Compressed air energy storage system of 600MW-level energy storage power station

Through the dual-wire arrangement of compressor system and thermal medium water tank circulation system, the efficiency and adaptability of the 600MW compressed air energy storage power station is improved, the system efficiency and cost problems are solved, and a more efficient and economical energy storage power station design is achieved.

CN223089481UActive Publication Date: 2025-07-11POWERCHINA HEBEI ELECTRIC POWER SURVEY & DESIGN INST CO LTD
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Patent Information

Application Number
CN202422503249.6
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-10-16
Publication Date
2025-07-11
Estimated Expiration
2034-10-16

AI Technical Summary

Technical Problem

The system efficiency of 600MW compressed air energy storage power stations is difficult to improve. The large sliding pressure range leads to high cost and large land area, and the efficiency is reduced when the ambient temperature changes. The existing compressor types limit the efficiency improvement.

Method used

A compressor system is adopted with a dual-wire arrangement, with each line compressor in four stages, and the first three stages of compressors are connected in series with energy storage heat exchanger and preheating cooler. The preheating heater is front-mounted and the expander system is three stages. A preheating circulation system and cooling system are set up. The compressor adopts axial flow type, combining high-temperature and low-temperature heat medium tank circulation system.

Benefits of technology

The compressor efficiency is improved by 4-5%, and the system efficiency is 1-1.5%, reducing system complexity and cost, covering an area, and adapting to environmental temperature changes.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model discloses a compressed air energy storage system of a 600MW level energy storage power station, and belongs to the technical field of compressed air energy storage power stations. Comprising a high-temperature heat medium water tank, a low-temperature heat medium water tank, a compressor system, an expansion machine system, a gas storage and a cooling tower, wherein the compressor system and the expansion machine system are arranged between the high-temperature heat medium water tank and the low-temperature heat medium water tank in a double-line mode, and the gas storage and the cooling tower are connected with the double-line compressor system. An energy storage heat exchanger is connected in series behind the first three stages of compressors, a preheating cooler is connected in series behind the third-stage energy storage heat exchanger, meanwhile, a preheating heater is arranged in front of the first-stage compressor, and the preheating coolers and the preheating heaters are connected through a preheating system to form a circulating system; and the expansion machine system comprises a three-stage expansion machine and an energy storage heater which are connected in series. The system disclosed by the utility model is simpler, low in cost and small in occupied area.
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Description

Technical Field

[0001] The utility model belongs to the technical field of compressed air energy storage power stations, and particularly relates to a compressed air energy storage system for a 600MW-level energy storage power station. Background Art

[0002] As a main component of new energy storage, compressed air energy storage is an effective means to improve the regulation ability of the power system and already has the conditions for large-scale commercial application. At present, the construction of 300MW-level compressed air energy storage power stations has been carried out. With the implementation of the project, higher requirements for efficiency are put forward for ultra-large-scale compressed air energy storage power stations.

[0003] Compared with 300MW-level energy storage power stations, the electric-electric efficiency of 600MW-level large-scale energy storage power stations needs to be further increased by 2-3% to be of construction significance. At present, the heat storage temperature, motor power, gas storage pressure, and sliding pressure range of energy storage power stations are limited by the current technical level and are difficult to be further improved. Especially for artificial caverns, a larger sliding pressure range will greatly reduce the power station cost, but a large sliding pressure range will lead to a low energy storage efficiency of the power station.

[0004] In the domestic energy storage power station on the compression side, except for the first-stage compressor using an axial-flow compressor, the rest of the compressors can only use centrifugal compressors due to the limited through-flow rate. The efficiency of centrifugal compressors is 4% lower than that of axial-flow compressors, resulting in difficulty in further improving the system efficiency. Moreover, when the ambient temperature changes, the heat storage temperature of the system will decrease by 10-15°C, and the off-design efficiency will decrease by 1-2%, affecting the economy of the energy storage power station and making it difficult to meet the efficiency requirements of 600MW-level energy storage power stations. In addition, for a 600MW-level compressed air energy storage power station arranged in a conventional way, the compressor needs to be made into three lines, making the system layout more complex, with high costs and large floor areas. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a 600MW-level compressed air energy storage power station system, which is more concise, has low costs, and small floor areas.

[0006] To achieve the above purpose, the technical solution adopted by the utility model is:

[0007] The compressed air energy storage system of a 600MW-level energy storage power station includes a high-temperature heat medium water tank, a low-temperature heat medium water tank, a compressor system and an expander system arranged in a double-line layout between the high-temperature heat medium water tank and the low-temperature heat medium water tank, and a gas storage reservoir and a cooling tower connected to the double-line compressor system. Each line of the compressor system arranged in a double-line layout includes a four-stage compressor connected in series. An energy storage heat exchanger is connected in series behind the compressors of the first three stages. A preheating cooler is connected in series behind the energy storage heat exchanger of the third stage. At the same time, a preheating heater is arranged in front of the first-stage compressor. A circulation system is formed by connecting the preheating cooler and the preheating heater through a preheating system; the expander system includes a three-stage expander connected in series and an energy storage heater.

[0008] A further improvement of the technical solution of the present invention lies in: the preheating system includes a preheating expansion water tank, a preheating circulation pump and a regulating valve for controlling the water volume of the preheating circulation pump connected in series in sequence. The energy storage heat exchangers of the first three stages are all connected to the high-temperature heat medium water tank.

[0009] A further improvement of the technical solution of the present invention lies in: a cooler is connected in series behind the fourth-stage compressor of each line of the compressor system. The cooler and the cooling tower form a circulation system. The cooler is connected to the gas storage reservoir and a gas-liquid separator II is arranged on the connecting pipeline between the cooler and the gas storage reservoir.

[0010] A further improvement of the technical solution of the present invention lies in: the third-stage compressor is sequentially connected to the energy storage heat exchanger, the preheating cooler, the gas-liquid separator I, and the fourth-stage compressor. The cooling tower is connected to the gas-liquid separator I to form a circulation system.

[0011] A further improvement of the technical solution of the present invention lies in: a low-temperature heat medium water circulation pump is arranged on the compression side and connected to the low-temperature heat medium water tank.

[0012] A further improvement of the technical solution of the present invention lies in: the expander system on the expansion side includes a three-stage expander system. In each stage of the expander system, the expander is connected to an energy storage heater. The expander includes a high-pressure cylinder expander, a medium-pressure cylinder expander and a low-pressure cylinder expander. The gas storage reservoir is sequentially connected to the three-stage expander system. The energy storage heaters of the three-stage expander system are all connected to the high-temperature heat medium water tank and the low-temperature heat medium water tank to form a circulation system.

[0013] A further improvement of the technical solution of the present invention lies in: a low-temperature water constant temperature heat exchanger is arranged on the expansion side and connected to the low-temperature heat medium water tank. A high-temperature heat medium water circulation pump is arranged and connected to the high-temperature heat medium water tank. The low-temperature water constant temperature heat exchanger is connected to the cooling tower for circulating cooling water.

[0014] A further improvement of the technical solution of the present invention lies in: the preheating heater adopts a small-end difference plate heat exchanger at 5°C, and regulating switch valves are arranged on both sides of the cooler.

[0015] A further improvement of the technical solution of the present utility model lies in that: the first three stages of compressors in the compressor system arranged in two lines are axial compressors.

[0016] Due to the adoption of the above technical solution, the technical progress achieved by the present utility model is:

[0017] The compressed air energy storage system of the 600MW-level energy storage power station in this application adopts a compressor system arranged in two lines. When the energy release hours are less than 4 hours, it is difficult to make the second-stage compressor of the compressor system arranged in three lines an axial compressor. When the present application adopts the two-line arrangement, the second-stage compressor can be made into an axial compressor under any energy storage and energy release conditions. Compared with the centrifugal compressor, the axial flow efficiency can be increased by 4-5%, and the system efficiency can be increased by 1-1.5%. Brief Description of the Drawings

[0018] Figure 1 It is the flowchart of the compressed air energy storage system of the 600MW-level energy storage power station of the present utility model during energy storage;

[0019] Figure 2 It is the flowchart of the compressed air energy storage system of the 600MW-level energy storage power station of the present utility model during energy release;

[0020] Among them, 1. Energy storage heat exchanger, 2. Preheating cooler, 3. First gas-liquid separator, 4. Second gas-liquid separator, 5. Preheating expansion water tank, 6. Gas storage reservoir, 7. High-temperature heat medium water tank, 8. Cooling tower, 9. Low-temperature heat medium water tank, 10. Preheating heater, 11. Compressor, 12. Cooler, 13. Preheating circulation pump, 14. Control valve, 15. Low-temperature heat medium water circulation pump, 16. Low-temperature water constant temperature heat exchanger, 17. High-temperature heat medium water circulation pump, 18. Energy storage heater, 19. High-pressure cylinder expander, 20. Medium-pressure cylinder expander, 21. Low-pressure cylinder expander. Detailed Embodiment

[0021] The following further elaborates on the present utility model in conjunction with the embodiments:

[0022] The compressed air energy storage system of the 600MW-level energy storage power station is characterized in that: it includes a high-temperature heat medium water tank 7, a low-temperature heat medium water tank 9, an expander system of a compressor system arranged in two lines disposed between the high-temperature heat medium water tank 7 and the low-temperature heat medium water tank 9, and a gas storage reservoir 6 and a cooling tower 8 connected to the two-line compressor system. Each line of the compressor system arranged in two lines includes four stages of compressors 11 connected in series. A energy storage heat exchanger 1 is connected in series behind the first three stages of compressors 11. A preheating cooler 2 is connected in series behind the energy storage heat exchanger 1 at the third stage. At the same time, a preheating heater 10 is arranged in front of the first stage of compressor 11. A circulation system is formed by connecting the preheating cooler 2 and the preheating heater 10 through a preheating system. The expander system includes three stages of expanders connected in series and an energy storage heater 18.

[0023] The preheating system includes a preheating expansion water tank 5, a preheating circulation pump 13, and a regulating valve 14 for controlling the water volume of the preheating circulation pump 13, which are connected in series in sequence. The first three-stage energy storage heat exchangers 1 are all connected to the high-temperature heat medium water tank 7. After the fourth-stage compressor 11 of each compressor system, a cooler 12 is connected in series. The cooler 12 and the cooling tower 8 form a circulation system. The cooler 12 is connected to the gas storage tank 6, and a second gas-liquid separator 4 is provided on the connecting pipeline between the cooler 12 and the gas storage tank 6.

[0024] The third-stage compressor 11 is connected to the energy storage heat exchanger 1, the preheating cooler 2, the first gas-liquid separator 3, and the fourth-stage compressor 11 in sequence. The cooling tower 8 is connected to the first gas-liquid separator 3 to form a circulation system.

[0025] On the compression side, a low-temperature heat medium water circulation pump 15 is provided and connected to the low-temperature heat medium water tank 9.

[0026] On the expansion side, a low-temperature water constant temperature heat exchanger 16 is provided and connected to the low-temperature heat medium water tank 9. A high-temperature heat medium water circulation pump 17 is provided and connected to the high-temperature heat medium water tank 7. The low-temperature water constant temperature heat exchanger 16 is connected to the cooling tower 8 to conduct the circulation of cooling water.

[0027] As Figure 1 shown, it is the flow chart of the compressed air energy storage system of the 600MW-level energy storage power station of the present utility model during energy storage. A preheating cooler 2 is provided after the third-stage compressor 11, and a preheating heater 10 is provided before the first-stage compressor. The preheating system is provided with a preheating expansion water tank 5, a regulating valve 14, and a preheating circulation pump 13. The water volume of the preheating circulation pump 13 is controlled by the regulating valve 14 to meet the inlet air temperature requirement of the first-stage compressor 11. Both the air side and the water side of the preheating heater 10 are at low pressure. The preheating heater 10 adopts a plate heat exchanger with a small end difference of 5°C. The volume of the preheating expansion water tank 5 meets the difference between the maximum water volume and the minimum water volume of the preheating system. When the closed water volume required by the system increases, the preheating expansion water tank 5 supplies water to the system. When the closed water volume required by the system decreases, the preheating expansion water tank 5 absorbs the excess water in the system.

[0028] When the ambient temperature is lower than the design temperature, the water temperature at the outlet of the preheating heater 10 decreases, the opening degree of the regulating valve 14 is reduced, the flow rate of the preheating circulation pump 13 is increased, the heat exchange capacity of the cooler 12 is increased, and the water temperature at the outlet of the preheating cooler 2 is increased, so that the heat exchange capacity of the preheating cooler 2 meets the heating requirement of the preheating heater 2.

[0029] When the ambient temperature is higher than the design temperature, the water temperature at the outlet of the preheating heater increases, the opening degree of the regulating valve 14 is increased, the flow rate of the preheating circulation pump 13 is reduced, the heat exchange capacity of the cooler 12 is reduced, and the water temperature at the outlet of the preheating cooler 2 is reduced, so that the heat exchange capacity of the preheating cooler 2 meets the heating requirement of the preheating heater 10.

[0030] AsFigure 2 As shown, it is the flow chart during the energy release of the compressed air energy storage system of the 600MW-level energy storage power station of the present utility model. In the expansion side, the expander system includes a three-stage expander system. In each stage of the expander system, an expander is connected to an energy storage heater 18. The expander includes a high-pressure cylinder expander, a medium-pressure cylinder expander, and a low-pressure cylinder expander. The gas storage reservoir 6 is sequentially connected to the three-stage expander system. The energy storage heaters 18 of the three-stage expander system are all connected to the high-temperature heat medium water tank 7 and the low-temperature heat medium water tank 9 to form a circulation system.

[0031] Specifically, along the gas flow direction during the energy release exhaust, the gas storage reservoir 6 is sequentially connected to the energy storage heater 18, the high-pressure cylinder expander 19, the energy storage heater 18, the medium-pressure cylinder expander 20, the energy storage heater 18, and the low-pressure cylinder expander 21, and is discharged to the atmosphere through the low-pressure cylinder expander 21.

[0032] On the expansion side, a low-temperature water constant temperature heat exchanger 16 is provided and connected to the low-temperature heat medium water tank 9. The low-temperature water constant temperature heat exchanger 16 is connected to the cooling tower 8 for the circulation of cooling water. The high-temperature heat medium water circulation pump 17 is connected to the high-temperature heat medium water tank 7. When the air temperature at the outlet of the gas storage reservoir 6, the exhaust temperatures of the high-pressure cylinder and the medium-pressure cylinder on the expansion side change, the cooling water volume is adjusted through the low-temperature water constant temperature heat exchanger 16 to maintain the temperature of the low-temperature heat medium water constant at T3, so as to maintain the inlet temperatures of the second-stage and third-stage compressors on the compression side constant at T2, enabling the second-stage and third-stage compressors on the compression side to always be in the design condition.

Claims

1. The compressed air energy storage system of a 600MW-level energy storage power station, characterized in that: It includes a high-temperature heat medium water tank (7), a low-temperature heat medium water tank (9), a compressor system and an expander system arranged in a double-line between the high-temperature heat medium water tank (7) and the low-temperature heat medium water tank (9), and a gas storage reservoir (6) and a cooling tower (8) connected to the double-line compressor system. Each line of the double-line arranged compressor system includes a four-stage compressor (11) connected in series. After the compressors (11) of the first three stages, an energy storage heat exchanger (1) is connected in series. After the energy storage heat exchanger (1) of the third stage, a preheating cooler (2) is connected in series. At the same time, a preheating heater (10) is arranged in front of the first-stage compressor (11). A circulation system is formed by connecting the preheating cooler (2) and the preheating heater (10) through a preheating system; the expander system includes a three-stage expander and an energy storage heater (18) connected in series.

2. The compressed air energy storage system of the 600MW-class energy storage power station according to claim 1, wherein: The preheating system includes a preheating expansion water tank (5), a preheating circulation pump (13) and a regulating valve (14) for controlling the water volume of the preheating circulation pump (13) connected in series in sequence. The energy storage heat exchangers (1) of the first three stages are all connected to the high-temperature heat medium water tank (7).

3. The compressed air energy storage system of a 600MW-class energy storage power station according to claim 1, characterized in that: A cooler (12) is connected in series after the fourth-stage compressor (11) of each line of the compressor system. The cooler (12) and the cooling tower (8) form a circulation system. The cooler (12) is connected to the gas storage reservoir (6), and a gas-liquid separator II (4) is arranged on the connecting pipeline between the cooler (12) and the gas storage reservoir (6).

4. The compressed air energy storage system of the 600MW-class energy storage power station according to claim 1, characterized in that: The third-stage compressor (11) is sequentially connected to the energy storage heat exchanger (1), the preheating cooler (2), the gas-liquid separator I (3), and the fourth-stage compressor (11). The cooling tower (8) is connected to the gas-liquid separator I (3) to form a circulation system.

5. The compressed air energy storage system of the 600MW-class energy storage power station according to claim 1, wherein: A low-temperature heat medium water circulation pump (15) is arranged on the compression side and is connected to the low-temperature heat medium water tank (9).

6. The compressed air energy storage system of the 600MW-class energy storage power station according to claim 1, wherein: The expander system on the expansion side includes a three-stage expander system. In each stage of the expander system, the expander is connected to an energy storage heater (18). The expander includes a high-pressure cylinder expander (19), a medium-pressure cylinder expander (20), and a low-pressure cylinder expander (21). The gas storage reservoir (6) is sequentially connected to the three-stage expander system. The energy storage heaters (18) of the three-stage expander system form a circulation system with both the high-temperature heat medium water tank (7) and the low-temperature heat medium water tank (9).

7. The compressed air energy storage system of the 600MW-class energy storage power station according to claim 6, characterized in that: A low-temperature water constant temperature heat exchanger (16) is arranged on the expansion side and is connected to the low-temperature heat medium water tank (9). A high-temperature heat medium water circulation pump (17) is arranged and is connected to the high-temperature heat medium water tank (7). The low-temperature water constant temperature heat exchanger (16) is connected to the cooling tower (8) for circulating cooling water.

8. The compressed air energy storage system of the 600MW-class energy storage power station according to claim 1, characterized in that: The preheating heater (10) adopts a plate heat exchanger with a small end difference of 5°C. Adjusting switch valves are arranged on both sides of the cooler (12).

9. The compressed air energy storage system of a 600MW-level energy storage power station according to claim 1, characterized in that: The first three stages of compressors in the double-line arranged compressor system are axial compressors.