A latent heat utilization thermal power peak shaving system and a working method thereof

Abstract

The application provides a thermal power peak shaving system using latent heat and a working method thereof, and aims to solve the huge challenge that thermal power as an energy supply bears the main peak shaving power source in a power grid system for a long time. The application relates to the technical field of thermal power peak shaving, and stores heat energy in a molten salt medium through steam and electricity to meet the peak shaving demand of a thermal power unit. Further, the molten salt releases heat back to the thermal power unit, so that the peak capacity and operation economy of the unit are improved.

Description

Technical Field

[0001] This invention belongs to the field of thermal power peak shaving technology, specifically relating to a thermal power peak shaving system utilizing latent heat and its working method. Background Technology

[0002] Under the "dual carbon" goal, the construction of a green and low-carbon new power system with new energy as the mainstay is underway. Renewable energy is entering a new stage of large-scale, high-quality development. The annual increase in installed capacity of new energy, along with its randomness and volatility, poses significant challenges to the safety and stability of the power grid. To absorb more new energy while ensuring the safety and stability of the power grid, thermal power, as the "ballast" of energy supply, will play a major role and will serve as the main peak-shaving power source in the power grid system for a long time. During periods when new energy generation decreases or cannot generate electricity, thermal power needs to operate at full capacity to ensure a balance between the "source" and "load" sides. Therefore, higher requirements are placed on the flexible operation of thermal power units.

[0003] Molten salt energy storage technology, as an energy storage technology spanning multiple time scales, can reduce energy losses during peak shaving when coupled with thermal power units, while simultaneously releasing stored energy. It represents a highly promising and flexible retrofitting solution for thermal power units. Molten salt energy storage features high safety, flexible operation, high efficiency, and long lifespan, aligning well with the needs and development direction of thermal power units. This solution addresses current challenges faced by thermal power units by designing a thermal power peak shaving system utilizing latent heat. This system stores thermal energy in a molten salt medium using both steam (utilizing sensible and latent heat) and electricity to meet the peak shaving requirements of thermal power units. The released heat from the molten salt is then returned to the thermal power unit, enhancing its peak capacity and operational economy. Summary of the Invention

[0004] This invention provides a thermal power peak-shaving system and its operating method that utilizes latent heat. The purpose is to address the significant challenges faced by thermal power as the main peak-shaving power source in the power grid system for extended periods. By storing thermal energy in a molten salt medium through both steam and electricity, the system meets the peak-shaving needs of thermal power units. Furthermore, it enhances the ability of the molten salt to release heat back to the thermal power units, thereby improving the peak capacity and operational economy of the units.

[0005] The present invention adopts the following technical solution: A thermal power peak-shaving system utilizing latent heat includes: a thermal power generation system and a molten salt energy storage and heat exchange system.

[0006] The thermal power generation system includes a boiler 1, a high-pressure cylinder of a steam turbine 2, a medium-pressure cylinder of a steam turbine 3, a low-pressure cylinder of a steam turbine 4, a generator 5, a condenser 6, a first feedwater pump 7, a first low-pressure heater 8, a second low-pressure heater 9, a third low-pressure heater 10, a deaerator 11, a second feedwater pump 12, a first high-pressure heater 13, a second high-pressure heater 14, a third high-pressure heater 15, and a steam supply manifold 19.

[0007] The molten salt heat exchange system includes a main steam-molten salt heat exchanger 16, a reheat steam-molten salt first heat exchanger 17, a reheat steam-molten salt second heat exchanger 18, a molten salt electric heater 20, a high-temperature molten salt pump set 21, a high-temperature molten salt storage tank 22, a superheater 23, an evaporator 24, a preheater 25, a low-temperature molten salt storage tank 26, a low-temperature molten salt pump set 27, a low-temperature molten salt regulating valve 29.1, a high-temperature molten salt regulating valve 29.2, a third feedwater pump 30, and regulating valves.

[0008] Preferably, the main steam of boiler 1 is divided into two paths: the first path is connected to the high-pressure cylinder 2 of the steam turbine, and the second path is connected to the main steam-molten salt heat exchanger 16; the reheat steam of boiler 1 is divided into three paths: the first path is connected to the intermediate-pressure cylinder 3 of the steam turbine, the second path is connected to the first reheat steam-molten salt heat exchanger 17, and the third path is connected to the second reheat steam-molten salt heat exchanger 18.

[0009] Preferably, the extraction port of the high-pressure cylinder 2 of the steam turbine is connected to the third high-pressure heater 15, and the exhaust of the high-pressure cylinder 2 is connected to the boiler 1 and the second high-pressure heater 14 respectively; the extraction port of the intermediate-pressure cylinder 3 of the steam turbine is connected to the first high-pressure heater 13 and the deaerator 11 respectively, and the exhaust of the intermediate-pressure cylinder 3 is connected to the low-pressure cylinder 4 of the steam turbine; the extraction port of the low-pressure cylinder 4 of the steam turbine is connected to the third low-pressure heater 10, the second low-pressure heater 9, and the first low-pressure heater 8 respectively, and the exhaust of the low-pressure cylinder 4 is connected to the condenser 6; the condensate in the condenser 6 is pressurized by the first feedwater pump 7 and flows through the first low-pressure heater. 8. After being pressurized by the second low-pressure heater 9, the third low-pressure heater 10, the deaerator 11, and the second feedwater pump 12, the water flows through the first high-pressure heater 13, the second high-pressure heater 14, and the third high-pressure heater 15, and then through the boiler 1 to generate steam. The third high-pressure heater 15 drains water to the second high-pressure heater 14; the second high-pressure heater 14 drains water to the first high-pressure heater 13; the first high-pressure heater 13 drains water to the deaerator 11; the third low-pressure heater 10 drains water to the second low-pressure heater 9; the second low-pressure heater 9 drains water to the first low-pressure heater 8; and the first low-pressure heater 8 drains water to the condenser 6.

[0010] Preferably, the main steam-molten salt heat exchanger 16 is connected to the main steam of the boiler 1 and the exhaust steam of the high-pressure cylinder 2 of the turbine on the steam-water side, and to the low-temperature molten salt regulating valve 29.1, the low-temperature molten salt pump group 27, the low-temperature molten salt storage tank 26, and the molten salt electric heater 20 on the molten salt side; the reheat steam-molten salt first heat exchanger 17 is connected to the reheat steam of the boiler 1 and the deaerator 11 on the steam-water side, and to the low-temperature molten salt regulating valve 29.1, the low-temperature molten salt pump group 27, the low-temperature molten salt storage tank 26, and the molten salt electric heater 20 on the molten salt side; the reheat steam-molten salt second heat exchanger 18 is connected to the reheat steam of the boiler 1 and the steam supply manifold 19 on the steam-water side, and to the low-temperature molten salt regulating valve 29.1, the low-temperature molten salt pump group 27, the low-temperature molten salt storage tank 26, and the molten salt electric heater 20 on the molten salt side. Molten salt pump set 27, low-temperature molten salt storage tank 26, molten salt electric heater 20, and high-temperature molten salt storage tank 22 are connected; molten salt electric heater 20 is connected to generator 5, high-temperature molten salt storage tank 22, main steam-molten salt heat exchanger 16, reheat steam-molten salt first heater 17, and reheat steam-molten salt second heater 18; high-temperature molten salt storage tank 22 is connected to high-temperature molten salt pump set 21, high-temperature molten salt regulating valve 29.2, superheater 23, evaporator 24, preheater 25, and low-temperature molten salt storage tank 26; high-temperature molten salt regulating valve 29.2 is connected to superheater 23, evaporator 24, and preheater 25; third feedwater pump 30 is connected to superheater 23, evaporator 24, preheater 25, and turbine intermediate pressure cylinder 3 exhaust.

[0011] The regulating valves include the first regulating valve 28.1, the second regulating valve 28.2, the third regulating valve 28.3, the fourth regulating valve 28.4, the fifth regulating valve 28.5, the sixth regulating valve 28.6, the seventh regulating valve 28.7, and the eighth regulating valve 28.8.

[0012] A method for operating a thermal power peak-shaving system utilizing latent heat includes: (1) When the thermal power unit receives the deep adjustment command, the molten salt energy storage system is in the process of storing heat. The boiler is operating at the minimum stable combustion load. One of the main steam generated enters the high pressure cylinder of the turbine to do work, and the other flows into the exhaust pipe of the high pressure cylinder of the turbine after heat storage and cooling through the main steam-molten salt heat exchanger. After merging with the exhaust steam of the high pressure cylinder, it enters the boiler for reheating. One of the reheat steam generated by the boiler enters the intermediate pressure cylinder of the turbine to do work, and the other continues to be divided into two paths to pass through the molten salt heat storage and cooling. The first path of reheat steam condenses into water after passing through the first reheat steam-molten salt heat exchanger and flows into the deaerator to utilize the latent heat of the reheat steam. The second path of reheat steam can enter the low pressure cylinder to continue to do work or flow into the steam supply header to provide steam to the outside according to the actual needs of the thermal power unit after passing through the second reheat steam-molten salt heat exchanger. (2) The low-temperature molten salt flows from the low-temperature molten salt storage tank through the low-temperature molten salt valve and is divided into three paths, which enter the main steam-molten salt heat exchanger, the first reheat steam-molten salt heat exchanger, and the second reheat steam-molten salt heat exchanger respectively. The molten salt is then combined and flows into the molten salt electric heater. After being heated by the molten salt electric heater, the molten salt flows out and enters the high-temperature molten salt storage tank for storage. (3) When the molten salt energy storage system releases heat, a condensate is taken from the outlet of the third low-pressure heater, pressurized by the third feed water pump, and then enters the preheater, evaporator and superheater to generate steam. According to the actual needs of the thermal power unit, it enters the low-pressure cylinder to continue to do work or flows into the steam supply header to provide steam to the outside or returns to the high-pressure heater system to replace the high-pressure heater extraction steam to boost the unit load. (4) The high-temperature molten salt flows out of the high-temperature molten salt tank driven by the high-temperature molten salt pump, and after passing through the heater, evaporator, preheater and exchanging heat with water or steam, it returns to the low-temperature molten salt tank for storage.

[0013] Preferably, in the operation of a thermal power peak-shaving system utilizing latent heat, the extraction rates of main steam and reheat steam are the same.

[0014] The present invention, by adopting the above technical solution, has the following beneficial effects: (1) Ensure that the extraction rates of main steam and reheat steam are consistent to avoid problems with turbine thrust. After the main steam is heated, it returns to the cold reheat pipeline to avoid overheating and overspeeding of the boiler reheater.

[0015] (2) It utilizes both the sensible heat and latent heat of reheated steam, which can make greater use of the heat of steam and improve energy efficiency.

[0016] (3) The operating mode of steam generation by molten salt exothermic can be flexibly adjusted according to different steam demand, thereby improving overall efficiency and economy.

[0017] (4) By utilizing the electric heating of the unit, the overall temperature of the molten salt can be increased, and more heat can be stored in the same volume of molten salt.

[0018] (5) Simultaneously utilize electric heating and steam heating of molten salt to decouple the turbine and boiler, thereby improving the unit's deep regulation range and the level of new energy consumption. Attached Figure Description

[0019] Figure 1 A schematic diagram of a thermal power peak-shaving system utilizing latent heat; Among them: 1-boiler, 2-high-pressure cylinder of steam turbine, 3-intermediate-pressure cylinder of steam turbine, 4-low-pressure cylinder of steam turbine, 5-generator, 6-condenser, 7-first feedwater pump, 8-first low-pressure heater, 9-second low-pressure heater, 10-third low-pressure heater, 11-deaerator, 12-second feedwater pump, 13-first high-pressure heater, 14-second high-pressure heater, 15-third high-pressure heater, 16-main steam-molten salt heat exchanger, 17-first reheat steam-molten salt heat exchanger, 18-second reheat steam-molten salt heat exchanger, 19-steam supply unit 20-Molten salt electric heater, 21-High temperature molten salt pump set, 22-High temperature molten salt storage tank, 23-Superheater, 24-Evaporator, 25-Preheater, 26-Low temperature molten salt storage tank, 27-Low temperature molten salt pump set, 28.1-First regulating valve, 28.2-Second regulating valve, 28.3-Third regulating valve, 28.4-Fourth regulating valve, 28.5-Fifth regulating valve, 28.6-Sixth regulating valve, 28.7-Seventh regulating valve, 28.8-Eighth regulating valve, 29.1-Low temperature molten salt regulating valve, 29.2-High temperature molten salt regulating valve, 30-Third feed water pump. Detailed Implementation

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0021] Example 1 A thermal power peak-shaving system utilizing latent heat, comprising a thermal power generation system and a molten salt heat storage and exchange system; The thermal power generation system includes a boiler 1, a high-pressure cylinder of a steam turbine 2, an intermediate-pressure cylinder of a steam turbine 3, a low-pressure cylinder of a steam turbine 4, a generator 5, a condenser 6, a first feedwater pump 7, a first low-pressure heater 8, a second low-pressure heater 9, a third low-pressure heater 10, a deaerator 11, a second feedwater pump 12, a first high-pressure heater 13, a second high-pressure heater 14, a third high-pressure heater 15, and a steam supply header 19. The molten salt heat exchange system includes a main steam-molten salt heat exchanger 16, a reheat steam-molten salt first heat exchanger 17, a reheat steam-molten salt second heat exchanger 18, a molten salt electric heater 20, a high-temperature molten salt pump set 21, a high-temperature molten salt storage tank 22, a superheater 23, an evaporator 24, a preheater 25, a low-temperature molten salt storage tank 26, a low-temperature molten salt pump set 27, a low-temperature molten salt regulating valve 29.1, a high-temperature molten salt regulating valve 29.2, a third feedwater pump 30, and regulating valves.

[0022] The main steam of boiler 1 is divided into two paths: the first path is connected to the high-pressure cylinder 2 of the steam turbine, and the second path is connected to the main steam-molten salt heat exchanger 16. The reheat steam of boiler 1 is divided into three paths: the first path is connected to the intermediate-pressure cylinder 3 of the steam turbine, the second path is connected to the first reheat steam-molten salt heat exchanger 17, and the third path is connected to the second reheat steam-molten salt heat exchanger 18. The extraction port of the high-pressure cylinder 2 of the steam turbine is connected to the third high-pressure heater 15, and the exhaust of the high-pressure cylinder 2 is connected to the boiler 1 and the second high-pressure heater 14. The extraction port of the intermediate-pressure cylinder 3 of the steam turbine is connected to the first high-pressure heater 13 and the deaerator 11, and the exhaust of the intermediate-pressure cylinder 3 is connected to the low-pressure cylinder 4 of the steam turbine. The extraction port of the low-pressure cylinder 4 of the steam turbine is connected to the third low-pressure heater 10, the second low-pressure heater 9, and the first low-pressure heater 8, and the exhaust of the low-pressure cylinder 4 is connected to the condenser 6. The condensate in the condenser 6 is pressurized by the first feedwater pump 7 and then flows through the first low-pressure heater 8. After being pressurized by the second low-pressure heater 9, the third low-pressure heater 10, the deaerator 11, and the second feedwater pump 12, the steam flows through the first high-pressure heater 13, the second high-pressure heater 14, and the third high-pressure heater 15, and then through the boiler 1 to generate steam. The third high-pressure heater 15 drains water to the second high-pressure heater 14; the second high-pressure heater 14 drains water to the first high-pressure heater 13; the first high-pressure heater 13 drains water to the deaerator 11; the third low-pressure heater 10 drains water to the second low-pressure heater 9; the second low-pressure heater 9 drains water to the first low-pressure heater 8; and the first low-pressure heater 8 drains water to the condenser 6. The main steam-molten salt heat exchanger 16 is connected to the main steam of the boiler 1 and the exhaust steam of the high-pressure cylinder 2 of the turbine on the steam-water side, and to the low-temperature molten salt regulating valve 29.1, the low-temperature molten salt pump group 27, the low-temperature molten salt storage tank 26, and the molten salt electric heater 20 on the molten salt side. The first reheat steam-molten salt heat exchanger 17 is connected to the reheat steam of the boiler 1 and the deaerator 11 on the steam-water side, and to the low-temperature molten salt regulating valve 29.1, the low-temperature molten salt pump group 27, the low-temperature molten salt storage tank 26, and the molten salt electric heater 20 on the molten salt side. The second reheat steam-molten salt heat exchanger 18 is connected to the reheat steam of the boiler 1 and the steam supply header 19 on the steam-water side, and to the low-temperature molten salt regulating valve 29.1 and the low-temperature molten salt on the molten salt side. Pump set 27, low-temperature molten salt storage tank 26, molten salt electric heater 20, and high-temperature molten salt storage tank 22 are connected; molten salt electric heater 20 is connected to generator 5, high-temperature molten salt storage tank 22, main steam-molten salt heat exchanger 16, reheat steam-molten salt first heater 17, and reheat steam-molten salt second heater 18; high-temperature molten salt storage tank 22 is connected to high-temperature molten salt pump set 21, high-temperature molten salt regulating valve 29.2, superheater 23, evaporator 24, preheater 25, and low-temperature molten salt storage tank 26; high-temperature molten salt regulating valve 29.2 is connected to superheater 23, evaporator 24, and preheater 25; third feedwater pump 30 is connected to superheater 23, evaporator 24, preheater 25, and turbine intermediate pressure cylinder 3 exhaust.

[0023] Example 2 A method for operating a thermal power peak-shaving system utilizing latent heat includes: (1) When the thermal power unit receives the deep adjustment command, the molten salt energy storage system is in the process of storing heat. The boiler is operating at the minimum stable combustion load. One of the main steam generated enters the high pressure cylinder of the turbine to do work, and the other flows into the exhaust pipe of the high pressure cylinder of the turbine after heat storage and cooling through the main steam-molten salt heat exchanger. After merging with the exhaust steam of the high pressure cylinder, it enters the boiler for reheating. One of the reheat steam generated by the boiler enters the intermediate pressure cylinder of the turbine to do work, and the other continues to be divided into two paths to pass through the molten salt heat storage and cooling. The first path of reheat steam condenses into water after passing through the first reheat steam-molten salt heat exchanger and flows into the deaerator to utilize the latent heat of the reheat steam. The second path of reheat steam can enter the low pressure cylinder to continue to do work or flow into the steam supply header to provide steam to the outside according to the actual needs of the thermal power unit after passing through the second reheat steam-molten salt heat exchanger. (2) The low-temperature molten salt flows from the low-temperature molten salt storage tank through the low-temperature molten salt valve and is divided into three paths, which enter the main steam-molten salt heat exchanger, the first reheat steam-molten salt heat exchanger, and the second reheat steam-molten salt heat exchanger respectively. The molten salt is then combined and flows into the molten salt electric heater. After being heated by the molten salt electric heater, the molten salt flows out and enters the high-temperature molten salt storage tank for storage. (3) When the molten salt energy storage system releases heat, a condensate is taken from the outlet of the third low-pressure heater, pressurized by the third feed water pump, and then enters the preheater, evaporator and superheater to generate steam. According to the actual needs of the thermal power unit, it enters the low-pressure cylinder to continue to do work or flows into the steam supply header to provide steam to the outside or returns to the high-pressure heater system to replace the high-pressure heater extraction steam to boost the unit load. (4) The high-temperature molten salt flows out of the high-temperature molten salt tank driven by the high-temperature molten salt pump, and after passing through the heater, evaporator, preheater and exchanging heat with water or steam, it returns to the low-temperature molten salt tank for storage.

[0024] The extraction rates of main steam and reheat steam are the same.

[0025] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A thermal power peak-shaving system utilizing latent heat, characterized in that: This includes thermal power generation systems and molten salt energy storage and heat exchange systems; The thermal power generation system includes: a boiler (1), a high-pressure cylinder of a steam turbine (2), a medium-pressure cylinder of a steam turbine (3), a low-pressure cylinder of a steam turbine (4), a generator (5), a condenser (6), a first feedwater pump (7), a first low-pressure heater (8), a second low-pressure heater (9), a third low-pressure heater (10), a deaerator (11), a second feedwater pump (12), a first high-pressure heater (13), a second high-pressure heater (14), a third high-pressure heater (15), and a steam supply manifold (19). The molten salt energy storage heat exchange system includes: a main steam-molten salt heat exchanger (16), a reheat steam-molten salt first heat exchanger (17), a reheat steam-molten salt second heat exchanger (18), a molten salt electric heater (20), a high-temperature molten salt pump group (21), a high-temperature molten salt storage tank (22), a superheater (23), an evaporator (24), a preheater (25), a low-temperature molten salt storage tank (26), a low-temperature molten salt pump group (27), a low-temperature molten salt regulating valve (29.1), a high-temperature molten salt regulating valve (29.2), a third feed water pump (30), and regulating valves; The main steam of the boiler (1) is divided into two paths. The first path is connected to the high-pressure cylinder (2) of the steam turbine, and the second path is connected to the main steam-molten salt heat exchanger (16). The reheat steam of the boiler (1) is divided into three paths: the first path is connected to the intermediate pressure cylinder (3) of the steam turbine, the second path is connected to the first reheat steam-molten salt heat exchanger (17), and the third path is connected to the second reheat steam-molten salt heat exchanger (18). The main steam-molten salt heat exchanger (16) is connected to the main steam of the boiler (1) and the exhaust steam of the high-pressure cylinder (2) of the steam turbine on the steam-water side, and to the low-temperature molten salt regulating valve (29.1), the low-temperature molten salt pump group (27), the low-temperature molten salt storage tank (26), and the molten salt electric heater (20) on the molten salt side; the first reheat steam-molten salt heat exchanger (17) is connected to the reheat steam and deaerator (11) of the boiler (1) on the steam-water side, and to the low-temperature molten salt regulating valve (29.1), the low-temperature molten salt pump group (27), the low-temperature molten salt storage tank (26), the molten salt electric heater (20), and the high-temperature molten salt storage tank (22) on the molten salt side; the second reheat steam-molten salt heat exchanger (18) is connected to the reheat steam and steam supply manifold (19) of the boiler (1) on the steam-water side, and to the low-temperature molten salt regulating valve (29.1), the low-temperature molten salt pump group (27), the low-temperature molten salt storage tank (26), the molten salt electric heater (20), and the high-temperature molten salt storage tank (22) on the molten salt side; The pump set (27), the low temperature molten salt storage tank (26), the molten salt electric heater (20), and the high temperature molten salt storage tank (22) are connected; the molten salt electric heater (20) is connected to the generator (5), the high temperature molten salt storage tank (22), the main steam-molten salt heat exchanger (16), the reheat steam-molten salt first heat exchanger (17), and the reheat steam-molten salt second heat exchanger (18); the high temperature molten salt storage tank (22) is connected to the high temperature molten salt pump set (21), the high temperature molten salt regulating valve (29.2), the superheater (23), the evaporator (24), the preheater (25), and the low temperature molten salt storage tank (26); the high temperature molten salt regulating valve (29.2) is connected to the superheater (23), the evaporator (24), and the preheater (25); the third feed water pump (30) is connected to the superheater (23), the evaporator (24), the preheater (25), and the exhaust of the turbine intermediate pressure cylinder (3).

2. The thermal power peak-shaving system utilizing latent heat according to claim 1, characterized in that: The steam extraction port of the high-pressure cylinder (2) of the steam turbine is connected to the third high-pressure heater (15), and the exhaust of the high-pressure cylinder of the steam turbine is connected to the boiler (1) and the second high-pressure heater (14) respectively; the steam extraction port of the intermediate-pressure cylinder (3) of the steam turbine is connected to the first high-pressure heater (13) and the deaerator (11) respectively, and the exhaust of the intermediate-pressure cylinder (3) of the steam turbine is connected to the low-pressure cylinder (4) of the steam turbine; the steam extraction port of the low-pressure cylinder (4) of the steam turbine is connected to the third low-pressure heater (10), the second low-pressure heater (9), and the first low-pressure heater (8) respectively, and the exhaust of the low-pressure cylinder (4) of the steam turbine is connected to the condenser (6); the condensate in the condenser (6) is pressurized by the first feedwater pump (7) and flows through the first low-pressure heater (8) and the second low-pressure heater (9). After being pressurized by the high-pressure heater (9), the third low-pressure heater (10), the deaerator (11), and the second feedwater pump (12), the steam flows through the first high-pressure heater (13), the second high-pressure heater (14), and the third high-pressure heater (15), and then through the boiler (1) to generate steam. The third high-pressure heater (15) drains water to the second high-pressure heater (14); the second high-pressure heater (14) drains water to the first high-pressure heater (13); the first high-pressure heater (13) drains water to the deaerator (11); the third low-pressure heater (10) drains water to the second low-pressure heater (9); the second low-pressure heater (9) drains water to the first low-pressure heater (8); and the first low-pressure heater drains water to the condenser (6).

3. The thermal power peak-shaving system utilizing latent heat according to claim 1, characterized in that: The regulating valves include a first regulating valve (28.1), a second regulating valve (28.2), a third regulating valve (28.3), a fourth regulating valve (28.4), a fifth regulating valve (28.5), a sixth regulating valve (28.6), a seventh regulating valve (28.7), and an eighth regulating valve (28.8).

4. A method for operating a thermal power peak-shaving system utilizing latent heat as described in claim 1 or 2, characterized in that, The working method includes: (1) When the thermal power unit receives the deep adjustment command, the molten salt energy storage system is in the process of storing heat. The boiler is operating at the minimum stable combustion load. One of the main steam generated enters the high pressure cylinder of the turbine to do work, and the other flows into the exhaust pipe of the high pressure cylinder of the turbine after heat storage and cooling through the main steam-molten salt heat exchanger. After merging with the exhaust steam of the high pressure cylinder, it enters the boiler for reheating. One of the reheat steam generated by the boiler enters the intermediate pressure cylinder of the turbine to do work, and the other continues to be divided into two paths to pass through the molten salt heat storage and cooling. The first path of reheat steam condenses into water after passing through the first reheat steam-molten salt heat exchanger and flows into the deaerator to utilize the latent heat of the reheat steam. The second path of reheat steam can enter the low pressure cylinder to continue to do work or flow into the steam supply header to provide steam to the outside according to the actual needs of the thermal power unit after passing through the second reheat steam-molten salt heat exchanger. (2) The low-temperature molten salt flows from the low-temperature molten salt storage tank through the low-temperature molten salt regulating valve and is divided into three streams, which enter the main steam-molten salt heat exchanger, the first reheat steam-molten salt heat exchanger, and the second reheat steam-molten salt heat exchanger respectively. The molten salt is then combined and flows into the molten salt electric heater. After being heated by the molten salt electric heater, the molten salt flows out and enters the high-temperature molten salt storage tank for storage. (3) When the molten salt energy storage system releases heat, a condensate is taken from the outlet of the third low-pressure heater, pressurized by the third feed water pump, and then enters the preheater, evaporator and superheater to generate steam. According to the actual needs of the thermal power unit, it enters the low-pressure cylinder to continue to do work or flows into the steam supply header to provide steam to the outside or returns to the high-pressure heater system to replace the high-pressure heater extraction steam to boost the unit load. (4) The high-temperature molten salt flows out of the high-temperature molten salt tank driven by the high-temperature molten salt pump, and after passing through the heater, evaporator, preheater and exchanging heat with water or steam, it returns to the low-temperature molten salt tank for storage.

5. The operating method of the thermal power peak-shaving system utilizing latent heat according to claim 4, characterized in that: The extraction rates of the main steam and reheat steam are the same.

Images