A heating unit coupled molten salt energy storage deep peak regulation system and method

Abstract

The present invention relates to a deep peak regulation system of a heating unit coupled with molten salt energy storage and a method thereof, wherein the system comprises: a circulating power generation mechanism, comprising a steam turbine unit and a waste heat utilization device, wherein the steam generated by the waste heat utilization device enters the steam turbine unit to perform work and generate electricity, and the waste heat utilization device comprises a feed water heater; a molten salt energy storage mechanism, comprising an energy storage component, a high-pressure steam generator, a low-pressure steam generator, a feed water reheater, a first feed water pump, a heat network heat exchanger, a high-pressure steam user, a medium-pressure steam user, a first steam temperature reduction and pressure reduction device, a steam pressure matcher, an industrial steam supply pipe and a molten salt bypass pipe. The technical solution of the present invention realizes the high-efficiency utilization of flue gas waste heat and high-temperature molten salt heat in a stepped manner, greatly reduces the irreversible loss caused by excessive heat exchange temperature difference, reduces the work capacity loss of high-parameter steam, and has significant economic benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of energy conservation and emission reduction, and in particular to a deep peak regulation system for a heating unit coupled with a molten salt energy storage system and a method thereof. Background Art

[0002] At present, the gas-steam combined cycle mode has become the fastest-growing form of power generation in the world with its advantages of high power generation efficiency, short construction period, and convenient operation. This also has important guiding significance for the current adjustment of my country's power structure. However, when the combined cycle unit participates in the peak load regulation of the power grid, the operating load fluctuates frequently with the fluctuation of power load and new energy power, resulting in a significant reduction in the efficiency of the combined cycle unit. For example, compared with the full load operation of the unit, the heat consumption increases by 8% when the unit load rate is 60%, and the heat consumption will increase by 20% when the unit load rate is 40%. In addition, for combined cycle units with heating needs, it is more difficult for the units to participate in the peak load regulation of the power grid due to the limitation of the small heat-to-electricity ratio. Therefore, it is very important to integrate energy storage devices into the combined cycle system to improve the flexibility and efficiency of the combined cycle system so as to realize the efficient participation of the units in the peak load regulation of the power grid.

[0003] Therefore, molten salt energy storage technology has developed into the most mainstream high-temperature heat storage technology in the world with its advantages of low cost, high heat capacity and good safety. Using molten salt energy storage technology to solve the problem of insufficient power peak-shaving capacity of combined cycle units is a very promising technical application method. In particular, for ternary molten salts with a maximum operating temperature below 500°C, it is more suitable for thermal power coupled molten salt energy storage peak-shaving systems that achieve efficient utilization of flue gas waste heat. In related technologies, molten salt energy storage is coupled with peak-shaving in the field of flue gas waste heat utilization, and high-temperature molten salt is used to produce low-parameter steam for heating, resulting in high-grade molten salt heat loss. Summary of the invention

[0004] The object of the present invention is to provide a deep peak regulation system and method for a heating unit coupled with a molten salt energy storage, which realizes the step-by-step and efficient utilization of high-temperature molten salt heat, greatly reduces the heat exchange temperature difference, and reduces irreversible losses.

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

[0006] A heating unit coupled molten salt energy storage deep peak regulation system, comprising:

[0007] A circulating power generation mechanism, comprising a steam turbine unit and a waste heat utilization device, wherein the steam generated by the waste heat utilization device enters the steam turbine unit to perform work and generate electricity, and the waste heat utilization device comprises a feed water heater;

[0008] The molten salt energy storage mechanism includes an energy storage component, a high-pressure steam generator, a low-pressure steam generator, a feedwater reheater, a first feedwater pump, a heat network heat exchanger, a high-pressure steam user, a medium-pressure steam user, a first steam temperature reduction and pressure reduction device, a steam pressure matcher, an industrial steam supply pipe and a molten salt bypass pipe;

[0009] Wherein, the molten salt outlet of the energy storage component is connected to the molten salt inlet of the high-pressure steam generator, the molten salt outlet of the high-pressure steam generator is connected to the molten salt inlet of the low-pressure steam generator, the molten salt outlet of the low-pressure steam generator is connected to the molten salt inlet of the feedwater reheater, the molten salt bypass pipe is arranged between the molten salt inlet and the molten salt outlet of the low-pressure steam generator, and the molten salt outlet of the feedwater reheater is connected to the molten salt inlet of the energy storage component;

[0010] The feedwater outlet of the feedwater heater is respectively connected to the feedwater inlet of the low-pressure steam generator and the feedwater inlet of the feedwater reheater, the feedwater inlet of the feedwater reheater is installed with the first feedwater pump, the steam outlet of the low-pressure steam generator is respectively connected to the steam inlet of the heat network heat exchanger and the steam inlet of the steam pressure matcher, the heat network heat exchanger performs heat exchange and provides external heating, the feedwater outlet of the feedwater reheater is connected to the steam inlet of the high-pressure steam generator, the steam outlet of the high-pressure steam generator is respectively connected to the high-pressure steam user, the first steam temperature reduction and pressure reduction device and the steam inlet of the steam pressure matcher through the industrial steam supply pipe, the steam outlet of the first steam temperature reduction and pressure reduction device and the steam outlet of the steam pressure matcher are both connected to the steam inlet of the medium-pressure steam user.

[0011] Preferably, the circulating power generation mechanism also includes a circulating water supply system, which includes a condensate pump, a deaerator, a desalted water storage tank, a circulating water pump, a condensate pipe, a condenser and a drain pipe. The water outlet of the condensate pump is connected to the water inlet of the desalted water storage tank, the water outlet of the desalted water storage tank is connected to the water inlet of the deaerator, the water outlet of the desalted water storage tank is installed with the circulating water pump, the water outlet of the deaerator is connected to the water inlet of the feed water heater, the water outlet of the condenser is connected to the water inlet of the deaerator through the condensate pipe, the condensate pump is installed on the condensate pipe, and the drain outlet of the heat network heat exchanger is connected to the water inlet of the deaerator through the drain pipe.

[0012] Preferably, the energy storage component includes a low-temperature molten salt storage tank, a high-temperature molten salt storage tank, a primary molten salt heater, a secondary molten salt heater, a low-temperature molten salt pump and a high-temperature molten salt pump, the molten salt outlet of the low-temperature molten salt storage tank is installed with the low-temperature molten salt pump, the molten salt outlet of the low-temperature molten salt storage tank is connected to the molten salt inlet of the primary molten salt heater, the molten salt outlet of the primary molten salt heater is connected to the molten salt inlet of the secondary molten salt heater, the molten salt outlet of the secondary molten salt heater is connected to the molten salt inlet of the high-temperature molten salt storage tank, the molten salt outlet of the high-temperature molten salt storage tank is connected to the molten salt inlet of the high-pressure steam generator, and the molten salt outlet of the high-temperature molten salt storage tank is installed with the high-temperature molten salt pump, and the molten salt outlet of the feed water reheater is connected to the molten salt inlet of the low-temperature molten salt storage tank 9.

[0013] Preferably, the waste heat utilization device also includes a waste heat boiler, a low-pressure steam drum, a low-pressure superheater, a high-pressure steam drum, a high-pressure superheater and a second feedwater pump. The high-pressure superheater, the high-pressure steam drum, the low-pressure superheater, the low-pressure steam drum and the feedwater heater are sequentially arranged in the waste heat boiler along the flow direction from the flue gas inlet to the flue gas outlet. The feedwater outlet of the feedwater heater is respectively connected to the feedwater inlets of the low-pressure steam drum and the high-pressure steam drum. The feedwater inlet of the high-pressure steam drum is installed with the second feedwater pump. The steam outlet of the high-pressure steam drum is connected to the steam inlet of the high-pressure superheater, the steam outlet of the high-pressure superheater is connected to the steam turbine unit and high-pressure steam enters the steam turbine unit to perform work and generate electricity. The steam outlet of the low-pressure steam drum is connected to the steam inlet of the low-pressure superheater, the steam outlet of the low-pressure superheater is connected to the steam turbine unit and low-pressure steam enters the steam turbine unit to perform work and generate electricity.

[0014] Preferably, the waste heat utilization device also includes a second steam cooling and pressure reduction device, a third steam cooling and pressure reduction device, a main steam pipe and a low-pressure supplementary steam pipe. The steam outlet of the high-pressure superheater is connected to the steam turbine unit through the main steam pipe, and high-pressure steam enters the steam turbine unit to perform work and generate electricity. The steam outlet of the main steam pipe is connected to the steam inlet of the second steam cooling and pressure reduction device, and the steam outlet of the second steam cooling and pressure reduction device is connected to the steam inlet of the medium-pressure steam user. The steam outlet of the main steam pipe is connected to the steam inlet of the third steam cooling and pressure reduction device, and the steam outlet of the third steam cooling and pressure reduction device is connected to the steam inlet of the high-pressure steam user. The steam outlet of the low-pressure superheater is connected to the steam turbine unit through the low-pressure supplementary steam pipe, and low-pressure steam enters the steam turbine unit to perform work and generate electricity. The low-pressure supplementary steam pipe is connected to the steam inlet of the heat network heat exchanger.

[0015] Preferably, the energy storage component includes a primary molten salt heater and a secondary molten salt heater, both of which are arranged in the waste heat boiler, the primary molten salt heater is located between the low-pressure superheater and the low-pressure steam drum, the secondary molten salt heater is located between the high-pressure steam drum and the low-pressure superheater, or the secondary molten salt heater is located between the high-pressure superheater and the high-pressure steam drum.

[0016] Preferably, the cycle power generation mechanism also includes a gas turbine unit, which 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 drives the first generator to generate electricity, and the exhaust port of the gas turbine turbine is connected to the air inlet of the waste heat boiler.

[0017] Preferably, the steam turbine unit includes medium and high pressure cylinders, a low pressure cylinder, a second generator and a connecting pipe, the steam outlet of the high pressure steam superheater is connected to the steam inlet of the medium and high pressure cylinders, the steam outlet of the low pressure steam superheater is connected to the steam inlet of the low pressure cylinder, the steam outlet of the waste heat utilization device is respectively connected to the steam inlets of the medium and high pressure cylinders and the low pressure cylinder, the steam outlet of the medium and high pressure cylinders is connected to the steam inlet of the low pressure cylinder through the connecting pipe, the medium and high pressure cylinders and the low pressure cylinder are both coaxially connected to the second generator, and the medium and high pressure cylinders and the low pressure cylinder simultaneously work to drive the second generator to generate electricity.

[0018] The present invention also provides a method for coupling the heating unit with the molten salt energy storage deep peak regulation system, comprising the following steps:

[0019] Determining whether the system participates in power peak regulation;

[0020] If the system participates in power peak regulation, determining whether it is necessary to reduce or increase the output power load;

[0021] If the output power load needs to be reduced, part of the flue gas waste heat is used to heat the waste heat utilization device to generate steam, and the steam from the waste heat utilization device drives the steam turbine unit to work and generate electricity, and the other part of the flue gas waste heat is used to heat the low-temperature molten salt in the molten salt energy storage mechanism for heat storage;

[0022] If the output power load needs to be increased, all the waste heat of the flue gas will be used to heat the waste heat utilization device to generate steam. The steam from the waste heat utilization device drives the steam turbine unit to work and generate electricity. If the output power load needs to be further increased, it is also necessary to supplement the water supply to the molten salt energy storage mechanism through the feed water heater. The molten salt energy storage mechanism releases heat to heat the feed water supplemented by the feed water heater into steam. The steam from the molten salt energy storage mechanism is used for external heating and steam supply to users.

[0023] Preferably, if the output electrical load is to be further increased, it is also necessary to supplement the water supply to the molten salt energy storage mechanism through a water supply heater. The molten salt energy storage mechanism releases heat to heat the water supply supplemented by the water supply heater into steam. The steam of the molten salt energy storage mechanism is used for external heating and steam supply to users. The specific steps are as follows:

[0024] The high-temperature molten salt output by the energy storage component is cooled step by step through the high-pressure steam generator, the low-pressure steam generator, the molten salt bypass pipe and the feedwater reheater to obtain low-temperature molten salt. The feedwater in the feedwater heater enters the low-pressure steam generator and the feedwater reheater respectively, and the feedwater is pressurized by the first feedwater pump before entering the feedwater reheater. The high-temperature and high-pressure feedwater output by the feedwater reheater then enters the high-pressure steam generator to absorb heat to obtain high-parameter steam, and steam is supplied to high-pressure steam users and medium-pressure steam users respectively through the industrial steam supply pipe; the low-parameter steam output by the low-pressure steam generator enters the heat exchanger of the heat network for heat exchange and then provides external heating;

[0025] When the amount of low-parameter steam output by the low-pressure steam generator is greater than the steam demand of the heat network heat exchanger, or the amount of high-parameter steam output by the high-pressure steam generator cannot simultaneously meet the steam demands of high-pressure steam users and medium-pressure steam users, the low-parameter steam output by the low-pressure steam generator also enters the steam pressure matcher, and is mixed and matched with the high-parameter steam from the high-pressure steam generator to generate medium-pressure steam, which is then supplied to the medium-pressure steam users.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The technical solution provides a deep peak-shaving system for a heating unit coupled with a molten salt energy storage, which not only achieves efficient power peak-shaving by storing waste heat from flue gas; in addition, the high-temperature molten salt output from the energy storage component is cooled in stages through a high-pressure steam generator, a low-pressure steam generator, a molten salt bypass pipe and a feedwater reheater, and the distribution positions of various heat exchangers utilizing high-temperature molten salt heat are reasonably designed to efficiently produce steam with different parameters based on energy grade step matching, and also realize the step-by-step efficient utilization of high-temperature molten salt heat, greatly reducing the heat exchange temperature difference and irreversible losses; and, the feedwater outlet of the feedwater heater is respectively connected to the feedwater inlet of the low-pressure steam generator and the feedwater reheater, and the heat released by the molten salt energy storage mechanism is used to step-heat the feedwater to produce steam of different qualities, thereby meeting the heating needs of high-pressure steam users and medium-pressure steam users, and avoiding the high-grade energy loss caused by direct cooling and pressure reduction of high-parameter main steam for heating, thereby increasing the power generation capacity of the steam turbine unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of a deep peak regulation system of a heating unit coupled with a molten salt energy storage in one embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of a deep peak regulation system of a heating unit coupled with a molten salt energy storage in another embodiment of the present invention.

[0030] Description of reference numerals:

[0031] 10. Waste heat utilization device; 101. Feed water heater; 102. Waste heat boiler; 103. Low pressure drum; 104. Low pressure superheater; 105. High pressure drum; 106. High pressure superheater; 107. Second feed water pump; 108. Main steam pipe; 109. Low pressure supplementary steam pipe; 20. Steam turbine unit; 201. Medium and high pressure cylinder; 202. Low pressure cylinder; 203. Second generator; 204. Connecting pipe; 30. Molten salt energy storage mechanism; 301. Low temperature molten salt storage tank; 302. High temperature molten salt storage tank; 303. Primary molten salt heater; 30 4. Secondary molten salt heater; 305. Low-temperature molten salt pump; 306. High-temperature molten salt pump; 307. High-pressure steam generator; 308. Low-pressure steam generator; 309. Feedwater reheater; 310. First feedwater pump; 311. Heat network heat exchanger; 312. High-pressure steam user; 313. Medium-pressure steam user; 314. First steam temperature and pressure reduction device; 315. Steam pressure matcher; 316. Industrial steam supply pipe; 317. Molten salt bypass pipe; 40. Circulating water supply system; 401. Condensate pump; 402. Deaerator; 403. Degassing Brine storage tank; 404, circulating water pump; 405, condensate pipe; 406, condenser; 407, drain pipe; 50, gas turbine unit; 501, gas turbine compressor; 502, gas turbine combustion chamber; 503, gas turbine turbine; 504, first generator; 601, valve No. 1; 602, valve No. 2; 603, valve No. 3; 604, valve No. 4; 605, valve No. 5; 606, valve No. 6; 607, valve No. 7; 608, valve No. 8; 609, valve No. 9; 610, valve No. 10; 611, valve No. 12; 612, valve No. 13; 613, valve No. 14; 614, valve No. 15; 615, valve No. 16; 616, valve No. 17; 617, valve No. 18; 618, valve No. 19; 619, valve No. 20; 620, valve No. 21; 621, valve No. 22; 622, valve No. 23; 623, valve No. 24; 624, valve No. 25; 625, valve No. 26; 626, valve No. 27; 627, valve No. 28; 628, valve No. 29; 630, valve No. 30; 631, valve No. 31; 632, valve No. 32; 633, valve No. 33; 634, valve No. 34; 635, valve No. 35; 636, valve No. 36; 637, valve No. 37; 63 1. Valve No. 11; 612. Valve No. 12; 613. Valve No. 13; 614. Valve No. 14; 615. Valve No. 15; 616. Valve No. 16; 617. Valve No. 17; 618. Valve No. 18; 619. Valve No. 19; 620. Valve No. 20; 621. Valve No. 21; 622. Valve No. 22; 623. Valve No. 23; 624. Valve No. 24; 625. Valve No. 25; 626. Valve No. 26; 627. Valve No. 27; 628. Valve No. 28. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In an embodiment of the present invention, a deep peak-shaving system of a heating unit coupled with a molten salt energy storage is provided. The system makes efficient use of the high-temperature molten salt heat in a step-by-step manner, greatly reduces the heat exchange temperature difference, and reduces irreversible losses. In addition, during power peak-shaving, the molten salt energy storage mechanism 30 is preferentially used to release heat to stepwise heat the feed water to produce steam of different qualities to meet the heating needs of different steam parameter requirements, thereby avoiding high-grade energy losses caused by direct cooling and pressure reduction of high-parameter main steam for heating, thereby increasing the work and power generation capacity of the steam turbine unit 20.

[0036] See also Figure 1 and Figure 2 In one embodiment, the heating unit is coupled with a molten salt energy storage deep peak-shaving system, and at least includes a cyclic power generation mechanism, which includes a gas turbine unit 50, and the gas turbine unit 50 includes a gas turbine compressor 501, a gas turbine combustion chamber 502, a gas turbine turbine 503, and a first generator 504; the exhaust port of the gas turbine compressor 501 is connected to the air inlet of the gas turbine combustion chamber 502, and the exhaust port of the gas turbine combustion chamber 502 is connected to the air inlet of the gas turbine turbine 503, and the gas turbine turbine 503 drives the first generator 504 to generate electricity, and the exhaust port of the gas turbine turbine 503 is connected to the air inlet of the waste heat boiler 102. The gas discharged by the gas turbine turbine 503 is flue gas, and the present invention meets the power peak-shaving demand of the heating unit by utilizing the waste heat of the flue gas.

[0037] In order to utilize the waste heat of the flue gas, the circulating power generation mechanism also includes a steam turbine unit 20, a waste heat utilization device 10 and a circulating water supply system 40. The steam generated by the waste heat utilization device 10 enters the steam turbine unit 20 to perform work and generate electricity; the system also includes a molten salt energy storage mechanism 30.

[0038] The steam turbine unit 20 includes a medium- and high-pressure cylinder 201, a low-pressure cylinder 202, a second generator 203 and a connecting pipe 204. The steam outlet of the high-pressure steam superheater is connected to the steam inlet of the medium- and high-pressure cylinder 201, the steam outlet of the low-pressure steam superheater is connected to the steam inlet of the low-pressure cylinder 202, the steam outlet of the waste heat utilization device 10 is respectively connected to the steam inlets of the medium- and high-pressure cylinder 201 and the low-pressure cylinder 202, the steam outlet of the medium- and high-pressure cylinder 201 is connected to the steam inlet of the low-pressure cylinder 202 through the connecting pipe 204, the medium- and high-pressure cylinder 201 and the low-pressure cylinder 202 are both coaxially connected to the second generator 203, and the medium- and high-pressure cylinder 201 and the low-pressure cylinder 202 simultaneously work to drive the second generator 203 to generate electricity.

[0039] The circulating water supply system 40 includes a condensate pump 401 , a deaerator 402 , a desalted water storage tank 403 , a circulating water pump 404 , a condensate pipe 405 , a condenser 406 and a drain pipe 407 .

[0040] The waste heat utilization device 10 includes a feed water heater 101, a waste heat boiler 102, a low-pressure drum 103, a low-pressure superheater 104, a high-pressure drum 105, a high-pressure superheater 106, a second feed water pump 107, a second steam temperature reduction and pressure reduction device, a third steam temperature reduction and pressure reduction device, a main steam pipe 108 and a low-pressure steam supplementary pipe 109. The high-pressure superheater 106, the high-pressure drum 105, the low-pressure superheater 104, the low-pressure drum 103 and the feed water heater 101 are sequentially arranged in the waste heat boiler 102 along the flow direction from the flue gas inlet to the flue gas outlet.

[0041] Circuit 1: In order to use the high-temperature flue gas from the gas turbine 503 to heat the feed water to produce steam, and then the steam enters the steam turbine unit 20 to generate power. Open and adjust valve No. 1 601, valve No. 2 602, valve No. 3 603, valve No. 4 604, valve No. 5 605, valve No. 606, valve No. 7 607, valve No. 27 627, and the feed water is heated by the feed water heater 101 and then divided into two feed water routes. The feed water outlet of the feed water heater 101 is connected to the feed water inlet of the low-pressure drum 103 and the high-pressure drum 105 respectively.

[0042] One of the branches: a No. 1 valve 601 is installed at the feed water inlet of the low-pressure drum 103, the steam outlet of the low-pressure drum 103 is connected to the steam inlet of the low-pressure superheater 104, the low-pressure steam generated by the low-pressure drum 103 enters the low-pressure superheater 104 for further heating, a No. 3 valve 603 is installed at the steam outlet of the low-pressure superheater 104, the steam outlet of the low-pressure superheater 104 is connected to the inlet of the low-pressure cylinder 202 through the low-pressure supplementary steam pipe 109, a No. 6 valve 606 is installed at the steam outlet end of the low-pressure supplementary steam pipe 109, and the steam from the low-pressure superheater 104 directly enters the low-pressure cylinder 202 to do work.

[0043] Another branch: The feed water inlet of the high-pressure drum 105 is installed with a second feed water pump 107 and a second valve 602. The feed water entering the high-pressure drum 105 is first pressurized by the first feed water pump. The steam outlet of the high-pressure drum 105 is connected to the steam inlet of the high-pressure superheater 106. The high-pressure steam generated by the high-pressure drum 105 enters the high-pressure superheater 106 for further heating. The steam outlet of the high-pressure superheater 106 is connected to the steam inlet of the medium and high-pressure cylinder 201 through the main steam pipe 108. A No. 4 valve 604 is installed at the steam outlet of the superheater 106, and a No. 5 valve 605 is installed at the steam outlet end of the main steam pipe 108. The steam in the high-pressure superheater 106 enters the medium- and high-pressure cylinders 201 and the low-pressure cylinder 202 in turn to perform work. The outlet of the medium- and high-pressure cylinder 201 is connected to the steam inlet of the low-pressure cylinder 202 through a connecting pipe 204, and a No. 7 valve 607 is installed on the connecting pipe 204. The medium- and high-pressure cylinders 201 and the low-pressure cylinder 202 perform work at the same time to drive the second generator 203 to generate electricity.

[0044] The steam outlet of the low-pressure cylinder 202 is connected to the exhaust steam inlet of the condenser 406, and the condensate outlet of the condenser 406 is connected to the water inlet of the deaerator 402 through the condensate pipe 405, and the condensate pump 401 and valve No. 27 627 are installed in sequence on the condensate pipe 405 along the water flow direction, and the water outlet of the deaerator 402 is connected to the feed water inlet of the feed water heater 101, thereby forming a loop one.

[0045] The desalted water storage tank 403 is used to meet the condensate demand of the system when participating in power peak regulation. The outlet of the condensate pump 401 is connected to the inlet of the desalted water storage tank 403, and a No. 28 valve 628 is installed at the inlet of the desalted water storage tank 403. The outlet of the desalted water storage tank 403 is connected to the inlet of the deaerator 402. The outlet of the desalted water storage tank 403 is installed with a circulating water pump 404 and a No. 26 valve 626. The outlet of the deaerator 402 is connected to the water inlet of the feed water heater 101.

[0046] It can be understood that when the system participates in power peak regulation and needs to reduce the output power load, valve No. 27 627 and valve No. 28 628 are opened and adjusted, and valve No. 26 626 is closed to reduce the amount of condensate delivered to the deaerator 402 through the condensate pump 401. The excess condensate from the condensate pump 401 is directly delivered to the desalted water storage tank 403 for storage, thereby reducing the flow of superheated steam delivered from the waste heat boiler 102 to the steam turbine unit 20, reducing the working capacity of the steam turbine unit 20, and thereby reducing the power load output by the second generator 203 to meet the power peak regulation demand.

[0047] When the system participates in power peak regulation and needs to increase the output power load, open and adjust valve No. 27 627 and valve No. 26 626, close valve No. 28 628, and the desalted water storage tank 403 replenishes the insufficient condensate of the system. When the system participates in power peak regulation and needs to continue to increase the output power load, it can also replenish the water supply required for producing steam when the molten salt energy storage mechanism 30 releases heat.

[0048] Specific implementation method of the molten salt energy storage mechanism 30: The molten salt energy storage mechanism 30 includes an energy storage component, a high-pressure steam generator 307, a low-pressure steam generator 308, a feed water reheater 309, a first feed water pump 310, a heat network heat exchanger 311, a high-pressure steam user 312, a medium-pressure steam user 313, a first steam temperature and pressure reduction device 314 and a steam pressure matcher 315, an industrial steam supply pipe 316 and a molten salt bypass pipe 317; wherein, the energy storage component includes a low-temperature molten salt storage tank 301, a high-temperature molten salt storage tank 302, a primary molten salt heater 303, a secondary molten salt heater 304, a low-temperature molten salt pump 305 and a high-temperature molten salt pump 306.

[0049] like Figure 1 As shown, the primary molten salt heater 303 and the secondary molten salt heater 304 are both arranged in the waste heat boiler 102, the primary molten salt heater 303 is located between the low-pressure superheater 104 and the low-pressure steam drum 103, and the secondary molten salt heater 304 is located between the high-pressure steam drum 105 and the low-pressure superheater 104.

[0050] Loop 2: The molten salt energy storage mechanism 30 stores energy or releases heat.

[0051] When the system participates in power peak regulation and needs to reduce the output power load, in order to keep the steam turbine unit 20 running at low load, a part of the flue gas waste heat from the gas turbine 503 needs to be stored in the molten salt energy storage mechanism 30. Specifically, the No. 8 valve 608 and the No. 9 valve 609 are opened and adjusted.

[0052] A low-temperature molten salt pump 305 and a No. 8 valve 608 are installed at the molten salt outlet of the low-temperature molten salt storage tank 301, the primary molten salt heater 303 is arranged between the low-pressure steam drum 103 and the low-pressure superheater 104 in the waste heat boiler 102, the molten salt outlet of the low-temperature molten salt storage tank 301 is connected to the molten salt inlet of the primary molten salt heater 303, the molten salt outlet of the primary molten salt heater 303 is connected to the molten salt inlet of the secondary molten salt heater 304, the molten salt outlet of the secondary molten salt heater 304 is connected to the molten salt inlet of the high-temperature molten salt storage tank 302, and a No. 9 valve 609 is installed at the molten salt inlet of the high-temperature molten salt storage tank 302.

[0053] It is understandable that the low-temperature molten salt in the low-temperature molten salt storage tank 301, driven by the low-temperature molten salt pump 305, enters the primary molten salt heater 303 and the secondary molten salt heater 304 in turn to be heated in stages to obtain high-temperature molten salt, which is then sent to the high-temperature molten salt storage tank 302 for storage, that is, the high-temperature flue gas waste heat is stored, achieving high-efficiency step-by-step utilization of the high-temperature flue gas waste heat, greatly reducing the heat exchange temperature difference, and reducing irreversible losses. The use of the molten salt energy storage mechanism 30 to store the high-temperature flue gas waste heat avoids the priority choice of reducing the operating load of the gas turbine unit 50, and largely ensures the high-efficiency operation of the cycle power generation mechanism.

[0054] When the system participates in power peak regulation and needs to continue to increase the output power load, the molten salt energy storage mechanism 30 is used to release heat to generate steam for external steam supply and heating, the main steam from the main steam pipe 108 is stopped from being used for external steam supply, and during the heating period, the low-pressure steam from the low-pressure steam supplementary pipe 109 is stopped from being used for external heating, thereby increasing the main steam flow and low-pressure steam flow entering the steam turbine unit 20 to do work, and continuing to increase the output power load of the steam turbine unit 20, thereby further increasing the output power load of the system.

[0055] A high-temperature molten salt pump 306 and a No. 10 valve 610 are installed at the molten salt outlet of the high-temperature molten salt storage tank 302, the molten salt outlet of the high-temperature molten salt storage tank 302 is connected to the molten salt inlet of the high-pressure steam generator 307, the molten salt outlet of the high-pressure steam generator 307 is connected to the molten salt inlet of the low-pressure steam generator 308, the molten salt outlet of the low-pressure steam generator 308 is connected to the molten salt inlet of the feed water reheater 309, the molten salt inlet and the molten salt outlet of the low-pressure steam generator 308 are respectively installed with a No. 12 valve 612 and a No. 13 valve 613, the molten salt bypass pipe 317 is arranged between the molten salt inlet and the molten salt outlet of the low-pressure steam generator 308, the No. 11 valve 611 is installed on the molten salt bypass pipe 317, the molten salt outlet of the feed water reheater 309 is connected to the molten salt inlet of the low-temperature molten salt storage tank 301, and the molten salt inlet of the low-pressure molten salt storage tank 301 is installed with a No. 14 valve 614.

[0056] It can be understood that the high-temperature molten salt output by the high-temperature molten salt storage tank 302 is sequentially cooled by the high-pressure steam generator 307, the low-pressure steam generator 308, the molten salt bypass pipe 317 and the feed water reheater 309 to obtain low-temperature molten salt and store it in the low-temperature molten salt storage tank 301, that is, the heat stored in the high-temperature molten salt storage tank 302 is released from the high-temperature molten salt storage tank 302 to the low-temperature molten salt storage tank 301. Based on the principle of energy cascade utilization, the distribution positions of various types of heat exchangers utilizing high-temperature molten salt heat are reasonably designed to efficiently produce steam of different qualities based on energy grade cascade matching. Therefore, the molten salt energy storage mechanism 30 is used to release heat to cascade heat the feed water to produce steam of different qualities, so as to meet the heating needs of the high-pressure steam users 312 and the medium-pressure steam users 313, thereby avoiding the high-grade energy loss caused by direct cooling and pressure reduction of the high-parameter main steam for heating, thereby increasing the power generation capacity of the steam turbine unit 20. The heat released by the high-temperature molten salt storage tank 302 is used together with the heat output from the feedwater heater 101 in loop three, and the steam is output to supply steam and heating to the outside.

[0057] Loop 3: When the system participates in power peak regulation and needs to continue to increase the output power load, the molten salt energy storage mechanism 30 is used to release heat to generate steam for external steam supply and heating, and the main steam from the main steam pipe 108 is stopped from being used for external steam supply, and the low-pressure steam from the low-pressure supplementary steam pipe 109 is stopped from being used for external heating during the heating period, thereby increasing the main steam flow and low-pressure steam flow entering the steam turbine unit 20 to perform work, and continuing to increase the output power load of the steam turbine unit 20, thereby further increasing the output power load of the system. In addition, the desalted water storage tank 403 is also required to supplement the feed water flow required to produce steam when the molten salt energy storage mechanism 30 releases heat.

[0058] One of the branches: open and adjust valve No. 16 616, valve No. 20 620, valve No. 21 621, valve No. 22 622, valve No. 23 623, valve No. 24 624 and valve No. 25 625.

[0059] The feedwater outlet of the feedwater heater 101 is connected to the feedwater inlet of the feedwater reheater 309, and the feedwater inlet of the feedwater reheater 309 is installed with the first feedwater pump 310 and the sixteenth valve 616. The feedwater outlet of the feedwater reheater 309 is connected to the steam inlet of the high-pressure steam generator 307. The steam outlet of the high-pressure steam generator 307 is connected to the steam inlet of the high-pressure steam user 312, the first steam temperature reduction and pressure reduction device 314 and the steam pressure matching device 315 through the industrial steam supply pipe 316. The industrial steam supply pipe 316 is installed with the twenty-second valve 620. The high-pressure steam inlet of the pressure matcher 315 is installed with valve No. 23 623, the steam inlet of the steam cooling and pressure reducing device 314 is installed with valve No. 22 622, the steam inlet of the high-pressure steam user 312 is installed with valve No. 21 621, the steam outlet of the first steam cooling and pressure reducing device 314 and the steam outlet of the steam pressure matcher 315 are both connected to the steam inlet of the medium-pressure steam user 313, the steam outlet of the first steam cooling and pressure reducing device 314 is installed with valve No. 25 625, and the steam outlet of the steam pressure matcher 315 is installed with valve No. 24 624.

[0060] It can be understood that the feed water entering the feed water reheater 309 is first pressurized by the first feed water pump 310, and the high-temperature and high-pressure feed water output by the feed water reheater 309 then enters the high-pressure steam generator 307 to absorb heat to generate high-parameter steam, and simultaneously supplies steam to the high-pressure steam user 312 and the medium-pressure steam user 313 through the industrial steam supply pipe 316, and the steam entering the medium-pressure steam user 313 is first cooled and reduced in pressure to become steam with the required parameters.

[0061] Another branch: When entering the heating period, the feed water outlet of the feed water heater 101 is connected to the feed water inlet of the low-pressure steam generator 308, and valve No. 15 615, valve No. 17 617, valve No. 18 618, valve No. 19 619, valve No. 12 612 and valve No. 13 613 are opened and adjusted, and valve No. 11 611 is closed, so that the heat released by the high-temperature molten salt acts on the low-pressure steam generator 308, and the feed water enters the low-pressure steam generator 308 and is heated into a large amount of steam. The steam outlet of the low-pressure steam generator 308 is connected to the steam inlet of the heat network heat exchanger 311, and the heat network heat exchanger 311 performs heat exchange and provides external heating. The steam generated by the heat network heat exchanger 311 is drained and connected to the water inlet of the deaerator 402 through the drain pipe 407. The steam outlet of the low-pressure steam generator 308 is also connected to the steam inlet of the steam pressure matcher 315, and the steam outlet of the steam pressure matcher 315 is connected to the steam inlet of the medium-pressure steam user 313. In other words, the low-pressure steam generator 308 generates a large amount of steam, part of which is used for external heating through the heat network heat exchanger 311, and the other part is used for steam supply to the medium-pressure steam user 313 through the steam pressure matcher 315.

[0062] If it is not in the heating period, the feed water outlet of the feed water heater 101 is connected to the feed water inlet of the low-pressure steam generator 308, and the openings of valve No. 12 612, valve No. 13 613 and valve No. 11 611 are adjusted so that a small amount of heat released by the high-temperature molten salt acts on the low-pressure steam generator 308, and the feed water enters the low-pressure steam generator 308 to generate a small amount of steam. The steam generated by the low-pressure steam generator 308 is supplied to the medium-pressure steam user 313 through the steam pressure matcher 315. At the same time, the high-parameter steam generated by the high-pressure steam generator 307 is parameter matched by the steam pressure matcher 315 to generate steam with corresponding parameters to supply steam to the medium-pressure steam user 313; that is, the steam from the low-pressure steam generator 308 and the steam from the high-pressure steam generator 307 simultaneously supply steam to the medium-pressure steam user 313.

[0063] In loop three, when the molten salt energy storage system releases heat to produce steam, the low-parameter steam generated by the low-pressure steam generator 308 and the high-parameter steam generated by the high-pressure steam generator 307 are preferentially used to match parameters through the steam pressure matcher 315 to generate steam with corresponding parameters to supply steam to the medium-pressure steam user 313, and the high-parameter steam generated by the high-pressure steam generator 307 is used to supply steam to the high-pressure steam user 312. Secondly, the high-parameter steam generated by the high-pressure steam generator 307 is directly used to cool and reduce the pressure through the steam cooling and pressure reducing device 314 to form steam with corresponding parameters to supply steam to the medium-pressure steam user 313, and the high-parameter steam generated by the high-pressure steam generator 307 is used to supply steam to the high-pressure steam user 312. Finally, the main steam from the main steam pipe 108 is used to cool and reduce the pressure to form steam with corresponding parameters to supply steam to the medium-pressure steam users 313 and the high-pressure steam users 312. It can be understood that the heat released by the molten salt energy storage mechanism 30 is preferentially utilized to stepwise heat the feed water to produce steam of different qualities so as to meet the heating needs of different steam parameter requirements, thereby avoiding the high-grade energy loss caused by direct cooling and pressure reduction of high-parameter main steam for heating, and increasing the work and power generation capacity of the steam turbine unit 20 to a certain extent.

[0064] Not shown in the figure, when the molten salt energy storage system does not release heat to produce steam, the steam outlet of the main steam pipe 108 is connected to the steam inlet of the second steam temperature reduction and pressure reduction device, the steam outlet of the second steam temperature reduction and pressure reduction device is connected to the steam inlet of the medium-pressure steam user 313, the steam outlet of the main steam pipe 108 is connected to the steam inlet of the third steam temperature reduction and pressure reduction device, and the steam outlet of the third steam temperature reduction and pressure reduction device is connected to the steam inlet of the high-pressure steam user 312; the main steam from the main steam pipe 108 is used to form steam with corresponding parameters after being cooled and reduced in pressure to supply steam to the medium-pressure steam users 313 and the high-pressure steam users 312.

[0065] Not shown in the figure, when the molten salt energy storage system does not release heat to produce steam and enters the heating period, the low-pressure steam supply pipe 109 is connected to the steam inlet of the heat network heat exchanger 311; the low-pressure steam from the low-pressure steam supply pipe 109 is used to provide external heating through the heat network heat exchanger 311.

[0066] See also Figure 2 In another embodiment, the main difference is that the secondary molten salt heater 304 is located between the high-pressure superheater 106 and the high-pressure steam drum 105, which has a similar technical effect to the previous embodiment.

[0067] Please continue reading Figure 1-Figure 2 In an embodiment of the present invention, there is also provided a method for coupling a heating unit with a molten salt energy storage deep peak regulation system, comprising the following steps:

[0068] Determine whether the system participates in power peak regulation.

[0069] If the system does not participate in power peak regulation, the gas turbine unit 50 and the steam turbine unit 20 both maintain high load operation to ensure high-efficiency operation of the combined cycle power generation mechanism. The high-temperature flue gas from the gas turbine turbine 503 is all used to heat the feed water to produce steam, and then enters the steam turbine unit 20 to generate power.

[0070] Specifically, open and adjust valve No. 1 601, valve No. 2 602, valve No. 3 603, valve No. 4 604, valve No. 5 605, valve No. 606, valve No. 7 607, and valve No. 27 627. The feed water from the deaerator 402 is heated by the feed water heater 101 and then divided into two feed water routes, which enter the low-pressure drum 103 and the high-pressure drum 105 respectively. The feed water entering the high-pressure drum 105 is first pressurized by the No. 1 feed water pump, and the high-pressure steam generated by the high-pressure drum 105 enters the feed water heater 101. The steam enters the high-pressure superheater 106 for further heating, and then enters the medium-pressure cylinder 201 and the low-pressure cylinder 202 in sequence to perform work; the low-pressure steam generated by the low-pressure drum 103 enters the low-pressure superheater 104 for further heating, and then directly enters the low-pressure cylinder 202 to perform work, and the medium-pressure cylinder 201 and the low-pressure cylinder 202 perform work at the same time to drive the second generator 203 to generate electricity, and the exhaust steam generated by the steam turbine unit 20 after performing work enters the condenser 406 to form condensate, and then returns to the deaerator 402 through the condensate pump 401. At this time, if the molten salt energy storage mechanism 30 does not release heat, the main steam from the main steam pipe 108 needs to be cooled and reduced in pressure by the second steam cooling and pressure reducing device and the third steam cooling and pressure reducing device to form two steams with corresponding parameters, which are used to supply steam to the high-pressure steam users 312 and the medium-pressure steam users 313 respectively. When external heating users have heating needs, the low-pressure steam from the low-pressure steam supplementary pipe 109 needs to be used to provide external heating through the heat network heat exchanger 311.

[0071] If the system participates in power peak regulation, determine whether it is necessary to reduce or increase the output power load.

[0072] If it is necessary to reduce the output power load, part of the high-temperature flue gas from the gas turbine 503 is used to heat the waste heat utilization device 10 to generate steam. The steam of the waste heat utilization device 10 drives the steam turbine unit 20 to work and generate electricity, and the other part of the flue gas waste heat heats the low-temperature molten salt in the molten salt energy storage mechanism 30 for heat storage. It can be understood that it is preferred to reduce the operating load of the steam turbine unit 20 while still maintaining the high-load operation of the gas turbine unit 50. At this time, the heat storage of the molten salt energy storage mechanism 30 is used to store the excess high-temperature flue gas waste heat, thereby ensuring the high-efficiency operation of the cycle power generation mechanism and avoiding the direct emission loss of flue gas waste heat.

[0073] Specifically, open and adjust valve No. 27 627 and valve No. 28 628, close valve No. 26 626, reduce the amount of condensate delivered to the deaerator 402 through the condensate pump 401, and directly deliver the excess condensate from the condensate pump 401 to the desalted water storage tank 403 for storage, open and adjust valve No. 1 601, valve No. 2 602, valve No. 3 603, valve No. 4 604, valve No. 5 605, valve No. 606, valve No. 7 607, and valve No. 27 627, and correspondingly reduce the feed water flow from the deaerator 402 to the waste heat boiler 102, thereby reducing the superheated steam flow from the waste heat boiler 102 to the steam turbine unit 20, reducing the working capacity of the steam turbine unit 20, and thereby reducing the electrical load output by the second generator 203 to meet the power peak regulation demand.

[0074] At the same time, open and adjust valve No. 8 608 and valve No. 9 609. Driven by the low-temperature molten salt pump 305, the low-temperature molten salt in the low-temperature molten salt storage tank 301 enters the primary molten salt heater 303 and the secondary molten salt heater 304 in turn to be heated in stages to obtain high-temperature molten salt. The high-temperature molten salt is sent to the high-temperature molten salt storage tank 302 for storage, that is, the high-temperature flue gas waste heat is stored, realizing the high-efficiency step-by-step utilization of the high-temperature flue gas waste heat, greatly reducing the heat exchange temperature difference, and reducing irreversible losses. The use of the molten salt energy storage mechanism 30 to store the high-temperature flue gas waste heat avoids the priority choice of reducing the operating load of the gas turbine unit 50, and largely ensures the high-efficiency operation of the cycle power generation mechanism.

[0075] If the output power load needs to be increased, the molten salt energy storage mechanism 30 stops storing heat, and all the high-temperature flue gas from the gas turbine 503 is used to heat the feed water to produce steam, and then enters the steam turbine unit 20 to perform work and generate electricity. The waste heat of the flue gas is all used to heat the waste heat utilization device 10 to generate steam, and the steam from the waste heat utilization device 10 drives the steam turbine unit 20 to perform work and generate electricity.

[0076] Specifically, open and adjust valve No. 1 601, valve No. 2 602, valve No. 3 603, valve No. 4 604, valve No. 5 605, valve No. 606, valve No. 7 607, and valve No. 27 627. The feed water from the deaerator 402 is heated by the feed water heater 101 and then divided into two feed water routes, which enter the low-pressure drum 103 and the high-pressure drum 105 respectively. The feed water entering the high-pressure drum 105 is first pressurized by the No. 1 feed water pump. The high-pressure steam generated by the high-pressure drum 105 enters the high-pressure superheater 106 for further heating, and then enters the medium and high-pressure cylinders 201 and the low-pressure drum 105 in sequence. The cylinder 202 performs work, the low-pressure steam generated by the low-pressure drum 103 enters the low-pressure superheater 104 for further heating, and then directly enters the low-pressure cylinder 202 to perform work, the medium and high-pressure cylinders 201 and the low-pressure cylinder 202 perform work at the same time to drive the second generator 203 to generate electricity, and the exhaust steam generated by the steam turbine unit 20 after working enters the condenser 406 to form condensate, and then returns to the deaerator 402 through the condensate pump 401. At the same time, open and adjust valve No. 26 626, close valve No. 28 628, and use the desalted water storage tank 403 to supplement the insufficient condensate flow of the combined cycle power generation system.

[0077] If the output power load is to be further increased, not only the gas turbine unit 50 and the steam turbine unit 20 need to maintain high load operation, but also the molten salt energy storage mechanism 30 needs to release heat to generate steam for external steam supply and heating, stop using the main steam from the main steam pipe 108 to supply steam to the outside, and stop using the low-pressure steam from the low-pressure supplementary steam pipe 109 for external heating during the heating period, thereby increasing the main steam flow and low-pressure steam flow entering the steam turbine unit 20 to do work, and continue to increase the output power load of the steam turbine unit 20, thereby further increasing the output power load of the system. After heating, the feedwater heater 101 is divided into two feedwaters, which continue to enter the low-pressure drum 103 and the high-pressure drum 105 respectively, and finally do work and generate electricity in the steam turbine unit 20. The specific steps will not be repeated.

[0078] In addition, the following steps need to be combined: open and adjust valve No. 10 610, valve No. 14 614, valve No. 16 616, valve No. 20 620, valve No. 21 621, valve No. 22 622, valve No. 23 623, valve No. 24 624 and valve No. 25 625.

[0079] The feed water from the deaerator 402 is heated by the feed water heater 101 and then divided into one feed water path and enters the feed water reheater 309. The feed water entering the feed water reheater 309 is first pressurized by the first feed water pump 310. The high-temperature and high-pressure feed water output by the feed water reheater 309 then enters the high-pressure steam generator 307 to absorb heat to generate high-parameter steam, and simultaneously supplies steam to the high-pressure steam user 312 and the medium-pressure steam user 313 through the industrial steam supply pipe 316. The steam entering the medium-pressure steam user 313 is first cooled and reduced in pressure to become steam with the required parameters.

[0080] When entering the heating period, open and adjust valve No. 17 617, valve No. 18 618, valve No. 19 619, valve No. 12 612 and valve No. 13 613, close valve No. 11 611, the feed water from the deaerator 402 is heated by the feed water heater 101 and then divided into one feed water to directly enter the low-pressure steam generator 308 to produce low-parameter steam, the heat released by the high-temperature molten salt acts on the low-pressure steam generator 308, the feed water enters the low-pressure steam generator 308 and is heated into a large amount of steam, and then enters the heat exchanger 311 for heat exchange and then provides external heating, the steam generated by the heat exchanger 311 directly enters the deaerator 402. The steam outlet of the low-pressure steam generator 308 is also connected to the steam inlet of the steam pressure matcher 315, and the steam outlet of the steam pressure matcher 315 is connected to the steam inlet of the medium-pressure steam user 313. That is to say, when the amount of low-parameter steam output by the low-pressure steam generator 308 is greater than the steam demand of the heat network heat exchanger 311, or the amount of high-parameter steam output by the high-pressure steam generator 307 cannot simultaneously meet the steam demands of the high-pressure steam user 312 and the medium-pressure steam user 313, the low-parameter steam output by the low-pressure steam generator 308 also enters the steam pressure matcher 315, and is mixed and matched with the high-parameter steam from the high-pressure steam generator 307 to generate medium-pressure steam, which is then supplied to the medium-pressure steam user 313. That is, the low-pressure steam generator 308 generates a large amount of steam, part of which is used for external heating through the heat network heat exchanger 311, and the other part is used for steam supply to the medium-pressure steam user 313.

[0081] Open and adjust valve No. 27 627 and valve No. 26 626, close valve No. 28 628, and use the desalted water storage tank 403 to supplement the feedwater flow required for steam production when the molten salt energy storage system releases heat. The feedwater heater 101 is connected to the low-pressure steam generator 308 and the feedwater reheater 309 to supplement the feedwater flow required for steam production when the molten salt energy storage mechanism 30 releases heat, thereby increasing the output of high-quality steam.

[0082] In addition, the high-temperature molten salt output from the high-temperature molten salt storage tank 302 is cooled in stages by the high-pressure steam generator 307, the low-pressure steam generator 308, the molten salt bypass pipe 317 and the feedwater reheater 309 to obtain low-temperature molten salt and store it in the low-temperature molten salt storage tank 301. Based on the principle of energy cascade utilization, the distribution positions of various heat exchangers utilizing the heat of high-temperature molten salt are reasonably designed, and steam with different parameters based on energy grade cascade matching is efficiently produced to release the heat stored in the high-temperature molten salt storage tank 302, thereby realizing the cascade efficient utilization of the heat of high-temperature molten salt, greatly reducing the heat exchange temperature difference, and reducing irreversible losses. In addition, the feed water outlet of the feed water heater 101 is connected to the feed water inlet of the low-pressure steam generator 308 and the feed water reheater 309 respectively, and the heat release of the molten salt energy storage mechanism 30 is used to step-heat the feed water to produce steam of different qualities to meet the heating needs of high-pressure steam users 312 and medium-pressure steam users 313, avoiding the high-grade energy loss caused by direct cooling and pressure reduction of high-parameter main steam for heating, thereby increasing the work and power generation capacity of the steam turbine unit 20.

[0083] The above-mentioned 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 substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A heating unit coupled with molten salt energy storage deep peak regulation system, characterized in that: include: A circulating power generation mechanism, comprising a steam turbine unit and a waste heat utilization device, wherein the steam generated by the waste heat utilization device enters the steam turbine unit to perform work and generate electricity, and the waste heat utilization device comprises a feed water heater; The molten salt energy storage mechanism includes an energy storage component, a high-pressure steam generator, a low-pressure steam generator, a feedwater reheater, a first feedwater pump, a heat network heat exchanger, a high-pressure steam user, a medium-pressure steam user, a first steam temperature reduction and pressure reduction device, a steam pressure matcher, an industrial steam supply pipe and a molten salt bypass pipe; Wherein, the molten salt outlet of the energy storage component is connected to the molten salt inlet of the high-pressure steam generator, the molten salt outlet of the high-pressure steam generator is connected to the molten salt inlet of the low-pressure steam generator, the molten salt outlet of the low-pressure steam generator is connected to the molten salt inlet of the feedwater reheater, the molten salt bypass pipe is arranged between the molten salt inlet and the molten salt outlet of the low-pressure steam generator, and the molten salt outlet of the feedwater reheater is connected to the molten salt inlet of the energy storage component; The feedwater outlet of the feedwater heater is respectively connected to the feedwater inlet of the low-pressure steam generator and the feedwater inlet of the feedwater reheater, the feedwater inlet of the feedwater reheater is installed with the first feedwater pump, the steam outlet of the low-pressure steam generator is respectively connected to the steam inlet of the heat network heat exchanger and the steam inlet of the steam pressure matcher, the heat network heat exchanger performs heat exchange and provides external heating, the feedwater outlet of the feedwater reheater is connected to the steam inlet of the high-pressure steam generator, the steam outlet of the high-pressure steam generator is respectively connected to the high-pressure steam user, the first steam temperature reduction and pressure reduction device and the steam inlet of the steam pressure matcher through the industrial steam supply pipe, the steam outlet of the first steam temperature reduction and pressure reduction device and the steam outlet of the steam pressure matcher are both connected to the steam inlet of the medium-pressure steam user.

2. The system according to claim 1, characterized in that The circulating power generation mechanism also includes a circulating water supply system, which includes a condensate pump, a deaerator, a desalted water storage tank, a circulating water pump, a condensate pipe, a condenser and a drain pipe. The water outlet of the condensate pump is connected to the water inlet of the desalted water storage tank, the water outlet of the desalted water storage tank is connected to the water inlet of the deaerator, the water outlet of the desalted water storage tank is installed with the circulating water pump, the water outlet of the deaerator is connected to the water inlet of the feed water heater, the water outlet of the condenser is connected to the water inlet of the deaerator through the condensate pipe, the condensate pump is installed on the condensate pipe, and the drain outlet of the heat network heat exchanger is connected to the water inlet of the deaerator through the drain pipe.

3. The system according to claim 1, characterized in that The energy storage component includes a low-temperature molten salt storage tank, a high-temperature molten salt storage tank, a primary molten salt heater, a secondary molten salt heater, a low-temperature molten salt pump and a high-temperature molten salt pump. The low-temperature molten salt pump is installed at the molten salt outlet of the low-temperature molten salt storage tank, the molten salt outlet of the low-temperature molten salt storage tank is connected to the molten salt inlet of the primary molten salt heater, the molten salt outlet of the primary molten salt heater is connected to the molten salt inlet of the secondary molten salt heater, the molten salt outlet of the secondary molten salt heater is connected to the molten salt inlet of the high-temperature molten salt storage tank, the molten salt outlet of the high-temperature molten salt storage tank is connected to the molten salt inlet of the high-pressure steam generator, and the high-temperature molten salt pump is installed at the molten salt outlet of the high-temperature molten salt storage tank, and the molten salt outlet of the feed water reheater is connected to the molten salt inlet of the low-temperature molten salt storage tank.

4. The system according to claim 1, characterized in that The waste heat utilization device also includes a waste heat boiler, a low-pressure steam drum, a low-pressure superheater, a high-pressure steam drum, a high-pressure superheater and a second feedwater pump. The high-pressure superheater, the high-pressure steam drum, the low-pressure superheater, the low-pressure steam drum and the feedwater heater are sequentially arranged in the waste heat boiler along the flow direction from the flue gas inlet to the flue gas outlet. The feedwater outlet of the feedwater heater is respectively connected to the feedwater inlets of the low-pressure steam drum and the high-pressure steam drum. The feedwater inlet of the high-pressure steam drum is installed with the second feedwater pump. The steam outlet of the high-pressure steam drum is connected to the steam inlet of the high-pressure superheater, the steam outlet of the high-pressure superheater is connected to the steam turbine unit and high-pressure steam enters the steam turbine unit to perform work and generate electricity. The steam outlet of the low-pressure steam drum is connected to the steam inlet of the low-pressure superheater, the steam outlet of the low-pressure superheater is connected to the steam turbine unit and low-pressure steam enters the steam turbine unit to perform work and generate electricity.

5. The system according to claim 4, characterized in that The waste heat utilization device also includes a second steam cooling and pressure reduction device, a third steam cooling and pressure reduction device, a main steam pipe and a low-pressure supplementary steam pipe. The steam outlet of the high-pressure superheater is connected to the steam turbine unit through the main steam pipe, and high-pressure steam enters the steam turbine unit to perform work and generate electricity. The steam outlet of the main steam pipe is connected to the steam inlet of the second steam cooling and pressure reduction device, and the steam outlet of the second steam cooling and pressure reduction device is connected to the steam inlet of the medium-pressure steam user. The steam outlet of the main steam pipe is connected to the steam inlet of the third steam cooling and pressure reduction device, and the steam outlet of the third steam cooling and pressure reduction device is connected to the steam inlet of the high-pressure steam user. The steam outlet of the low-pressure superheater is connected to the steam turbine unit through the low-pressure supplementary steam pipe, and low-pressure steam enters the steam turbine unit to perform work and generate electricity. The low-pressure supplementary steam pipe is connected to the steam inlet of the heat network heat exchanger.

6. The system according to claim 4, characterized in that The energy storage component includes a primary molten salt heater and a secondary molten salt heater, both of which are arranged in the waste heat boiler, the primary molten salt heater is located between the low-pressure superheater and the low-pressure steam drum, the secondary molten salt heater is located between the high-pressure steam drum and the low-pressure superheater, or the secondary molten salt heater is located between the high-pressure superheater and the high-pressure steam drum.

7. The system according to claim 4, characterized in that The cycle power generation mechanism also includes a gas turbine unit, which 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 drives the first generator to generate electricity, and the exhaust port of the gas turbine turbine is connected to the air inlet of the waste heat boiler.

8. The system of claim 1, wherein: The steam turbine unit includes medium- and high-pressure cylinders, a low-pressure cylinder, a second generator and a connecting pipe. The steam outlet of the high-pressure steam superheater is connected to the steam inlet of the medium- and high-pressure cylinders, the steam outlet of the low-pressure steam superheater is connected to the steam inlet of the low-pressure cylinder, the steam outlet of the waste heat utilization device is respectively connected to the steam inlets of the medium- and high-pressure cylinders and the low-pressure cylinder, the steam outlet of the medium- and high-pressure cylinders is connected to the steam inlet of the low-pressure cylinder through the connecting pipe, the medium- and high-pressure cylinders and the low-pressure cylinder are both coaxially connected to the second generator, and the medium- and high-pressure cylinders and the low-pressure cylinder simultaneously work to drive the second generator to generate electricity.

9. A method for a heating unit coupled with a molten salt energy storage deep peak regulation system as claimed in claim 1, characterized in that: The steps include: Determining whether the system participates in power peak regulation; If the system participates in power peak regulation, determining whether it is necessary to reduce or increase the output power load; If the output power load needs to be reduced, part of the flue gas waste heat is used to heat the waste heat utilization device to generate steam, and the steam from the waste heat utilization device drives the steam turbine unit to work and generate electricity, and the other part of the flue gas waste heat is used to heat the low-temperature molten salt in the molten salt energy storage mechanism for heat storage; If the output power load needs to be increased, all the waste heat of the flue gas will be used to heat the waste heat utilization device to generate steam. The steam from the waste heat utilization device drives the steam turbine unit to work and generate electricity. If the output power load needs to be further increased, it is also necessary to supplement the water supply to the molten salt energy storage mechanism through the feed water heater. The molten salt energy storage mechanism releases heat to heat the feed water supplemented by the feed water heater into steam. The steam from the molten salt energy storage mechanism is used for external heating and steam supply to users.

10. The method according to claim 9, characterized in that If the output electrical load is to be further increased, it is necessary to supplement the water supply to the molten salt energy storage mechanism through the water supply heater. The molten salt energy storage mechanism releases heat to heat the water supplied by the water supply heater into steam. The steam of the molten salt energy storage mechanism is used for external heating and steam supply to users. The specific steps are as follows: The high-temperature molten salt output by the energy storage component is cooled step by step through the high-pressure steam generator, the low-pressure steam generator, the molten salt bypass pipe and the feedwater reheater to obtain low-temperature molten salt. The feedwater in the feedwater heater enters the low-pressure steam generator and the feedwater reheater respectively, and the feedwater is pressurized by the first feedwater pump before entering the feedwater reheater. The high-temperature and high-pressure feedwater output by the feedwater reheater then enters the high-pressure steam generator to absorb heat to obtain high-parameter steam, and steam is supplied to high-pressure steam users and medium-pressure steam users respectively through the industrial steam supply pipe; the low-parameter steam output by the low-pressure steam generator enters the heat exchanger of the heat network for heat exchange and then provides external heating; When the amount of low-parameter steam output by the low-pressure steam generator is greater than the steam demand of the heat network heat exchanger, or the amount of high-parameter steam output by the high-pressure steam generator cannot simultaneously meet the steam demands of high-pressure steam users and medium-pressure steam users, the low-parameter steam output by the low-pressure steam generator also enters the steam pressure matcher, and is mixed and matched with the high-parameter steam from the high-pressure steam generator to generate medium-pressure steam, which is then supplied to the medium-pressure steam users.

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