CN106567748B - The compressed-air energy-storage system of nonadiabatic gas expansion - Google Patents

Abstract

The invention discloses a compressed air energy storage system for non-adiabatic gas expansion. The motor is connected to a compressor unit and an expander unit; the expander unit is composed of several expanders connected in series, and a reheater is arranged in front of each expander. ; The gas outlet of the compressor unit is connected to the inlet of the high-pressure gas storage chamber through the intercooler, and the outlet of the high-pressure gas storage chamber is connected to the first fluid inlet of the first reheater; the first fluid outlet of the first reheater is connected to the first The gas inlet of the expander; the gas outlet of the previous expander is connected to the gas outlet of the next expander through a reheater; the gas outlet of the last expander is connected to the atmosphere; the outlet of the U-tube heat exchanger is connected to all reheaters The second fluid inlet of the reheater, the second fluid inlet and outlet of all reheaters are connected to the inlet of the pressure pump, and the outlet of the pressure pump is connected to the inlet of the U-shaped tube heat exchanger. The system of the invention has high operation efficiency, good operation economy and environmental friendliness.

Description

Compressed air energy storage system with non-adiabatic gas expansion

technical field

The invention relates to the technical field of physical energy storage, in particular to a compressed air energy storage system in which non-adiabatic gas expands.

Background technique

Compressed air energy storage technology is recognized as one of the best technologies for large-scale storage of electric energy. In 2009, it was rated as one of the top ten promising technologies in the future by the United States. In recent years, developed countries in the West (Britain, Australia, the United States, Japan, Switzerland, etc.) have made great achievements in the development of this technology. Among them, the compressed air energy storage technology proposed by the Light sail energy company in the United States has been awarded by Microsoft Corporation. huge investment ($1.7 billion). Countries around the world expect to use this technology to solve the grid-connected problems of wind power and photovoltaic power generation with the characteristics of volatility and randomness, as well as the problem of "peak-shaving and valley-filling" of the power grid.

Compressed air energy storage technology was proposed in 1949. In 1978, the world's first commercially operated power station was built in Germany. In 1991, the second commercially operated power station was built in the United States. Since then, such power stations have been built successively around the world. and test stations. Compressed air energy storage is a technology based on gas turbines, and its principle is to separate the compressor and turbine in the gas turbine unit [1]. When storing energy, use electric energy to drive the compressor to compress the air and store it in a high-pressure container. The temperature of the gas in the high-pressure container generally does not exceed 80°C. When releasing energy, the high-pressure air is released from the container. Due to the low temperature of the gas, it first enters the combustion chamber to support combustion, and the gas enters the turbine to expand and drive the turbine to generate power. At the same time, a large amount of natural gas is consumed [2]. In recent years, Giuseppe Grazzini et al. [3] proposed the adiabatic compressed air energy storage system (AA-CAES), Liu Jia, Chen Haisheng et al. [4] proposed the supercritical compressed air energy storage system, Mehmet [5] proposed a supercritical CO ₂ energy storage system. The common purpose of all researchers is to solve the heating problem in the energy storage system and avoid the fuel consumption problem caused by heating; in addition, the expansion air in these systems The heating is still outside the inlet of the expander, and the expansion process is still an adiabatic expansion process. To sum up, the main problems existing in all existing compressed air energy storage power stations are: the need for external supplementary heat energy during the power generation process will cause a large amount of fuel consumption, low power conversion efficiency, and high power conversion costs, resulting in the popularization and application of this technology. restricted.

[1] Ibrahim H., Ilinca A., Perron J. Energy storage systems—Characteristics and comparisons [J]. Renewable and Sustainable Energy Reviews, 2008, 12(5): 1221-1250.

[2] Bazmi A.A., Zahedi G. Sustainable energy systems: Role of optimization modeling techniques in power generation and supply—A review [J]. Renewable and Sustainable Energy Reviews, 2011, 15(8): 3480-3500.

[3]Liu W., Lund H., Mathiesen B.V.Large-scale integration of wind powerinto the existing Chinese energy system[J].Energy,2011,36(8):4753-4760.

[4] Blarke M.B., Lund H. The effectiveness of storage and relocation options in renewable energy systems [J]. Renewable Energy, 2008, 33(7): 1499-1507.

[5] Chen H., Cong T.N., Yang W., et al. Progress in electrical energy storage system: A critical review [J]. Progress in Natural Science, 2009, 19(3): 291-312.

Contents of the invention

The purpose of the present invention is to provide a compressed air energy storage system with non-adiabatic gas expansion, which can not only reduce the cost of the energy storage system, improve the energy conversion efficiency of the energy storage device, but also solve the problem of high power conversion cost of the energy storage system and the utilization of gas compression heat. Low efficiency, fuel consumption in the process of energy release, high resistance and poor heat transfer effect in the process of hot dry rock collection, so as to further improve the economy of the system.

To achieve the above object, the present invention takes the following technical solutions to achieve:

Compressed air energy storage system for non-adiabatic gas expansion, including compressor unit, motor, expander unit, high-pressure gas storage chamber, pressure pump and U-shaped tube heat exchanger; the motor is connected to the compressor unit and expander unit; the expander unit It is composed of several expanders connected in series, each expander is equipped with a reheater; the gas outlet of the compressor unit is connected to the inlet of the high-pressure gas storage chamber through the intercooler, and the outlet of the high-pressure gas storage chamber is connected to the first reheater The first fluid inlet of the first reheater; the first fluid outlet of the first reheater is connected to the gas inlet of the first expander; the gas outlet of the previous expander is connected to the gas outlet of the next expander through a reheater; the last expander The gas outlet of the machine is connected to the atmosphere; the outlet of the U-tube heat exchanger is connected to the second fluid inlet of all reheaters, and the second fluid inlet and outlet of all reheaters are connected to the inlet of the pressure pump, and the outlet of the pressure pump is connected to the U-tube exchanger entrance to the heater.

Further, a first valve is provided at the outlet of the U-shaped tube heat exchanger; a second valve is provided between the intercooler and the inlet of the high-pressure gas storage chamber; the outlet of the high-pressure gas storage chamber is connected to the first valve of the first reheater A third valve and a throttle valve are provided between the fluid inlets.

Further, the U-shaped tube heat exchanger includes an outer tube and an inner tube arranged in the outer tube; the outer tube is a blind tube with an inlet at the top; the inner tube is a hollow pipe, and the lower end of the inner tube is close to the bottom of the outer tube; The gap between the upper inlet of the tube and the inner tube is used as the inlet of the U-shaped tube heat exchanger; the upper outlet of the inner tube is used as the outlet of the U-shaped tube heat exchanger.

Furthermore, the U-shaped tube heat exchanger is buried in the underground hot dry rock for collecting geothermal heat.

Further, the tube wall of the inner tube of the U-shaped tube metal heat exchanger is coated with a heat insulating material layer to prevent heat loss; the cavity of the tube wall of the inner tube is evacuated.

Further, the expander includes a shaft on which a number of moving blades are arranged, a casing is arranged on the outer periphery of the shaft and the moving blades, a geothermal water heat exchange flow channel is arranged in the inner wall of the casing, and a geothermal water flow channel is arranged on the outside of the casing. The geothermal water inlet and geothermal water outlet of the heat exchange flow channel; the geothermal water inlet of the expander is connected to the second fluid inlet of the previous reheater, and the geothermal water outlet is connected to the second fluid outlet of the rear reheater; The geothermal water outlet of the last expander is connected to the second fluid outlet of the last reheater.

Further, the expansion process of the gas in the expander is non-adiabatic expansion.

Further, in the period of excess electric energy, the second valve is opened, and the electric energy drives the motor to rotate. At this time, the motor is used as a motor; the motor drives the compressor unit to do work through the rotating shaft and the coupling, and the compressor unit compresses the air to a certain temperature and pressure. , into the intercooler to cool to the ambient temperature; at the same time, the heat generated by the cooler is directly supplied to the user or enters the lithium bromide unit for refrigeration to provide cooling capacity for the user; the inlet temperature of the compressor unit and the high-pressure gas storage chamber are equal.

Furthermore, during the peak period of power grid load, the third valve and the first valve are opened, and the high-pressure air flows out from the high-pressure gas storage chamber, passes through the throttle valve, and enters the first reheater after the gas pressure is reduced to the set value. When the pressure pump starts to work, the cooling water as the second fluid is pressed into the U-shaped metal heat exchange tube, the cooling water gradually flows from the ground to the ground, and heat exchange is performed at the same time, the cooling water is heated into a hot fluid; the heated fluid finally enters the The first reheater and the shell of the first expander heat the air, wherein the flow of the two fluids in the reheater is countercurrent, and the flow of the expander is forward flow; the heated high-pressure air is in the expander unit The non-adiabatic expansion is performed in the internal expansion machine, and the tail gas of the last expander is directly discharged into the atmosphere.

The invention is a compressed air energy storage system for non-adiabatic gas expansion. The compressor unit is driven by a motor to rotate, and the air is compressed into high-pressure air and stored in the air storage chamber; the intercooler is installed between the compressors for cooling. High-pressure air, so that the temperature of the air entering the lower-stage compressor is basically the same as the ambient temperature; the heat generated by the intercooler of the system will be directly provided to the user or converted into cooling capacity through the lithium bromide unit for use by the user, avoiding the heat generated by air compression The storage problem and the low heat utilization rate of high-temperature compressed air;

The reheater is installed between the expansion units to heat the expanded high-pressure air so that the temperature of the air entering the lower expander is maintained at a specific temperature value; the expander is a non-adiabatic expander heated by dry hot rock The final water passes through the casing of the gas turbo expander and the interstage heater to heat the gas flowing through the turbo expander. The entire expansion process of the gas is non-adiabatic expansion. Compared with the traditional adiabatic expander, it has a higher High expansion efficiency and output work; In addition, the expansion unit of the traditional compressed air energy storage system is composed of a high-pressure end and a low-pressure end, and both are adiabatic expansion, while the expansion unit in the present invention is composed of multiple non-adiabatic expanders connected in series;

The U-tube heat exchanger is used to extract the heat generated by the hot dry rock and provide it to the reheater and expander. The U-tube heat exchanger is in the form of a sleeve, and the bottom port is closed; the inner small-diameter tube is a shell structure, and the inner tube shell cavity is vacuumed, and the center of the bottom end is open; the liquid flows from the ring of the inner tube and the outer tube. The space flows through the bottom opening of the inner tube and flows into the inner tube, finally supplying geothermal energy to the reheater and expander.

The temperature of the tail gas expanded by the expander is relatively low, and it is directly discharged into the atmosphere; the pressure pump and the expander will run simultaneously during the energy release process, and will stop running at the same time.

Compared with the prior art, the present invention has the following beneficial effects: 1. Directly utilize the heat generated by the compression of the compressor unit, improve the operation efficiency of the energy storage process, and reduce the waste of system energy; 2. Combine dry hot rock with compressed air The combination of energy storage solves the problems of heat consumption in the process of high-pressure air expansion, low power conversion efficiency of the system, and low heat extraction efficiency of hot dry rock, and improves the operation economy and environmental friendliness of the entire energy storage system. 3. The use of U-tube metal heat exchangers solves the current problems of high investment cost, difficulty and heat loss in geothermal collection. 4. The non-adiabatic expansion of the gas in the expander improves the output work and power generation efficiency of the energy storage system.

The present invention uses dry hot rock as the heating heat source required for the compressed air energy storage system to release energy for power generation. Compared with the traditional gas heating heat source, the heat source mainly has the following differences: the heat source from dry hot rock belongs to continuous renewable energy, Clean, without any carbon emissions, usually the temperature of the heat source is lower than 350 degrees; while the temperature of the natural gas combustion heat source is greater than 500 degrees, a stable natural gas source is required, and there is a problem of carbon emissions. Therefore, in order to make the compressed air energy storage system better utilize the hot dry rock heat source, it is necessary to redesign the energy release and power generation stage in the existing compressed air energy storage system suitable for natural gas heating heat source, and replace the traditional gas adiabatic expander It is a non-adiabatic expansion machine, that is, the geothermal water passes through the underground "U" type metal heat exchanger with a vacuum tube to bring the heat of the dry hot rock from the deep underground to the ground, and the heated water passes through the gas turbo expander. The shell and interstage heaters heat the gas flowing through the interior of the turboexpander, and the gas expands non-adiabatically.

The main innovation point of the present invention is that water is used as a carrier for extracting heat from dry hot rocks. The hot water is directly passed into the casing of the gas expander and the interstage heater to heat the expanded air. The underground "U"-shaped metal heat exchanger with a vacuum structure is used to extract the heat of dry hot rocks, and the heat transfer between cold water and hot water is minimized through the vacuum structure to reduce irreversible losses. The gas expansion process in the expander is non-adiabatic expansion.

Description of drawings

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a structural schematic diagram of a non-adiabatic gas expansion compressed air energy storage system according to the present invention. In Fig. 1: 1, the first compressor; 2, the second compressor; 3, the first expander; 4, the second expander; 7, the third expander; 5, the motor; 6, the high-pressure gas storage chamber; 8. The first intercooler; 9. The second intercooler; 10. The first valve; 20. The second valve; 21. The third valve; 11. Throttle valve; 12. The first reheater; 13. Second reheater; 17. Third reheater; 14. Pressure pump; 15. Casing connection; 16. U-tube heat exchanger; 18. First coupling; 19. Second coupling .

Fig. 2 is a sectional view of the U-shaped tube heat exchanger in Fig. 1 . Among the figure: 22, inner pipe; 23, outer pipe.

Fig. 3 is a schematic diagram of a single-stage shell structure of an expander.

Fig. 4 is the view of another perspective of the single-stage shell structure of the expander shown in Fig. 3; in the figure: 24, shell; 25, geothermal water outlet; 26, moving blade; 27, geothermal water inlet; 28, shaft .

Detailed ways

As shown in Figure 1, a compressed air energy storage system for non-adiabatic gas expansion in the present invention includes a compressor unit, a motor 5, an expander unit, a high-pressure gas storage chamber 6, a reheater group, a pressure pump 14 and a U-shaped Tube heat exchanger 16.

The compressor unit includes the first compressor 1 and the second compressor 2 connected to each other; the expander unit includes the first expander 3, the second expander 4 and the third expander 7 connected at one time; the reheater unit includes the first A reheater 12 , a second reheater 13 and a third reheater 17 . The motor 5 is connected to the compressor unit through a first coupling 18 and connected to the expander unit through a second coupling 19 . The gas outlet of the first compressor 1 is connected to the gas inlet of the second compressor 2 through the first intercooler 8, and the gas outlet of the second compressor 2 is connected to the high pressure through the second intercooler 9 and the second valve 20 connected in sequence The inlet of the gas storage chamber 6 and the outlet of the high-pressure gas storage chamber 6 are connected to the first fluid inlet of the first reheater 12 through the third valve 21 and the throttle valve 11 connected in sequence, and the first fluid of the first reheater 12 The outlet is connected to the gas inlet of the first expander 3, the gas outlet of the first expander 3 is connected to the first fluid inlet of the second reheater 13, and the first fluid outlet of the second reheater 13 is connected to the second expander 4 The gas inlet and the gas outlet of the second expander 4 are connected to the first fluid inlet of the third reheater 17, and the first fluid outlet of the third reheater 17 is connected to the atmosphere.

The second fluid outlet of the first reheater 12, the second reheater 13, and the third reheater 17 is connected to the inlet of the pressure pump 14, and the outlet of the pressure pump 14 is connected to the inlet of the sleeve pipe joint 15, and the sleeve pipe joint The inlet of 15 is connected to the inlet of U-shaped tube heat exchanger 16, the outlet of U-shaped tube heat exchanger 16 is connected to the outlet of sleeve pipe joint 15, and the outlet of sleeve pipe joint 15 is connected to the first reheater through the first valve 10 12. The second fluid inlet of the second reheater 13 and the third reheater 17 .

The U-shaped tube heat exchanger 16 includes an outer tube 23 and an inner tube 22 arranged in the outer tube 23; the outer tube 23 is a blind pipe with an inlet at the top; the inner tube 22 is a hollow pipe, and the lower end of the inner tube 22 is close to the outer tube. The bottom of the tube 23; the gap between the upper end inlet of the outer tube 23 and the inner tube 22 is used as the inlet of the U-shaped tube heat exchanger 16; the upper end outlet of the inner tube 22 is used as the outlet of the U-shaped tube heat exchanger 16.

The present invention is a compressed air energy storage system for non-adiabatic gas expansion. The motor 5 drives the first compressor 1 and the second compressor 2. The motor 5 is driven by the first expander 3, the second expander 4 and the third expander 7. drive power generation.

In the period of excess electric energy, open the second valve 20, the electric energy drives the motor 5 to rotate, and the motor 5 is used as a motor at this time; the motor 5 drives the first compressor 1 and the second compressor 2 to do work through the rotating shaft and the coupling, and the first After the compressor 1 compresses the air to a certain temperature and pressure, the air enters the first intercooler 8, is cooled to the ambient temperature, and then enters the second compressor 2 to be compressed again to raise the temperature, and then enters the second intercooler 9 to cool down to the ambient temperature ; At the same time, the heat generated by the first intercooler 8 and the second intercooler 9 is directly supplied to the user or enters the lithium bromide unit for refrigeration to provide cooling capacity for the user. The inlet temperatures of the second compressor 2 and the high-pressure gas storage chamber 6 are equal and close to atmospheric temperature.

During the peak period of power grid load, the third valve 21 and the first valve 10 are opened, and the high-pressure air flows out from the high-pressure gas storage chamber 6, passes through the throttle valve 11, and the gas pressure drops to a set value before entering the first reheater 12 At this time, the pressure pump 14 starts to work, and the cooling water as the second fluid is pressed into the annular space between the inner tube 22 and the outer tube 23 of the U-shaped metal heat exchange tube 16, and the cooling water gradually flows from the ground to the ground, and at the same time, it is in contact with the outer tube. The tube 23 performs heat exchange, and the cooling water is heated into a hot fluid; the heated fluid enters the inner tube from the bottom opening of the inner tube 22, and finally enters the shell of the first reheater 12 and the first expander 3. The air is heated, and the flow of the two fluids in the reheater is a counter-flow type, and the flow in the expander is a forward-flow type; the heated high-pressure air expands in the first expander 3 to perform work, and at the same time, the hot water is cooled for the next Circulation: After the high-pressure air undergoes non-adiabatic expansion in the first expander 3, it enters the second reheater 13 to be heated to a certain temperature, and then enters the second expander 4 to perform non-adiabatic expansion to perform work again. The tail gas discharged from the second expander 4 It is heated again by the third reheater 17, and enters the third expander 7 to perform non-adiabatic expansion; since the heated geothermal water temperature is not high, the tail gas temperature of the third expander 7 is not high, so it is directly into the atmosphere. The working mode of the second reheater 13 and the third reheater 17 is the same as that of the first reheater 12 . During the energy release process, the first expander 3 , the second expander 4 and the third expander 7 drive the motor 5 to generate electricity and supply the electric energy to the grid, and the motor 5 is used as a generator. In addition, the expansion ratios of the first expander 3 , the second expander 4 and the third expander 7 are relatively small, so that the entire expansion and energy release process is close to isothermal expansion.

The tube wall of the inner tube 22 of the U-shaped tube metal heat exchanger 16 is coated with a heat-insulating material layer to prevent heat loss; the outer tube is made of copper or other cheap materials with strong thermal conductivity and certain hardness. The cavity of the inner tube 22 shell structure is evacuated to effectively prevent heat dissipation. The bottom of the inner tube 22 is an open structure; the working fluid in the U-shaped heat exchanger is water; the pressure pump 14 requires The electrical energy is provided by the electrical energy that motor 5 sends. The geothermal collection device is assembled by a large number of U-tube heat exchangers, and each section of U-tube heat exchanger is a standard part directly processed by the factory; the length of the geothermal collection device is generally 2-3km (the depth of geothermal resources in different regions is different, so the geothermal The length of the collection device can be determined according to the actual local geological conditions), and the heat collection is generally below 2km.

The diameter of the outer tube 23 of the U-tube metal heat exchanger 16 can be determined according to the local geological conditions and the thermal fluid flow required by the energy storage system, while the inner tube diameter can be determined based on the principle of minimum fluid flow and fluid flow resistance.

Please refer to Fig. 3 and Fig. 4, the first expander 3, the second expander 4 and the third expander 7 have the same structure, and all adopt a single-stage shell structure, including a shaft 28 on which a number of movable blades are arranged. 26. A casing 24 is provided on the outer periphery of the shaft 28 and the movable blade 26. The inner wall of the casing is provided with a geothermal water heat exchange channel, and the outer side of the casing 24 is provided with a geothermal water first connected to the geothermal water heat exchange channel. The inlet 27, the second inlet 29, the third inlet 30 and the geothermal water outlet 25, the entry of the hot water at the second inlet and the hot water at the third inlet can reheat the expanded gas and improve the ability of the gas to expand and do work. The flow area of the casing 24 gradually increases to ensure that the geothermal circulating water will not suffer too much resistance during the flow process inside the casing.

The valves in the present invention are all electronically controlled valves, and the start and stop of the valves and equipment are controlled through an automatic console. In actual industrial applications, the required stages of the compressor unit and the expansion unit can be determined according to actual needs. The present invention illustrates the working process of the system with two-stage compression and three-stage expansion.

Claims (4)

1. A compressed air energy storage system for non-adiabatic gas expansion, characterized in that it includes a compressor unit, a motor (5), an expander unit, a high-pressure gas storage chamber (6), a pressure pump (14) and a U-shaped tube for heat exchange device (16); The motor (5) is connected to the compressor unit and the expander unit; The expander unit is composed of several expanders connected in series, each expander is equipped with a reheater; The gas outlet of the compressor unit is connected to the inlet of the high-pressure gas storage chamber (6) through the intercooler, and the outlet of the high-pressure gas storage chamber (6) is connected to the first fluid inlet of the first reheater; the first fluid inlet of the first reheater The fluid outlet is connected to the gas inlet of the first expander; the gas outlet of the previous expander is connected to the gas outlet of the next expander through a reheater; the gas outlet of the last expander is connected to the atmosphere; The outlet of the U-shaped tube heat exchanger (16) is connected to the second fluid inlet of all reheaters, the second fluid outlet of all reheaters is connected to the inlet of the pressure pump (14), and the outlet of the pressure pump (14) is connected to the U-shaped The inlet of the tube heat exchanger (16); The U-shaped tube heat exchanger (16) comprises an outer tube (23) and an inner tube (22) arranged in the outer tube (23); the outer tube (23) is a blind tube with an inlet at the top; the inner tube (22) It is a hollow pipeline, and the lower end of the inner pipe (22) is close to the bottom of the outer pipe (23); the gap between the upper end inlet of the outer pipe (23) and the inner pipe (22) is used as the U-shaped tube heat exchanger (16) Inlet; the upper outlet of the inner pipe (22) is used as the outlet of the U-shaped tube heat exchanger (16); The U-shaped tube heat exchanger (16) is buried in the underground hot dry rock for collecting geothermal heat; The tube wall of the inner tube (22) of the U-shaped tube heat exchanger (16) is coated with a heat insulating material layer to prevent heat loss; the tube wall cavity of the inner tube (22) is evacuated; The expander includes a shaft (28), on which a number of movable blades (26) are arranged, and a casing (24) is arranged on the outer circumference of the shaft (28) and the movable blades (26), and a geothermal heat source is arranged in the inner wall of the casing. The water heat exchange channel, the outer side of the housing (24) is provided with a geothermal water inlet (27) and a geothermal water outlet (25) connected to the geothermal water heat exchange channel; the geothermal water inlet (27) of the expander is connected to The second fluid inlet and geothermal water outlet (25) of the previous reheater are connected to the second fluid outlet of the latter reheater; the geothermal water outlet (25) of the last expander is connected to the first fluid outlet of the last reheater Second fluid outlet; The expansion process of gas in the expander is non-adiabatic expansion. 2. The compressed air energy storage system for non-adiabatic gas expansion according to claim 1, characterized in that, the outlet of the U-shaped tube heat exchanger (16) is provided with a first valve (10); A second valve (20) is provided between the inlets of the gas chamber (6); a third valve (21) and a throttle are provided between the outlet of the high-pressure gas storage chamber (6) and the first fluid inlet of the first reheater. flow valve (11). 3. The compressed air energy storage system for non-adiabatic gas expansion according to claim 2, characterized in that, during the period of excess electric energy, the second valve (20) is opened, and the electric energy drives the motor (5) to rotate, at this time the electric motor (5) ) is used as a motor; the motor (5) drives the compressor unit to do work through the rotating shaft and the coupling, and the compressor unit compresses the air to a certain temperature and pressure, and then enters the intercooler for cooling to the ambient temperature; at the same time, the air produced by the cooler The heat is directly supplied to the user or enters the lithium bromide unit for refrigeration to provide cooling capacity for the user; the inlet temperatures of the compressor unit and the high-pressure gas storage chamber (6) are equal. 4. The compressed air energy storage system for non-adiabatic gas expansion according to claim 2, characterized in that, during the peak period of power grid electric energy load, the third valve (21) and the first valve (10) are opened, and the high-pressure air flows from the high-pressure The gas flows out of the gas storage chamber (6), passes through the throttle valve (11), and enters the first reheater after the gas pressure drops to the set value. At this time, the pressure pump (14) starts to work, and the cooling water as the second fluid is Pressed into the U-shaped heat exchange tube (16), the cooling water gradually flows from the ground to the ground, and at the same time heat exchange is performed, and the cooling water is heated into a hot fluid; the heated fluid finally enters the shell of the first reheater and the first expander The air is heated in the body, and the flow of the two fluids in the reheater is a counter-flow type, and the flow in the expander is a co-flow type; the heated high-pressure air performs non-adiabatic expansion in the expander unit, and the last expander The exhaust gas is discharged directly into the atmosphere.