A compressed air energy storage power generation system

Abstract

A compressed air energy storage power generation system includes a pumped-storage unit, a pressurized water tank group, a water-air tank group, an air storage tank group, an external water source, and a water pump unit. The pumped-storage unit is connected at both ends to a first pressurized water tank and a second pressurized water tank, respectively. The first water-air tank is equipped with a first air supply / release valve, and the second water-air tank is equipped with a second air supply / release valve. The first water-air tank is connected to the first pressurized water tank via a first on / off valve and to the second pressurized water tank via a second on / off valve. The second water-air tank is connected to the first pressurized water tank via a third on / off valve and to the second pressurized water tank via a fourth on / off valve. The first water-air tank is connected to the air storage tank group via a first air filling / discharging valve, and the second water-air tank is connected to the air storage tank group via a second air filling / discharging valve. One end of the water pump unit is connected to the external water source, and the first and second water-air tanks are connected to the other end of the water pump unit. This invention has low water consumption, helps prevent cavitation, allows for sustainable operation, has strong adaptability, and high water resource utilization.

Description

Technical Field

[0001] This invention relates to the field of power storage technology, and in particular to a compressed air energy storage power generation system. Background Technology

[0002] The randomness, intermittency, and volatility of power generation from new energy sources such as wind and solar power pose a severe challenge to the safe and stable operation of the power grid, while also creating greater demand for power grid peak shaving and frequency regulation, i.e., energy storage power generation.

[0003] Currently, the main large-scale energy storage methods that have been officially put into use are pumped hydro storage and compressed air storage. Large-scale pumped hydro storage is subject to many geographical limitations, has a long construction period, huge initial investment, and high grid connection voltage, making it difficult to meet the regulation requirements of widely distributed, rapidly developing, and low-voltage grid-connected new energy sources.

[0004] Chinese patent document CN102797613B discloses a pumped compressed air energy storage system. During off-peak electricity demand, the system uses a water pump to pressurize water from a reservoir into a pressure tank, compressing the gas inside and converting electrical energy into the internal energy of the air for storage. During peak electricity demand, the high-pressure air in the pressure tank forces the water out, which then drives a water turbine and a generator through a water pipeline to produce electricity. The applicant has found that this system still has some shortcomings:

[0005] 1) The energy storage capacity is small. If the energy storage capacity needs to be increased, the number of pressure tanks needs to be increased. At the same time, since the water storage tank is used as the water source for direct air compression, increasing the number of pressure tanks will lead to a significant increase in water demand and low water resource utilization.

[0006] 2) Pumped storage units are directly connected to water storage tanks and pressure tanks. During operation, air is easily drawn in, causing cavitation, which leads to a reduction in pump head and may even cause mechanical damage, affecting the safety of the unit.

[0007] 3) High-pressure gas and water coexist. If energy is stored for a long time, a large amount of air will dissolve in the water, reducing the energy storage efficiency. At the same time, it will also cause cavitation during the operation of the unit. Summary of the Invention

[0008] To address the problems existing in the use of the prior art, this invention provides a compressed air energy storage power generation system that has low water consumption, helps prevent cavitation caused by the intake of air or gas dissolution, can operate sustainably, is highly adaptable, and has a high water resource utilization rate.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] A compressed air energy storage power generation system includes a pumped-storage unit, a pressurized water tank group, a water-air tank group, an air storage tank group, an external water source, and a water pump unit. The pressurized water tank group includes a first pressurized water tank and a second pressurized water tank. One end of the pumped-storage unit is connected to the first pressurized water tank, and the other end of the pumped-storage unit is connected to the second pressurized water tank. The water-air tank group includes a first water-air tank and a second water-air tank. The first water-air tank is equipped with a first air supply / release valve, and the second water-air tank is equipped with a second air supply / release valve. The water-gas tank is connected to the first pressure water tank through a first on / off valve. The first water-gas tank is connected to the second pressure water tank through a second on / off valve. The second water-gas tank is connected to the first pressure water tank through a third on / off valve. The second water-gas tank is connected to the second pressure water tank through a fourth on / off valve. The first water-gas tank is connected to the gas storage tank group through a first inflation / deflation valve. The second water-gas tank is connected to the gas storage tank group through a second inflation / deflation valve. One end of the water pump unit is connected to an external water source, and both the first and second water-gas tanks are connected to the other end of the water pump unit.

[0011] As a further improvement to the above technical solution:

[0012] The compressed air energy storage power generation system also includes an auxiliary tank group. One end of the auxiliary tank group is connected to the water pump unit, and the first water-air tank and the second water-air tank are both connected to the other end of the auxiliary tank group. A first water replenishment and recovery valve is provided between the auxiliary tank group and the first pressure water tank, and a second water replenishment and recovery valve is provided between the auxiliary tank group and the second pressure water tank.

[0013] The auxiliary tank group includes multiple auxiliary tanks, which are connected in parallel.

[0014] The auxiliary tank is equipped with a first auxiliary tank valve, and the auxiliary tank is connected to the gas storage tank group through the first auxiliary tank valve.

[0015] The auxiliary tank is equipped with a second auxiliary tank valve, and the first water replenishment and recovery valve and the second water replenishment and recovery valve are connected to the auxiliary tank through the second auxiliary tank valve.

[0016] The auxiliary tank is also equipped with a third auxiliary tank valve, a fourth auxiliary tank valve and a fifth auxiliary tank valve. The auxiliary tank is connected to the water pump unit through the third auxiliary tank valve, connected to an external water source through the fourth auxiliary tank valve, and connected to the atmosphere through the fifth auxiliary tank valve.

[0017] The gas storage tank group includes multiple gas storage tanks, which are connected in parallel.

[0018] The gas storage tank is equipped with a first gas storage tank valve and a second gas storage tank valve. The first and second gas filling and discharging valves are connected to the gas storage tank through the first gas storage tank valve, and the gas storage tank is connected to the first auxiliary tank valve through the second gas storage tank valve.

[0019] The height of the external water source and the water-gas tank group is lower than the height of the auxiliary tank group, while the height of the water-gas tank group is higher than the height of the pressurized water tank group.

[0020] The pumped storage unit is connected to the first pressure tank through the first unit valve, and the pumped storage unit is connected to the second pressure tank through the second unit valve.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] The compressed air energy storage and power generation system of this invention achieves water circulation in the pressure water tank group and water-air tank group by adjusting and controlling relevant valves during the pumped water compressed air energy storage process and the pressurized water power generation process. This ensures that even if the capacity of the air storage tank group is increased, the water consumption will not increase, thus reducing the system's water demand. By setting cross-connections between the pressure water tank group and the water-air tank group at both ends of the pumped water storage unit and adjusting the opening and closing of the corresponding valves, the first water-air tank and the second water-air tank can alternately perform pumped water compressed air energy storage or pressurized water power generation, thereby achieving system water circulation and enabling the unit to operate continuously. By setting up a water pump unit connected to an external water source, the system can use the external water source as a supplementary water source in addition to its own water circulation, making full use of local water resources to supplement the system. Water is adaptable to different geological conditions, exhibiting high adaptability and efficient water resource utilization. By connecting the first and second pressure water tanks to the pumped storage unit respectively, water is not directly pumped from the first and second water-gas tanks, preventing air from entering the unit and causing cavitation. By setting up a separate gas storage tank group to store compressed gas, long-term coexistence of compressed gas and water during energy storage is avoided. Furthermore, when the first and second water-gas tanks work alternately, they are also alternately connected to the atmospheric pressure, reducing the coexistence of compressed gas and water and minimizing cavitation caused by gas dissolution. The use of gas storage tank groups for energy storage is adaptable to different terrains, has a high degree of standardization, and can be adapted to different capacity requirements simply by expanding the capacity of the gas storage tank group, demonstrating strong adaptability. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the compressed air energy storage power generation system of the present invention.

[0024] Figure 2 This is a schematic diagram of the compressed air energy storage and power generation system of the present invention during energy storage.

[0025] Figure 3 This is another schematic diagram of the compressed air energy storage power generation system of the present invention during energy storage.

[0026] Figure 4 This is a schematic diagram of the compressed air energy storage power generation system of the present invention during power generation.

[0027] Figure 5This is another schematic diagram of the compressed air energy storage power generation system of the present invention during power generation.

[0028] Figure 6 This is a schematic diagram of the process of replenishing water in the compressed air energy storage power generation system of the present invention.

[0029] Figure 7 This is a schematic diagram of the process of recovering residual pressure during power generation in the compressed air energy storage power generation system of the present invention.

[0030] Figure 8 This is a schematic diagram of the process of the compressed air energy storage power generation system of the present invention when the auxiliary tank group stores energy for the water-gas tank group.

[0031] Figure 9 This is a schematic diagram of the process of the compressed air energy storage power generation system of the present invention, in which the recovery of residual pressure and the energy storage of auxiliary tank groups are carried out simultaneously during power generation.

[0032] Figure 10 This is another schematic diagram of the compressed air energy storage power generation system of the present invention, in which the recovery of residual pressure and the energy storage of auxiliary tank groups are carried out simultaneously during power generation.

[0033] Legend: 11. Pumped storage unit; 12. Pump unit; 2. Pressure tank group; 21. First pressure tank; 22. Second pressure tank; 3. Water-air tank group; 31. First water-air tank; 32. Second water-air tank; 4. Gas storage tank group; 41. Gas storage tank; 51. First unit valve; 52. Second unit valve; 53. First on / off valve; 54. Fourth on / off valve; 55. Third on / off valve; 56. Second on / off valve; 57. First air supply / release valve; 58. Second air supply / release valve; 5 9. First inflation / deflation valve; 510. Second inflation / deflation valve; 511. First water replenishment / recovery valve; 512. Second water replenishment / recovery valve; 513. First auxiliary tank valve; 514. Second auxiliary tank valve; 515. Third auxiliary tank valve; 516. Fourth auxiliary tank valve; 517. Fifth auxiliary tank valve; 518. First gas storage tank valve; 519. Second gas storage tank valve; 520. First water pump unit valve; 521. Second water pump unit valve; 7. Auxiliary tank group; 71. Auxiliary tank; 8. External water source. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] In the description of this invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and 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 this invention.

[0036] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] like Figure 1 As shown, the compressed air energy storage power generation system of this embodiment includes a pumped storage unit 11, a pressure water tank group 2, a water-air tank group 3, an air storage tank group 4, an external water source 8, and a water pump unit 12. The pressure water tank group 2 includes a first pressure water tank 21 and a second pressure water tank 22. One end of the pumped storage unit 11 is connected to the first pressure water tank 21, and the other end of the pumped storage unit 11 is connected to the second pressure water tank 22. The water-air tank group 3 includes a first water-air tank 31 and a second water-air tank 32. The first water-air tank 31 is equipped with a first air supply valve 57, and the second water-air tank 32 is equipped with a second air supply valve 58. The first water-air tank 31 is connected to... The first water tank 31 is connected to the first pressure water tank 21 via the first shut-off valve 53. The second water tank 32 is connected to the second pressure water tank 22 via the second shut-off valve 56. The second water tank 32 is connected to the first pressure water tank 21 via the third shut-off valve 55. The second water tank 32 is connected to the second pressure water tank 22 via the fourth shut-off valve 54. The first water tank 31 is connected to the air storage tank group 4 via the first air filling and releasing valve 59. The second water tank 32 is connected to the air storage tank group 4 via the second air filling and releasing valve 510. One end of the water pump unit 12 is connected to the external water source 8. The first water tank 31 and the second water tank 32 are both connected to the other end of the water pump unit 12.

[0039] like Figure 2 and Figure 3 As shown, in this embodiment, during the energy storage process of the compressed air energy storage power generation system (solid arrows indicate water flow direction, hollow arrows indicate airflow direction), step X1, the pumped storage unit 11 is started to build pressure in pumping mode, the first on / off valve 53, the fourth on / off valve 54, the second charging / discharging valve 510, and the first replenishing / draining valve 57 are opened, and other valves are closed, so that all the water in the first water-air tank 31 is pumped into the second water-air tank 32. The water flow process is: first water-air tank 31 - first on / off valve 53 - first pressure water tank 21 - pumped storage unit 11 - second pressure water tank 22 - fourth on / off valve 54 - second water-air tank 32. The airflow process is: atmosphere - first replenishing / draining valve 57 - first water-air tank 31, second water-air tank 32 - second charging / discharging valve 510 - storage tank group 4; step X2, pumped storage... When the pumping unit 11 is operating in pumping mode, the first shut-off valve 53, the fourth shut-off valve 54, the second charge / discharge valve 510, and the first replenishment / release valve 57 are closed, and the third shut-off valve 55, the second shut-off valve 56, the first charge / discharge valve 59, and the second replenishment / discharge valve 58 are opened, pumping all the water in the second water-air tank 32 into the first water-air tank 31. The water flow process is: second water-air tank 32 - third shut-off valve 55 - first pressure water tank 21 - pumped storage unit 11 - second pressure water tank 22 - second shut-off valve 56 - first water-air tank 31. The air flow process is: atmosphere - second replenishment / discharge valve 58 - second water-air tank 32, first water-air tank 31 - first charge / discharge valve 59 - storage tank group 4. Step X3 is repeated, and steps X1-X2 are repeated until the compressed air pressure of the storage tank group 4 reaches the design pressure value, thus completing the energy storage.

[0040] like Figure 4 and Figure 5As shown, in the compressed air energy storage power generation system of this embodiment, during the power generation process (solid arrows indicate water flow direction, hollow arrows indicate airflow direction), step F1: open the second charging / discharging valve 510, open the fourth on / off valve 54, the first on / off valve 53, and the first replenishment / release valve 57, start the pumped storage unit 11 in power generation mode, and keep other valves closed. Water in the second water-air tank 32 is forced into the first water-air tank 31. The water flow process is: second water-air tank 32 - fourth on / off valve 54 - second pressure water tank 22 - pumped storage unit 11 - first pressure water tank 21 - first on / off valve 53 - first water-air tank 31. The airflow process is: storage tank group 4 - second charging / discharging valve 510 - second water-air tank 32, first water-air tank 31 - first replenishment / release valve 57 - atmosphere; step F2: pumped storage unit 11 starts in power generation mode. Under normal operating conditions, open the first charging / discharging valve 59, the third shut-off valve 55, the second shut-off valve 56, and the second replenishment / release valve 58, and gradually close the second charging / discharging valve 510, the fourth shut-off valve 54, and the first shut-off valve 53. Keep other valves closed. Pressurize the water in the first water-air tank 31 into the second water-air tank 32. The water flow process is: first water-air tank 31 - second shut-off valve 56 - second pressure water tank 22 - pumped storage unit 11 - first pressure water tank 21 - third shut-off valve 55 - second water-air tank 32. The airflow process is: gas storage tank group 4 - first charging / discharging valve 59 - first water-air tank 31, second water-air tank 32 - second replenishment / release valve 58 - atmosphere. Step F3, repeat steps F1-F2 until the compressed air pressure of the gas storage tank group 4 drops to the minimum design pressure for power generation operation of the pumped storage unit 11, and power generation is completed.

[0041] like Figure 6 As shown (solid arrows indicate water flow direction), in this embodiment, one end of the pump unit 12 is connected to an external water source 8, and the other end is connected to the first water-air tank 31 and the second water-air tank 32 respectively. Preferably, the external water source 8 is a water storage tank, which can be connected to a river, pond or other water source as appropriate. In this embodiment, because the water-air tank group 3 is connected to the external atmosphere, the water volume in the pressure water tank group 2 and the water-air tank group 3 will decrease after the system has been running for a period of time. At the same time, the system needs to be refilled before the first operation and after maintenance. When refilling, the pump unit 12 draws water from the external water source 8 into the water-air tank group 3, and then flows into the pressure water tank group 2 to complete the refilling.

[0042] In this embodiment, the compressed air energy storage and power generation system achieves water circulation in the pressure water tank group 2 and water-air tank group 3 by adjusting and controlling relevant valves during the pumped water compressed air energy storage and pressurized water power generation processes. This ensures that even if the capacity of the air storage tank group 4 is increased, the water consumption will not increase, thus reducing the system's water demand. By setting cross-connections between the pressure water tank group 2 and the water-air tank group 3 at both ends of the pumped water storage unit 11 and adjusting the opening and closing of the corresponding valves, the first water-air tank 31 and the second water-air tank 32 can alternately perform pumped water compressed air energy storage or pressurized water power generation, thereby achieving system water circulation and enabling the unit to operate continuously. By setting up a water pump unit 12 connected to an external water source 8, the system can use the external water source 8 as a supplementary water source in addition to its own water circulation, making full use of local water resources to replenish the system. This system is adaptable to various geological conditions, exhibiting strong adaptability and high water resource utilization. By connecting the first pressure water tank 21 and the second pressure water tank 22 to the pumped storage unit 11, water is not directly drawn from the first water-air tank 31 and the second water-air tank 32, preventing air from entering the unit and causing cavitation. The system also uses a separate gas storage tank group 4 to store compressed gas, avoiding long-term coexistence of compressed gas and water during energy storage. Furthermore, when the first water-air tank 31 and the second water-air tank 32 operate alternately, they are alternately connected to the atmospheric pressure, further reducing the coexistence of compressed gas and water and minimizing cavitation caused by gas dissolution. The use of the gas storage tank group 4 allows for adaptability to different terrains, a high degree of standardization, and adaptability to varying capacity requirements simply by expanding the capacity of the gas storage tank group 4. This compressed air energy storage power generation system has the advantages of low water consumption, prevention of cavitation caused by air intake or gas dissolution, sustainable operation, strong adaptability, and high water resource utilization.

[0043] Furthermore, in this embodiment, the compressed air energy storage power generation system also includes an auxiliary tank group 7. One end of the auxiliary tank group 7 is connected to the water pump unit 12, and the first water-air tank 31 and the second water-air tank 32 are both connected to the other end of the auxiliary tank group 7. A first water replenishment and recovery valve 511 is provided between the auxiliary tank group 7 and the first pressure water tank 21, and a second water replenishment and recovery valve 512 is provided between the auxiliary tank group 7 and the second pressure water tank 22. In this embodiment, a first water replenishment and recovery valve 511 is provided between the auxiliary tank group 7 and the first pressure water tank 21, and a second water replenishment and recovery valve 512 is provided between the auxiliary tank group 7 and the second pressure water tank 22. By setting the auxiliary tank group 7 as a transfer point for water replenishment by the water pump unit 12, when the compressed air energy storage power generation system is operating normally in energy storage or power generation mode, the water pump unit 12 is started to draw water from the external water source 8 into the auxiliary tank group 7 for storage in advance. When the system needs water replenishment, the first water replenishment and recovery valve 511 and the second water replenishment and recovery valve 512 are opened to replenish water quickly and efficiently, realizing the water replenishment function of the auxiliary tank group 7. Figure 7As shown (solid arrows indicate water flow direction, hollow arrows indicate airflow direction), during the power generation operation of the compressed air energy storage power generation system, the second water replenishment and recovery valve 512 can be closed and the first water replenishment and recovery valve 511 opened, or the second water replenishment and recovery valve 512 can be opened and the first water replenishment and recovery valve 511 closed. This allows the first water-air tank 31 or the second water-air tank 32 to discharge into the auxiliary tank group 7 for recovery during power generation, thus realizing the function of the auxiliary tank group 7 in recovering residual pressure. After the recovery is completed, the first water replenishment and recovery valve 511 and the second water replenishment and recovery valve 512 are closed again, and the first air replenishment and release valve 57 or the second air replenishment and release valve 58 is opened to perform the following... Figure 4 and Figure 5 The diagram illustrates the conventional power generation process. By recovering the residual pressure during the power generation process through auxiliary tank group 7, it can be ensured that during the next energy storage process, the pumped storage unit 11 can quickly build up pressure and respond rapidly by relying on the residual pressure in auxiliary tank group 7.

[0044] Furthermore, in this embodiment, the auxiliary tank group 7 includes multiple auxiliary tanks 71, which are connected in parallel. By setting multiple parallel auxiliary tanks 71, water replenishment or residual pressure recovery can be performed by one or more auxiliary tanks 71 in combination.

[0045] Furthermore, in this embodiment, the auxiliary tank 71 is provided with a first auxiliary tank valve 513, and the auxiliary tank 71 is connected to the gas storage tank group 4 through the first auxiliary tank valve 513. Figure 8 As shown (solid arrows indicate water flow direction, hollow arrows indicate airflow direction), the auxiliary tank 71 is equipped with a first auxiliary tank valve 513. When the pump unit 12 draws water into the auxiliary tank 71, the first auxiliary tank valve 513 is opened, and the first water replenishment and recovery valve 511 and the second water replenishment and recovery valve 512 are closed, realizing the energy storage function of the auxiliary tank 71. This allows for full utilization of local water resources and improves resource utilization. Even when the pumped storage unit 11 needs to be shut down due to malfunction or maintenance, it can continue to store energy without interruption. Furthermore, the auxiliary tanks 71 are connected in parallel, and one or more auxiliary tanks 71 can be combined to store energy for the gas storage tank group 4. When the auxiliary tank group 7 stores energy for the gas storage tank group 4, the water flow process is: external water source 8 - pump unit 12 - auxiliary tank 71, and the airflow process is: auxiliary tank 71 - first auxiliary tank valve 513 - gas storage tank group 4.

[0046] Furthermore, in this embodiment, the auxiliary tank 71 is equipped with a second auxiliary tank valve 514, and the first water replenishment and recovery valve 511 and the second water replenishment and recovery valve 512 are connected to the auxiliary tank 71 through the second auxiliary tank valve 514. By setting the second auxiliary tank valve 514 on the auxiliary tank 71, opening the second auxiliary tank valve 514 and closing the first auxiliary tank valve 513 can realize the water replenishment or residual pressure recovery function of the auxiliary tank 71, and closing the second auxiliary tank valve 514 and opening the first auxiliary tank valve 513 can realize the energy storage function of the auxiliary tank 71. At the same time, since the auxiliary tanks 71 are connected in parallel, the water replenishment or residual pressure recovery function and the energy storage function can be carried out simultaneously in different auxiliary tanks 71 without interference.

[0047] Furthermore, in this embodiment, the auxiliary tank 71 is also equipped with a third auxiliary tank valve 515, a fourth auxiliary tank valve 516, and a fifth auxiliary tank valve 517. The auxiliary tank 71 is connected to the water pump unit 12 through the third auxiliary tank valve 515, connected to the external water source 8 through the fourth auxiliary tank valve 516, and connected to the atmosphere through the fifth auxiliary tank valve 517. By setting the third auxiliary tank valve 515 and closing it, the water pump unit 12 can be maintained without affecting the stored water or residual pressure in the auxiliary tank 71. It also prevents the water pump unit 12 from being directly connected to the auxiliary tank 71 with residual pressure, thus preventing damage to the water pump unit 12. At the same time, it allows the state of the water pump unit 12 to adapt to different water replenishment, residual pressure recovery, or energy storage functions in different auxiliary tanks 71. By setting the fourth auxiliary tank valve 516, the water stored in the auxiliary tank 71 can be discharged to the external water source 8. When the auxiliary tank 71 is in its energy storage function, after the water in the auxiliary tank 71 is full, water can be discharged through the fourth auxiliary tank valve 516. After the water is discharged, it can be stored again, realizing the continuous energy storage of the auxiliary tank 71. By setting the fifth auxiliary tank valve 517 to be connected to the atmosphere, the fifth auxiliary tank valve 517 can be opened when the auxiliary tank 71 is replenished, preventing pressure buildup in the auxiliary tank 71, allowing the auxiliary tank 71 to store water smoothly. It can also balance the pressure inside the tank when the auxiliary tank 71 is discharged, making the discharge faster.

[0048] Furthermore, in this embodiment, the gas storage tank group 4 includes multiple gas storage tanks 41, which are connected in parallel. The system's energy storage capacity is proportional to the number of gas storage tanks 41 connected to the system, which helps to increase the system's energy storage capacity. At the same time, by connecting the gas storage tanks 41 in parallel, each gas storage tank 41 is independent of the others and will not affect each other, thus improving the system's reliability and stability.

[0049] Furthermore, in this embodiment, the gas storage tank 41 is provided with a first gas storage tank valve 518 and a second gas storage tank valve 519. The first filling and discharging valve 59 and the second filling and discharging valve 510 are connected to the gas storage tank 41 through the first gas storage tank valve 518. The gas storage tank 41 is connected to the second filling and discharging valve 510 through the first gas storage tank valve 518. The gas storage tank 41 is connected to the first auxiliary tank valve 513 through the second gas storage tank valve 519. By installing independent first air storage tank valve 518 and second air storage tank valve 519 on each air storage tank 41, multiple compressed air injection methods can be adopted during energy storage operation: Method 1, synchronous injection into all air storage tanks 41 to simultaneously reach the design pressure value; Method 2, sequential injection of compressed air into air storage tanks 41, injecting compressed air into the next air storage tank 41 after one air storage tank 41 reaches the design pressure; Method 3, when there are many air storage tanks 41, compressed air can be injected in groups. During power generation operation, multiple water pressure methods can be adopted: Method 1, synchronous water pressure in all air storage tanks 41; Method 2, sequential water pressure in individual air storage tanks 41; Method 3, when there are many air storage tanks 41, synchronous water pressure can be grouped. This system is flexible, convenient, and highly adaptable, suitable for energy storage power generation operations under various conditions. Furthermore, it can also achieve simultaneous energy storage or power generation of air storage tanks 41 by pumped storage unit 11 and energy storage of air storage tanks 41 by pump unit 12.

[0050] In this embodiment, when the compressed air energy storage power generation system simultaneously recovers residual pressure and stores energy in auxiliary tank 7 during power generation, the water flow process for power generation is the same as in steps F1 or F2. Figure 9 As shown (solid arrows indicate the direction of water flow, hollow arrows indicate the direction of airflow), Figure 9 The water flow process for power generation is the same as in step F2. The airflow process for power generation is as follows: gas storage tank 41 - first charging / discharging valve 59 - first water-gas tank 31, which is a pressurized water power generation process; second water-gas tank 32 - second water replenishment and recovery valve 512 - second auxiliary tank valve 514 - auxiliary tank 71, which is a residual pressure recovery process. The water flow process in the auxiliary tank group 7 for energy storage is as follows: external water source 8 - water pump unit 12 - third auxiliary tank valve 515 - auxiliary tank 71, and the airflow process is as follows: auxiliary tank 71 - first auxiliary tank valve 513 - second gas storage tank valve 519 - gas storage tank 41, realizing the auxiliary tank group 7 storing energy in the gas storage tank 41. By setting the auxiliary tank 71 used for residual pressure recovery and the auxiliary tank 71 used for energy storage of the gas storage tank 41 to be different auxiliary tanks 71, it is possible to generate electricity and store energy in the gas storage tank 41 at the same time. This allows the power grid to perform peak shaving while also regulating frequency, thus maintaining the stability and reliability of the power grid.

[0051] like Figure 10 As shown (solid arrows indicate the direction of water flow, hollow arrows indicate the direction of airflow), in Figure 9After the auxiliary tank 71 used for energy storage of the gas storage tank 41 is filled with water (i.e. Figure 9 and Figure 10 In the lowest auxiliary tank 71), open the fifth auxiliary tank valve 517 and the fourth auxiliary tank valve 516 to drain the water in the lowest auxiliary tank 71 into the external water source 8; Figure 9 Auxiliary tank 71 used for residual pressure recovery (i.e. Figure 9 and Figure 10 The middle auxiliary tank 71 is pumped by the water pump unit 12 to store energy in the gas storage tank 41; the uppermost auxiliary tank 71 is used for residual pressure recovery. The auxiliary tank 71 can switch between different functions to achieve continuous operation of the system.

[0052] Furthermore, in this embodiment, the heights of the external water source 8 and the water-gas tank group 3 are both lower than the height of the auxiliary tank group 7, while the height of the water-gas tank group 3 is higher than the height of the pressurized water tank group 2. Because the auxiliary tank group 7 is higher than the water-gas tank group 3, during water replenishment, the water stored in the auxiliary tank group 7 can flow into the water-gas tank group 3 by gravity, resulting in a simple structure and high reliability. Because the auxiliary tank group 7 is higher than the external water source 8, when the auxiliary tank group 7 stores energy in the gas storage tank group 4, the water in the auxiliary tank group 7 can flow into the external water source 8 by gravity, enabling water recycling, further simplifying the structure and improving reliability. Because the water-gas tank group 3 is higher than the pressurized water tank group 2, the submersion depth requirements of the pumped storage unit 11 are met, and the water in the water-gas tank group 3 can all flow into the pressurized water tank group 2 by gravity, preventing cavitation caused by insufficient submersion depth.

[0053] Preferably, the installation is divided into three layers according to the installation position: ground level L-0, lower ground level L-1, and upper ground level L+1. The pressure water tank group 2 and water-air tank group 3 are installed on the L-1 layer to meet the high suction requirements of the water pump turbine; the auxiliary tank group 7 is installed on the L+1 layer to allow water to flow back to the external water source 8 and water-air tank group 3 naturally; and the air storage tank group 4 is installed on the L-0 layer to facilitate the maintenance and replacement of the air storage tank 41.

[0054] Furthermore, in this embodiment, the pumped storage unit 11 is connected to the first pressure tank 21 via the first unit valve 51, and to the second pressure tank 22 via the second unit valve 52. The first unit valve 51 and the second unit valve 52 can disconnect the pumped storage unit 11 from the pressure tank group 2. During energy storage, after successful pressurization, the second unit valve 52 is opened to connect with the pressure tank group 2, preventing damage to the unit from starting before successful pressurization. When the pumped storage unit 11 requires maintenance, it can also be disconnected from the pressure tank group 2 to prevent water in the pressure tank group 2 from interfering with the maintenance of the pumped storage unit 11.

[0055] Preferably, the water pump unit 12 is connected to the third auxiliary tank valve 515 via the first water pump unit valve 520, and the water pump unit 12 is connected to the external water source 8 via the second water pump unit valve 521. When the water pump unit 12 needs maintenance, the water pump unit 12 can also be disconnected from the auxiliary tank group 7 to prevent water or air in the auxiliary tank group 7 from interfering with the maintenance of the water pump unit 12.

[0056] Preferably, all valves are remote control valves, which facilitate remote control and automated operation.

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.

Claims

1. A compressed air energy storage power generation system, characterized in that: The system includes a pumped storage unit (11), a pressure water tank group (2), a water-air tank group (3), an air storage tank group (4), an external water source (8), and a water pump unit (12). The pressure water tank group (2) includes a first pressure water tank (21) and a second pressure water tank (22). One end of the pumped storage unit (11) is connected to the first pressure water tank (21), and the other end of the pumped storage unit (11) is connected to the second pressure water tank (22). The water-air tank group (3) includes a first water-air tank (31) and a second water-air tank (32). The first water-air tank (31) is equipped with a first air supply valve (57), and the second water-air tank (32) is equipped with a second air supply valve (58). The first water-air tank (31) is connected to the second water-air tank through a first on / off valve (58). 53) The first water tank (21) is connected to the first pressure water tank (21). The first water gas tank (31) is connected to the second pressure water tank (22) through the second shut-off valve (56). The second water gas tank (32) is connected to the first pressure water tank (21) through the third shut-off valve (55). The second water gas tank (32) is connected to the second pressure water tank (22) through the fourth shut-off valve (54). The first water gas tank (31) is connected to the gas storage tank group (4) through the first inflation / deflation valve (59). The second water gas tank (32) is connected to the gas storage tank group (4) through the second inflation / deflation valve (510). One end of the water pump unit (12) is connected to the external water source (8). The first water gas tank (31) and the second water gas tank (32) are both connected to the other end of the water pump unit (12).

2. The compressed air energy storage power generation system according to claim 1, characterized in that: The compressed air energy storage power generation system also includes an auxiliary tank group (7). One end of the auxiliary tank group (7) is connected to the water pump unit (12). The first water-air tank (31) and the second water-air tank (32) are both connected to the other end of the auxiliary tank group (7). A first water replenishment and recovery valve (511) is provided between the auxiliary tank group (7) and the first pressure water tank (21). A second water replenishment and recovery valve (512) is provided between the auxiliary tank group (7) and the second pressure water tank (22).

3. The compressed air energy storage power generation system according to claim 2, characterized in that: The auxiliary tank group (7) includes multiple auxiliary tanks (71), and each of the auxiliary tanks (71) is connected in parallel.

4. The compressed air energy storage power generation system according to claim 3, characterized in that: The auxiliary tank (71) is provided with a first auxiliary tank valve (513), and the auxiliary tank (71) is connected to the gas storage tank group (4) through the first auxiliary tank valve (513).

5. The compressed air energy storage power generation system according to claim 4, characterized in that: The auxiliary tank (71) is provided with a second auxiliary tank valve (514), and the first water replenishment and recovery valve (511) and the second water replenishment and recovery valve (512) are connected to the auxiliary tank (71) through the second auxiliary tank valve (514).

6. The compressed air energy storage power generation system according to claim 5, characterized in that: The auxiliary tank (71) is also equipped with a third auxiliary tank valve (515), a fourth auxiliary tank valve (516) and a fifth auxiliary tank valve (517). The auxiliary tank (71) is connected to the water pump unit (12) through the third auxiliary tank valve (515), the auxiliary tank (71) is connected to the external water source (8) through the fourth auxiliary tank valve (516), and the auxiliary tank (71) is connected to the atmosphere through the fifth auxiliary tank valve (517).

7. The compressed air energy storage power generation system according to claim 6, characterized in that: The gas storage tank group (4) includes multiple gas storage tanks (41), and each of the gas storage tanks (41) is connected in parallel.

8. The compressed air energy storage power generation system according to claim 7, characterized in that: The gas storage tank (41) is provided with a first gas storage tank valve (518) and a second gas storage tank valve (519). The first gas filling and discharging valve (59) and the second gas filling and discharging valve (510) are connected to the gas storage tank (41) through the first gas storage tank valve (518). The gas storage tank (41) is connected to the first auxiliary tank valve (513) through the second gas storage tank valve (519).

9. The compressed air energy storage power generation system according to any one of claims 2 to 8, characterized in that: The height of the external water source (8) and the water-gas tank group (3) is lower than the height of the auxiliary tank group (7), and the height of the water-gas tank group (3) is higher than the height of the pressure water tank group (2).

10. The compressed air energy storage power generation system according to any one of claims 1 to 8, characterized in that: The pumped storage unit (11) is connected to the first pressure tank (21) through the first unit valve (51), and the pumped storage unit (11) is connected to the second pressure tank (22) through the second unit valve (52).

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