A molten salt energy storage heat supply power generation system

Abstract

The present application relates to molten salt energy storage technical field, specifically to a kind of molten salt energy storage heat supply power generation system, including low temperature molten salt tank, first high temperature molten salt tank, second high temperature molten salt tank, also include: first heat exchanger, second heat exchanger, third heat exchanger and fourth heat exchanger.In molten salt energy storage heat supply power generation system peak shaving and frequency modulation, using gas turbine body and steam turbine body work power generation peak shaving, while also can be steam turbine body extraction steam produces external heating.In system without starting machine peak shaving and frequency modulation, heating steam is generated by high temperature molten salt in fourth heat exchanger with feed water heat exchange.In gas turbine body shutdown maintenance period, third heat exchanger works, and heat energy in molten salt is replaced into medium water in its low temperature side through third heat exchanger, so that it forms high temperature and high pressure steam to drive steam turbine body operation and external power generation.Outside continuous stable heating is realized, and peak shaving and frequency modulation operation is also realized when gas turbine body shutdown maintenance.

Description

Technical Field

[0001] This invention relates to the field of molten salt energy storage technology, and more specifically to a molten salt energy storage heating and power generation system. Background Technology

[0002] Molten salt energy storage technology uses high-temperature molten salt as a medium to convert excess electrical energy into heat energy using energy storage devices. This heat energy is then stored and converted back into electricity to supply the power grid when needed. Molten salt energy storage technology mainly consists of two stages: energy storage and energy release. In the energy storage stage, electrical energy is converted into heat energy through an electrothermal conversion device, and the heat energy is transferred to the molten salt for storage. In the energy release stage, the molten salt converts the stored heat energy back into electricity through a thermal energy conversion device, supplying it to the power grid.

[0003] In existing technologies, molten salt energy storage power generation and heating systems utilize a pair of molten salt tanks. High-temperature molten salt circulates within these tanks, absorbing or releasing heat from the outside environment during the circulation process to achieve energy storage or release. This is often coupled with coal-fired power units for deep peak shaving. However, in gas turbine power plants, power generation for peak shaving and frequency regulation is impossible when the gas turbine is shut down for maintenance. Furthermore, combined cycle gas turbine systems cannot continuously and efficiently provide external heat. Therefore, a molten salt energy storage system suitable for heat and power generation in gas turbine power plants has been designed. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the inability of gas turbine power plants to generate electricity for peak shaving and frequency regulation during shutdown and maintenance, and the inability of combined cycle systems to continuously and efficiently supply heat to the outside world, thereby providing a molten salt energy storage heating and power generation system.

[0005] To address the aforementioned technical problems, this invention provides a molten salt energy storage and thermal power generation system, comprising a low-temperature molten salt tank, a first high-temperature molten salt tank, and a second high-temperature molten salt tank, and further comprising:

[0006] The first heat exchanger has its high-temperature side inlet connected to the flue gas outlet of the gas turbine body, its low-temperature side inlet connected to the low-temperature molten salt tank, and its low-temperature side outlet connected to the second high-temperature molten salt tank.

[0007] The second heat exchanger has its high-temperature side inlet connected to the high-temperature side outlet of the first heat exchanger, its high-temperature side outlet connected to the flue gas side inlet of the waste heat boiler, its low-temperature side inlet connected to the low-temperature molten salt tank, and its low-temperature side outlet connected to the first high-temperature molten salt tank.

[0008] The third heat exchanger has its high-temperature side inlet connected to the second high-temperature molten salt tank, its high-temperature side outlet connected to the low-temperature molten salt tank, its low-temperature side inlet connected to the condenser outlet in the steam turbine generator system, and its low-temperature side outlet connected to the steam turbine body in the steam turbine generator system.

[0009] The fourth heat exchanger has its high-temperature side inlet connected to the first high-temperature molten salt tank, its high-temperature side outlet connected to the low-temperature molten salt tank, and its low-temperature side inlet and outlet connected to the heating channel.

[0010] Optionally, it also includes a gas turbine subsystem, which includes a gas turbine body, the flue gas outlet of which is also connected to the flue gas inlet of the waste heat boiler.

[0011] Optionally, the turbine power generation system includes a waste heat boiler, a turbine body, and a condenser that are connected in sequence. The outlet of the condenser is connected to the steam-side inlet of the waste heat boiler, and the turbine body is provided with an extraction steam passage connected to the heating passage.

[0012] Optionally, a No. 1 three-way valve is provided between the gas turbine body and the first heat exchanger, and the bypass of the No. 1 three-way valve is connected to the high-temperature side inlet of the second heat exchanger.

[0013] Optionally, a No. 2 three-way valve is provided between the high-temperature side outlet of the first heat exchanger and the high-temperature side inlet of the second heat exchanger, and the bypass of the No. 2 three-way valve is connected to the flue gas side inlet supplied by the waste heat boiler.

[0014] Optionally, a water supply channel is connected to the condenser, and a water supply pump is installed on the water supply channel.

[0015] Optionally, a heating booster pump is installed on the heating channel.

[0016] Optionally, a heating water pump is installed on the heating channel upstream of the fourth heat exchanger, and a heating water filter is installed between the heating water pump and the fourth heat exchanger.

[0017] Optionally, a first molten salt pump is installed at the outlet end of the cryogenic molten salt tank, and a first circulation channel and a second circulation channel are connected in parallel at the outlet of the first molten salt pump. The first circulation channel is connected to the first heat exchanger, and the second circulation channel is connected to the second heat exchanger.

[0018] A second molten salt pump is installed between the outlet end of the first high-temperature molten salt tank and the fourth heat exchanger;

[0019] A third molten salt pump is installed between the outlet of the second high-temperature molten salt tank and the third heat exchanger.

[0020] Optionally, the outlet end of the low-temperature molten salt tank is connected to the inlet end of the first high-temperature molten salt tank via a first auxiliary channel;

[0021] And / or the outlet end of the low-temperature molten salt tank is connected to the inlet end of the second high-temperature molten salt tank by a second auxiliary channel;

[0022] And / or the inlet end of the low-temperature molten salt tank is connected to the outlet end of the first high-temperature molten salt tank by a third auxiliary channel;

[0023] And / or the inlet end of the low-temperature molten salt tank is connected to the outlet end of the second high-temperature molten salt tank via a fourth auxiliary channel.

[0024] The technical solution of this invention has the following advantages:

[0025] 1. The molten salt energy storage and heating power generation system provided by the present invention includes a low-temperature molten salt tank, a first high-temperature molten salt tank, and a second high-temperature molten salt tank, and further includes: a first heat exchanger, whose high-temperature side inlet is connected to the flue gas outlet of the gas turbine body, its low-temperature side inlet is connected to the low-temperature molten salt tank, and its low-temperature side outlet is connected to the second high-temperature molten salt tank; a second heat exchanger, whose high-temperature side inlet is connected to the high-temperature side outlet of the first heat exchanger, its high-temperature side outlet is connected to the flue gas side inlet of the waste heat boiler, its low-temperature side inlets are all connected to the low-temperature molten salt tank, and its low-temperature side outlet is connected to the first high-temperature molten salt tank; a third heat exchanger, whose high-temperature side inlet is connected to the second high-temperature molten salt tank, its high-temperature side outlet is connected to the low-temperature molten salt tank, its low-temperature side inlet is connected to the condenser outlet in the steam turbine power generation system, and its low-temperature side outlet is connected to the steam turbine body in the steam turbine power generation system; and a fourth heat exchanger, whose high-temperature side inlet is connected to the first high-temperature molten salt tank, its high-temperature side outlet is connected to the low-temperature molten salt tank, and its low-temperature side inlet and outlet are connected to the heating channel.

[0026] A molten salt energy storage system is coupled to the gas turbine power generation system and the steam turbine power generation system. The molten salt tanks are configured as separate units, and a first heat exchanger and a second heat exchanger are installed in parallel at the inlets of the first and second high-temperature molten salt tanks. These heat exchangers work in conjunction with the gas turbine to absorb heat from the flue gas output from the gas turbine and transfer the waste heat from the flue gas to a waste heat boiler for reuse. A third heat exchanger and a fourth heat exchanger are installed at the outlets of the first and second high-temperature molten salt tanks, respectively. The third heat exchanger heats the return water in the steam turbine power generation system, and the fourth heat exchanger provides external heat through a heating channel. During peak shaving and frequency regulation, the gas turbine and steam turbine power generation systems drive their respective generators to generate electricity, and the steam turbine can also extract steam for external heat supply. When the system is not operating for peak shaving and frequency regulation, the heating steam is generated by the heat exchange between high-temperature molten salt and feedwater in the fourth heat exchanger, ensuring continuous and stable heating 24 hours a day. During gas turbine maintenance shutdowns, when the gas turbine cannot start, if a peak shaving and frequency regulation instruction is received, the molten salt in the molten salt energy storage heating and power generation system circulates in the second high-temperature molten salt tank and the low-temperature molten salt tank. The third heat exchanger operates, transferring the heat energy from the molten salt to the low-temperature medium water, causing the water to evaporate and form high-temperature, high-pressure steam to drive the turbine for power generation. By configuring the high-temperature molten salt storage components as separate first and second high-temperature molten salt tanks, continuous and stable heating is achieved, while peak shaving and frequency regulation are also possible when the gas turbine is shut down for maintenance.

[0027] 2. The molten salt energy storage heating and power generation system provided by this invention includes a steam turbine power generation system comprising a waste heat boiler, a steam turbine body, and a condenser connected in a sequential cycle. The outlet of the condenser is connected to the steam inlet on the waste heat boiler side. The steam turbine body is equipped with an extraction steam channel connected to the heating channel. During system peak shaving and frequency regulation, the heating steam in the heating channel is generated by steam extraction from the steam turbine body to ensure that the system can still provide stable heating during peak shaving and frequency regulation. The steam turbine body shares a heating channel for external heating via extraction steam and external heating via heat exchange in the fourth heat exchanger, reducing the piping layout within the system. Attached Figure Description

[0028] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1This is a schematic diagram of a molten salt energy storage and heating power generation system provided in an embodiment of the present invention.

[0030] Explanation of reference numerals in the attached drawings: 1. First generator; 2. Compressor; 3. Fuel inlet; 4. Combustion chamber; 5. Gas turbine; 6. Waste heat boiler; 7. Flue gas treatment device; 8. Chimney; 9. Turbine body; 10. Second generator; 11. Condenser; 12. Circulating water pump; 13. Deaerator; 14. Makeup water filter; 15. Makeup water pump; 16. First return water switch; 17. Second return water switch; 18. No. 1 three-way valve; 19. First heat exchanger; 20. No. 2 three-way valve; 21. Second heat exchanger; 22. Flue gas switch; 23. First circulation switch; 24. Second circulation switch. 25. Switch; 26. First molten salt pump; 27. Third circulation switch; 28. Fourth circulation switch; 29. ​​Low-temperature molten salt tank; 30. First high-temperature molten salt tank; 31. Second molten salt pump; 32. Fifth circulation switch; 33. Sixth circulation switch; 34. Second high-temperature molten salt tank; 35. Third molten salt pump; 36. Seventh circulation switch; 37. Eighth circulation switch; 38. Third heat exchanger; 39. Fourth heat exchanger; 40. Heating water supply pump; 41. Heating water supply filter; 42. First heating switch; 43. Second heating switch; 44. Heating pressurization pump; 45. User; 46. Power grid. Detailed Implementation

[0031] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] Figure 1 The diagram shows a molten salt energy storage and heating power generation system provided in this embodiment, including a low-temperature molten salt tank 28, a first high-temperature molten salt tank 29, a second high-temperature molten salt tank 33, a first heat exchanger 19, a second heat exchanger 21, a third heat exchanger 37, and a fourth heat exchanger 38. The high-temperature inlet of the first heat exchanger 19 is connected to the flue gas outlet of the gas turbine body, the low-temperature inlet of the first heat exchanger 19 is connected to the low-temperature molten salt tank 28, and the low-temperature outlet of the first heat exchanger 19 is connected to the second high-temperature molten salt tank 33. The high-temperature inlet of the second heat exchanger 21 is connected to the high-temperature outlet of the first heat exchanger 19, the high-temperature outlet of the second heat exchanger 21 is connected to the flue gas inlet of the waste heat boiler 6, the low-temperature inlet of the second heat exchanger 21 is connected to the low-temperature molten salt tank 28, and the low-temperature outlet of the second heat exchanger 21 is connected to the first high-temperature molten salt tank 29. The high-temperature side inlet of heat exchanger 37 is connected to the second high-temperature molten salt tank 33, the high-temperature side outlet of the third heat exchanger 37 is connected to the low-temperature molten salt tank 28, the low-temperature side inlet of the third heat exchanger 37 is connected to the outlet of the condenser 11 in the turbine generator system, and the low-temperature side outlet of the third heat exchanger 37 is connected to the turbine body 9 in the turbine generator system; the high-temperature side inlet of the fourth heat exchanger 38 is connected to the first high-temperature molten salt tank 29, the high-temperature side outlet of the fourth heat exchanger 38 is connected to the low-temperature molten salt tank 28, and the low-temperature side inlet and outlet of the fourth heat exchanger 38 are connected to the heating channel.

[0036] In the molten salt energy storage and power generation system provided in this embodiment, the gas turbine body is adapted to convert the chemical energy of fuel into mechanical energy. A first generator 1 is connected to the gas turbine and is adapted to convert the mechanical energy generated by the gas turbine into electrical energy. A waste heat boiler 6 is connected to the gas turbine and is adapted to use the high-temperature flue gas generated by the gas turbine to generate high-temperature, high-pressure steam. A steam turbine body 9 is connected to the waste heat boiler 6 and is adapted to pass the high-temperature, high-pressure steam generated by the waste heat boiler 6 into the steam turbine to perform work. A second generator 10 is connected to the steam turbine and is adapted to convert the mechanical energy generated by the steam turbine into electrical energy.

[0037] Downstream of the waste heat boiler 6, a flue gas treatment device 7 and a chimney 8 are installed, suitable for denitrification and desulfurization treatment of the exhaust gas after work is completed, and the flue gas is discharged under the premise of meeting local emission requirements. When the power grid 45 needs peak shaving and frequency regulation, the entire unit starts up quickly, and the first generator 1 and the second generator 10 quickly generate electricity and connect to the grid, realizing rapid peak shaving and frequency regulation on the power grid 45 side.

[0038] The steam turbine power generation system includes a waste heat boiler 6 (steam side), a steam turbine body 9, and a condenser 11, which are connected in a sequential cycle. The outlet of the condenser 11 is connected to the steam inlet of the waste heat boiler 6. The steam turbine body 9 is equipped with an extraction steam channel connected to a heating channel. The molten salt energy storage heating and power generation system also includes a gas turbine subsystem, which includes a gas turbine body. The flue gas outlet of the gas turbine body is also connected to the flue gas side of the waste heat boiler 6.

[0039] A No. 1 three-way valve 18 is installed between the turbine body 9 and the first heat exchanger 19, with its bypass connected to the high-temperature side inlet of the second heat exchanger 21. A No. 2 three-way valve 20 is installed between the high-temperature side outlet of the first heat exchanger 19 and the high-temperature side inlet of the second heat exchanger 21, with its bypass connected to the heat-side inlet of the waste heat boiler 6. A makeup water channel is connected to the condenser 11, and a makeup water pump 15 is installed on the makeup water channel. A heating pressurization pump 43 is installed on the heating channel. A heating feedwater pump 39 is installed on the heating channel upstream of the fourth heat exchanger 38, and a heating feedwater filter 40 is installed between the heating feedwater pump 39 and the fourth heat exchanger 38.

[0040] A first molten salt pump 25 is installed at the outlet end of the cryogenic molten salt tank 28. A first circulation channel and a second circulation channel are connected in parallel at the outlet of the first molten salt pump 25. The first circulation channel is connected to the first heat exchanger 19, and the second circulation channel is connected to the second heat exchanger 21. A first auxiliary channel is connected to the inlet end of the first high-temperature molten salt tank 29 at the outlet end of the cryogenic molten salt tank 28, and a third circulation switch 26 is installed on the first auxiliary channel. A second auxiliary channel is connected to the inlet end of the second high-temperature molten salt tank 33 at the outlet end of the cryogenic molten salt tank 28, and a fourth circulation switch 27 is installed on the second auxiliary channel. A third auxiliary channel is connected to the outlet end of the first high-temperature molten salt tank 29 at the inlet end of the cryogenic molten salt tank 28, and a sixth circulation switch 32 is installed on the third auxiliary channel. A fourth auxiliary channel is connected to the outlet end of the second high-temperature molten salt tank 33 at the inlet end of the cryogenic molten salt tank 28, and an eighth circulation switch 36 is installed on the fourth auxiliary channel.

[0041] Furthermore, a first molten salt pump 25, a second molten salt pump 30, and a third molten salt pump 34 are respectively installed at the outlets of the low-temperature molten salt tank 28, the first high-temperature molten salt tank 29, and the second high-temperature molten salt tank 33, which are suitable for realizing the circulation of the molten salt medium during heat storage and heat release. The steam side of the molten salt energy storage heating and power generation system realizes water recycling through a closed-loop system, and a condenser 11, a circulating water pump 12, and a deaerator 13 are installed in the return water pipeline. A water replenishment device is installed at the condenser 11, which is suitable for finely filtering municipal water and then feeding it into the waste heat boiler 6 or the third heat exchanger 37 to replenish the water consumed by the turbine body 9 in the process of generating electricity by driving the second generator 10.

[0042] When the molten salt energy storage heating and power generation system starts up for peak shaving and frequency regulation, according to the power demand on the grid side 45, a portion of the flue gas downstream of the gas turbine is introduced into the first heat exchanger 19 and the second heat exchanger 21. Energy is stored in the first high-temperature molten salt tank 29 and the second high-temperature molten salt tank 33 through circulation between the low-temperature molten salt tank 28, the first high-temperature molten salt tank 29, and the second high-temperature molten salt tank 33. When the gas turbine experiences a temporary shutdown or periodic maintenance, the high-temperature molten salt tank in the second high-temperature molten salt tank 33 releases heat in the third heat exchanger 37, converting water from the return water pipe into high-temperature, high-pressure steam, which is then fed into the turbine to drive the second generator 10 to generate electricity. When the gas-steam combined cycle subsystem is not starting up for peak shaving and frequency regulation, the high-temperature molten salt tank in the first high-temperature molten salt tank 29 releases heat in the fourth heat exchanger 38, converting water into superheated steam for heating.

[0043] During heating, steam can be generated through the extraction steam passage of the turbine or through the fourth heat exchanger 38. A heating pressurization pump 43 is located on the power plant side heating pipeline, suitable for pressurizing the steam to meet long-distance transportation needs. The user side 44 utilizes the heating steam itself or the heat energy within it. A heating feedwater pump 39 is installed on the heating passage upstream of the fourth heat exchanger 38, and a heating feedwater filter 40 is installed between the heating feedwater pump 39 and the fourth heat exchanger 38, suitable for providing the water required for heating to the fourth heat exchanger 38. During system peak shaving and frequency regulation, heating steam is generated through the extraction steam passage of the turbine body 9; when the system is not operating for peak shaving and frequency regulation, heating steam is generated by the fourth heat exchanger 38 to ensure continuous heating throughout the day for the gas turbine power plant.

[0044] In the gas turbine, air is heated and pressurized by compressor 2 before entering combustion chamber 4. Fuel is mixed with air and burned in combustion chamber 4 through fuel inlet 3. The high-temperature gas drives gas turbine 5 to do work, converting the chemical energy of the fuel into mechanical energy. The gas turbine drives the first generator 1 to generate electricity, converting the mechanical energy generated by the gas turbine into electrical energy. In addition, to improve the thermal efficiency of the gas turbine, the high-temperature flue gas discharged from gas turbine 5 is introduced into waste heat boiler 6 through flue gas passage to heat water from deaerator 13 and form high-temperature and high-pressure steam. The high-temperature and high-pressure steam is then introduced into steam turbine 9 to do work. The second generator 10 is connected to the steam turbine and converts the mechanical energy generated by the steam turbine into electrical energy. The exhaust gas formed by heat exchange in waste heat boiler 6 is desulfurized and denitrified by flue gas treatment device 7, and then discharged through chimney 8 while meeting local emission requirements.

[0045] Because the gas turbine and steam turbine 9 start up quickly, when peak shaving and frequency regulation are required on the grid side 45, the entire unit starts up rapidly, and the first generator 1 and the second generator 10 generate electricity and connect to the grid, achieving rapid peak shaving and frequency regulation on the grid side 45, while also providing heating. The molten salt energy storage subsystem consists of two modules: molten salt energy storage for power generation and molten salt energy storage for heating. On the one hand, when the gas turbine experiences a temporary shutdown or periodic maintenance, it can achieve peak shaving and frequency regulation on the grid side 45; on the other hand, when the system does not start up for peak shaving and frequency regulation, it can provide continuous heating.

[0046] For the molten salt energy storage power generation module, during the thermal storage stage, the direct passage of the No. 1 three-way valve 18 is opened, the bypass passage of the No. 2 three-way valve 20 is opened, and both the first cycle switch 23 and the eighth cycle switch 36 are opened. The high-temperature flue gas discharged from the gas turbine 5 enters the first heat exchanger 19 through the flue gas passage. The low-temperature molten salt, after being pressurized by the first molten salt pump 25, enters the first heat exchanger 19 from the low-temperature molten salt tank 28 to exchange heat with the high-temperature flue gas. The heated high-temperature molten salt then enters the second high-temperature molten salt tank 33 from the first heat exchanger 19 for storage, and is then processed through the eighth cycle switch. The heat storage circuit where switch 36 is located forms a heat storage cycle. During the heat release and power generation stage, the second return water switch 17, the fourth circulation switch 27, and the seventh circulation switch 35 are all opened. After being pressurized by the third molten salt pump 34, the high-temperature molten salt enters the third heat exchanger 37 from the second high-temperature molten salt tank 33 to exchange heat with the water from the deaerator 13. The molten salt forms a heat release cycle through the heat release circuit where the fourth circulation switch 27 is located. The water becomes high-temperature and high-pressure steam in the third heat exchanger 37. Then, the high-temperature and high-pressure steam is fed into the steam turbine to do work and drive the second generator 10 to generate electricity.

[0047] For the molten salt energy storage and heating module, during the heat storage stage, the bypass channel of the No. 1 three-way valve 18 is opened, and the flue gas switch 22, the second circulation switch 24, and the sixth circulation switch 32 are all opened. The high-temperature flue gas discharged from the gas turbine 5 enters the second heat exchanger 21 through the flue gas channel. The low-temperature molten salt is pressurized by the first molten salt pump 25 and enters the second heat exchanger 21 from the low-temperature molten salt tank 28 to exchange heat with the high-temperature flue gas. The heated high-temperature molten salt enters the first high-temperature molten salt tank 29 from the second heat exchanger 21 for storage and forms a heat storage cycle through the heat storage circuit where the sixth circulation switch 32 is located. During the heat release and heating stage, the third circulation switch 26 and the fifth circulation switch 31 are both opened. The high-temperature molten salt is pressurized by the second molten salt pump 30 and enters the fourth heat exchanger 38 from the first high-temperature molten salt tank 29 to exchange heat with the water from the heating water supply channel. The molten salt forms a heat release cycle through the heat release circuit where the third circulation switch 26 is located. The water becomes superheated steam in the fourth heat exchanger 38 for external heating.

[0048] The heat storage process of the molten salt energy storage power generation module and the molten salt energy storage heating module can be controlled by the No. 1 three-way valve 18, the No. 2 three-way valve 20, and the flue gas switch 22. When the No. 1 three-way valve 18 and the No. 2 three-way valve 20 are in the direct-flow state and the flue gas switch 22 is in the open state, the molten salt energy storage power generation module and the molten salt energy storage heating module can store heat simultaneously. Since the steam temperature and pressure required by the molten salt energy storage power generation module are much higher than those of the molten salt energy storage heating module, in this embodiment, the second heat exchanger 21 is set downstream of the first heat exchanger 19 to realize the step-by-step utilization of high-temperature flue gas. When the No. 1 three-way valve 18 is in the direct-flow state, the No. 2 three-way valve 20 is in the bypass state, and the flue gas switch 22 is in the closed state, only the molten salt energy storage power generation module can store heat. When the No. 1 three-way valve 18 is in the bypass state, the No. 2 three-way valve 20 is in the closed state, and the flue gas switch 22 is in the open state, only the molten salt energy storage heating module can store heat.

[0049] Furthermore, during the power generation process of the molten salt energy storage heating and power generation system, the water entering the waste heat boiler 6, the third heat exchanger 37, and the turbine undergoes special treatment, and its value is far higher than that of ordinary municipal water. In order to improve the economic efficiency of the gas turbine power plant, the steam side of the molten salt energy storage heating and power generation system realizes water recycling through a closed-loop system. A return water pipe is set downstream of the turbine body 9, and a condenser 11, a circulating water pump 12, and a deaerator 13 are installed in the return water pipe. The condenser 11 condenses the steam that has done its work into water, which is pressurized by the circulating water pump 12 and deoxygenated by the deaerator 13 before being returned to the waste heat boiler 6 for recycling through the first return water switch 16, or returned to the third heat exchanger 37 for recycling through the second return water switch 17. The deoxygenation of the circulating water is to avoid corrosion of the waste heat boiler 6, the third heat exchanger 37, and the turbine as much as possible, and to extend the service life of the equipment. A water supply device is also installed at the condenser 11. Municipal water is pressurized and finely filtered by the water supply pump 15 and the water supply filter 14 and then fed into the waste heat boiler 6 or the third heat exchanger 37 to replenish the water consumed by steam extraction from the steam turbine for heating or natural evaporation.

[0050] When the system starts up for peak shaving and frequency regulation, the heating steam is generated by the extraction steam channel of the turbine body 9. At this time, the first heating switch 41 is opened and the second heating switch 42 is closed. When the system does not start up for peak shaving and frequency regulation, the heating steam is generated by the fourth heat exchanger 38 in the molten salt energy storage heating module to ensure that the gas turbine power plant can provide continuous heating throughout the day. The water consumed for heating is provided by the heating feedwater channel. When the molten salt energy storage provides heating, the heating feedwater channel pressurizes and filters the municipal water according to the heat demand and then passes it into the fourth heat exchanger 38 to generate heating steam. At this time, the second heating switch 42 is opened and the first heating switch 41 is closed.

[0051] The molten salt energy storage heating and power generation system provided in this embodiment, suitable for peak shaving, frequency regulation, and heating in gas turbine power plants, enables rapid startup when the system is normal. The first generator 1 and the second generator 10 generate electricity and connect to the grid, achieving rapid peak shaving and frequency regulation on the grid side 45. When the gas turbine experiences a temporary shutdown or periodic maintenance, the molten salt energy storage power generation module generates high-temperature, high-pressure steam to drive the turbine, achieving rapid peak shaving and frequency regulation on the grid 45. This system avoids economic penalties for gas turbine power plants due to untimely peak shaving and frequency regulation, and effectively ensures the stable operation of the local grid 45. During peak shaving and frequency regulation, the heating steam is generated by steam extraction from the turbine body 9. When the system is not starting for peak shaving and frequency regulation, the heating steam is generated by the molten salt energy storage heating module. Based on actual heating needs, a suitable low-temperature molten salt tank 28 and two high-temperature molten salt tanks are designed to ensure continuous and stable heating 24 hours a day, solving the problem of gas turbine power plants being unable to provide continuous heating 24 hours a day or having excessively high heating costs despite being able to provide continuous heating 24 hours a day. The molten salt energy storage heating and power generation system provided in this embodiment can systematically solve the problems of gas turbine power plants being unable to regulate peak and frequency during gas turbine temporary shutdowns or regular maintenance, and the increased maintenance frequency and operating costs caused by long-term low-load operation of gas turbines for heating. It ensures that the gas turbine is always in a high-efficiency state after startup, greatly improving the economic efficiency of gas turbine power plants.

[0052] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A molten salt energy storage and heating power generation system, characterized in that, Including a low-temperature molten salt tank (28), a first high-temperature molten salt tank (29), and a second high-temperature molten salt tank (33), and also including: The first heat exchanger (19) has its high-temperature side inlet connected to the flue gas outlet of the gas turbine body, its low-temperature side inlet connected to the low-temperature molten salt tank (28), and its low-temperature side outlet connected to the second high-temperature molten salt tank (33). The second heat exchanger (21) has its high-temperature side inlet connected to the high-temperature side outlet of the first heat exchanger (19), its high-temperature side outlet connected to the flue gas side inlet of the waste heat boiler (6), its low-temperature side inlet connected to the low-temperature molten salt tank (28), and its low-temperature side outlet connected to the first high-temperature molten salt tank (29). The third heat exchanger (37) has its high-temperature side inlet connected to the second high-temperature molten salt tank (33), its high-temperature side outlet connected to the low-temperature molten salt tank (28), its low-temperature side inlet connected to the outlet of the condenser (11) in the steam turbine generator system, and its low-temperature side outlet connected to the steam turbine body (9) in the steam turbine generator system. The fourth heat exchanger (38) has its high-temperature side inlet connected to the first high-temperature molten salt tank (29), its high-temperature side outlet connected to the low-temperature molten salt tank (28), and its low-temperature side inlet and outlet connected to the heating channel.

2. The molten salt energy storage and heating power generation system according to claim 1, characterized in that, It also includes a gas turbine subsystem, which includes the gas turbine body and the first generator (1), and the flue gas outlet of the gas turbine body is also connected to the flue gas inlet of the waste heat boiler (6).

3. The molten salt energy storage and heating power generation system according to claim 2, characterized in that, The steam turbine power generation system includes the steam side of the waste heat boiler (6), the steam turbine body (9), and the condenser (11) connected in sequence. The steam outlet of the steam turbine body (9) is connected to the inlet of the condenser, and the outlet of the condenser (11) is connected to the steam side inlet of the waste heat boiler (6). The steam turbine body (9) is provided with an extraction steam channel connected to the heating channel.

4. The molten salt energy storage and thermal power generation system according to any one of claims 1 to 3, characterized in that, A three-way valve (18) is provided between the gas turbine body and the first heat exchanger (19), and the bypass of the three-way valve (18) is connected to the high-temperature side inlet of the second heat exchanger (21).

5. The molten salt energy storage and thermal power generation system according to any one of claims 1 to 3, characterized in that, A No. 2 three-way valve (20) is provided between the high-temperature side outlet of the first heat exchanger (19) and the high-temperature side inlet of the second heat exchanger (21), and the bypass of the No. 2 three-way valve (20) is connected to the flue gas side inlet of the waste heat boiler (6).

6. The molten salt energy storage and thermal power generation system according to claim 3, characterized in that, The condenser (11) is connected to a water supply channel, and a water supply pump (15) is installed on the water supply channel.

7. The molten salt energy storage and thermal power generation system according to any one of claims 1 to 3, characterized in that, A heating booster pump (43) is installed on the heating channel.

8. The molten salt energy storage and thermal power generation system according to any one of claims 1 to 3, characterized in that, A heating water pump (39) is installed on the heating channel upstream of the fourth heat exchanger (38), and a heating water filter (40) is installed between the heating water pump (39) and the fourth heat exchanger (38).

9. The molten salt energy storage and thermal power generation system according to any one of claims 1 to 3, characterized in that, The outlet end of the low-temperature molten salt tank (28) is equipped with a first molten salt pump (25). The outlet of the first molten salt pump (25) is connected in parallel with a first circulation channel and a second circulation channel. The first circulation channel is connected to the first heat exchanger (19), and the second circulation channel is connected to the second heat exchanger (21). A second molten salt pump (30) is installed between the outlet end of the first high-temperature molten salt tank (29) and the fourth heat exchanger (38); A third molten salt pump (34) is installed between the outlet end of the second high-temperature molten salt tank (33) and the third heat exchanger (37).

10. The molten salt energy storage and thermal power generation system according to any one of claims 1 to 3, characterized in that, The outlet end of the low-temperature molten salt tank (28) is connected to the inlet end of the first high-temperature molten salt tank (29) by a first auxiliary channel; And / or the outlet end of the low-temperature molten salt tank (28) is connected to the inlet end of the second high-temperature molten salt tank (33) by a second auxiliary channel; And / or the inlet end of the low-temperature molten salt tank (28) is connected to the outlet end of the first high-temperature molten salt tank (29) by a third auxiliary channel; And / or the inlet end of the low-temperature molten salt tank (28) is connected to the outlet end of the second high-temperature molten salt tank (33) via a fourth auxiliary channel.

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