A compressed air energy storage system with adjustable air intake and injection temperatures

Abstract

The utility model relates to compressed air energy storage system technical field, concretely is a kind of compressed air energy storage system of adjustable air intake and gas injection temperature, including air compression system, air expansion system, air bypass system, gas storage system, air intake and gas injection temperature regulating system, the air compression system is used to provide power, the air expansion system is used to provide doing function power, the air bypass system is used to adjust output power, the gas storage system is used to store high pressure air, the air intake and gas injection temperature regulating system are used to adjust the temperature of compressed air;The import and export temperature of the present application is realized reasonable distribution by air intake and gas injection temperature regulation, effectively promotes system operating efficiency, improves system operating safety.

Description

Technical Field

[0001] This utility model relates to the technical field of compressed air energy storage systems, specifically a compressed air energy storage system with adjustable intake and injection temperatures. Background Technology

[0002] Against the backdrop of "dual carbon" (carbon dioxide, carbon emissions, and carbon sequestration), building a new power system is a strategic task to ensure my country's energy security. New energy sources such as photovoltaics, solar thermal power, wind power, and hydropower are intermittent and unstable, easily leading to energy supply and demand mismatches, necessitating the integration of energy storage technologies. Molten salt thermal energy storage is a relatively safe energy storage method that utilizes molten salts such as nitrates as a heat transfer medium. Energy is stored and released through the thermal storage and release cycles of the molten salt, achieving efficient energy transfer.

[0003] Currently, key technologies and equipment for molten salt energy storage include molten salt, electric heaters, storage tanks, and heat exchangers, and are widely used in solar thermal power generation, peak shaving and frequency regulation of coupled thermal power units, and green electricity heating from coupled new energy sources. Current applications of molten salt energy storage mainly include: molten salt-steam heat exchange in solar thermal power generation systems and coupled thermal power units; electric-molten salt thermal storage for frequency regulation and peak shaving; and molten salt-steam and electric-molten salt energy storage in green electricity heating. However, in practical use, existing air-molten salt heat exchange systems cannot adjust the parameters of the system's air inlet and outlet, making it difficult for the system to operate efficiently and stably under different seasonal conditions. Utility Model Content

[0004] The purpose of this invention is to address the above-mentioned shortcomings by providing a compressed air energy storage system with adjustable intake and injection temperatures, which can maintain stable air inlet parameters and enable the system to operate efficiently and stably under different seasonal conditions.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] An adjustable intake and injection temperature compressed air energy storage system includes an air compression system, an air expansion system, an air bypass system, an air storage system, and an intake and injection temperature regulation system. The air compression system provides power, the air expansion system provides work capacity, the air bypass system regulates the output power, the air storage system stores high-pressure air, and the intake and injection temperature regulation system regulates the temperature of the compressed air.

[0007] Furthermore, the air compression system is arranged in three stages, including an air preheater, a first compressor, a second compressor, a third compressor, a first molten salt heat exchanger, a first pressurized water heat exchanger, a first atmospheric pressure cooler, a second molten salt heat exchanger, a second pressurized water heat exchanger, and a second atmospheric pressure cooler. The first compressor is connected to the output terminal of a first motor, the second compressor is connected to the output terminal of a second motor, and the third compressor is connected to the output terminal of a third motor. The air preheated by the air preheater enters the first compressor. The air outlet of the first compressor absorbs heat through the first molten salt heat exchanger and the first pressurized water heat exchanger, and is then cooled by the first atmospheric pressure cooler before entering the second compressor. The air outlet of the second compressor absorbs heat through the second molten salt heat exchanger and the second pressurized water heat exchanger, and is then cooled by the second atmospheric pressure cooler before entering the third compressor. The air outlet of the third compressor enters the intake and injection temperature regulation system.

[0008] Furthermore, the first atmospheric pressure cooler and the second atmospheric pressure cooler are connected in parallel. The cold air after heat exchange in the air preheater is divided into two streams after passing through the second circulating pump. One stream enters the first atmospheric pressure cooler and the other stream enters the second atmospheric pressure cooler. The air flowing out of the first atmospheric pressure cooler and the second atmospheric pressure cooler merges and flows through the first water-to-water heat exchanger and the first regulating valve before returning to the air preheater.

[0009] Furthermore, the gas storage system is a gas storage tank; the gas inlet and injection temperature regulation system includes a dual cold and hot water tank, a second regulating valve, a second water-to-water heat exchanger, a third atmospheric pressure cooler, a fourth regulating valve, a gas-to-water heat exchanger, a mechanical cooling tower, a first circulating water pump, and a third regulating valve. Cold water flows out from the cold water side of the dual cold and hot water tank, passes through the second regulating valve and the second water-to-water heat exchanger for further cooling, and then enters the third atmospheric pressure cooler to cool the gas side of the third atmospheric pressure cooler. The water side flows back into the hot side of the dual cold and hot water tank; hot water flows out from the hot water side of the dual cold and hot water tank, passes through the gas-to-water heat exchanger, and then heats the gas exiting the gas storage tank. The hot water, after cooling, flows back into the cold water side of the hot and cold dual water tank, maintaining the stability of the outlet temperature of the gas storage tank. The hot water discharged from the second water-to-water heat exchanger and the hot water discharged from the first water-to-water heat exchanger merge and enter the mechanical cooling tower, forming an open cooling cycle. This cycle is used to further reduce the cold water flowing out from the cold side of the hot and cold dual water tank, thereby reducing the water side temperature of the third atmospheric pressure cooler and further reducing the temperature of the compressed air entering the gas storage tank. The water cooled by the mechanical cooling tower splits into two streams: one stream returns to the second water-to-water heat exchanger through the first circulating water pump and the third regulating valve, and the other stream returns to the first water-to-water heat exchanger through the fifth regulating valve.

[0010] Furthermore, the air expansion system is arranged in two stages, including a third pressure water heat exchanger, a third molten salt heat exchanger, a high-pressure expander, a fourth pressure water heat exchanger, a fourth molten salt heat exchanger, and a low-pressure expander. The low-pressure expander is connected to the output end of the generator. Compressed air flows out from the air storage tank, enters the air-water heat exchanger through the seventh regulating valve, and then enters the third pressure water heat exchanger and the third molten salt heat exchanger for heating. Then it enters the high-pressure expander to do work, and from the outlet of the high-pressure expander, it enters the fourth pressure water heat exchanger and the fourth molten salt heat exchanger for heating, and then enters the low-pressure expander to do work. The first motor, the second motor, the third motor, and the generator are all connected to the power grid through transformers.

[0011] Furthermore, the air bypass system includes a first bypass valve and a second bypass valve. The pipelines between the gas-water heat exchanger and the third pressure water heat exchanger, and between the third molten salt heat exchanger and the high-pressure expander are connected by a connecting pipe one. The first bypass valve is installed on the connecting pipe one. The pipelines between the high-pressure expander and the fourth pressure water heat exchanger, and between the fourth molten salt heat exchanger and the low-pressure expander are connected by a connecting pipe two. The second bypass valve is installed on the connecting pipe two.

[0012] Furthermore, it also includes a molten salt hot tank, a molten salt cold tank, a pressurized water hot tank, and a pressurized water cold tank. Air that has undergone heat exchange in the first molten salt heat exchanger is split into two streams after passing through the molten salt hot tank; one stream enters the fourth molten salt heat exchanger, and the other enters the third molten salt heat exchanger. The air that has undergone heat exchange in the fourth molten salt heat exchanger merges with the air that has undergone heat exchange in the third molten salt heat exchanger, flows through the first molten salt pump into the molten salt cold tank, and then, after passing through the second molten salt pump, is split into two streams; one stream returns to the first molten salt heat exchanger, and the other enters the second molten salt heat exchanger. Air that has undergone heat exchange in the first pressurized water heat exchanger... After the air exchanged with the second pressure water heat exchanger merges, it enters the pressure water heat tank. After passing through the sixth regulating valve, it is divided into two streams: one enters the third pressure water heat exchanger, and the other enters the fourth pressure water heat exchanger. After the air exchanged with the third and fourth pressure water heat exchangers merges, it flows through the first pressure water circulation pump into the pressure water cooling tank. After flowing out of the pressure water cooling tank, it is divided into two streams by the second pressure water circulation pump: one enters the second pressure water heat exchanger, and the other enters the first pressure water heat exchanger, forming a cycle and recovering waste heat through multi-stage heat exchange.

[0013] Furthermore, a shut-off valve and a vacuum pump bypass are installed after the low-pressure expander exhausts.

[0014] The beneficial effects of this utility model are:

[0015] This application achieves a reasonable distribution of inlet and outlet temperatures through intake and injection temperature regulation, effectively improving system operating efficiency and safety. Furthermore, when the ambient temperature is lower than the compressor inlet design temperature, the system can transfer heat from the first and second stage terminals of the compressor to the inlet of the first stage compressor to heat the air, maintaining stable system air inlet parameters and enabling efficient and stable operation under different seasonal conditions. The bypass design of the expansion-side heat exchanger can effectively and quickly adjust the operating power of the expander, which is of practical significance for high-inertia reactive operation of the system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0017] Reference numerals: 1. Air preheater; 2. First compressor; 3. First electric motor; 4. Second electric motor; 5. Second compressor; 6. Third electric motor; 7. Third compressor; 8. First molten salt heat exchanger; 9. First pressurized water heat exchanger; 10. First atmospheric pressure cooler; 11. Second molten salt heat exchanger; 12. Second pressurized water heat exchanger; 13. Second atmospheric pressure cooler; 14. Molten salt hot tank; 15. Molten salt cold tank; 16. First molten salt pump; 17. Second molten salt pump; 18. Pressurized water hot tank; 19. Sixth regulating valve; 20. Pressurized water cold tank; 21. First pressurized water circulation pump; 22. Second pressurized water circulation pump; 23. Third pressurized water heat exchanger; 24. Third molten salt heat exchanger. 25. High-pressure expander; 26. Fourth pressure water heat exchanger; 27. Fourth molten salt heat exchanger; 28. Low-pressure expander; 29. ​​Generator; 30. Vacuum pump; 31. Shut-off valve; 32. Hot and cold dual water storage tank; 33. Second regulating valve; 34. Second water-to-water heat exchanger; 35. Third atmospheric pressure cooler; 36. Fourth regulating valve; 37. Gas-water heat exchanger; 38. Gas storage tank; 39. Mechanical cooling tower; 40. First circulating water pump; 41. Third regulating valve; 42. First regulating valve; 43. First water-to-water heat exchanger; 44. Second circulating pump; 45. Fifth regulating valve; 46. First bypass valve; 47. Second bypass valve; 48. Seventh regulating valve; 49. Transformer; 50. Power grid. Detailed Implementation

[0018] like Figure 1 As shown, a compressed air energy storage system with adjustable intake and injection temperatures includes an air compression system, an air expansion system, an air bypass system, an air storage system, and an intake and injection temperature regulation system. The air compression system provides power, the air expansion system provides work capacity, the air bypass system regulates the output power, the air storage system stores high-pressure air, and the intake and injection temperature regulation system regulates the temperature of the compressed air.

[0019] like Figure 1As shown, the air compression system is a three-stage arrangement, including an air preheater 1, a first compressor 2, a second compressor 5, a third compressor 7, a first molten salt heat exchanger 8, a first pressurized water heat exchanger 9, a first atmospheric pressure cooler 10, a second molten salt heat exchanger 11, a second pressurized water heat exchanger 12, and a second atmospheric pressure cooler 13. The first compressor 2 is connected to the output terminal of the first motor 3, the second compressor 5 is connected to the output terminal of the second motor 4, and the third compressor 7 is connected to the output terminal of the third motor 6. The air preheated by the air preheater 1 enters the first compressor 2, and the air outlet of the first compressor 2 passes through... After absorbing heat from the first molten salt heat exchanger 8 and the first pressurized water heat exchanger 9, the air is cooled by the first atmospheric pressure cooler 10 and then enters the second compressor 5. The outlet air of the second compressor 5 absorbs heat from the second molten salt heat exchanger 11 and the second pressurized water heat exchanger 12, and is cooled by the second atmospheric pressure cooler 13 before entering the third compressor 7. The outlet air of the third compressor 7 enters the intake and injection temperature regulation system. In this embodiment, the outlet of the first compressor 2 is cooled by the first molten salt heat exchanger 8 and the first pressurized water heat exchanger 9, and the outlet of the second compressor 5 is cooled by the second molten salt heat exchanger 11 and the second pressurized water heat exchanger 12, ensuring the efficient operation of the system.

[0020] like Figure 1 As shown, the first atmospheric pressure cooler 10 and the second atmospheric pressure cooler 13 are connected in parallel. The cold air after heat exchange in the air preheater 1 is divided into two streams after passing through the second circulating pump 44. One stream enters the first atmospheric pressure cooler 10 and the other stream enters the second atmospheric pressure cooler 13. The air flowing out from the first atmospheric pressure cooler 10 and the second atmospheric pressure cooler 13 merges and flows through the first water-to-water heat exchanger 43 and the first regulating valve 42 before returning to the air preheater 1.

[0021] In this embodiment, a closed-loop water circulation is formed by connecting the first atmospheric pressure cooler 10 and the second atmospheric pressure cooler 13 in parallel.

[0022] like Figure 1As shown, the gas storage system is a gas storage tank 38; the gas inlet and injection temperature regulation system includes a dual hot and cold water tank 32, a second regulating valve 33, a second water-to-water heat exchanger 34, a third atmospheric pressure cooler 35, a fourth regulating valve 36, a gas-water heat exchanger 37, a mechanical cooling tower 39, a first circulating water pump 40, and a third regulating valve 41. Cold water flows out from the cold water side of the dual hot and cold water tank 32, passes through the second regulating valve 33 and the second water-to-water heat exchanger 34 for further cooling, and then enters the third atmospheric pressure cooler 35 to cool the gas side of the third atmospheric pressure cooler 35. The water side flows back into the hot side of the dual hot and cold water tank 32; hot water flows out from the hot water side of the dual hot and cold water tank 32, passes through the gas-water heat exchanger 37, and then cools the gas storage tank 38. The exhaust gas is heated, and the cooled water flows back into the cold water side of the hot and cold dual water storage tank 32, maintaining the stability of the outlet temperature of the gas storage tank 38. The hot water discharged from the second water-to-water heat exchanger 34 and the hot water discharged from the first water-to-water heat exchanger 43 merge and enter the mechanical cooling tower 39, forming an open cooling cycle. This cycle is used to further reduce the cold water flowing out from the cold side of the hot and cold dual water storage tank 32, thereby reducing the water side temperature of the third atmospheric pressure cooler 35 and further reducing the temperature of the compressed air entering the gas storage tank 38. The water cooled by the mechanical cooling tower 39 is divided into two streams. One stream returns to the second water-to-water heat exchanger 34 through the first circulating water pump 40 and the third regulating valve 41, and the other stream returns to the first water-to-water heat exchanger 43 through the fifth regulating valve 45.

[0023] In this embodiment, during winter operation, the fifth regulating valve 45 is closed, and the circulating cooling water circuit containing the regulating valve stops working. The first atmospheric pressure cooler 10 and the second atmospheric pressure cooler 13 absorb the heat from the compressed air and preheat the inlet air through a closed water circulation. During summer operation, the fifth regulating valve 45 is open, and the first water-to-water heat exchanger 43 is connected to the inlet and outlet of the mechanical cooling tower 39. The cold water on the cooling tower side of the first water-to-water heat exchanger 43 is used to absorb the heat from the compressed air brought by the first atmospheric pressure cooler 10 and the second atmospheric pressure cooler 13 in the closed water circulation, thereby regulating the temperature of the compressed air.

[0024] like Figure 1As shown, the air expansion system is arranged in two stages, including a third pressure water heat exchanger 23, a third molten salt heat exchanger 24, a high-pressure expander 25, a fourth pressure water heat exchanger 26, a fourth molten salt heat exchanger 27, and a low-pressure expander 28. The low-pressure expander 28 is connected to the output end of the generator 29. Compressed air flows out from the air storage tank 38, enters the air-water heat exchanger 37 through the seventh regulating valve 48, and then enters the third pressure water heat exchanger 23 and the third molten salt heat exchanger 24 for heating. Then it enters the high-pressure expander 25 to do work, and from the outlet of the high-pressure expander 25 it enters the fourth pressure water heat exchanger 26 and the fourth molten salt heat exchanger 27 for heating, and then enters the low-pressure expander 28 to do work. The first motor 3, the second motor 4, the third motor 6, and the generator 29 are all connected to the power grid 50 through the transformer 49.

[0025] In this embodiment, the air entering the high-pressure expander 25 is first heated by the third pressure water heat exchanger 23 and the third molten salt heat exchanger 24, and the air entering the low-pressure expander 28 is first heated by the fourth pressure water heat exchanger 26 and the fourth molten salt heat exchanger 27 to improve its work capacity; under normal operating conditions, the air is discharged from the shut-off valve 31.

[0026] like Figure 1 As shown, the air bypass system includes a first bypass valve 46 and a second bypass valve 47. The pipelines between the gas-water heat exchanger 37 and the third pressure water heat exchanger 23, and between the third molten salt heat exchanger 24 and the high-pressure expander 25 are connected by a connecting pipe one. The first bypass valve 46 is installed on the connecting pipe one. The pipelines between the high-pressure expander 25 and the fourth pressure water heat exchanger 26, and between the fourth molten salt heat exchanger 27 and the low-pressure expander 28 are connected by a connecting pipe two. The second bypass valve 47 is installed on the connecting pipe two.

[0027] In this embodiment, after the first bypass valve 46 is opened, the high-pressure air flowing out of the gas storage tank can flow directly into the high-pressure expander 25 without passing through the third pressure water heat exchanger 23 and the third molten salt heat exchanger 24. After the second bypass valve 47 is opened, the medium-pressure air flowing out of the high-pressure expander 25 can flow directly into the low-pressure expander 28 without passing through the fourth pressure water heat exchanger 26 and the fourth molten salt heat exchanger 27, thus forming a bypass for the pressure heat exchangers before the two-stage expanders and realizing output power regulation.

[0028] like Figure 1As shown, it also includes a molten salt hot tank 14, a molten salt cold tank 15, a pressurized water hot tank 18, and a pressurized water cold tank 20. Air that has undergone heat exchange in the first molten salt heat exchanger 8 is divided into two streams after passing through the molten salt hot tank 14. One stream enters the fourth molten salt heat exchanger 27, and the other enters the third molten salt heat exchanger 24. The air that has undergone heat exchange in the fourth molten salt heat exchanger 27 and the air that has undergone heat exchange in the third molten salt heat exchanger 24 merge and flow through the first molten salt pump 16 into the molten salt cold tank 15. After passing through the second molten salt pump 17, it is divided into two streams: one returns to the first molten salt heat exchanger 8, and the other enters the second molten salt heat exchanger 11. Air that has undergone heat exchange in the first pressurized water heat exchanger 9... After the air exchanged with the second pressure water heat exchanger 12, the air flows into the pressure water heat exchange tank 18. After passing through the sixth regulating valve 19, it is divided into two streams: one stream enters the third pressure water heat exchanger 23, and the other stream enters the fourth pressure water heat exchanger 26. After the air exchanged with the third pressure water heat exchanger 23 and the fourth pressure water heat exchanger 26, the air flows through the first pressure water circulation pump 21 and enters the pressure water cooling tank 20. After flowing out of the pressure water cooling tank 20, it is divided into two streams after passing through the second pressure water circulation pump 22: one stream enters the second pressure water heat exchanger 12, and the other stream enters the first pressure water heat exchanger 9, forming a cycle and recovering waste heat through multi-stage heat exchange.

[0029] like Figure 1 As shown, a shut-off valve 31 and a bypass for the vacuum pump 30 are installed after the low-pressure expander 28 exhausts.

[0030] In this embodiment, if the first bypass valve 46 is opened, the air in the gas storage tank 38 can directly enter the high-pressure expander 25 without heating. Similarly, if the second bypass valve 47 is opened, the exhaust gas from the high-pressure expander 25 can directly enter the low-pressure expander 28 without heating, thereby reducing the output power of the expander by lowering the temperature of the gas entering the expander. At this time, the air intake of the expander is further reduced by the seventh regulating valve 48 until it approaches the point where the generator outputs reactive power for high-inertia phasing operation. A shut-off valve 31 and a vacuum pump 30 bypass are set after the low-pressure cylinder exhaust. During phasing operation, the back pressure of the unit is reduced by the vacuum system, which can reduce the gas consumption during phasing operation and thus improve the economy of phasing operation.

[0031] The specific embodiments described herein are merely illustrative examples of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the scope defined by this utility model.

Claims

1. A compressed air energy storage system with adjustable intake and injection temperatures, characterized in that: It includes an air compression system, an air expansion system, an air bypass system, an air storage system, and an intake and injection temperature regulation system. The air compression system is used to provide power, the air expansion system is used to provide work capacity, the air bypass system is used to regulate the output power, the air storage system is used to store high-pressure air, and the intake and injection temperature regulation system is used to regulate the temperature of the compressed air.

2. The compressed air energy storage system with adjustable intake and injection temperatures according to claim 1, characterized in that, The air compression system is arranged in three stages, including an air preheater (1), a first compressor (2), a second compressor (5), a third compressor (7), a first molten salt heat exchanger (8), a first pressurized water heat exchanger (9), a first atmospheric pressure cooler (10), a second molten salt heat exchanger (11), a second pressurized water heat exchanger (12), and a second atmospheric pressure cooler (13). The first compressor (2) is connected to the output of the first motor (3), the second compressor (5) is connected to the output of the second motor (4), and the third compressor (7) is connected to the output of the third motor (6). The air is connected to the output end of the air preheater (1). The air preheated by the air preheater (1) enters the first compressor (2). The air outlet of the first compressor (2) absorbs heat through the first molten salt heat exchanger (8) and the first pressure water heat exchanger (9), and then enters the second compressor (5) after being cooled by the first atmospheric pressure cooler (10). The air outlet of the second compressor (5) absorbs heat through the second molten salt heat exchanger (11) and the second pressure water heat exchanger (12), and then enters the third compressor (7) after being cooled by the second atmospheric pressure cooler (13). The air outlet of the third compressor (7) enters the intake and injection temperature regulation system.

3. The compressed air energy storage system with adjustable intake and injection temperatures according to claim 2, characterized in that, The first atmospheric pressure cooler (10) and the second atmospheric pressure cooler (13) are connected in parallel. The cold air after heat exchange in the air preheater (1) is divided into two streams after passing through the second circulating pump (44). One stream enters the first atmospheric pressure cooler (10) and the other stream enters the second atmospheric pressure cooler (13). The air flowing out from the first atmospheric pressure cooler (10) and the second atmospheric pressure cooler (13) merges and flows through the first water-to-water heat exchanger (43) and the first regulating valve (42) before returning to the air preheater (1).

4. The compressed air energy storage system with adjustable intake and injection temperatures according to claim 3, characterized in that, The gas storage system is a gas storage tank (38); The intake and injection temperature regulation system includes a dual cold and hot water tank (32), a second regulating valve (33), a second water-to-water heat exchanger (34), a third atmospheric pressure cooler (35), a fourth regulating valve (36), a gas-water heat exchanger (37), a mechanical cooling tower (39), a first circulating water pump (40), and a third regulating valve (41). Cold water flows out from the cold water side of the dual cold and hot water tank (32), passes through the second regulating valve (33), and is further cooled by the second water-to-water heat exchanger (34) before entering the third atmospheric pressure cooler (35) to cool the gas side of the third atmospheric pressure cooler (35). The water side flows back into the hot side of the dual cold and hot water tank (32). Hot water flows out from the hot water side of the dual cold and hot water tank (32), passes through the gas-water heat exchanger (37), and then cools the gas outlet of the gas storage tank (38). The heated and cooled water flows back into the cold water side of the hot and cold dual water tank (32), maintaining the stability of the outlet temperature of the gas storage tank (38). The hot water discharged from the second water-to-water heat exchanger (34) and the hot water discharged from the first water-to-water heat exchanger (43) merge and enter the mechanical cooling tower (39) to form an open cooling cycle, which is used to further reduce the cold water flowing out from the cold side of the hot and cold dual water tank (32) to reduce the water side temperature of the third atmospheric pressure cooler (35), and further reduce the temperature of the compressed air entering the gas storage tank (38). The water cooled by the mechanical cooling tower (39) is divided into two streams. One stream returns to the second water-to-water heat exchanger (34) through the first circulating water pump (40) and the third regulating valve (41), and the other stream returns to the first water-to-water heat exchanger (43) through the fifth regulating valve (45).

5. A compressed air energy storage system with adjustable intake and injection temperatures according to claim 4, characterized in that, The air expansion system is arranged in two stages, including a third pressure water heat exchanger (23), a third molten salt heat exchanger (24), a high-pressure expander (25), a fourth pressure water heat exchanger (26), a fourth molten salt heat exchanger (27), and a low-pressure expander (28). The low-pressure expander (28) is connected to the output end of the generator (29). Compressed air flows out from the air storage tank (38), enters the air-water heat exchanger (37) through the seventh regulating valve (48), and then enters the third pressure water heat exchanger (23) and the third molten salt heat exchanger (24) for heating. Then it enters the high-pressure expander (25) to do work. From the outlet of the high-pressure expander (25), it enters the fourth pressure water heat exchanger (26) and the fourth molten salt heat exchanger (27) for heating, and then enters the low-pressure expander (28) to do work. Among them, the first motor (3), the second motor (4), the third motor (6) and the generator (29) are all connected to the power grid (50) through the transformer (49).

6. The compressed air energy storage system with adjustable intake and injection temperatures according to claim 5, characterized in that, The air bypass system includes a first bypass valve (46) and a second bypass valve (47). The pipeline between the gas-water heat exchanger (37) and the third pressure water heat exchanger (23), and the pipeline between the third molten salt heat exchanger (24) and the high-pressure expander (25) are connected by a connecting pipe. The first bypass valve (46) is installed on the connecting pipe. The pipeline between the high-pressure expander (25) and the fourth pressure water heat exchanger (26), and the pipeline between the fourth molten salt heat exchanger (27) and the low-pressure expander (28) are connected by a connecting pipe. The second bypass valve (47) is installed on the connecting pipe.

7. A compressed air energy storage system with adjustable intake and injection temperatures according to claim 6, characterized in that, It also includes a molten salt hot tank (14), a molten salt cold tank (15), a pressurized water hot tank (18), and a pressurized water cold tank (20). After heat exchange in the first molten salt heat exchanger (8), the air is divided into two streams after passing through the molten salt hot tank (14). One stream enters the fourth molten salt heat exchanger (27), and the other stream enters the third molten salt heat exchanger (24). The air after heat exchange in the fourth molten salt heat exchanger (27) and the air after heat exchange in the third molten salt heat exchanger (24) merge and flow through the first molten salt pump (16) into the molten salt cold tank (15). After passing through the second molten salt pump (17), it is divided into two streams. One stream returns to the first molten salt heat exchanger (8), and the other stream enters the second molten salt heat exchanger (11). After heat exchange in the first pressurized water heat exchanger (9), After the air exchanged with the second pressure water heat exchanger (12) merges, it enters the pressure water heat tank (18). After passing through the sixth regulating valve (19), it is divided into two streams. One stream enters the third pressure water heat exchanger (23), and the other stream enters the fourth pressure water heat exchanger (26). After the air exchanged with the third pressure water heat exchanger (23) merges with the air exchanged with the fourth pressure water heat exchanger (26), it flows through the first pressure water circulation pump (21) and enters the pressure water cooling tank (20). After flowing out of the pressure water cooling tank (20), it is divided into two streams after passing through the second pressure water circulation pump (22). One stream enters the second pressure water heat exchanger (12), and the other stream enters the first pressure water heat exchanger (9), forming a cycle and recovering waste heat through multi-stage heat exchange.

8. A compressed air energy storage system with adjustable intake and injection temperatures according to claim 6, characterized in that, After the low-pressure expander (28) exhausts, a shut-off valve (31) and a vacuum pump (30) bypass are installed.

Images