Compressed air pumping energy storage system

Abstract

The invention provides a compressed air water pumping and energy storage system which comprises an air compression set, a first heat exchanger, a second heat exchanger, an energy storage device, a third heat exchanger, a fourth heat exchanger, a turbine unit, a water pump unit, a normal-pressure water storage tank, a water wheel set, a water-gas co-containing cabin and a high-pressure air storage tank. A first throttling valve is arranged between the high-pressure gas storage tank and the water-gas co-containing cabin, and the water pump set, the normal-pressure water storage tank, the water wheel set, the water-gas co-containing cabin and the high-pressure gas storage tank are sequentially connected to form a first energy storage stage. The compressed air water pumping energy storage system is adopted, the characteristics of compressed air energy storage are combined, air is compressed and stored in a high-pressure air storage tank in the energy storage process, in the energy release process, high-pressure air is released, water in a water storage tank is compressed to be in a high-pressure state, and high-pressure water pushes a water turbine to do work for power generation.

Description

Technical Field

[0001] The present invention relates to the technical field of power storage, in particular to a compressed air pumped water energy storage system. Background Art

[0002] As the capacity of my country's power grid continues to grow, the difference between peak and valley power continues to increase. Some power grids have had to take compulsory power outages due to the shortage of peak power supply. This not only hinders the development of productivity, but also may bring social problems. Therefore, the introduction of energy storage systems in the power grid is an urgent need to achieve peak load regulation. In addition, with the vigorous development of renewable energy, distributed energy supply and smart grids, the actual demand for large-scale development of the energy storage industry is also increasing.

[0003] Conventional energy storage technologies mainly include flywheel energy storage, battery energy storage, superconducting energy storage, supercapacitor energy storage, pumped storage and compressed air energy storage. However, energy storage technologies that can output large capacity for several hours at a relatively low cost mainly include battery energy storage, pumped storage and compressed air energy storage. Battery energy storage is difficult to promote to the field of large-scale energy storage due to its high cost, environmental pollution in production and subsequent treatment, etc. Pumped storage, as the most mature large-scale energy storage application technology, has the advantages of high efficiency, large energy storage capacity, and mature equipment technology, but at the same time it is limited by the difficulty of site selection for reservoirs, which hinders its large-scale promotion and application. Compressed air energy storage stores energy in the form of air internal energy, but traditional compressed air energy storage technology requires underground salt caverns as gas storage space, which also has the problem of difficult site selection. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the present invention provides a compressed air pumped water energy storage system, which solves the problems of difficult site selection and inability to miniaturize in compressed air energy storage and pumped water energy storage.

[0006] (II) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a compressed air pumping energy storage system, comprising: an air compression group, a No. 1 heat exchanger, a No. 2 heat exchanger, an energy storage device, a No. 3 heat exchanger, a No. 4 heat exchanger, a turbine unit, a water pump group, a normal pressure water storage tank, a water wheel group, a water-gas co-containment tank and a high-pressure gas storage tank, a No. 2 throttle valve is arranged between the high-pressure gas storage tank and the No. 4 heat exchanger, a No. 1 throttle valve is arranged between the high-pressure gas storage tank and the water-gas co-containment tank, the water pump group, the normal pressure water storage tank, the water wheel group, the water-gas co-containment tank and the high-pressure gas storage tank are connected in sequence to form a first stage of energy storage, the air compression group, the No. 1 heat exchanger, the No. 2 heat exchanger and the high-pressure gas storage tank are connected in sequence to form a second stage of energy storage, the air compression group, the No. 1 heat exchanger, the No. 2 heat exchanger and the high-pressure gas storage tank are connected in sequence to form a second stage of energy storage, The first heat exchanger, the second heat exchanger and the energy accumulator are connected in sequence to form a heat storage channel, the atmospheric pressure water storage tank, the turbine group, the water-gas co-containment tank, the high-pressure gas storage tank and the first throttle valve are connected in sequence to form the first stage of energy release, the high-pressure gas storage tank, the water-gas co-containment tank, the second throttle valve, the third heat exchanger, the fourth heat exchanger and the turbine unit are connected in sequence to form the second stage of energy release, the water pump group, the atmospheric pressure water storage tank, the turbine group and the water-gas co-containment tank are connected in sequence to form a return water channel, the air compression group is fixedly connected to the first heat exchanger and the second heat exchanger respectively, the first heat exchanger and the second heat exchanger are fixedly connected to the energy accumulator, the energy accumulator is fixedly connected to the third heat exchanger and the fourth heat exchanger, and the third heat exchanger and the fourth heat exchanger are fixedly connected to the turbine unit.

[0008] Preferably, the working pressure range of the high-pressure gas storage tank is 1.0MPa-50.0MPa.

[0009] Preferably, the pressure in the water-vapor co-containment chamber is medium pressure, and the working range of the water pressure and air pressure in the water-vapor co-containment chamber is 0.2MPa-40.0MPa.

[0010] Preferably, the water pump group includes a water pump and a No. 1 stop valve, and the water pump is one of a centrifugal pump, a vortex pump, an axial flow pump, a piston pump, a Roots pump or a screw pump.

[0011] Preferably, the high-pressure gas storage tank is a vertical or horizontal airbag-type pressure tank, a diaphragm-type pressure tank or a full-displacement pressure tank.

[0012] Preferably, the air compression group adopts a multi-stage compression system, the multi-stage compression is three-stage, and the compression process includes pre-compression and isothermal compression.

[0013] Preferably, the compressor in the air compression group is a combination of one or more of screw type, piston type or centrifugal type.

[0014] Preferably, the energy storage device includes a heat storage device and a cold storage device, the hot gas ends of the heat exchanger No. 1, heat exchanger No. 2, heat exchanger No. 3 and heat exchanger No. 4 are all fixedly connected to the heat storage device, and the cold gas ends of the hot gas ends of the heat exchanger No. 1 and heat exchanger No. 2, heat exchanger No. 3 and heat exchanger No. 4 are all fixedly connected to the cold storage device.

[0015] Preferably, the water wheel group includes a turbine and a No. 2 stop valve, the turbine is a reaction turbine or an impulse turbine, the reaction turbine is one of mixed flow, axial flow, diagonal flow or cross-flow, and the mixed flow turbine is one of bucket type, diagonal flow or double-flow type.

[0016] (III) Beneficial effects

[0017] The present invention provides a compressed air pumping energy storage system. It has the following beneficial effects:

[0018] 1. The present invention adopts a compressed air pumping energy storage system, combined with the characteristics of compressed air energy storage. In the process of storing energy, the air is compressed and stored in a high-pressure air storage tank. In the process of releasing energy, the high-pressure air is released, compressing the water in the water storage tank to a high-pressure state, and the high-pressure water drives the turbine to generate electricity.

[0019] 2. In the present invention, compressed air does not need to be stored in underground caves, and the pressure head of water replaces the gravity head. There is no need to send water to a reservoir at a very high position, which solves the problem of difficult site selection in compressed air energy storage and pumped water energy storage.

[0020] 3. The compressed air pumped energy storage system in the present invention is more flexible and can be large or small in scale, and is more suitable for urban power storage systems. Moreover, electricity consumption is mainly concentrated in cities, so the compressed air pumped energy storage system is of great significance for alleviating the peak-shaving pressure of the power grid.

[0021] 4. The biggest difference between the present invention and traditional compressed air energy storage technology is that a high-pressure water pump is used instead of a compressor, and a water turbine is used instead of an expander, which solves the problem of cooling the compressed gas in the compressed air energy storage system during the energy storage process and the problem of heating the high-pressure gas during the power generation process. Moreover, the new pumped compressed air energy storage technology has superior operating performance and can effectively solve the problems of wind and solar power abandonment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the composition of the compressed air pumped water energy storage system proposed by the present invention;

[0023] Figure 2 The first schematic diagram of the energy storage process of the compressed air pumped water energy storage system proposed by the present invention;

[0024] Figure 3The second schematic diagram of the energy storage process of the compressed air pumping energy storage system proposed by the present invention;

[0025] Figure 4 The first schematic diagram of the energy release process of the compressed air pumped water energy storage system proposed by the present invention;

[0026] Figure 5 This is the second schematic diagram of the energy release process of the compressed air pumping water energy storage system proposed in the present invention.

[0027] Among them, 1. Air compression group; 2. Heat exchanger No. 1; 3. Heat exchanger No. 2; 4. Energy storage device; 6. Heat exchanger No. 3; 7. Heat exchanger No. 4; 8. Turbine unit; 9. Water pump unit; 10. Normal pressure water storage tank; 11. Water wheel unit; 12. Water and gas common containment tank; 13. High-pressure gas storage tank; 14. Throttle valve No. 1; 15. Throttle valve No. 2; 16. Water pump; 17. Stop valve No. 1; 18. Turbine; 19. Stop valve No. 2; 20. Heat storage device; 21. Cold storage device. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] like Figure 1-5As shown, the embodiment of the present invention provides a compressed air pumping energy storage system, including: an air compression group 1, a No. 1 heat exchanger 2, a No. 2 heat exchanger 3, an energy storage device 4, a No. 3 heat exchanger 6, a No. 4 heat exchanger 7, a turbine unit 8, a water pump group 9, a normal pressure water storage tank 10, a water wheel group 11, a water-gas common containment tank 12 and a high-pressure gas storage tank 13, a No. 2 throttle valve 15 is arranged between the high-pressure gas storage tank 13 and the No. 4 heat exchanger 7, a No. 1 throttle valve 14 is arranged between the high-pressure gas storage tank 13 and the water-gas common containment tank 12, and the water pump group 9, the normal pressure water storage tank 10, the water wheel group 11, the water-gas common containment tank 12 and The high-pressure gas storage tank 13 is connected in sequence to form the first stage of energy storage, the air compression group 1, the No. 1 heat exchanger 2, the No. 2 heat exchanger 3 and the high-pressure gas storage tank 13 are connected in sequence to form the second stage of energy storage, the air compression group 1, the No. 1 heat exchanger 2, the No. 2 heat exchanger 3 and the energy storage device 4 are connected in sequence to form a heat storage channel, the atmospheric pressure water storage tank 10, the water wheel group 11, the water-gas co-containment tank 12, the high-pressure gas storage tank 13 and the No. 1 throttle valve 14 are connected in sequence to form the first stage of energy release, the high-pressure gas storage tank 13, the water-gas co-containment tank 12, the No. 2 throttle valve 15, the No. 3 heat exchanger 6, the No. 4 heat exchanger 7 and the turbine group 8 are connected in sequence to form the second stage of energy release, the water pump group 9, the atmospheric water storage tank 10, the water wheel group 11 and the water-gas common containment tank 12 are connected in sequence to form a return water channel, the air compression group 1 is fixedly connected to the No. 1 heat exchanger 2 and the No. 2 heat exchanger 3 respectively, the No. 1 heat exchanger 2 and the No. 2 heat exchanger 3 are fixedly connected to the energy accumulator 4, the energy accumulator 4 is fixedly connected to the No. 3 heat exchanger 6 and the No. 4 heat exchanger 7, the No. 3 heat exchanger 6 and the No. 4 heat exchanger 7 are fixedly connected to the turbine group 8, the energy accumulator 4 includes a heat storage 20 and a cold storage 21, the No. 1 heat exchanger 2, the No. 2 heat exchanger 3, and the No. 3 heat exchanger The hot gas ends of heat exchangers No. 6 and No. 4 7 are fixedly connected to the heat storage 20, and the cold gas ends of the hot gas ends of heat exchangers No. 1 2 and No. 2 heat exchanger 3, heat exchanger No. 3 6 and No. 4 heat exchanger 7 are fixedly connected to the cold storage 21. The outlet of the compressor in the air compression group 1 is connected to two parts, one part is connected to heat exchanger No. 1 2 and heat exchanger No. 2 3, and the other part is connected to the inlet of the next compressor. The outlet of the last compressor is connected to the high-pressure gas storage tank 13, and the No. 4 heat exchanger 7 is connected to two parts, one part is connected to the high-pressure gas storage tank 13, and the other part is connected to the turbine unit 8.

[0030] The compressor in the air compression group 1 is a combination of one or more of screw type, piston type or centrifugal type.

[0031] The high-pressure gas storage tank 13 is a vertical or horizontal airbag type pressure tank, a diaphragm type pressure tank or a full-displacement type pressure tank.

[0032] The working pressure range of the high-pressure gas storage tank 13 is 1.0MPa-50.0MPa, the pressure in the water-gas co-containment chamber 12 is medium pressure, the working range of the water pressure and air pressure in the water-gas co-containment chamber 12 are both 0.2MPa-40.0MPa, and the pressure in the water-gas co-containment chamber 12 is lower than that of the high-pressure gas storage tank 13.

[0033] The air compression group 1 adopts a multi-stage compression system, the multi-stage compression is three-stage, and the compression process includes pre-compression and isothermal compression.

[0034] The water pump group 9 includes a water pump 16 and a No. 1 stop valve 17. The water pump 16 is one of a centrifugal pump, a vortex pump, an axial flow pump, a piston pump, a Roots pump or a screw pump.

[0035] The water wheel group 11 includes a turbine 18 and a No. 2 stop valve 19. The turbine 18 is a reaction turbine or an impulse turbine. The reaction turbine is one of mixed flow, axial flow, diagonal flow or cross-flow. The mixed flow turbine is one of bucket type, diagonal flow or double-flow type.

[0036] See also Figure 2-Figure 4 , the working principle of the energy storage process of the compressed air pumped water energy storage system is as follows:

[0037] In the pumping and energy storage part, the normal pressure water storage tank 10 is connected to the inlet of the water pump 16 through the water pipeline, the outlet of the water pump 16 is connected to the inner cavity through the water pipeline and the inlet of the water-gas common containment tank 12, the outlet of the water-gas common containment tank 12 is connected to the normal pressure water storage tank 10 through the water pipeline and the turbine 18, the motor drive shaft is fixedly connected to the rotating shaft of the water pump 16, and the turbine 18 drive shaft is fixedly connected to the rotating shaft of the generator;

[0038] The working process is as follows: at the initial moment of the energy storage process, compressed air is stored in the water-gas co-containment chamber 12, the pressure vessel is connected to the water pump 16, the No. 1 stop valve 17 is opened, the No. 2 stop valve 19 is closed, water is injected into the pressure vessel through the water pump 16, and the water pump 16 pumps the liquid piston to compress the air into high-pressure air and store it in the high-pressure gas storage tank 13; when storing energy, renewable energy is used to drive the air compression group 1 to compress the air to a high-pressure state, and multi-stage compression is adopted, and compression and cooling are performed alternately. The compressed air is cooled through a heat exchanger, and the heat storage medium heated by the air is stored in the heat storage device 20, and the heat storage medium cooled by the air is stored in the cold storage device 21, and the high-pressure gas is stored in the high-pressure gas storage tank 13.

[0039] See also Figure 4 and Figure 5 , the working principle of the energy release process of the compressed air pumped water energy storage system is as follows:

[0040] In the energy release part, when releasing energy, the high-pressure air stored in the high-pressure air storage tank 13 passes through the No. 1 throttle valve 14, enters the water-gas common containment tank 12, and pushes the water in the water-gas common containment tank 12 into the turbine 18. The turbine 18 works under rated conditions and supplies power to the outside.

[0041] In the compressed air energy release part, when releasing energy, the high-pressure air in the high-pressure air storage tank 13 and the water-gas common containment chamber 12 passes through the No. 2 throttle valve 15, and exchanges heat with the high-temperature heat medium released by the No. 4 heat exchanger 7. After the high-pressure air is heated, it enters the air turbine unit 8 to perform work and output electrical energy.

[0042] The compressed air energy storage part and the pumped water energy storage part are connected through a high-pressure air storage tank 13, so as to achieve the coupling of the two parts and combine the two parts into one to form a compressed air pumped water energy storage system.

[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Compressed air pumped water energy storage system, characterized in that: include: An air compression group (1), a No. 1 heat exchanger (2), a No. 2 heat exchanger (3), an energy storage device (4), a No. 3 heat exchanger (6), a No. 4 heat exchanger (7), a turbine group (8), a water pump group (9), a normal pressure water storage tank (10), a water wheel group (11), a water-gas common containment tank (12) and a high-pressure gas storage tank (13), wherein a No. 2 throttle valve (15) is arranged between the high-pressure gas storage tank (13) and the No. 4 heat exchanger (7), and the high-pressure gas storage tank (13) and the water-gas common containment tank (12) are connected to each other. A No. 1 throttle valve (14) is arranged between the pump group (9), the atmospheric water storage tank (10), the turbine group (11), the water-gas co-containment chamber (12) and the high-pressure gas storage tank (13) are sequentially connected to form a first stage of energy storage, the air compression group (1), the No. 1 heat exchanger (2), the No. 2 heat exchanger (3) and the high-pressure gas storage tank (13) are sequentially connected to form a second stage of energy storage, and the air compression group (1), the No. 1 heat exchanger (2), the No. 2 heat exchanger (3) and the energy storage device (4) are sequentially connected to form a second stage of energy storage. The normal pressure water storage tank (10), the water turbine group (11), the water-gas common containment chamber (12), the high pressure gas storage tank (13) and the first throttle valve (14) are sequentially connected to form the first stage of energy release. The high pressure gas storage tank (13), the water-gas common containment chamber (12), the second throttle valve (15), the third heat exchanger (6), the fourth heat exchanger (7) and the turbine group (8) are sequentially connected to form the second stage of energy release. The water pump group (9), the normal pressure water storage tank (10), The water wheel group (11) and the water-gas common containment tank (12) are connected in sequence to form a water return channel. The air compression group (1) is fixedly connected to the first heat exchanger (2) and the second heat exchanger (3), respectively. The first heat exchanger (2) and the second heat exchanger (3) are fixedly connected to the energy storage device (4). The energy storage device (4) is fixedly connected to the third heat exchanger (6) and the fourth heat exchanger (7). The third heat exchanger (6) and the fourth heat exchanger (7) are fixedly connected to the turbine group (8).

2. The compressed air pumped water energy storage system according to claim 1, characterized in that: The compressor in the air compression group (1) is a combination of one or more of a screw type, a piston type or a centrifugal type.

3. The compressed air pumped water energy storage system according to claim 1, characterized in that: The high-pressure gas storage tank (13) is a vertical or horizontal airbag type pressure tank, a diaphragm type pressure tank or a full-displacement type pressure tank.

4. The compressed air pumped water energy storage system according to claim 1, characterized in that: The working pressure range of the high-pressure gas storage tank (13) is 1.0 MPa-50.0 MPa.

5. The compressed air pumped water energy storage system according to claim 1, characterized in that: The pressure in the water-gas co-containment chamber (12) is medium pressure, and the working range of the water pressure and air pressure in the water-gas co-containment chamber (12) is 0.2MPa-40.0MPa.

6. The compressed air pumped water energy storage system according to claim 1, characterized in that: The air compression group (1) adopts a multi-stage compression system, the multi-stage compression is three-stage, and the compression process includes pre-compression and isothermal compression.

7. The compressed air pumped water energy storage system according to claim 1, characterized in that: The water pump group (9) comprises a water pump (16) and a No. 1 stop valve (17); the water pump (16) is one of a centrifugal pump, a vortex pump, an axial flow pump, a piston pump, a Roots pump or a screw pump.

8. The compressed air pumped water energy storage system according to claim 1, characterized in that: The water wheel assembly (11) comprises a water turbine (18) and a No. 2 stop valve (19); the water turbine (18) is a reaction turbine or an impulse turbine; the reaction turbine is one of a mixed flow type, an axial flow type, an oblique flow type or a cross-flow type; the mixed flow turbine is one of a bucket type, an oblique flow type or a double-flow type.

9. The compressed air pumped water energy storage system according to claim 1, characterized in that: The energy storage device (4) comprises a heat storage device (20) and a cold storage device (21); the hot gas ends of the first heat exchanger (2), the second heat exchanger (3), the third heat exchanger (6) and the fourth heat exchanger (7) are all fixedly connected to the heat storage device (20); and the cold gas ends of the hot gas ends of the first heat exchanger (2), the second heat exchanger (3), the third heat exchanger (6) and the fourth heat exchanger (7) are all fixedly connected to the cold storage device (21).

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