A peak-shaving system and method for high-temperature molten salt heat storage coupled with gas-fired combined heat and power

Abstract

The present invention relates to a peak-shaving system and method for high-temperature molten salt heat storage coupled gas-fired cogeneration, comprising a gas turbine generator set, a molten salt waste heat boiler, a molten salt heat storage device, a molten salt steam heat exchange mechanism, a steam turbine generator set and a circulating water supply pipeline, wherein the flue gas outlet of the gas turbine generator set is connected to the flue gas inlet of the molten salt waste heat boiler; the molten salt heat storage device comprises a low-temperature molten salt storage tank, a low-temperature molten salt pump, a low-temperature heater, a high-temperature heater, a high-temperature molten salt storage tank and a high-temperature molten salt pump which are connected in sequence; the molten salt steam heat exchange mechanism comprises a high-pressure superheater, a high-pressure steam drum, a medium-pressure superheater and a medium-pressure steam drum; the medium-pressure steam outlet of the medium-pressure superheater is connected to the medium and low-pressure steam inlets of the steam turbine generator set via a medium-pressure superheated steam main pipe, and the medium-pressure superheated steam main pipe is connected to industrial steam users; this system can not only regulate peak power to meet the needs of the power grid, but also greatly reduce the irreversible loss of high-temperature molten salt thermal energy and generate steam with corresponding parameters to meet the needs of residential users.

Description

Technical Field

[0001] The present invention relates to the field of thermal power flexibility technology, and in particular to a peak-shaving system and method for high-temperature molten salt heat storage coupled with gas-fired combined heat and power. Background Art

[0002] When combined cycle units participate in power peak regulation, their operating load fluctuates frequently with fluctuations in electricity demand and renewable energy sources, significantly reducing their efficiency. For example, when operating at low load, the heat consumption increases by 8% at a 60% load factor, and by 20% at a 40% load factor, compared to full load. Therefore, integrating energy storage devices into combined cycle systems is crucial to ensure that the units can operate at higher loads during power peak regulation, thereby improving the efficiency and flexibility of the overall system.

[0003] Using molten salt heat storage technology to solve the problem of insufficient power peak-shaving capacity in thermal power plants based on combined cycle units is a very promising technical application method. Among the relevant patented technologies, the main ones are the direct heating of molten salt by high-temperature flue gas for heat storage and peak-shaving, the direct heating of molten salt by electric energy for heat storage and peak-shaving, and the direct heating of molten salt by high-parameter steam for heat storage and peak-shaving. On the one hand, the direct use of high-quality energy to directly heat low-temperature molten salt into high-temperature molten salt causes serious irreversible losses due to the large heat exchange temperature difference; on the other hand, the direct use of high-temperature molten salt to produce low-parameter steam for heating also causes irreversible losses of high-quality molten salt thermal energy, and cannot produce steam of corresponding parameters for residential users, which cannot meet the needs of residential users. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the defects in the prior art of irreversible loss of high-grade molten salt thermal energy and inability to produce steam with corresponding parameters to meet the needs of steam residential users, thereby providing a peak-shaving system and method for high-temperature molten salt heat storage coupled with gas-fired cogeneration.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A high-temperature molten salt heat storage coupled with gas-fired combined heat and power peak-shaving system comprises a gas turbine generator set, a molten salt waste heat boiler, a molten salt heat storage device, a molten salt steam heat exchange mechanism, a steam turbine generator set, and a circulating water supply pipeline, wherein the flue gas outlet of the gas turbine generator set is connected to the flue gas inlet of the molten salt waste heat boiler;

[0007] The molten salt heat storage device comprises a low-temperature molten salt storage tank, a low-temperature molten salt pump, a low-temperature heater, a high-temperature heater, a high-temperature molten salt storage tank and a high-temperature molten salt pump connected in sequence, and a low-temperature molten salt bypass pipe is connected between the molten salt inlet and the molten salt outlet of the low-temperature molten salt storage tank, and a high-temperature molten salt bypass pipe is connected between the molten salt inlet of the high-temperature molten salt storage tank and the molten salt outlet of the high-temperature molten salt pump;

[0008] The molten salt steam heat exchange mechanism includes a high-pressure superheater, a high-pressure steam drum, a medium-pressure superheater and an medium-pressure steam drum; the molten salt outlet of the high-pressure superheater is connected to the molten salt inlet of the high-pressure steam drum and the molten salt inlet of the medium-pressure superheater, the molten salt inlet of the medium-pressure steam drum is connected to the molten salt outlet of the high-pressure steam drum and the molten salt outlet of the medium-pressure superheater, the molten salt inlet of the high-pressure superheater is connected to the molten salt outlet of the high-temperature molten salt pump, and the molten salt outlet of the medium-pressure steam drum is connected to the molten salt inlet of the low-temperature molten salt storage tank;

[0009] A No. 1 feed water pump is provided at the water inlet of the high-pressure drum, a No. 2 feed water pump is provided at the water inlet of the medium-pressure drum, the water outlets of the circulating water supply pipeline are both connected with the No. 1 feed water pump and the No. 2 feed water pump, the steam outlet of the high-pressure drum is connected with the steam inlet of the high-pressure superheater, the steam outlet of the medium-pressure drum is connected with the steam inlet of the medium-pressure superheater, a high-pressure superheated steam main pipe is connected between the high-pressure steam outlet of the high-pressure superheater and the high-pressure steam inlet of the steam turbine generator set, a medium-pressure superheated steam main pipe is connected between the medium-pressure steam outlet of the medium-pressure superheater and the medium and low-pressure steam inlets and outlets of the steam turbine generator set, and the medium-pressure superheated steam main pipe is connected with industrial steam users;

[0010] The flue gas outlet of the molten salt waste heat boiler is connected to a heating steam generator, the water inlet of the heating steam generator is connected to the water outlet of the circulating water supply pipeline, and the steam outlet of the heating steam generator is connected to the first station of the heating network.

[0011] Preferably, the above-mentioned circulating water supply pipeline includes a condenser, a condensate pump, a No. 3 feed water pump, a condensate storage tank, a deaerator, a No. 4 feed water pump and a feed water heater. The exhaust steam inlet of the above-mentioned condenser is connected to the exhaust port of the above-mentioned steam turbine generator set. The above-mentioned condenser, the above-mentioned condensate pump, the above-mentioned deaerator, the above-mentioned No. 4 feed water pump and the above-mentioned feed water heater are connected in sequence. The water outlets of the above-mentioned feed water heaters are connected to the water inlet of the above-mentioned No. 1 feed water pump, the water inlet of the above-mentioned No. 2 feed water pump and the water inlet of the above-mentioned heating steam generator. The water inlet of the above-mentioned deaerator is connected to the water supply pipe. The water outlet of the above-mentioned condensate storage tank is connected to the above-mentioned water supply pipe. The above-mentioned No. 3 feed water pump is connected to the above-mentioned water supply pipe.

[0012] Preferably, the water outlet of the condensate pump is also connected to the water inlet of the condensate storage tank.

[0013] Preferably, the flue gas inlet of the feedwater heater is connected to the flue gas outlet of the heating steam generator, and the flue gas outlet of the feedwater heater is connected to the outside.

[0014] Preferably, the steam outlet of the heating steam generator is communicated with the steam inlet of the deaerator.

[0015] Preferably, the gas turbine generator set includes a gas turbine compressor, a gas turbine combustor, a gas turbine turbine and a first generator, the exhaust port of the gas turbine compressor is connected to the air inlet of the gas turbine combustor, the exhaust port of the gas turbine combustor is connected to the air inlet of the gas turbine turbine, the gas turbine turbine is coaxially connected to the gas turbine compressor, the gas turbine compressor and the gas turbine turbine jointly drive the first generator to generate electricity; the exhaust port of the gas turbine turbine is connected to the flue gas inlet of the molten salt waste heat boiler.

[0016] Preferably, the above-mentioned steam turbine generator set includes a steam turbine medium- and high-pressure cylinder, a steam turbine low-pressure cylinder and a second generator, the steam inlet of the above-mentioned steam turbine medium- and high-pressure cylinder is connected to the above-mentioned high-pressure superheated steam main pipe, the steam exhaust port of the above-mentioned steam turbine medium- and high-pressure cylinder is connected to the steam inlet of the above-mentioned steam turbine low-pressure cylinder, the steam inlet of the above-mentioned steam turbine low-pressure cylinder is connected to the above-mentioned medium-pressure superheated steam main pipe, the above-mentioned steam turbine medium- and high-pressure cylinder and the above-mentioned steam turbine low-pressure cylinder are coaxially connected to the above-mentioned second generator; the steam exhaust port of the above-mentioned steam turbine low-pressure cylinder is connected to the steam inlet of the above-mentioned circulating water supply pipeline.

[0017] A method for a high-temperature molten salt heat storage coupled with gas-fired combined heat and power (CCHP) peak-shaving system, comprising: when the thermal power plant is not participating in power peak-shaving, the gas turbine generator set and the steam turbine generator set both maintain high-load operation to ensure high-efficiency operation of the thermal power plant; at this time, the molten salt heat storage device does not store or release heat, but only performs heat exchange; the heating steam generator normally provides steam to the first station of the heating network; and the medium-pressure superheated steam main pipe normally provides steam to the industrial steam users;

[0018] When the thermal power plant participates in power peak regulation and needs to reduce the grid-connected power load, the gas turbine generator set maintains high-load operation, and the grid-connected power load is reduced by reducing the operating load of the steam turbine generator set. At this time, the molten salt heat storage device not only stores heat but also participates in heat exchange, thereby reducing the grid-connected load. The heating steam generator normally provides steam to the first station of the heating network, and the medium-pressure superheated steam main pipe normally provides steam to the industrial steam users.

[0019] When the thermal power plant participates in power peak regulation and needs to increase the on-grid power load, the above-mentioned gas turbine generator set maintains high-load operation, and the on-grid power load is increased by increasing the operating load of the above-mentioned steam turbine generator set. At this time, the above-mentioned molten salt heat storage device releases heat and also participates in heat exchange, thereby increasing the on-grid power load. The above-mentioned heating steam generator normally provides steam to the above-mentioned heating network first station, and the above-mentioned medium-pressure superheated steam main pipe normally provides steam to the above-mentioned industrial steam users.

[0020] Preferably, when the thermal power plant participates in power peak regulation and needs to reduce the on-grid power load, the high-temperature molten salt from the above-mentioned molten salt waste heat boiler is divided into two paths, one path enters the above-mentioned high-temperature molten salt storage tank for heat storage, and the above-mentioned high-temperature molten salt pump does not operate, and the other path enters the above-mentioned molten salt steam heat exchange mechanism through the above-mentioned high-temperature molten salt bypass pipe, performs step heat exchange, exchanges heat with the circulating water therein, and is heated into steam. The steam enters the above-mentioned steam turbine generator set through the above-mentioned high-pressure superheated steam main pipe and the above-mentioned medium-pressure superheated steam main pipe to generate electricity. The low-temperature molten salt finally formed enters the above-mentioned low-temperature molten salt bypass pipe and merges with the low-temperature molten salt output from the above-mentioned low-temperature molten salt storage tank. After that, it is driven by the above-mentioned low-temperature molten salt pump and returns to the above-mentioned molten salt waste heat boiler again. It is then heated by the above-mentioned low-temperature heater and the above-mentioned high-temperature heater to form high-temperature molten salt, and then enters the above-mentioned high-temperature molten salt storage tank for storage and enters the above-mentioned high-pressure superheater for recycling.

[0021] Preferably, when the thermal power plant participates in power peak regulation and needs to increase the on-grid power load, the high-temperature molten salt from the above-mentioned molten salt waste heat boiler passes through the above-mentioned high-temperature molten salt bypass pipe and merges with the high-temperature molten salt from the above-mentioned high-temperature molten salt storage tank under the action of the above-mentioned high-temperature molten salt pump, and then enters the above-mentioned molten salt steam heat exchange mechanism together, performs step heat exchange, and exchanges heat with the circulating water therein to be heated into steam, thereby increasing the steam volume. The steam enters the above-mentioned steam turbine generator set through the above-mentioned high-pressure superheated steam main pipe and the above-mentioned medium-pressure superheated steam main pipe to generate electricity, and finally forms low-temperature molten salt and is divided into two paths. One path returns to the above-mentioned low-temperature molten salt storage tank for storage, and the other path passes through the above-mentioned low-temperature molten salt bypass pipe and returns to the above-mentioned molten salt waste heat boiler again under the drive of the above-mentioned low-temperature molten salt pump, and then is heated by the above-mentioned low-temperature heater and the above-mentioned high-temperature heater to form high-temperature molten salt for recycling.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] On the one hand, by using molten salt as the flue gas waste heat carrier, under the joint operation of low-temperature molten salt storage tank, low-temperature molten salt pump, low-temperature heater, high-temperature heater, high-temperature molten salt storage tank, high-temperature molten salt pump, low-temperature molten salt bypass pipe and high-temperature molten salt bypass pipe, it can overcome the defect of the existing technology that uses high-parameter steam or part of high-temperature flue gas to heat molten salt for heat storage and cannot make the operating load of the steam turbine generator set unable to drop to zero while the gas turbine generator set operates at high efficiency. It can achieve high-efficiency power peak regulation with higher peak regulation capacity; on the other hand, by reasonably arranging the high-pressure superheater, high-pressure drum, medium-pressure superheater and medium-pressure drum, the high-pressure superheater and medium-pressure drum are connected. The molten salt circulation pipeline and the steam circulation pipeline enable the molten salt to efficiently generate steam with different parameters based on energy grade tiered matching during heat exchange, which not only realizes the tiered and efficient utilization of high-temperature molten salt heat, greatly reduces the heat exchange temperature difference, greatly reduces irreversible losses, but also increases the output of high-quality steam, greatly improves the power generation capacity of the steam turbine generator set, and can produce steam with corresponding parameters to meet the needs of steam residential users. In addition, the corresponding flue gas waste heat can be used by the heating steam generator to generate saturated steam to supply the first station of the heat network for heating residents, making full use of the flue gas waste heat and being able to provide heating for most heating residential users. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 2 is a system block diagram of an embodiment of the present invention.

[0026] Description of reference numerals:

[0027] 1. Gas turbine generator set; 101. Gas turbine compressor; 102. Gas turbine combustion chamber; 103. Gas turbine turbine; 104. First generator; 2. Molten salt waste heat boiler; 3. Low-temperature molten salt storage tank; 4. Low-temperature molten salt pump; 5. Low-temperature heater; 6. High-temperature heater; 7. High-temperature molten salt storage tank; 8. High-temperature molten salt pump; 9. Low-temperature molten salt bypass pipe; 10. High-temperature molten salt bypass pipe; 11. Molten salt steam heat exchange mechanism; 111. High-pressure superheater; 112. High-pressure steam drum; 113. Medium-pressure superheater; 114. Medium-pressure steam drum; 115. Feedwater pump No. 1; 116. Feedwater pump No. 2; 12. High-pressure superheated steam main pipe; 13. Medium-pressure superheated steam main pipe; 14. Steam turbine generator set; 141. Steam turbine medium and high-pressure cylinders; 142. Steam turbine low-pressure cylinder; 143. Second generator ;15. Condensate pump;16. Feedwater pump No. 3;18. Condensate storage tank;19. Deaerator;20. Feedwater heater;21. Feedwater pump No. 4;22. Heating steam generator;23. Heat network first station;24. Industrial steam supply pipe;25. Industrial steam user;26. First valve;27. Second valve;28. Third valve;29. Fourth valve;30. Fifth valve;31. Sixth valve;32. Seventh valve;33. Eighth valve;34. Ninth valve;35. Tenth valve;36. Eleventh valve;37. Twelfth valve;38. Thirteenth valve;39. Fourteenth valve;40. Fifteenth valve;41. Sixteenth valve;42. Seventeenth valve;43. Eighteenth valve;44. Nineteenth valve;45. Twentieth valve;46. Twenty-first valve;47. Twenty-second valve;48. Condensate pipe. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0031] like Figure 1 As shown, an embodiment of the present invention provides a high-temperature molten salt heat storage coupled gas-fired combined heat and power peak-shaving system, including a gas turbine generator set 1, a molten salt waste heat boiler 2, a molten salt heat storage device, a molten salt steam heat exchange mechanism 11, a steam turbine generator set 14 and a circulating water supply pipeline.

[0032] The gas turbine generator set 1 includes a gas turbine compressor 101, a gas turbine combustor 102, a gas turbine turbine 103 and a first generator 104. The exhaust port of the gas turbine compressor 101 is connected to the air inlet of the gas turbine combustor 102, the exhaust port of the gas turbine combustor 102 is connected to the air inlet of the gas turbine turbine 103, the exhaust port of the gas turbine turbine 103 is connected to the flue gas inlet of the molten salt waste heat boiler 2, the gas turbine turbine 103 is coaxially connected to the gas turbine compressor 101, the gas turbine compressor 101 and the gas turbine turbine 103 drive the first generator 104 to generate electricity; the flue gas outlet of the gas turbine generator set 1 is connected to the flue gas inlet of the molten salt waste heat boiler 2 via a flue gas duct.

[0033] The steam turbine generator set 14 includes a steam turbine medium- and high-pressure cylinder 141, a steam turbine low-pressure cylinder 142 and a second generator 143. The exhaust port of the steam turbine medium- and high-pressure cylinder 141 is connected to the steam inlet of the steam turbine low-pressure cylinder 142 through a medium- and low-pressure connecting pipe, and a twenty-second valve 47 is installed on the medium- and low-pressure connecting pipe. The steam turbine medium- and high-pressure cylinder 141 and the steam turbine low-pressure cylinder 142 are coaxially connected to the second generator 143, and simultaneously work to drive the second generator 143 to generate electricity.

[0034] The molten salt heat storage device includes a low-temperature molten salt storage tank 3, a low-temperature molten salt pump 4, a low-temperature heater 5, a high-temperature heater 6, a high-temperature molten salt storage tank 7 and a high-temperature molten salt pump 8. The molten salt outlet of the low-temperature molten salt storage tank 3 is connected to a first pipe, a first valve 26 is provided on the first pipe, a second pipe is connected between the first pipe and the low-temperature heater 5, the low-temperature molten salt pump 4 is provided at the molten salt inlet of the low-temperature heater 5 and the low-temperature molten salt pump 4 is provided on the second pipe, the low-temperature heater 5 and the high-temperature heater 6 are sequentially installed in the molten salt waste heat boiler 2 along the direction of flue gas flow, the low-temperature heater 5 and the high-temperature heater 6 are connected, and the molten salt outlet of the high-temperature heater 6 is connected to the third pipe. The molten salt inlet of the high-temperature molten salt storage tank 7 is connected with a fourth pipe, the fourth pipe is connected with a second valve 27, the third pipe is connected with the fourth pipe, the molten salt outlet of the high-temperature molten salt storage tank 7 is connected with a fifth pipe, the fifth pipe is connected with a third valve 28 and the high-temperature molten salt pump 8 is located on the fifth pipe, a high-temperature molten salt bypass pipe 10 is connected between the third pipe and the fifth pipe, the high-temperature molten salt bypass pipe 10 is connected with a fourth valve 29, the fifth pipe is connected with the high-temperature molten salt inlet of the molten salt steam heat exchange mechanism 11, the low-temperature molten salt outlet of the molten salt steam heat exchange mechanism 11 is connected with the molten salt inlet of the low-temperature molten salt storage tank 3 through a sixth pipe, the sixth pipe is connected with a fifth valve 30, the sixth pipe and the first The pipes are connected with a low-temperature molten salt bypass pipe 9, and the low-temperature molten salt bypass pipe 9 is connected with a sixth valve 31; when the circulating heat storage and heat exchange circuit is in use, four closed loops can be formed in the system according to the usage, as follows, loop one: the fourth valve 29, the sixth valve 31 and the low-temperature molten salt pump 4 are opened, the low-temperature heater 5, the high-temperature heater 6, the high-temperature molten salt bypass pipe 10, the molten salt steam heat exchange mechanism 11 and the low-temperature molten salt bypass pipe 9 form a closed loop, the low-temperature molten salt storage tank 3 and the high-temperature molten salt storage tank 7 are not used. In this loop, the molten salt heat storage device only participates in the heat exchange process, does not participate in heat storage and heat release, and transports the waste heat of the flue gas into the molten salt steam exchange The heating circulating water in the heat mechanism 11 is steam; loop 2: the first valve 26, the second valve 27, the fourth valve 29, the sixth valve 31 and the low-temperature molten salt pump 4 are opened, the low-temperature heater 5, the high-temperature heater 6, the high-temperature molten salt bypass pipe 10, the molten salt steam heat exchange mechanism 11 and the low-temperature molten salt bypass pipe 9 form a closed loop, and the low-temperature molten salt storage tank 3 and the high-temperature molten salt storage tank 7 are used. In this loop, the molten salt heat storage device participates in the heat exchange process and also participates in heat storage. Part of the molten salt transports the waste heat of the flue gas into the molten salt steam heat exchange mechanism 11 to heat the circulating water into steam, and part of the molten salt that transports the waste heat of the flue gas enters the high-temperature molten salt storage tank 7 for storage;Loop three: the third valve 28, the fourth valve 29, the fifth valve 30, the sixth valve 31, the low-temperature molten salt pump 4 and the high-temperature molten salt pump 8 are opened, the low-temperature heater 5, the high-temperature heater 6, the high-temperature molten salt bypass pipe 10, the molten salt steam heat exchange mechanism 11 and the low-temperature molten salt bypass pipe 9 form a closed loop, and the low-temperature molten salt storage tank 3 and the high-temperature molten salt storage tank 7 are used. In this loop, the molten salt heat storage device participates in the heat exchange process and also participates in heat release. Part of the molten salt transports the waste heat of the flue gas into the molten salt steam heat exchange mechanism 11 to heat the circulating water into steam, and part of the high-temperature molten salt stored in the high-temperature molten salt storage tank 7 is transported out by the high-temperature molten salt pump 8 to release heat, and the circulating water is heated to steam to replenish the heat in the system. The low-temperature molten salt after heat release enters the low-temperature molten salt storage tank 3 for storage; Loop four: the first valve 26, the second valve 27 and the low-temperature When the molten salt pump 4 is turned on, the low-temperature molten salt storage tank 3, the low-temperature heater 5, the high-temperature heater 6, and the high-temperature molten salt storage tank 7 form a one-way loop. The molten salt only participates in the heat storage process. At this time, the steam turbine generator set 14 is not running, and only the gas turbine generator set 1 is running, performing deep peak-shaving of the power grid. In summary, the combined operation of the low-temperature molten salt storage tank 3, the low-temperature molten salt pump 4, the low-temperature heater 5, the high-temperature heater 6, the high-temperature molten salt storage tank 7, the high-temperature molten salt pump 8, the low-temperature molten salt bypass pipe 9, and the high-temperature molten salt bypass pipe 10 can overcome the drawback of the prior art of using high-parameter steam or part of the high-temperature flue gas to heat the molten salt for heat storage, which makes it impossible to reduce the operating load of the steam turbine generator set 14 to zero while the gas turbine generator set 1 is operating efficiently. This can achieve highly efficient power peak-shaving with higher peak-shaving capacity.

[0035] The molten salt steam heat exchange mechanism 11 includes a high-pressure superheater 111, a high-pressure steam drum 112, a medium-pressure superheater 113 and a medium-pressure steam drum 114; the molten salt inlet of the high-pressure superheater 111 is connected to the seventh pipe, the fifth pipe and the high-temperature molten salt bypass pipe 10 are both connected to the seventh pipe, the molten salt outlet of the high-pressure superheater 111 is connected to the eighth pipe, the eighth pipe is connected to the molten salt inlet of the high-pressure steam drum 112 via the ninth pipe, the ninth pipe is connected to the seventh valve 32, the molten salt outlet of the high-pressure steam drum 112 is connected to the tenth pipe, the tenth pipe is connected to the eighth valve 33, the eighth pipe is connected to the molten salt inlet of the medium-pressure superheater 113 via the eleventh pipe, the eleventh pipe is connected to the ninth valve 34, the molten salt outlet of the medium-pressure superheater 113 is connected to the twelfth pipe. The twelfth pipe is connected to the tenth valve 35, the molten salt inlet of the medium-pressure drum 114 is connected to the thirteenth pipe, the tenth pipe and the twelfth pipe are both connected to the thirteenth pipe, and the molten salt outlet of the medium-pressure drum 114 is connected to the low-temperature molten salt storage tank 3 through the sixth pipe; the water inlet of the high-pressure drum 112 is connected to the circulating water supply pipeline with a fourteenth pipe, and the fourteenth pipe is connected to the No. 1 feed water pump 115 and the eleventh valve 36 in sequence. The high-pressure drum 112 heats the water therein into saturated steam, and the steam outlet of the high-pressure drum 112 is connected to the steam inlet of the high-pressure superheater 111 through the fifteenth pipe. The steam outlet of the high-pressure superheater 111 is connected to the steam inlet of the medium and high-pressure cylinder 141 of the steam turbine through the high-pressure superheated steam main pipe 12, and the high-pressure The superheated steam main pipe 12 is connected with a twelfth valve 37; the water inlet of the medium-pressure drum 114 is connected with a sixteenth pipe connected with the circulating water supply pipeline, the sixteenth pipe is connected with the No. 2 feed water pump 116 and the thirteenth valve 38 in sequence, the medium-pressure drum 114 heats the water therein into saturated steam, the steam outlet of the medium-pressure drum 114 is connected with the steam inlet of the medium-pressure superheater 113 via a seventeenth pipe, the steam outlet of the medium-pressure superheater 113 is connected with the steam inlet of the low-pressure cylinder 142 of the steam turbine via the medium-pressure superheated steam main pipe 13, the medium-pressure superheated steam main pipe 13 is connected with a fourteenth valve 39, the fourteenth valve 39 is located at the steam inlet of the low-pressure cylinder 142 of the steam turbine; by reasonably arranging the high-pressure superheater 111, The molten salt circulation pipeline and the steam circulation pipeline between the high-pressure steam drum 112, the medium-pressure superheater 113 and the medium-pressure steam drum 114 allow the molten salt to flow from the high-pressure superheater 111, then enter the high-pressure steam drum 112 and the medium-pressure superheater 113 in two ways, and then converge into the medium-pressure steam drum 114. After three heat exchanges, the heated circulating water is converted into high-pressure steam and medium-pressure steam, which fully enables the molten salt to exchange heat with water or steam, and can efficiently generate steam with different parameters based on energy grade tiered matching, thereby realizing the tiered and efficient utilization of high-temperature molten salt heat, greatly reducing the heat exchange temperature difference, greatly reducing irreversible losses, and increasing the output of high-quality steam, thereby greatly improving the power generation capacity of the steam turbine generator set 14.

[0036] Specifically, the medium-pressure superheated steam main pipe 13 is connected to the industrial steam supply pipe 24, the industrial steam supply pipe 24 is connected to the industrial steam user 25, and the fifteenth valve 40 is connected to the industrial steam supply pipe 24. The steam in the medium-pressure superheated steam main pipe 13 is discharged from the medium-pressure superheater 113, and the molten salt circulation pipeline and the medium-pressure steam circulation pipeline between the high-pressure superheater 111, the high-pressure steam drum 112, the medium-pressure superheater 113 and the medium-pressure steam drum 114 are set, so that the medium-pressure superheater 113 finally produces medium-pressure superheated steam with corresponding parameters, which is supplied to the industrial steam user 25 for use to meet the needs of the industrial steam user 25; specifically, when the power grid is performing deep peak regulation, the steam turbine generator set 14 is not running. At this time, the heating steam generator 22 can provide steam for the industrial steam user 25, and the flue gas temperature entering the heating steam generator 22 is increased to increase the steam parameters output by the heating steam generator 22.

[0037] Specifically, the circulating water supply pipeline includes a condenser 15, a condensate pump 16, a No. 3 feed water pump 17, a condensate storage tank 18, a deaerator 19, a No. 4 feed water pump 21 and a feed water heater 20. The exhaust steam inlet of the condenser 15 is connected to the exhaust port of the low-pressure cylinder 142 of the steam turbine, and the water outlet of the condenser 15 is connected to the water inlet of the condensate pump 16. A condensate pipe 48 is connected between the condensate pump 16 and the deaerator 19. The condensate pipe 48 is connected to the sixteenth valve 41. The deaerator 19 and the feed water heater 2 0 is connected to the 18th pipe, the 4th water supply pump 21 is connected to the 18th pipe, the outlet of the water heater 20 is connected to the 19th pipe, the 19th pipe is connected to the 1st water supply pump 115 and the 2nd water supply pump 116, the condensate pipe 48 is connected to the water supply pipe, the water supply pipe is connected to the outlet of the condensate storage tank 18, the 3rd water supply pump 17 is connected to the water supply pipe, and the water supply pipe is connected to the 17th valve 42, and the condensate pipe 48 between the water inlet of the condensate storage tank 18 and the outlet of the condensate pump 16 The twentieth pipe is connected to the eighteenth valve 43, and the sixteenth valve 41 is located on the condensate pipe 48 in parallel with the condensate storage tank 18; the condensate storage tank 18 plays the role of water storage and water replenishment. First, when the steam turbine generator set 14 is operating normally, it is used to supplement the water required for heating the industrial steam user 25. Second, when the steam turbine generator set 14 reduces the operating load, the steam required is reduced, and the excess water is generated, which is greater than the water required for heating the industrial steam user 25. , the condensate storage tank 18 is used to store the excess feed water; when the steam turbine generator set 14 reduces the operating load and the steam demand is reduced, resulting in excess feed water, which is less than the feed water required for heating the industrial steam user 25, the condensate storage tank 18 is used to supplement the missing feed water; thirdly, when the steam turbine generator set 14 increases the operating load and the steam demand increases, the condensate storage tank 18 is used to supplement water for the deaerator 19 to supplement the feed water required for heating the industrial steam user 25.

[0038] Specifically, the flue gas outlet of the molten salt waste heat boiler 2 is connected to the heating steam generator 22, the water inlet of the heating steam generator 22 is connected to the nineteenth pipe via the twenty-first pipe, the twenty-first pipe is connected to the nineteenth valve 44, the steam outlet of the heating steam generator 22 is connected to the twenty-second pipe, the twenty-second pipe is connected to the heating network first station 23, and the twenty-second pipe is connected to the twentieth valve 45. The remaining flue gas waste heat of the molten salt waste heat boiler 2 heats the heating steam generator 22, and heats the water inside into saturated low-pressure steam, thereby supplying it to the heating network first station 23, and then supplies it to general heating residential users through the heating network first station 23, which can meet the heating needs of general residential users; and the twenty-second pipe is also connected to the steam inlet of the deaerator 19 via the twenty-third pipe, and the twenty-third pipe is connected to the twenty-first valve 46, which supplies steam to the deaerator 19 and makes full use of the flue gas waste heat.

[0039] In summary, a method for a peak-shaving system using high-temperature molten salt heat storage coupled with gas-fired combined heat and power generation includes:

[0040] When the thermal power plant does not participate in power peak regulation, the gas turbine generator set 1 and the steam turbine generator set 14 both maintain high-load operation to ensure high-efficiency operation of the thermal power plant, and the molten salt heat storage device does not store or release heat. The high-temperature flue gas from the gas turbine 103 heats the molten salt and is all used to heat the circulating water to produce steam, and then enters the steam turbine generator set 14 to perform work and supply heat to the outside. At this time: operating loop 1, the fourth valve 29, the sixth valve 31 and the low-temperature molten salt pump 4 are opened, the molten salt low-temperature heater 5, the molten salt high-temperature heater 6, the high-temperature molten salt bypass pipe 10, the molten salt steam heat exchange mechanism 11 and the low-temperature molten salt bypass pipe 9 form a closed loop, and the low-temperature molten salt The storage tank 3 and the high-temperature molten salt storage tank 7 are not used. Specifically, the seventh valve 32, the eighth valve 33, the ninth valve 34 and the tenth valve 35 are opened at the same time. The high-temperature molten salt from the high-temperature heater 6 first enters the high-pressure superheater 111 for the first stage cooling, and then enters the high-pressure steam drum 112 and the medium-pressure superheater 113 in two ways for the second stage cooling. The high-temperature molten salt cooled by the high-pressure steam drum 112 and the medium-pressure superheater 113 is merged and then enters the medium-pressure steam drum 114 for the third stage cooling. Finally, low-temperature molten salt is formed and returned to the molten salt waste heat boiler 2. It is heated by the low-temperature heater 5 and the high-temperature heater 6 in turn to form high-temperature molten salt for reuse.

[0041] At the same time, the eleventh valve 36, the twelfth valve 37, the thirteenth valve 38, the fourteenth valve 39 and the sixteenth valve 41 are opened. The high-temperature feed water from the feed water heater 20 is transported by the No. 1 feed water pump 115 to the high-pressure drum 112 to be heated to form high-pressure saturated steam. The high-pressure saturated steam then enters the high-pressure superheater 111 to be further heated to form high-pressure superheated steam. The high-pressure superheated steam then enters the high-pressure cylinder 141 and the low-pressure cylinder 142 of the steam turbine in turn through the high-pressure superheated steam main pipe 12 to perform work, thereby driving the second generator 143 to generate electricity. The high-temperature feed water from the feed water heater 20 is transported by the No. 2 feed water pump 115 to the high-pressure drum 112 to be heated to form high-pressure saturated steam. The high-pressure saturated steam then enters the high-pressure superheated steam main pipe 12 to enter the high-pressure cylinder 141 and the low-pressure cylinder 142 of the steam turbine in turn to perform work, thereby driving the second generator 143 to generate electricity. The feedwater pump 116 delivers steam to the medium-pressure drum 114 to be heated to form medium-pressure saturated steam, and the medium-pressure saturated steam then enters the medium-pressure superheater 113 to be further heated to form medium-pressure superheated steam, and then the medium-pressure superheated steam enters the low-pressure cylinder 142 of the steam turbine through the medium-pressure superheated steam main pipe 13 to perform work, thereby driving the second generator 143 to generate electricity, and the exhaust steam discharged after the steam turbine generator set 14 performs work enters the condenser 15 to condense into condensate, and then is delivered to the deaerator 19 for heating by the condensate pump 16, and then is delivered to the feedwater heater 20 by the No. 4 feedwater pump 21 for further heating and recycling.

[0042] At the same time, the fifteenth valve 40, the nineteenth valve 44, the twentieth valve 45 and the twenty-first valve 46 are opened, and the high-temperature feed water from the feed water heater 20 is also transported to the heating steam generator 22 for heating to form steam, and then enters the heating network first station 23 and the deaerator 19 respectively, to provide heating to residents and heat the condensate from the condenser 15 respectively. The medium-pressure superheated steam output by the medium-pressure superheater 113 is also transported to the industrial steam user 25 through the industrial steam supply pipe 24 for external heating; at the same time, the seventeenth valve 42 needs to be opened, and the condensate storage tank 18 is used to replenish water for the deaerator 19, which is used to supplement the water supply required for heating the industrial steam user 25.

[0043] When the thermal power plant participates in power peak regulation and needs to reduce the on-grid power load, the gas turbine generator set 1 still maintains high-load operation, and the operating load of the steam turbine generator set 14 is reduced to reduce the on-grid power load, thereby causing the excess high-temperature molten salt output by the molten salt waste heat boiler 2 to be stored in the molten salt heat storage device. At this time: operating loop two, the first valve 26, the second valve 27, the fourth valve 29, the sixth valve 31 and the low-temperature molten salt pump 4 are opened, the low-temperature heater 5, the high-temperature heater 6, the high-temperature molten salt bypass pipe 10, the molten salt steam heat exchange mechanism 11 and the low-temperature molten salt bypass pipe 9 form a closed loop, and the low-temperature molten salt storage tank 3 and the high-temperature molten salt storage tank 7 are used. Specifically, the seventh valve 32, the eighth valve 33, the ninth valve 34 and the tenth valve 35 are opened at the same time, and the high-temperature molten salt from the high-temperature heater 6 is divided into two paths, one path enters the high-temperature molten salt storage tank 7 for heat storage. , thereby reducing the amount of high-temperature molten salt transported to the molten salt steam heat exchange mechanism 11 to reduce the amount of superheated steam transported to the steam turbine generator set 14 by the molten salt steam heat exchange mechanism 11, thereby reducing the operating load of the steam turbine generator set 14, and the other path enters the high-pressure superheater 111 for the first stage cooling, and then is divided into two paths to enter the high-pressure steam drum 112 and the medium-pressure superheater 113 for the second stage cooling. The high-temperature molten salt cooled by the high-pressure steam drum 112 and the medium-pressure superheater 113 is merged and then enters the medium-pressure steam drum 114 for the third stage cooling, and finally forms low-temperature molten salt and merges with the low-temperature molten salt output from the low-temperature molten salt storage tank 3 and then returns to the molten salt waste heat boiler 2, and is heated by the low-temperature heater 5 and the high-temperature heater 6 in turn to form high-temperature molten salt, which enters the high-temperature molten salt storage tank 7 for storage and enters the high-pressure superheater 111 for recycling.

[0044] At the same time, open the eleventh valve 36, the twelfth valve 37, the thirteenth valve 38, the fourteenth valve 39 and the sixteenth valve 41. The high-temperature feed water from the feed water heater 20 is transported by the No. 1 feed water pump 115 to the high-pressure drum 112 to be heated to form high-pressure saturated steam. The high-pressure saturated steam then enters the high-pressure superheater 111 to be further heated to form high-pressure superheated steam. Then, the high-pressure superheated steam enters the high-pressure cylinder 141 and the low-pressure cylinder 142 of the steam turbine in turn through the high-pressure superheated steam main pipe 12 to perform work, thereby driving the second generator 143 to generate electricity. The high-temperature feed water from the feed water heater 20 is transported by the No. 3 feed water pump 17 to the medium-pressure drum 114 to be heated. Medium-pressure saturated steam is formed, and the medium-pressure saturated steam enters the medium-pressure superheater 113 to be further heated to form medium-pressure superheated steam. The medium-pressure superheated steam then enters the low-pressure cylinder 142 of the steam turbine through the medium-pressure superheated steam main pipe 13 to perform work, thereby driving the second generator 143 to generate electricity. At this time, the steam flow entering the steam turbine generator set 14 is reduced, thereby reducing the operating load of the steam turbine generator set 14. The exhaust steam formed after the steam turbine generator set 14 performs work enters the condenser 15 for condensation. After the condensate is formed, it is transported to the deaerator 19 by the condensate pump 16 for heating, and then transported to the feedwater heater 20 by the No. 4 feedwater pump 21 for further heating.

[0045] At the same time, the fifteenth valve 40, the nineteenth valve 44, the twentieth valve 45 and the twenty-first valve 46 are opened, and the high-temperature feed water from the feed water heater 20 is also transported to the heating steam generator 22 for heating to form steam, and then enters the heating network first station 23 and the deaerator 19 respectively, to provide heating to residents and heat the condensate from the condenser 15 respectively. The medium-pressure superheated steam output by the medium-pressure superheater 113 is also transported to the industrial steam user 25 through the industrial steam supply pipe 24 for external heating.

[0046] Specifically, when the steam turbine generator set 14 reduces its operating load and the amount of steam required is reduced, resulting in excess water supply, which is greater than the amount of water required for heating the industrial steam users 25, the eighteenth valve 43 is opened, and the excess water supply is stored in the condensate storage tank 18; when the steam turbine generator set 14 reduces its operating load and the amount of steam required is reduced, resulting in excess water supply, which is less than the amount of water required for heating the industrial steam users 25, the seventeenth valve 42 is opened, and the condensate storage tank 18 is used to supplement the missing water supply.

[0047] When the thermal power plant participates in power peak regulation and needs to increase the on-grid power load, the gas turbine generator set 1 and the steam turbine generator set 14 both maintain high-load operation, and release heat through the molten salt heat storage device to continuously increase the operating load of the steam turbine generator set 14, thereby increasing the on-grid power load. At this time: operation loop three, the third valve 28, the fourth valve 29, the fifth valve 30, the sixth valve 31, the low-temperature molten salt pump 4 and the high-temperature molten salt pump 8 are opened, the molten salt low-temperature heater 5, the molten salt high-temperature heater 6, the high-temperature molten salt bypass pipe 10, the molten salt steam heat exchange mechanism 11 and the low-temperature molten salt bypass pipe 9 form a closed loop, and the low-temperature molten salt storage tank 3 and the high-temperature molten salt storage tank 7 are used. Specifically, the seventh valve 32, the eighth valve 33, the ninth valve 34 and the tenth valve 35 are opened at the same time, and the high-temperature molten salt from the high-temperature heater 6 and the high-temperature molten salt from the high-temperature molten salt storage tank 7 merge and enter The high-pressure superheater 111 performs the first stage cooling, thereby releasing heat through the molten salt heat storage device to increase the amount of high-temperature molten salt transported to the molten salt steam heat exchange mechanism 11, thereby increasing the amount of superheated steam transported to the steam turbine generator set 14 by the molten salt steam heat exchange mechanism 11, thereby further increasing the operating load of the steam turbine generator set 14. The high-temperature molten salt after cooling by the high-pressure superheater 111 is divided into two paths and enters the high-pressure steam drum 112 and the medium-pressure superheater 113 respectively for the second stage cooling. The high-temperature molten salt after cooling by the high-pressure steam drum 112 and the medium-pressure superheater 113 is merged and then enters the medium-pressure steam drum 114 for the third stage cooling. Finally, the low-temperature molten salt is formed into two paths, one path returns to the low-temperature molten salt storage tank 3 for storage, and the other path returns to the molten salt waste heat boiler 2, and is heated by the low-temperature heater 5 and the high-temperature heater 6 in turn to form high-temperature molten salt for reuse.

[0048] At the same time, the eleventh valve 36, the twelfth valve 37, the thirteenth valve 38, the fourteenth valve 39 and the sixteenth valve 41 are opened. The high-temperature feed water from the feed water heater 20 is transported by the No. 1 feed water pump 115 to the high-pressure drum 112 to be heated to form high-pressure saturated steam. The high-pressure saturated steam then enters the high-pressure superheater 111 to be further heated to form high-pressure superheated steam. The high-pressure superheated steam then enters the medium- and high-pressure cylinders 141 and the low-pressure cylinder 142 of the steam turbine in turn through the high-pressure superheated steam main pipe 12 to perform work, thereby driving the second generator 143 to generate electricity. The high-temperature feed water from the feed water heater 20 is transported by the No. 2 feed water pump 116 to the medium-pressure drum 114 to be heated. Then medium-pressure saturated steam is formed, and the medium-pressure saturated steam enters the medium-pressure superheater 113 to be further heated to form medium-pressure superheated steam. Then the medium-pressure superheated steam enters the low-pressure cylinder 142 of the steam turbine through the medium-pressure superheated steam main pipe 13 to perform work, so as to drive the second generator 143 to generate electricity. At this time, the steam flow entering the steam turbine generator set 14 increases, thereby increasing the operating load of the steam turbine generator set 14. The exhaust steam formed after the steam turbine generator set 14 performs work enters the condenser 15 for condensation. After the condensate is formed, it is transported to the deaerator 19 by the condensate pump 16 for heating, and then transported to the feed water heater 20 by the No. 4 feed water pump 21 for further heating.

[0049] At the same time, the fifteenth valve 40, the nineteenth valve 44, the twentieth valve 45 and the twenty-first valve 46 are opened, and the high-temperature feed water from the feed water heater 20 is also transported to the heating steam generator 22 for heating to form steam, and then enters the heating network first station 23 and the deaerator 19 respectively, to provide heating to residents and heat the condensate from the condenser 15 respectively. The medium-pressure superheated steam output by the medium-pressure superheater 113 is also transported to the industrial steam user 25 through the industrial steam supply pipe 24 for external heating.

[0050] At the same time, the seventeenth valve 42 is opened, and the condensate storage tank 18 is used to replenish water for the deaerator 19, and at the same time, the water supply required for heating for the industrial steam user 25 and the water supply required for the increase in steam demand due to the increase in operating load of the steam turbine generator set 14.

[0051] The above embodiments are only preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the present invention fall within the scope of protection required by the present invention.

Claims

1. A high-temperature molten salt heat storage coupled with gas-fired combined heat and power peak shaving system, characterized in that: It includes a gas turbine generator set, a molten salt waste heat boiler, a molten salt heat storage device, a molten salt steam heat exchange mechanism, a steam turbine generator set and a circulating water supply pipeline, wherein the flue gas outlet of the gas turbine generator set is connected to the flue gas inlet of the molten salt waste heat boiler; The molten salt heat storage device includes a low-temperature molten salt storage tank, a low-temperature molten salt pump, a low-temperature heater, a high-temperature heater, a high-temperature molten salt storage tank and a high-temperature molten salt pump that are connected in sequence, and a low-temperature molten salt bypass pipe is connected between the molten salt inlet and the molten salt outlet of the low-temperature molten salt storage tank, and a high-temperature molten salt bypass pipe is connected between the molten salt inlet of the high-temperature molten salt storage tank and the molten salt outlet of the high-temperature molten salt pump; The molten salt steam heat exchange mechanism includes a high-pressure superheater, a high-pressure steam drum, a medium-pressure superheater and an medium-pressure steam drum; the molten salt outlet of the high-pressure superheater is connected to the molten salt inlet of the high-pressure steam drum and the molten salt inlet of the medium-pressure superheater, the molten salt inlet of the medium-pressure steam drum is connected to the molten salt outlet of the high-pressure steam drum and the molten salt outlet of the medium-pressure superheater, the molten salt inlet of the high-pressure superheater is connected to the molten salt outlet of the high-temperature molten salt pump, and the molten salt outlet of the medium-pressure steam drum is connected to the molten salt inlet of the low-temperature molten salt storage tank; A No. 1 feed water pump is provided at the water inlet of the high-pressure steam drum, a No. 2 feed water pump is provided at the water inlet of the medium-pressure steam drum, the water outlets of the circulating water supply pipeline are both in communication with the No. 1 feed water pump and the No. 2 feed water pump, the steam outlet of the high-pressure steam drum is in communication with the steam inlet of the high-pressure superheater, the steam outlet of the medium-pressure steam drum is in communication with the steam inlet of the medium-pressure superheater, a high-pressure superheated steam main pipe is in communication between the high-pressure steam outlet of the high-pressure superheater and the high-pressure steam inlet of the steam turbine generator set, a medium-pressure superheated steam main pipe is in communication between the medium-pressure steam outlet of the medium-pressure superheater and the medium and low-pressure steam inlets of the steam turbine generator set, and the medium-pressure superheated steam main pipe is in communication with industrial steam users; The flue gas outlet of the molten salt waste heat boiler is connected to a heating steam generator, the water inlet of the heating steam generator is connected to the water outlet of the circulating water supply pipeline, and the steam outlet of the heating steam generator is connected to the first station of the heating network.

2. The peak shaving system according to claim 1, characterized in that: The circulating water supply pipeline includes a condenser, a condensate pump, a No. 3 feed water pump, a condensate storage tank, a deaerator, a No. 4 feed water pump and a feed water heater. The exhaust steam inlet of the condenser is connected to the exhaust port of the steam turbine generator set. The condenser, the condensate pump, the deaerator, the No. 4 feed water pump and the feed water heater are connected in sequence. The water outlet of the feed water heater is connected to the water inlet of the No. 1 feed water pump, the water inlet of the No. 2 feed water pump and the water inlet of the heating steam generator. The water inlet of the deaerator is also connected to the water supply pipe. The water outlet of the condensate storage tank is connected to the water supply pipe. The No. 3 feed water pump is connected to the water supply pipe.

3. The peak shaving system according to claim 2, characterized in that: The water outlet of the condensate pump is also communicated with the water inlet of the condensate storage tank.

4. The peak shaving system according to claim 3, characterized in that: The flue gas inlet of the feedwater heater is connected to the flue gas outlet of the heating steam generator, and the flue gas outlet of the feedwater heater is connected to the outside.

5. The peak shaving system according to claim 2, characterized in that: The steam outlet of the heating steam generator is communicated with the steam inlet of the deaerator.

6. The peak shaving system according to claim 1, characterized in that: The gas turbine generator set includes a gas turbine compressor, a gas turbine combustion chamber, a gas turbine turbine and a first generator. The exhaust port of the gas turbine compressor is connected to the air inlet of the gas turbine combustion chamber, the exhaust port of the gas turbine combustion chamber is connected to the air inlet of the gas turbine turbine, the gas turbine turbine is coaxially connected to the gas turbine compressor, the gas turbine compressor and the gas turbine turbine jointly drive the first generator to generate electricity; the exhaust port of the gas turbine turbine is connected to the flue gas inlet of the molten salt waste heat boiler.

7. The peak shaving system according to claim 1, characterized in that: The steam turbine generator set includes a steam turbine medium- and high-pressure cylinder, a steam turbine low-pressure cylinder and a second generator. The steam inlet of the steam turbine medium- and high-pressure cylinder is connected to the high-pressure superheated steam main pipe, the steam exhaust port of the steam turbine medium- and high-pressure cylinder is connected to the steam inlet of the steam turbine low-pressure cylinder, the steam inlet of the steam turbine low-pressure cylinder is connected to the medium-pressure superheated steam main pipe, the steam turbine medium- and high-pressure cylinder and the steam turbine low-pressure cylinder are coaxially connected to the second generator; the steam exhaust port of the steam turbine low-pressure cylinder is connected to the steam inlet of the circulating water supply pipeline.

8. A method for a peak-shaving system of high-temperature molten salt heat storage coupled with gas-fired combined heat and power according to any one of claims 1 to 7, characterized in that: include: When the thermal power plant is not involved in power peak regulation, the gas turbine generator set and the steam turbine generator set both maintain high-load operation to ensure high-efficiency operation of the thermal power plant. At this time, the molten salt heat storage device does not store or release heat, but only performs heat exchange. The heating steam generator normally provides steam to the first station of the heating network, and the medium-pressure superheated steam main pipe normally provides steam to the industrial steam users. When the thermal power plant participates in power peak regulation and needs to reduce the grid-connected power load, the gas turbine generator set maintains high-load operation, and the grid-connected power load is reduced by reducing the operating load of the steam turbine generator set. At this time, the molten salt heat storage device not only stores heat but also participates in heat exchange, thereby reducing the grid-connected load. The heating steam generator normally provides steam to the first station of the heating network, and the medium-pressure superheated steam main pipe normally provides steam to the industrial steam users. When the thermal power plant participates in power peak regulation and needs to increase the on-grid power load, the gas turbine generator set maintains high-load operation, and the on-grid power load is increased by increasing the operating load of the steam turbine generator set. At this time, the molten salt heat storage device releases heat and also participates in heat exchange, thereby increasing the on-grid power load. The heating steam generator normally provides steam to the first station of the heating network, and the medium-pressure superheated steam main pipe normally provides steam to the industrial steam users.

9. The peak shaving system method according to claim 8, characterized in that: When the thermal power plant participates in power peak regulation and needs to reduce the on-grid power load, the high-temperature molten salt from the molten salt waste heat boiler is divided into two paths. One path enters the high-temperature molten salt storage tank for heat storage, and the high-temperature molten salt pump does not operate. The other path enters the molten salt steam heat exchange mechanism through the high-temperature molten salt bypass pipe, performs step heat exchange, exchanges heat with the circulating water therein, and is heated into steam, thereby reducing the steam amount. The steam enters the steam turbine generator set through the high-pressure superheated steam main pipe and the medium-pressure superheated steam main pipe to generate electricity. The low-temperature molten salt finally formed enters the low-temperature molten salt bypass pipe and merges with the low-temperature molten salt output from the low-temperature molten salt storage tank. After that, it is driven by the low-temperature molten salt pump and returns to the molten salt waste heat boiler again. It is then heated by the low-temperature heater and the high-temperature heater to form high-temperature molten salt, and then enters the high-temperature molten salt storage tank for storage and enters the high-pressure superheater for recycling.

10. The peak shaving system method according to claim 8, characterized in that: When the thermal power plant participates in power peak regulation and needs to increase the on-grid power load, the high-temperature molten salt from the molten salt waste heat boiler passes through the high-temperature molten salt bypass pipe and merges with the high-temperature molten salt from the high-temperature molten salt storage tank under the action of the high-temperature molten salt pump, and then enters the molten salt steam heat exchange mechanism together, performs step heat exchange, exchanges heat with the circulating water therein, and is heated into steam, thereby increasing the steam amount. The steam enters the steam turbine generator set through the high-pressure superheated steam main pipe and the medium-pressure superheated steam main pipe to generate electricity, and finally forms low-temperature molten salt and is divided into two paths. One path returns to the low-temperature molten salt storage tank for storage, and the other path passes through the low-temperature molten salt bypass pipe and returns to the molten salt waste heat boiler again under the drive of the low-temperature molten salt pump, and then is heated by the low-temperature heater and the high-temperature heater to form high-temperature molten salt for recycling.

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