Air compressor unit and compressed air energy storage power station

Abstract

The invention relates to an air compressor unit and a compressed air energy storage power station, which adopt a multi-stage water spray screw compressor and an interstage air-water separation air compression process to realize near isothermal compression of air, and spray water only needs desalination treatment and does not need deoxygenation, so that the equipment of the air compressor unit is simplified, the process is simplified, and the cost is reduced. By combining the multi-stage water spraying screw compressor and the water pumping compressed air energy storage air turbine and hydraulic turbine set power generation technology, the circulation energy efficiency of the compressed air energy storage system can be effectively improved, and the expected social and economic benefits are obvious.

Description

Technical Field

[0001] The invention relates to an air compressor unit and a compressed air energy storage power station, and in particular to an air compressor unit and a pumped compressed air energy storage power station using a multi-stage water-spraying screw compressor technology. Background Art

[0002] my country is striving to achieve its carbon neutrality goal, and energy storage will be a core link in this process.

[0003] Since photovoltaic and wind power generation are random and intermittent, and electricity has the characteristics of real-time balance of supply and demand and is difficult to store on a large scale, the large-scale grid-connected photovoltaic and wind power generation will aggravate the dual volatility and uncertainty on both the supply and demand sides of the power system, making system peak regulation difficult and bringing about a series of problems such as abandoned solar and wind power. Energy storage can smooth out the instability of photovoltaic and wind power generation and achieve a dynamic balance of electricity supply and demand.

[0004] Electricity demand is strong in summer, and the peak-valley electricity price difference continues to widen. For example, in the first half of 2024, the peak-valley electricity price difference in 17 provinces and regions exceeded 0.7 yuan / kWh. The economic feasibility of industrial and commercial energy storage projects is highlighted, and the economic feasibility of peak-valley arbitrage is significantly improved.

[0005] The new energy power supply system will face problems such as mismatch between electricity supply and demand. Regulation measures such as energy storage, virtual power plants, and microgrids are indispensable. The role of new energy storage in promoting the development and consumption of new energy and the safe and stable operation of power systems is gradually emerging.

[0006] Compressed air energy storage (CAES) is considered to be one of the most promising large-scale energy storage technologies. It has a wide variety of technologies. The types of demonstration projects currently include non-adiabatic, supplementary combustion, advanced adiabatic and constant temperature types. It has the advantages of large energy storage scale, long storage cycle and low environmental pollution.

[0007] Current electricity storage technologies include pumped storage, compressed air storage, battery storage, superconducting storage, flywheel storage and capacitor storage, but due to capacity, storage cycle, energy density, charging and discharging efficiency, life, operating costs, environmental protection and other reasons, only pumped storage and compressed air storage are used in large commercial systems.

[0008] The pumped storage system uses a water pump to send water from a low-level reservoir to a high-level reservoir during low electricity consumption, thereby converting electrical energy into water potential energy and storing it. During peak electricity consumption, water is discharged from the high-level reservoir to the low-level reservoir to drive the turbine to generate electricity. The pumped storage system has the advantages of mature technology, high efficiency, large energy storage capacity, and unlimited energy storage cycle. It is currently a widely used power storage system. However, large-scale pumped storage systems require special geographical conditions to build two reservoirs and dams, with a long construction period and huge initial investment. What is even more difficult is that the construction of large reservoirs will flood vegetation and even cities on a large scale, causing ecological and immigration problems. Therefore, the construction of large-scale pumped storage systems has been increasingly restricted.

[0009] Based on the principle of compressed air energy storage, the technical team of Xi'an Jiaotong University has developed a "new type of pumped compressed air energy storage technology" (such as CN201810291346.X-a high-pressure adiabatic gas storage pumped compressed air energy storage system). The operating efficiency of this system can reach 65%. During the energy storage process of the system, near-isothermal compression can be achieved in the water-gas co-containment cavity, and near-isothermal expansion can be achieved during the energy release process.

[0010] The screw water-jet compressor is a device that uses water as the working medium to compress gas, and its air outlet pressure is 0.6-1.3MPa. Its working principle combines the traditional compressor principle with the physical properties of water, especially in cooling and sealing. This working principle of the water-jet compressor makes it particularly suitable for applications that require oil-free or low-oil compressed gas, such as food processing, pharmaceutical manufacturing, and the electronics industry, because these industries have high requirements for the purity of compressed gas. The water-jet compressor has high thermal efficiency and low operating costs.

[0011] The Chinese patent (patent number: CN91108225.5; inventors: Wang Shixiang, Sun Zhuxing, Kong Xianglin, Yu Jinlong, Fan Guangyu, Gu Zhengzhong; authorization publication number: CN1020270C) provides a process for "improvement of the pressurization process of raw gas before entering the conversion furnace in the ammonia production process". It uses a screw compressor to replace the primary and secondary low-pressure sections of the existing piston compressor. The desulfurized raw gas enters the screw compressor for pressurization. The single stage can be compressed to 1.3MPa. At the same time, desalted and deoxygenated cooling water is sprayed into the compressor, so that the compression and cooling processes are carried out simultaneously, eliminating the huge inter-stage cooling device and oil-water separator, streamlining the equipment, simplifying the process, reducing investment and the required plant area, and the heat generated during the gas compression process is used for by-product steam and hot water for use in the conversion furnace and boiler, with obvious energy-saving effects. The cooling water sprayed into the screw compressor must be desalted and deoxygenated to prevent compressor scaling and excessive oxygen from being brought into the conversion furnace system to produce harmful effects. The process flow and the schematic diagram of the screw water spray compressor are attached. Figure 3 .

[0012] Therefore, it is worthy of in-depth study how to combine the advantages of pumped energy storage and compressed air energy storage, improve the existing air compression process, and provide an efficient and energy-saving air compressor unit and pumped compressed air energy storage power station. Summary of the invention

[0013] The purpose of the present invention is to solve the above-mentioned problems and to provide an air compressor unit and a compressed air energy storage power station. The air compressor unit adopts a multi-stage screw compressor and a high-pressure water pump to provide an air compression process of desalted water injection cooling and inter-stage gas-water separation to supply high-pressure air output. The power station adopts a multi-stage water-spraying screw compressor and an air compression process of inter-stage gas-water separation to replace the existing multi-stage adiabatic compression and inter-stage cooling air compression process.

[0014] An air compressor unit (see Figure 1 ), the air compressor unit adopts a multi-stage water-spraying screw compressor, a high-pressure water pump to provide desalted water to be sprayed into the screw compressor, and an air compression process of air-water separation between and after the screw compressor stages. The air enters the multi-stage water-spraying screw compressor through the filter 2 for compression. During the compression process, the desalted water 21 pressurized by the high-pressure water pump 15 is sprayed into the corresponding level of the screw compressor through the desalted water pipeline, so that the air compression and cooling processes are carried out simultaneously. The multi-stage water-spraying screw compressor is provided with an inter-stage air-water separator. The air separated by the air-water separator enters the next-stage screw compressor. The water separated by the air-water separator is discharged through the return water pipeline. The air-water mixture at the outlet of the multi-stage screw compressor enters the air-water co-containing tank 25 for air-water separation, and the high-pressure air 30 is output, and the separated water is discharged.

[0015] The multi-stage water-sprayed screw compressor adopts three to six stages, and the air pressure after being compressed by the multi-stage water-sprayed screw compressor is ≥5.0MPa.

[0016] A compressed air energy storage power station, which realizes near-isothermal compression and high-pressure gas transmission of air through a multi-stage water-spraying screw compressor and inter-stage air-water separation, uses high-pressure air to store energy in an air-water common containment chamber and a high-pressure air storage tank, and then releases energy through the energy-stored air in the air-water common containment chamber and the high-pressure air storage tank to drive an air turbine and / or a water turbine unit to generate electricity. The pumped energy storage power station and the compressed air energy storage power station can be efficiently combined together, and the implementation process is as follows: When storing energy: The air enters the multi-stage water-injected screw compressor (e.g. Figure 2The air is compressed by the three-stage water-sprayed screw compressor shown in the figure. During the compression process, the desalted water 21 pressurized by the high-pressure water pump 15 is sprayed into the corresponding screw compressor through the first-stage desalted water pipeline 16, the second-stage desalted water pipeline 17, the third-stage desalted water pipeline 18, etc., so that the air compression and cooling processes are carried out simultaneously. The gas-water mixture 10 at the outlet of the multi-stage screw compressor enters the gas-water common containment tank 25 for gas-water separation. The air in the air space in the gas-water common containment tank and the air entering the high-pressure gas storage tank 27 through the balance pipe 38 or the power generation side balance pipe 39 are stored for energy. Alternatively, the water in the water reservoir 19 is pressurized by the circulating pump 24 and sent to the gas-water common containment tank 25. The water level rises in the gas-water common containment tank 25, and the air in the gas space of the gas-water common containment tank 25 is compressed for energy storage. The multi-stage water-sprayed screw compressor adopts three to six stages, and the air pressure after being compressed by the multi-stage water-sprayed screw compressor is ≥5.0MPa; The multi-stage water-injected screw compressor is provided with an inter-stage gas-water separator and an outlet gas-water separator, for example Figure 1 The three-stage water-injected screw compressor shown in the figure: a primary air-water separator 4 is arranged between the primary screw compressor 3 and the secondary screw compressor 6, a secondary air-water separator 7 is arranged between the secondary screw compressor 6 and the third-stage screw compressor 9, and an air-water common containing tank 25 is arranged at the outlet of the third-stage screw compressor 9, and the air-water common containing tank 25 plays the role of air-water separation; The primary outlet air 5 separated by the primary air-water separator 4 enters the secondary screw compressor 6, and the water separated by the primary air-water separator 4 is discharged through the primary return water pipeline 22. The secondary outlet air 8 separated by the secondary air-water separator 7 enters the tertiary screw compressor 9, and the water separated by the secondary air-water separator 7 is discharged through the secondary return water pipeline 23. The outlet air-water mixture 10 of the tertiary screw compressor 9 enters the air-water co-containment tank 25, and the air-water co-containment tank 25 plays the role of air-water separation. The separated high-pressure air is stored in the gas phase space of the high-pressure air storage 27 and the air-water co-containment tank 25. When a four-stage or five-stage water-spraying screw compressor is used, a corresponding interstage air-water separator is provided; A desalter 20 is provided: The inlet or outlet pipeline of the high-pressure water pump 15 is provided with a desalter 20 for removing salt from the water to prevent scaling of the screw compressor; the desalter 20 uses a reverse osmosis membrane or ion exchange resin process commonly used in power plants to desalinate the feed water; The multi-stage water-injected screw compressors are driven by electric motors respectively or by a common electric motor; the high-pressure water pump 15 is driven by a matching high-pressure water pump motor 14; When releasing energy: The air in the high-pressure air storage tank 27 and the air-water common chamber 25 is heated by the air turbine side regulating valve 29 and the supplementary heat device 31, and then enters the air turbine 32 to expand and do work, driving the air generator 36 to generate electricity, and the air turbine outlet gas 33 is discharged; Alternatively, the high-pressure air storage tank 27 and the air in the air-water co-containment chamber 25 push the water flow in the water-air co-containment chamber 25 into the turbine 26, driving the turbine generator 42 to generate electricity, and the water flowing through the turbine 26 returns to the water reservoir 19.

[0017] A regenerator 35 is provided: the air in the high-pressure air storage tank 27 and the air-water common chamber 25 is heated by the air turbine side regulating valve 29, the regenerator 35 and the supplementary heat device 31, and then enters the air turbine 32 to expand and do work, driving the air generator 36 to generate electricity. The air turbine outlet gas 33 is cooled by the regenerator 35 to form the exhaust gas 34 for discharge.

[0018] The heat source of the supplementary heat device 31 adopts one or more of the following thermal energies: industrial waste heat or waste heat; solar thermal energy; heat energy released by fuel combustion; geothermal energy; heat energy stored in a heat storage medium (converted from photovoltaic power, wind power, etc.); the heat source of the supplementary heat device 31 heats the high-pressure air 30 directly or indirectly.

[0019] The air turbine 32 and the water turbine 26 can be started and operated simultaneously to drive corresponding generators to generate electricity.

[0020] A hollow steel plate 40 is provided: a hollow steel plate 40 capable of floating with the liquid level in the air-water co-containing chamber 25 is provided in the air-water co-containing chamber 25, so as to reduce the contact between the air in the air-water co-containing chamber and the water surface, thereby reducing the amount of dissolved gas in the water; a vertical or spiral guide rail is provided inside the wall of the air-water co-containing chamber 25, and the hollow steel plate 40 slides upward along the guide rail as the liquid level rises; the hollow steel plate 40 is provided with a balancing hole 41 or a hollow balancing pipe connected to the air space of the air-water co-containing chamber 25, so that the cavity pressure of the hollow steel plate is balanced with the air space pressure of the air-water co-containing chamber 25.

[0021] The multi-stage water-sprayed screw compressor adopts an integrated or split structure.

[0022] By adjusting the amount of water sprayed into the screw compressor, the outlet air temperature of the screw compressor can be conveniently controlled within the range of 40°C to 60°C, making the entire air compression process close to isothermal compression and ambient temperature.

[0023] Equipment and its systems, pipelines, instruments, valves, bypass facilities with regulating functions, etc. not described in this application are matched with reference to or in accordance with mature technologies in well-known traditional processes.

[0024] Parts not mentioned in this application, such as safety accessories, interlocking protection devices and automatic control, are equipped with existing publicly known technologies, that is, existing mature, reliable and reasonable technical measures are applied to this power station.

[0025] Compared with the prior art, the present invention has the following advantages: 1. Compared with the existing air compressor units and compressed air energy storage power stations with multi-stage compression and inter-stage cooling, the air compression process using multi-stage water-spraying screw compressors and inter-stage air-water separation can achieve near-isothermal compression of air, effectively improve the cycle energy efficiency of the compressed air energy storage system, reduce the power consumption of the air compression process, and eliminate the need for large inter-stage cooling devices and oil-water separators. Water spraying only requires desalination and no deoxygenation, which makes the equipment of the high-pressure air compressor unit streamlined, the process simplified, and the investment and plant area reduced; 2. Compared with the existing pumped energy storage power station technology, the turbine power generation technology combined with multi-stage water-spraying screw compressor and compressed air energy storage solves the problems of poor adaptability to terrain and water sources, high investment cost, and low efficiency of energy storage system of traditional pumped energy storage power station system; 3. Compared with the existing pumped compressed air energy storage power station technology, the multi-stage water-sprayed screw compressor process of the present invention realizes the near-isothermal power generation process of the pumped compressed air turbine unit, avoiding the influence of large water temperature changes on the turbine; 4. Compared with the prior art, the hollow steel plate 40 that can float with the liquid surface is arranged in the air-water common containment chamber 25, and is provided with a balance hole 41 or a hollow balance pipe that communicates with the air space of the air-water common containment chamber 25, so that the cavity pressure of the hollow steel plate 40 is balanced with the air space pressure of the air-water common containment chamber 25, and the amount of dissolved gas in the energy storage water in the air-water common containment chamber 25 is reduced, and the deformation of the hollow steel plate caused by the imbalance between the cavity pressure of the hollow steel plate 40 and the air space pressure of the air-water common containment chamber 25 can be effectively prevented, so as to ensure that the hollow steel plate 40 can move smoothly along the guide rail, and also ensure the safe and efficient operation of the turbine unit; 5. Compared with the existing technology, the multi-stage water-spraying screw compressor air compression process is adopted, so that the air-water temperature entering the air-water co-containment chamber 25 is close to the water temperature of the pumped energy storage water, which can effectively prevent the material deformation problem of the hollow steel plate caused by the large temperature difference between air and water; 6. Compared with the existing technology, the compressed air energy storage power generation and pumped storage power generation combined with the multi-stage water-sprayed screw compressor air compression process have a large load adjustment range, flexible and convenient operation adjustment, retaining the advantages of gas-liquid driven turbine power generation, and eliminating the disadvantages of low-grade compression heat recovery and heat utilization difficulties of the traditional multi-stage compression and inter-stage cooling air compression process; 7. Compared with the existing technology, the compressed air driven water flow turbine power generation technology combining the compressed air of the multi-stage water-spraying screw compressor and the pumped energy storage has simple operation and maintenance and multiple application scenarios. The turbines, water pumps and other equipment involved in the energy storage power station are highly efficient, and the installed capacity of the unit can be flexibly selected and changed according to the application scenario. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of a compressed air unit.

[0027] Figure 1 In: 1-air, 2-filter, 3-first-stage screw compressor, 4-first-stage air-water separator, 5-first-stage outlet air, 6-second-stage screw compressor, 7-second-stage air-water separator, 8-second-stage outlet air, 9-third-stage screw compressor, 10-gas-water mixture at the outlet of multi-stage screw compressor, 11-first-stage motor, 12-second-stage motor, 13-third-stage motor, 14-high-pressure water pump motor, 15-high-pressure water pump, 16-first-stage desalted water pipeline, 17-second-stage desalted water pipeline, 18-third-stage desalted water pipeline, 19-water reservoir, 20-desalter, 21-desalted water, 22-first-stage return water pipeline, 23-second-stage return water pipeline, 25-gas-water common containment tank, 30-high-pressure air.

[0028] Figure 2 It is a schematic diagram of the structure of a compressed air energy storage power station.

[0029] Figure 2 In: 1-air, 2-filter, 3-first-stage screw compressor, 4-first-stage air-water separator, 5-first-stage outlet air, 6-second-stage screw compressor, 7-second-stage air-water separator, 8-second-stage outlet air, 9-third-stage screw compressor, 10-multi-stage screw compressor outlet air-water mixture, 11-first-stage motor, 12-second-stage motor, 13-third-stage motor, 14-high-pressure water pump motor, 15-high-pressure water pump, 16-first-stage desalination pipeline, 17-second-stage desalination pipeline, 18-third-stage desalination pipeline, 19-reservoir, 20-desalter, 21-desalination Brine, 22-primary return water pipeline, 23-secondary return water pipeline, 24-circulating pump, 25-gas-water common containment tank, 26-water turbine, 27-high-pressure gas storage device (such as gas storage tank, gas storage well or gas storage salt cave, etc.), 28-gas-water common containment tank side regulating valve, 29-air turbine side regulating valve, 30-high-pressure air, 31-recharger, 32-air turbine, 33-air turbine outlet gas, 34-exhaust gas, 35-regenerator, 36-air generator, 37-power grid, 38-balance pipe, 39-balance pipe on power generation side, 40-hollow steel plate, 41-balance hole, 42-water turbine generator.

[0030] Figure 3It is the process flow of CN91108225.5-"Improvement of the pressurization process of raw gas before entering the shift furnace in the ammonia production process" and the structural diagram of the screw water injection compressor. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0032] Embodiment 1: like Figure 1 As shown, an air compressor unit adopts a multi-stage water-spraying screw compressor, a high-pressure water pump to provide desalted water to be sprayed into the screw compressor, and an air compression process of air-water separation between and after the screw compressor stages. The air enters the multi-stage water-spraying screw compressor through a filter 2 for compression. During the compression process, the desalted water 21 pressurized by the high-pressure water pump 15 is sprayed into the corresponding level of the screw compressor through the desalted water pipeline, so that the air compression and cooling processes are carried out simultaneously. The multi-stage water-spraying screw compressor is provided with an inter-stage air-water separator, and the air separated by the air-water separator enters the next-stage screw compressor. The water separated by the air-water separator is discharged through the return water pipeline, and the air-water mixture at the outlet of the multi-stage screw compressor enters the air-water co-containing tank 25 for air-water separation, and the high-pressure air 30 is output, and the separated water is discharged; the multi-stage water-spraying screw compressor adopts three to six stages, and the air pressure after compression by the multi-stage water-spraying screw compressor is ≥5.0MPa.

[0033] Embodiment 2: like Figure 2 As shown, a compressed air energy storage power station, the implementation process of the power station is as follows: The power station uses a three-stage water-sprayed screw compressor and inter-stage gas-water separation to achieve near-isothermal compression and high-pressure gas transmission of air. High-pressure air is used to store energy in the gas-water common containment chamber and high-pressure gas storage tank, and then the energy is released through the energy-stored air in the gas-water common containment chamber and high-pressure gas storage tank to drive the air turbine and water turbine unit to generate electricity. The pumped energy storage power station and the compressed air energy storage power station can be efficiently combined: When storing energy: The air enters the three-stage water-spraying screw compressor through the filter 2 for compression. During the compression process, the desalted water 21 pressurized by the high-pressure water pump 15 is sprayed into the corresponding screw compressor through the first-stage desalted water pipeline 16, the second-stage desalted water pipeline 17, and the third-stage desalted water pipeline 18, so that the air compression and cooling processes are carried out simultaneously. The gas-water mixture 10 at the outlet of the three-stage screw compressor enters the gas-water common containment tank 25 for gas-water separation. The air in the air space in the gas-water common containment tank and the air entering the high-pressure gas storage tank 27 through the balance pipe 38 or the power generation side balance pipe 39 are stored for energy, or the water in the water reservoir 19 is pressurized by the circulating pump 24 and sent to the gas-water common containment tank 25. The water level rises in the gas-water common containment tank 25, and the air in the gas space of the gas-water common containment tank 25 is compressed for energy storage. The air pressure after compression by the three-stage water-injected screw compressor is ≥5.0MPa; The three-stage water-sprayed screw compressor is provided with an interstage gas-water separator and an outlet gas-water separator: a first-stage gas-water separator 4 is provided between the first-stage screw compressor 3 and the second-stage screw compressor 6, a second-stage gas-water separator 7 is provided between the second-stage screw compressor 6 and the third-stage screw compressor 9, and a gas-water common containing tank 25 is provided at the outlet of the third-stage screw compressor 9, and the gas-water common containing tank 25 plays a role in gas-water separation; The primary outlet air 5 separated by the primary air-water separator 4 enters the secondary screw compressor 6, and the water separated by the primary air-water separator 4 is discharged through the primary return water pipeline 22. The secondary outlet air 8 separated by the secondary air-water separator 7 enters the tertiary screw compressor 9, and the water separated by the secondary air-water separator 7 is discharged through the secondary return water pipeline 23. The outlet air-water mixture 10 of the tertiary screw compressor 9 enters the air-water co-containment tank 25, and the air-water co-containment tank 25 plays the role of air-water separation. The separated high-pressure air is stored in the gas phase space of the high-pressure air storage 27 and the air-water co-containment tank 25. A desalter 20 is provided: The inlet pipeline of the high-pressure water pump 15 is provided with a desalter 20 for removing salt from the water to prevent scaling of the screw compressor; the desalter 20 uses a reverse osmosis membrane commonly used in power plants to desalinate the feed water; The three-stage water-sprayed screw compressors are each driven by an electric motor; the high-pressure water pump 15 is driven by a matching high-pressure water pump motor 14; When releasing energy: The air in the high-pressure air storage tank 27 and the air-water common chamber 25 is heated by the air turbine side regulating valve 29 and the supplementary heat device 31, and then enters the air turbine 32 to expand and do work, driving the air generator 36 to generate electricity, and the air turbine outlet gas 33 is discharged; The high-pressure air storage tank 27 and the air in the air-water co-containment chamber 25 push the water flow in the water-air co-containment chamber 25 into the turbine 26, driving the turbine generator 42 to generate electricity, and the water flowing through the turbine 26 returns to the water reservoir 19.

[0034] A regenerator 35 is provided: the air in the high-pressure air storage tank 27 and the air-water common chamber 25 is heated by the air turbine side regulating valve 29, the regenerator 35 and the supplementary heat device 31, and then enters the air turbine 32 to expand and do work, driving the air generator 36 to generate electricity. The air turbine outlet gas 33 is cooled by the regenerator 35 to form the exhaust gas 34 for discharge.

[0035] The heat source of the supplementary heat device 31 adopts one or more of the following thermal energies: industrial waste heat or waste heat; solar thermal energy; heat energy released by fuel combustion; geothermal energy; heat energy stored in a heat storage medium (converted from photovoltaic power, wind power, etc.); the heat source of the supplementary heat device 31 heats the high-pressure air 30 directly or indirectly.

[0036] The air turbine 32 and the water turbine 26 can be started and operated simultaneously to drive corresponding generators to generate electricity.

[0037] A hollow steel plate 40 is provided: a hollow steel plate 40 capable of floating with the liquid level in the air-water co-containing chamber 25 is provided in the air-water co-containing chamber 25, so as to reduce the contact between the air in the air-water co-containing chamber and the water surface, thereby reducing the amount of dissolved gas in the water; a vertical or spiral guide rail is provided inside the wall of the air-water co-containing chamber 25, and the hollow steel plate 40 slides upward along the guide rail as the liquid level rises; the hollow steel plate 40 is provided with a balancing hole 41 or a hollow balancing pipe connected to the air space of the air-water co-containing chamber 25, so that the cavity pressure of the hollow steel plate is balanced with the air space pressure of the air-water co-containing chamber 25.

[0038] The three-stage water-sprayed screw compressor adopts a split structure.

[0039] By adjusting the amount of water sprayed into the screw compressor, the outlet air temperature of the screw compressor can be easily controlled within the range of 40 to 60°C, making the entire air compression process close to isothermal compression and ambient temperature.

[0040] Equipment and its systems, pipelines, instruments, valves, bypass facilities with regulating functions, etc. not described in this application are matched with reference to or in accordance with mature technologies in well-known traditional processes.

[0041] Parts not mentioned in this application, such as safety accessories, interlocking protection devices and automatic control, are equipped with existing publicly known technologies, that is, existing mature, reliable and reasonable technical measures are applied to this power station.

[0042] Although the present invention has been disclosed as above with preferred embodiments, they are not intended to limit the present invention. Anyone familiar with the art can make various changes or modifications without departing from the spirit and scope of the present invention, which also belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the definition of the claims of this application.

Claims

1. An air compressor unit, which uses a multi-stage water-spraying screw compressor to compress, a high-pressure water pump to spray desalted water, and an air compression process of separating air and water between and after the water-spraying screw compressor stages, characterized in that: The air enters the multi-stage water-spray screw compressor through the filter (2) for compression. During the compression process, the desalted water (21) pressurized by the high-pressure water pump (15) is sprayed into the corresponding level screw compressor through the desalted water pipeline, so that the air compression and cooling processes are carried out simultaneously. The multi-stage water-spray screw compressor is provided with an inter-stage air-water separator. The air separated by the air-water separator enters the next level screw compressor. The water separated by the air-water separator is discharged through the return water pipeline. The air-water mixture at the outlet of the multi-stage water-spray screw compressor enters the air-water co-containment chamber (25) for air-water separation. The high-pressure air (30) is output and the separated water is discharged. The multi-stage water-sprayed screw compressor adopts three to six stages, and the air pressure after being compressed by the multi-stage water-sprayed screw compressor is ≥5.0MPa.

2. A compressed air energy storage power station, characterized in that: The power station uses a multi-stage water-injected screw compressor, and the implementation process is as follows: When storing energy: The air is compressed by a multi-stage water-spraying screw compressor. During the compression process, the desalted water (21) pressurized by the high-pressure water pump (15) is sprayed into the corresponding level screw compressor through the desalted water pipeline, so that the air compression and cooling processes are carried out simultaneously. The air-water mixture at the outlet of the multi-stage screw compressor enters the air-water co-containment chamber (25) for air-water separation. The air in the air space in the air-water co-containment chamber and the air entering the high-pressure air storage device (27) through the balance pipe are used to store energy. Alternatively, the water in the water reservoir (19) is pressurized by the circulating pump (24) and then sent to the air-water common containment chamber (25), the liquid level rises in the air-water common containment chamber (25), and the air in the air space of the air-water common containment chamber (25) is compressed to store energy; The multi-stage water-sprayed screw compressor is provided with an inter-stage air-water separator, the air separated by the air-water separator enters the next-stage screw compressor, and the water separated by the air-water separator is discharged through a return water pipeline; When releasing energy: The air in the high-pressure air storage tank (27) and the air-water common chamber (25) is heated by the air turbine side regulating valve (29) and the supplementary heat device (31), and then enters the air turbine (32) to expand and perform work, driving the air generator (36) to generate electricity, and the air turbine outlet gas (33) is discharged; The high-pressure air storage device (27) and the air in the air-water co-containment chamber (25) push the water in the water-air co-containment chamber (25) into the water turbine (26), driving the water turbine generator (42) to generate electricity, and the water passing through the water turbine (26) returns to the water reservoir (19).

3. The compressed air energy storage power station according to claim 2, characterized in that: The multi-stage water-sprayed screw compressor adopts three to six stages, and the air pressure after being compressed by the multi-stage water-sprayed screw compressor is ≥5.0Mpa.

4. The compressed air energy storage power station according to claim 2, characterized in that: The heat source of the supplementary heat device (31) is one or more of the following thermal energies: industrial waste heat or waste heat; solar thermal energy; thermal energy released by fuel combustion; geothermal energy; and thermal energy stored in a heat storage medium.

5. The compressed air energy storage power station according to claim 4, characterized in that: The heat source of the supplementary heater (31) heats the high-pressure air (30) directly or indirectly.

6. The compressed air energy storage power station according to claim 2, characterized in that: A regenerator (35) is provided: the air in the high-pressure air storage tank (27) and the air-water common chamber (25) is heated by the air turbine side regulating valve (29), the regenerator (35), and the supplementary heat device (31), and then enters the air turbine (32) to expand and perform work, driving the air generator (36) to generate electricity, and the air turbine outlet gas (33) passes through the regenerator (35) to form exhaust gas (34) and is discharged.

7. The compressed air energy storage power station according to claim 2, characterized in that: A hollow steel plate (40) is provided: the air-water co-containment chamber (25) is provided with a hollow steel plate (40) that floats along with the water surface in the air-water co-containment chamber (25); a vertical or spiral guide rail is provided inside the wall of the air-water co-containment chamber (25); the hollow steel plate (40) slides upward along the guide rail along with the liquid surface; the hollow steel plate (40) is provided with a balance hole (41) or a hollow balance pipe that is connected to the air space of the air-water co-containment chamber (25), so that the cavity pressure of the hollow steel plate is balanced with the air space pressure of the air-water co-containment chamber (25).

8. The compressed air energy storage power station according to claim 2, characterized in that: A desalter (20) is provided: The inlet pipeline between the water reservoir (19) and the high-pressure water pump (15) is provided with a desalter (20) for removing salt from the water to prevent scaling of the screw compressor.

9. The compressed air energy storage power station according to claim 8, characterized in that: The desalter (20) uses a reverse osmosis membrane or an ion exchange resin to desalinate the feed water.

10. The compressed air energy storage power station according to claim 3, characterized in that: The air turbine (32) and the water turbine (26) are started and operated simultaneously, driving corresponding generators to generate electricity.

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