pressure cylinder 7 is connected to the steam inlet of the high-pressure heater 16 via a pipeline. The reheat steam from the high-pressure cylinder 7 enters boiler 1 and is connected to the steam inlet of the intermediate-pressure cylinder 8 of the steam turbine. The extraction steam from the intermediate-pressure cylinder 8 is connected to the steam inlet of the deaerator 14 via a pipeline. The steam outlet of the intermediate-pressure cylinder 8 is connected to the steam inlet of the low-pressure cylinder 9 of the steam turbine via the intermediate-pressure cylinder outlet regulating valve 33. The extraction steam outlet of the low-pressure cylinder 9 is connected to the steam inlet of the low-pressure heater 13 via a pipeline. The steam outlet of the low-pressure cylinder 9 is connected to the condenser 11. The condensate outlet of the condenser 11 is connected to the condensate inlet of the low-pressure heater 13 via the condensate pump 12. The condensate outlet of the low-pressure heater 13 is connected to the deaerator 14 via the deaerator 15. The feedwater inlet of the deaerator 14 is connected to the feedwater outlet of the deaerator 14, which is connected to the feedwater inlet of the high-pressure heater 16 via a feedwater pump 15. The feedwater outlet of the high-pressure heater 16 is connected to the boiler 1 via a molten salt-feedwater heat exchanger 26 in the heat storage circuit. The bypass feedwater outlet of the deaerator 14 flows through a feedwater bypass regulating valve 17, a feedwater bypass pump 18, and a feedwater bypass heater 19, and then mixes with the feedwater from the outlet of the high-pressure heater 16. The boiler 1 is equipped with a recirculation system. The saturated water separated by the steam-water separator 2 enters the separator storage tank 3. The recirculated water from the outlet of the separator storage tank 3 is divided into two paths by a recirculation pump 4. One path passes through a recirculation regulating valve 5 and mixes with the turbine feedwater before entering the boiler 1. The high-pressure cylinder 7, the intermediate-pressure cylinder 8, and the low-pressure cylinder 9 of the turbine are coaxial and connected to the power grid via a generator 10.

[0020] like Figure 1 As shown, the molten salt at the outlet of hot tank 21 is connected to the molten salt inlet of molten salt-recirculating water heat exchanger 25 via hot tank outlet regulating valve 22 and hot tank outlet pump 23. The boiler recirculating water is connected to the working fluid inlet of molten salt-recirculating water heat exchanger 25 via recirculating water second regulating valve 6. The steam outlet of molten salt-recirculating water heat exchanger 25 is connected to the steam inlet of turbine high-pressure cylinder 7. The molten salt outlet of molten salt-recirculating water heat exchanger 25 flows through molten salt-feed water heat exchanger 26 and is connected to the molten salt inlet of cold tank 27. The molten salt outlet of cold tank 27 is connected to the molten salt inlet of steam-molten salt heat exchanger 20 via cold tank outlet regulating valve 28 and cold tank outlet pump 29. The molten salt outlet of steam-molten salt heat exchanger 20 is connected to the molten salt inlet of hot tank 21.

[0021] like Figure 1As shown, the bypass reheat steam flows through the steam-molten salt heat exchanger 20 and is collected in the high-pressure steam storage tank 35. Part of the bypass reheat steam flows through the first regulating valve 30 of the first steam ejector and enters the first steam ejector 31. The exhaust steam from the outlet of the intermediate-pressure cylinder 8 of the ejector turbine flows through the second regulating valve 32 of the first steam ejector and enters the first steam ejector 31. The working fluid from the outlet of the first steam ejector 31 enters the low-pressure cylinder 9 of the turbine. The extraction steam from the low-pressure cylinder 9 of the turbine flows through the extraction valve 34 of the low-pressure steam storage tank and is stored in the low-pressure steam storage tank 37. The steam from the outlet of the high-pressure steam storage tank 35 flows through the regulating valve 36 of the high-pressure steam storage tank and ejects the low-pressure steam from the low-pressure steam storage tank 37 through the regulating valve 38 of the low-pressure steam storage tank. The working fluid from the outlet of the second steam ejector 39 heats the feedwater in the feedwater bypass heater 19 and then returns to the deaerator 14.

[0022] The present invention provides an operation method for the deep peak-shaving system configured with a steam ejector and a thermal storage device as follows:

[0023] When the coal-fired power generation system transitions from a wet to a dry state during load increase, the first regulating valve 5 for recirculating water is closed, the second regulating valve 6 for recirculating water is opened, the reheat steam bypass regulating valve 24, the first regulating valve 30 for the first steam ejector, and the second regulating valve 32 for the first steam ejector are closed, the hot tank outlet regulating valve 22 is opened, and the cold tank outlet regulating valve 28 is closed. Hot molten salt flows through the molten salt-recirculating water heat exchanger 25 to heat the recirculating water before it is collected and fed into the main steam, increasing the steam flow rate at the inlet of the high-pressure cylinder 7 of the turbine and improving its performance. Force; close the low-pressure steam storage tank extraction valve 34, open the high-pressure steam storage tank regulating valve 36 and the low-pressure steam storage tank regulating valve 38, open the feedwater bypass regulating valve 17, the steam extraction flow of the turbine high-pressure heater decreases after the feedwater bypass, the flow of the working fluid increases, and the working capacity is improved; the temperature decreases after the feedwater bypass, and it is heated by the working fluid at the outlet of the steam ejector in the feedwater bypass heater 19, and flows into the main feedwater line, and is further heated in the molten salt-feedwater heat exchanger 26, reducing the under-enthalpy of the working fluid at the inlet of the water-cooled wall, and realizing a rapid wet-to-dry state conversion;

[0024] When the coal-fired power generation system is operating from a dry state to a wet state during load reduction, the second regulating valve 6 of the recirculating water is closed, the first regulating valve 5 of the recirculating water is opened, and the recirculating water separated by the steam-water separator 2 enters the boiler 1. The hot tank outlet regulating valve 22 is closed, the cold tank outlet regulating valve 28 is opened, and the reheat steam bypass regulating valve 24 is opened. The bypass reheat steam heats the molten salt, and at the same time, the working fluid flow of the turbine's intermediate and low-pressure cylinders is reduced to achieve rapid load reduction. The first regulating valve 30 of the first steam ejector, the second regulating valve 32 of the first steam ejector, and the turbine intermediate-pressure cylinder outlet regulating valve 33 are opened. The heated reheat steam ejects the exhaust steam from the intermediate-pressure cylinder 8. The second regulating valve 32 of the first steam ejector and the intermediate-pressure cylinder outlet regulating valve 33 are adjusted to increase the inlet pressure of the turbine low-pressure cylinder 9 and reduce the final stage humidity of the turbine low-pressure cylinder 9.

Claims

1. A deep peak-shaving system configured with a steam ejector and a thermal storage device, characterized in that, This includes coal-fired power generation systems, thermal storage circuits, and steam ejector circuits; The coal-fired power generation system includes a boiler (1), a high-pressure cylinder (7) of a steam turbine, an intermediate-pressure cylinder (8) of a steam turbine, a low-pressure cylinder (9) of a steam turbine, a generator (10), a condenser (11), a condensate pump (12), a low-pressure heater (13), a deaerator (14), a feedwater pump (15), a high-pressure heater (16), a feedwater bypass regulating valve (17), a feedwater bypass pump (18), a feedwater bypass heater (19), and an intermediate-pressure cylinder outlet regulating valve (33). The main steam outlet of the boiler (1) is connected to the steam inlet of the high-pressure cylinder (7) of the steam turbine through a pipeline, and the extraction steam outlet of the high-pressure cylinder (7) of the steam turbine is connected to the steam inlet of the high-pressure heater (16) through a pipeline. The reheat steam from the high-pressure cylinder (7) of the steam turbine enters the boiler (1) and is connected to the steam inlet of the intermediate-pressure cylinder (8) of the steam turbine. The extraction steam from the intermediate-pressure cylinder (8) of the steam turbine is connected to the steam inlet of the deaerator (14) through a pipeline. The steam outlet of the intermediate-pressure cylinder (8) of the steam turbine is connected to the steam inlet of the low-pressure cylinder (9) of the steam turbine through the intermediate-pressure cylinder outlet regulating valve (33). The extraction steam outlet of the low-pressure cylinder (9) of the steam turbine is connected to the steam inlet of the low-pressure heater (13) through a pipeline. The steam outlet of the low-pressure cylinder (9) of the steam turbine is connected to the condenser (11). The condensate outlet of the condenser (11) is connected to the condensate inlet of the low-pressure heater (13) through the condensate pump (12). The outlet of the low-pressure heater (13) is connected to the feedwater inlet of the deaerator (14), and the feedwater outlet of the deaerator (14) is connected to the feedwater inlet of the high-pressure heater (16) via a feedwater pump (15). The feedwater outlet of the high-pressure heater (16) is connected to the boiler (1) via a molten salt-feedwater heat exchanger (26) in the heat storage circuit. The bypass feedwater outlet of the deaerator (14) flows through the feedwater bypass regulating valve (17), the feedwater bypass pump (18), and the feedwater bypass heater (19) and then mixes with the feedwater from the high-pressure heater (16). The boiler (1) is equipped with a recirculation system, which includes steam and water. The separator (2), separator water tank (3), recirculation pump (4), recirculation water first regulating valve (5) and recirculation water second regulating valve (6) are used. The saturated water separated by the steam-water separator (2) enters the separator water tank (3). The recirculation water at the outlet of the separator water tank (3) is divided into two paths after passing through the recirculation pump (4). One path passes through the recirculation regulating valve (5) and mixes with the steam turbine feedwater before entering the boiler (1). The other path passes through the recirculation water second regulating valve (6) and enters the molten salt-recirculation water heat exchanger (25) of the heat storage circuit. The high-pressure cylinder (7), intermediate-pressure cylinder (8) and low-pressure cylinder (9) of the steam turbine are coaxial and connected to the power grid through the generator (10). The heat storage circuit includes a steam-molten salt heat exchanger (20), a hot tank (21), a hot tank outlet regulating valve (22), a hot tank outlet pump (23), a molten salt-recirculating water heat exchanger (25), a molten salt-feedwater heat exchanger (26), a cold tank (27), a cold tank outlet regulating valve (28), a cold tank outlet pump (29), and pipelines connecting various equipment. The molten salt at the outlet of the hot tank (21) is connected to the molten salt inlet of the molten salt-recirculating water heat exchanger (25) through the hot tank outlet regulating valve (22) and the hot tank outlet pump (23). The boiler recirculating water is connected to the second recirculating water regulating valve (6) and... The working fluid inlet of the molten salt-recirculating water heat exchanger (25) is connected, the steam outlet of the molten salt-recirculating water heat exchanger (25) is connected to the steam inlet of the high-pressure cylinder (7) of the steam turbine, the molten salt outlet of the molten salt-recirculating water heat exchanger (25) flows through the molten salt-feed water heat exchanger (26) and is connected to the molten salt inlet of the cold tank (27), the molten salt outlet of the cold tank (27) is connected to the molten salt inlet of the steam-molten salt heat exchanger (20) through the cold tank outlet regulating valve (28) and the cold tank outlet pump (29), and the molten salt outlet of the steam-molten salt heat exchanger (20) is connected to the molten salt inlet of the hot tank (21); The steam ejector circuit includes a reheat steam bypass regulating valve (24), a first steam ejector (31), a first regulating valve (30) for the first steam ejector, a second regulating valve (32) for the first steam ejector, a low-pressure steam tank extraction valve (34), a high-pressure steam tank (35), a high-pressure steam tank regulating valve (36), a low-pressure steam tank (37), a low-pressure steam tank regulating valve (38), and a second steam ejector (39). The bypass reheat steam flows through a steam-molten salt heat exchanger (20) and collects in the high-pressure steam tank (35). Part of the bypass reheat steam flows through the first regulating valve (30) of the first steam ejector and enters the first steam ejector (31). Steam from the outlet of the intermediate-pressure cylinder (8) of the steam ejector turbine flows through the second regulating valve (32) of the first steam ejector and enters the first steam ejector (31). The working medium from the outlet of the first steam ejector (31) enters the low-pressure cylinder (9) of the steam turbine. Steam extracted from the low-pressure cylinder (9) flows through the extraction valve (34) of the low-pressure storage tank and is stored in the low-pressure storage tank (37). Steam from the outlet of the high-pressure storage tank (35) flows through the regulating valve (36) of the high-pressure storage tank and ejects the low-pressure steam from the low-pressure storage tank (37) through the regulating valve (38). The working medium from the outlet of the second steam ejector (39) heats the feedwater in the feedwater bypass heater (19) and then returns to the deaerator (14).

2. The operation method of a deep peak-shaving system with a steam ejector and a thermal storage device as described in claim 1, characterized in that: When the coal-fired power generation system transitions from a wet to a dry state during load increase, the first regulating valve (5) of the recirculating water is closed, the second regulating valve (6) of the recirculating water is opened, the reheat steam bypass regulating valve (24), the first regulating valve (30) of the first steam ejector, and the second regulating valve (32) of the first steam ejector are closed, the hot tank outlet regulating valve (22) is opened, and the cold tank outlet regulating valve (28) is closed. The hot molten salt flows through the molten salt-recirculating water heat exchanger (25) to heat the recirculating water before it is collected into the main steam, increasing the... Increase the steam flow rate at the inlet of the high-pressure cylinder (7) of the steam turbine to improve its work capacity; close the extraction valve (34) of the low-pressure steam storage tank, open the regulating valve (36) of the high-pressure steam storage tank and the regulating valve (38) of the low-pressure steam storage tank, and open the feedwater bypass regulating valve (17). After the feedwater bypass, the steam extraction flow rate of the high-pressure heater of the steam turbine decreases, and the flow rate of the working fluid increases, thus improving the work capacity; after the feedwater bypass, the temperature decreases, and it is heated by the working fluid at the outlet of the steam ejector in the feedwater bypass heater (19), and flows into the main feedwater line, passing through the molten salt-feedwater exchanger. The water is further heated in the heater (26), reducing the underenthalpy of the working fluid at the inlet of the water-cooled wall and achieving a rapid transition from wet to dry state. When the coal-fired power generation system is operating at reduced load and transitioning from dry to wet state, the second regulating valve (6) of the recirculating water is closed, the first regulating valve (5) of the recirculating water is opened, and the recirculating water separated by the steam-water separator (2) enters the boiler (1). The regulating valve (22) of the hot tank outlet is closed, the regulating valve (28) of the cold tank outlet is opened, and the reheat steam bypass regulating valve (24) is opened, and the bypass reheat steam is added. Hot molten salt, while reducing the working fluid flow of the low-pressure cylinder of the steam turbine, to achieve rapid load reduction, open the first regulating valve (30) of the first steam ejector, the second regulating valve (32) of the first steam ejector, and the regulating valve (33) of the intermediate-pressure cylinder outlet, and the reheated steam ejects the exhaust steam of the intermediate-pressure cylinder (8) of the steam turbine, and adjust the second regulating valve (32) of the first steam ejector and the regulating valve (33) of the intermediate-pressure cylinder outlet to increase the inlet pressure of the low-pressure cylinder (9) of the steam turbine and reduce the final stage humidity of the low-pressure cylinder (9) of the steam turbine.

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