A multi-stage adjustable pumped compressed air energy storage system

Abstract

This invention relates to a multi-stage adjustable pumped compressed air energy storage system, comprising a pumped energy storage unit and a compressed air energy storage unit. The pumped energy storage unit includes a first water-air co-containment chamber (1), a second water-air co-containment chamber (2), a third water-air co-containment chamber (3), a second water pump turbine unit (13), a fourth water pump turbine unit (15), and a reservoir (18). The first water-air co-containment chamber (1), the second water-air co-containment chamber (2), and the third water-air co-containment chamber (3) are connected sequentially through air pipelines. The first water-air co-containment chamber (1), the second water-air co-containment chamber (2), and the third water-air co-containment chamber (3) are also connected to the reservoir (18) through water pipelines. The second water pump turbine unit (13) and the fourth water pump turbine unit (15) are used to pump water during energy storage.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and in particular to a multi-stage adjustable pumped compressed air energy storage system. Background Technology

[0002] With the continuous depletion of fossil fuels, people are constantly seeking to develop and utilize new energy sources. Currently, wind power and photovoltaic power generation are widely used new energy technologies, but they are subject to randomness and fluctuations, which can have a huge impact on the power grid and seriously affect its safe operation.

[0003] Large-scale energy storage is an important way to establish new power systems and ensure the safe operation of the power grid. Pumped hydro power generation and compressed air energy storage are two common energy storage methods, but the effects of these two methods are not ideal.

[0004] It should be noted that the information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of this invention, and should not be construed as an admission or implication in any way that such information constitutes prior art known to those skilled in the art. The foregoing statements are only for providing background information related to this application and do not necessarily constitute prior art. Summary of the Invention

[0005] This invention provides a multi-stage adjustable pumped compressed air energy storage system.

[0006] According to one aspect of the present invention, a multi-stage regulating pumped compressed air energy storage system includes a pumped storage unit and a compressed air energy storage unit. The pumped storage unit includes a first water-air co-containment chamber, a second water-air co-containment chamber, a third water-air co-containment chamber, a second water pump turbine unit, a fourth water pump turbine unit, and a reservoir. The first water-air co-containment chamber, the second water-air co-containment chamber, and the third water-air co-containment chamber are sequentially connected by air pipelines. A first regulating valve is provided on the air pipeline between the first water-air co-containment chamber and the second water-air co-containment chamber, and a third regulating valve is provided on the air pipeline between the second water-air co-containment chamber and the third water-air co-containment chamber. Through the first regulating valve and the third regulating valve, air pressure communication between the first water-air co-containment chamber, the second water-air co-containment chamber, the third water-air co-containment chamber, and the reservoir is realized.

[0007] The first water-air co-containment chamber, the second water-air co-containment chamber, and the third water-air co-containment chamber are also connected to the reservoir via water pipelines. A first shut-off valve is installed on the water pipeline between the first water-air co-containment chamber and the reservoir, a second shut-off valve is installed on the water pipeline between the second water-air co-containment chamber and the reservoir, and a third shut-off valve is installed on the water pipeline between the third water-air co-containment chamber and the reservoir. Through the first shut-off valve, the second shut-off valve, and the third shut-off valve, water communication between the first water-air co-containment chamber, the second water-air co-containment chamber, the third water-air co-containment chamber, and the reservoir is achieved.

[0008] The second and fourth pump-turbine units are used for pumping water during energy storage. During energy storage, the first, second, and third shut-off valves are opened, and the fourth pump-turbine unit operates to pump water. During energy release, the first, second, and third shut-off valves are opened, and the second and fourth pump-turbine units operate to generate electricity.

[0009] In some embodiments, an eleventh shut-off valve is provided above the first water-gas co-containment chamber, a twelfth shut-off valve is provided above the second water-gas co-containment chamber, and a thirteenth shut-off valve is provided above the third water-gas co-containment chamber.

[0010] In some embodiments, the compressed air energy storage unit includes an energy storage subunit, which includes a first compressor, a second compressor, a third compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a first water pump turbine unit, a second water-air co-containment chamber, a hot water tank, and a gas storage tank. During energy storage, the first compressor, the second compressor, and the third compressor compress the air, and the first water pump turbine unit pumps water from the second water-air co-containment chamber and sends it into the first heat exchanger, the second heat exchanger, and the third heat exchanger. The water after heat exchange is stored in the hot water tank, and the compressed gas after heat exchange is stored in the gas storage tank.

[0011] In some embodiments, the compressed air energy storage unit includes an energy release subunit, which includes a fourth heat exchanger, an expander generator set, a third water pump turbine set, a hot water tank, and an air storage tank. When releasing energy, the compressed air in the air storage tank exchanges heat with the water drawn from the hot water tank by the third water pump turbine set in the fourth heat exchanger, thereby driving the expander generator set to generate electricity.

[0012] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0013] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0014] Figure 1 This is a schematic diagram of a structure of an embodiment of the multi-stage adjustable pumped compressed air energy storage system provided by the present invention.

[0015] In the picture:

[0016] 1. First water-air co-containment chamber; 2. Second water-air co-containment chamber; 3. Third water-air co-containment chamber; 4. First compressor; 5. First heat exchanger; 6. Second compressor; 7. Second heat exchanger; 8. Third compressor; 9. Third heat exchanger; 10. Fourth heat exchanger; 11. Expander generator set; 12. First water pump turbine unit; 13. Second water pump turbine unit; 14. Third water pump turbine unit; 15. Fourth water pump turbine unit; 16. Hot water tank; 17. Gas storage tank; 18. Reservoir; 19. Electrical control equipment; 20. 21. First regulating valve; 22. Second regulating valve; 23. Third regulating valve; 24. Fourth regulating valve; 25. First shut-off valve; 26. Second shut-off valve; 27. Third shut-off valve; 28. Fourth shut-off valve; 29. ​​Fifth shut-off valve; 30. Fifth regulating valve; 31. Seventh shut-off valve; 32. Eighth shut-off valve; 33. Ninth shut-off valve; 34. Tenth shut-off valve; 35. Eleventh shut-off valve; 36. Twelfth shut-off valve; 37. Thirteenth shut-off valve; 38. Sixth regulating valve; 39. Seventh regulating valve. Detailed Implementation

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be understood that the terms "center," "lateral," "longitudinal," "front," "rear," "left," "right," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate directions or...

[0019] The positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of the present invention.

[0020] like Figure 1 As shown, in one embodiment of the multi-stage adjustable pumped compressed air energy storage system provided by the present invention, the multi-stage adjustable pumped compressed air energy storage system is designed as a combination of multi-stage pumped energy storage and multi-stage compressed air energy storage.

[0021] The pumped storage unit includes a first water-air co-location chamber 1, a second water-air co-location chamber 2, a third water-air co-location chamber 3, a second pump-turbine unit 13, a fourth pump-turbine unit 15, and a reservoir 18. The first water-air co-location chamber 1, the second water-air co-location chamber 2, and the third water-air co-location chamber 3 are connected sequentially via air pipelines. A first regulating valve 20 is installed on the air pipeline between the first water-air co-location chamber 1 and the second water-air co-location chamber 2, and a third regulating valve 22 is installed on the air pipeline between the second water-air co-location chamber 2 and the third water-air co-location chamber 3. Through the first regulating valve 20 and the third regulating valve 22, air pressure exchange and regulation can be achieved between the first water-air co-location chamber 1, the second water-air co-location chamber 2, the third water-air co-location chamber 3, and the reservoir 18.

[0022] The first water-air co-containment chamber 1, the second water-air co-containment chamber 2, and the third water-air co-containment chamber 3 are also connected to the reservoir 18 via water pipelines. A first shut-off valve 24 is installed on the water pipeline between the first water-air co-containment chamber 1 and the reservoir 18. A second shut-off valve 25 is installed on the water pipeline between the second water-air co-containment chamber 2 and the reservoir 18. A third shut-off valve 26 is installed on the water pipeline between the third water-air co-containment chamber 3 and the reservoir 18. Through the first shut-off valve 24, the second shut-off valve 25, and the third shut-off valve 26, water communication between the first water-air co-containment chamber 1, the second water-air co-containment chamber 2, the third water-air co-containment chamber 3, and the reservoir 18 can be achieved.

[0023] An eleventh shut-off valve 35 is installed above the first water-air co-containment chamber 1, a twelfth shut-off valve 36 is installed above the second water-air co-containment chamber 2, and a thirteenth shut-off valve 37 is installed above the third water-air co-containment chamber 3. Through the eleventh shut-off valve 35, the twelfth shut-off valve 36, and the thirteenth shut-off valve 37, the flow between the first water-air co-containment chamber 1, the second water-air co-containment chamber 2, and the third water-air co-containment chamber 3 and the outside atmosphere can be controlled. When the corresponding shut-off valve is closed, the pressure inside the chamber can be regulated.

[0024] The first pump-turbine unit 12, the second pump-turbine unit 13, the third pump-turbine unit 14, and the fourth pump-turbine unit 15 can function as pumps for energy storage. During energy storage, the first shut-off valve 24, the second shut-off valve 25, and the third shut-off valve 26 in the pumped-storage unit are opened, and the fourth pump-turbine unit 15 operates to pump water. During energy release, the first shut-off valve 24, the second shut-off valve 25, the third shut-off valve 26, and the seventh shut-off valve 31 in the pumped-storage unit are opened, and the second pump-turbine unit 13 and the fourth pump-turbine unit 15 operate to generate electricity. During the pumping and energy release process, when all valves of the eleventh shut-off valve 35, the twelfth shut-off valve 36, and the thirteenth shut-off valve 37 are open, the first water-air co-containment chamber 1, the second water-air co-containment chamber 2, and the third water-air co-containment chamber 3 become water storage tanks. By controlling the opening and closing of different combinations of valves of the first shut-off valve 24, the second shut-off valve 25, and the third shut-off valve 26, conventional pumping and energy release can be carried out. The operation is simple and suitable for different power level requirements.

[0025] The compressed air energy storage unit includes an energy storage subunit and an energy release subunit.

[0026] The energy storage subunit includes a first compressor 4, a second compressor 6, a third compressor 8, a first heat exchanger 5, a second heat exchanger 7, a third heat exchanger 9, a first water pump turbine unit 12, a second water-gas co-containment chamber 2, and a gas storage tank 17.

[0027] During energy storage, the first compressor 4, the second compressor 6, and the third compressor 8 compress air, and the first water pump turbine unit 12 pumps water into the second water-air co-containment chamber 2. The water then enters the first heat exchanger 5, the second heat exchanger 7, and the third heat exchanger 9 through the fourth shut-off valve 27, the fifth shut-off valve 28, and the sixth shut-off valve 29. The amount of water entering the heat exchangers can be adjusted by the valve opening. After heat exchange, the water is stored in the hot water tank 16, and the gas after the final stage of compression and heat exchange is stored in the gas storage tank 17.

[0028] The energy release subunit includes a fourth heat exchanger 10, an expander generator set 11, a third water pump turbine set 14, an air storage tank 17, and a hot water tank 16. During energy release, the second shut-off valve 25 and the ninth shut-off valve 33 are opened. Compressed air in the air storage tank 17 exchanges heat with water from the hot water tank 16, which is then transported to the fourth heat exchanger 10 via the third water pump turbine set 14. This heat exchange drives the expander generator set 11 to generate electricity. During this process, the water used for heat exchange can be supplied to the fourth heat exchanger 10 by opening the tenth shut-off valve 34 and using the first water pump turbine set 12 to increase the water level difference in the hot water tank 16.

[0029] The function is achieved by coupling pumped hydro storage and compressed air energy storage.

[0030] During air energy storage, a closed-chamber mode can be adopted, with the second regulating valve 21 opened to pressurize the second water-air co-containment chamber 2. When the first regulating valve 20 and the third regulating valve 22 are opened, the first water-air co-containment chamber 1, the second water-air co-containment chamber 2, and the third water-air co-containment chamber 3 can be pressurized simultaneously, thereby increasing the compressed air storage power and capacity, and also providing pressure for the pumped hydro storage unit.

[0031] Based on the above, when the pressure inside the chamber is high, the fifth regulating valve 30 can be opened, allowing cold water to be directly delivered to the hot water tank via the heat exchanger. Simultaneously, the flow rate of water passing through the first heat exchanger 5 can be adjusted by changing the opening degree of the fifth regulating valve 30. Similarly, the second heat exchanger 7 and the third heat exchanger 9 operate in the same manner. Therefore, the investment in a water pump can be eliminated.

[0032] During air energy storage, when a larger energy storage capacity is required, pumped-storage can be activated to increase the pressure in the sealed second water-air co-containment chamber 2. Alternatively, by opening the second regulating valve 21, supplemental air can be supplied to the second-stage compressor, thereby increasing the compressor's power consumption.

[0033] During the pumped storage process, a staged energy storage method is adopted. A suitable enclosed chamber is selected as the upper water tank. At the same time, the pressure inside the chamber, which is also the water pressure, can be regulated by adjusting the eleventh shut-off valve 35, the twelfth shut-off valve 36, and the thirteenth shut-off valve 37, so that the first water pump turbine unit 12 can work in the high-efficiency zone and achieve the pumped storage operation at the highest efficiency.

[0034] During the pumping and energy release process, the pressure generated in the closed chamber during the initial pressurization can be used to select a suitable turbine for power generation, and the output power can be adjusted accordingly.

[0035] When one unit fails, the multi-stage energy storage system can operate normally through other units, achieving backup between multiple units.

[0036] The above process allows for multi-stage regulation by adjusting the opening and closing of different valves according to varying needs. This multi-stage regulation also increases the system's flexibility and stability, enabling operation through alternative pathways in the event of a malfunction in one device.

[0037] In this invention:

[0038] The first compressor 4, the second compressor 6, and the third compressor 8 are used to store energy by using electrical energy to drive compressed air.

[0039] The first heat exchanger 5, the second heat exchanger 7, the third heat exchanger 9, and the fourth heat exchanger 10 are used to realize the heat conversion between water and gas.

[0040] The first water-air co-containment chamber 1, the second water-air co-containment chamber 2, and the third water-air co-containment chamber 3 are used to store compressed air and water, and have valves at the top to allow for communication and shut-off with the outside air. There is a height difference between the first water-air co-containment chamber 1, the second water-air co-containment chamber 2, and the third water-air co-containment chamber 3.

[0041] The first water pump turbine unit 12 is mainly used in the energy storage process to drive cold water through the first heat exchanger 5, the second heat exchanger 7, and the third heat exchanger 9 to exchange heat with compressed air, thereby reducing the compressor intake temperature. When the pressure in the second water-air co-containment chamber 2 is high, it can be used as a turbine to generate electricity.

[0042] The third water pump turbine unit 14 is mainly used as a water pump to drive hot water through the fourth heat exchanger 10 to exchange heat with compressed air during the energy release process, thereby increasing the inlet air temperature of the expander. When the pressure in the hot water tank 16 is high, it can be used as a water turbine to generate electricity.

[0043] The second pump-turbine unit 13 and the fourth pump-turbine unit 15 act as pumps to draw water during the energy storage process and as turbines to generate electricity during the energy release process.

[0044] The expander generator set 11 is used to expand and drive the generator to generate electricity during the energy release process.

[0045] Hot water tank 16 is used to store water after heat exchange.

[0046] The air storage tank 17 is used to store the compressed air after heat exchange.

[0047] Reservoir 18 is used to replenish water to the first water-air co-containment chamber 1, the second water-air co-containment chamber 2 and the third water-air co-containment chamber 3, and also serves as a low-level reservoir.

[0048] The electrical control equipment 19 is used for power supply and power consumption, and also for power control.

[0049] The first regulating valve 20, the second regulating valve 21, the third regulating valve 22, the fourth regulating valve 23, the fifth regulating valve 30, the sixth regulating valve 38, and the seventh regulating valve 39 are used to regulate the flow rate and pressure of the water and gas circuits.

[0050] The first shut-off valve 24, the second shut-off valve 25, the third shut-off valve 26, the fourth shut-off valve 27, the fifth shut-off valve 28, the sixth shut-off valve 29, the seventh shut-off valve 31, the eighth shut-off valve 32, the ninth shut-off valve 33, the tenth shut-off valve 34, the eleventh shut-off valve 35, the twelfth shut-off valve 36, and the thirteenth shut-off valve 37 are switches used to control pipelines.

[0051] This invention provides a multi-stage adjustable pumped hydro storage and compressed air energy storage coupled energy storage system. While retaining the original functions of pumped hydro storage and compressed air energy storage, it enhances the complementarity between the two and achieves gradient energy utilization through multi-stage adjustment, enabling a wider range of regulation to meet the needs of different application conditions. This design includes a multi-stage air compressor, a multi-stage heat exchanger, a multi-stage water-air co-containment chamber, an air expander, as well as a water pump turbine unit, electrical control equipment, an air storage tank, and a water storage tank.

[0052] The multi-stage pumped-water compressed air energy storage system provided by this invention can adjust the system's power generation by regulating the opening and closing of different valves according to different power demands, thus achieving flexible system control. Simultaneously, the compressed air energy storage system can control the pressure within the water-air co-containment chamber of the pumped-water energy storage system to meet varying power requirements.

[0053] Through the description of several embodiments of the multi-stage adjustable pumped compressed air energy storage system of the present invention, it can be seen that the embodiments of the multi-stage adjustable pumped compressed air energy storage system of the present invention have at least one or more of the following advantages:

[0054] 1. The system adopts a combination of pumped hydro storage and compressed air storage, which increases the capacity of a system compared to the traditional single energy storage system, thus broadening the range of energy storage capacity adjustment.

[0055] 2. Both pumped water storage and compressed air storage units can be multi-stage regulated, and the opening and closing of different valves can be controlled to enable different pipelines in the system to work. This multi-stage regulation of the system can meet different power demands and improve the system's flexibility.

[0056] 3. The water-air co-containment chamber in the pumped storage unit can be switched between a water-air co-containment chamber and a water storage tank by opening and closing valves. When used as a water-air co-containment chamber, the pressure inside the chamber can be changed by a compressor to provide power instead of a water pump, and different power outputs of the system can also be achieved. When used as a water storage tank, different power outputs can be achieved by adjusting the opening and closing of different valves.

[0057] 4. In a multi-stage regulating pumped compressed air energy storage system, when one device fails, other pathways can ensure the normal operation of the system, achieving backup between multiple units.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can still be made to some technical features without departing from the principle of the present invention, and such modifications and equivalent substitutions should all be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A multi-stage adjustable pumped compressed air energy storage system, characterized in that, The system includes a pumped-storage unit and a compressed-air energy storage unit. The pumped-storage unit includes a first water-air co-containment chamber (1), a second water-air co-containment chamber (2), a third water-air co-containment chamber (3), a second water pump turbine unit (13), a fourth water pump turbine unit (15), and a reservoir (18). The first water-air co-containment chamber (1), the second water-air co-containment chamber (2), and the third water-air co-containment chamber (3) are connected sequentially through air pipelines. A first regulating valve (20) is provided on the air pipeline between the first water-air co-containment chamber (1) and the second water-air co-containment chamber (2), and a third regulating valve (22) is provided on the air pipeline between the second water-air co-containment chamber (2) and the third water-air co-containment chamber (3). Through the first regulating valve (20) and the third regulating valve (22), the air pressure between the first water-air co-containment chamber (1), the second water-air co-containment chamber (2), the third water-air co-containment chamber (3), and the reservoir (18) is interconnected. The first water-air co-containment chamber (1), the second water-air co-containment chamber (2), and the third water-air co-containment chamber (3) are also connected to the reservoir (18) through water pipelines. A first shut-off valve (24) is provided on the water pipeline between the first water-air co-containment chamber (1) and the reservoir (18), a second shut-off valve (25) is provided on the water pipeline between the second water-air co-containment chamber (2) and the reservoir (18), and a third shut-off valve (26) is provided on the water pipeline between the third water-air co-containment chamber (3) and the reservoir (18). Through the first shut-off valve (24), the second shut-off valve (25), and the third shut-off valve (26), water communication between the first water-air co-containment chamber (1), the second water-air co-containment chamber (2), the third water-air co-containment chamber (3), and the reservoir (18) is realized. The second water pump turbine unit (13) and the fourth water pump turbine unit (15) are used to pump water during energy storage. During energy storage, the valves of the first shut-off valve (24), the second shut-off valve (25) and the third shut-off valve (26) are opened, and the fourth water pump turbine unit (15) works to pump water. During energy release, the valves of the first shut-off valve (24), the second shut-off valve (25) and the third shut-off valve (26) are opened, and the second water pump turbine unit (13) and the fourth water pump turbine unit (15) work to generate electricity.

2. The multi-stage adjustable pumped compressed air energy storage system according to claim 1, characterized in that, The first water-air co-containment chamber (1) is provided with an eleventh shut-off valve (35), the second water-air co-containment chamber (2) is provided with a twelfth shut-off valve (36), and the third water-air co-containment chamber (3) is provided with a thirteenth shut-off valve (37).

3. The multi-stage adjustable pumped compressed air energy storage system according to claim 1, characterized in that, The compressed air energy storage unit includes an energy storage subunit, which includes a first compressor (4), a second compressor (6), a third compressor (8), a first heat exchanger (5), a second heat exchanger (7), a third heat exchanger (9), a first water pump turbine unit (12), a second water-air co-containment chamber (2), a hot water tank (16), and a gas storage tank (17). During energy storage, the first compressor (4), the second compressor (6), and the third compressor (8) compress the air. The first water pump turbine unit (12) pumps water from the second water-air co-containment chamber (2) and sends it into the first heat exchanger (5), the second heat exchanger (7), and the third heat exchanger (9). The water after heat exchange is stored in the hot water tank (16), and the compressed gas after heat exchange is stored in the gas storage tank (17).

4. The multi-stage adjustable pumped compressed air energy storage system according to claim 1, characterized in that, The compressed air energy storage unit includes an energy release subunit, which includes a fourth heat exchanger (10), an expander generator set (11), a third water pump turbine set (14), a hot water tank (16), and an air storage tank (17). When releasing energy, the compressed air in the air storage tank (17) exchanges heat with the water drawn from the hot water tank (16) by the third water pump turbine set (14) in the fourth heat exchanger (10), which then drives the expander generator set (11) to generate electricity.

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