CN110701022A - A compressed air energy storage system and control method for efficiently utilizing low-grade thermal energy - Google Patents

Abstract

The invention discloses a compressed air energy storage system that efficiently utilizes low-grade heat energy and a control method thereof. By adding a low-grade heat source input part and a high-temperature heat energy utilization part to the existing compressed air energy storage system, the The inlet air entering the energy storage compressor unit is heated, thereby also increasing the compressed air temperature of the outlet gas of the energy storage compressor unit, and using the heat at the outlet of the energy storage compressor unit as the heat source of the heat engine gas working medium, the heat engine can be simultaneously The energy storage compressor and the heat engine side compressor provide power. Using this coupling system, the low-grade thermal energy is converted into high-grade thermal energy for utilization, and the efficient utilization of low-grade energy is realized. At the same time, due to the flexibility of the system, the wide-load operation of the energy storage system can be realized. In addition, the invention makes the exhaust gas of the expander close to normal temperature by releasing the heat of the energy storage process, thereby realizing the high-efficiency utilization of low-grade thermal energy, and further improving the energy utilization rate of the system.

Description

A compressed air energy storage system and control method for efficiently utilizing low-grade thermal energy

technical field

The invention belongs to the technical fields of compressed air energy storage and the like, and relates to a compressed air energy storage system, in particular to a compressed air energy storage system for efficiently utilizing low-grade thermal energy and a control method thereof, which can realize the efficient utilization of low-grade thermal energy and improve the system performance. Efficiency and range of operating conditions.

Background technique

The sustainable development of energy and environmental problems is the foundation of national economic development, and solving the energy and environmental problems in the power industry is an important part of ensuring the sustainable development of my country's economy. Electric energy storage is one of the key technologies for adjusting my country's energy structure, developing renewable energy on a large scale, and improving energy security. The research on large-scale energy storage technology has important theoretical and practical value.

The current energy storage systems include pumped hydro storage, compressed air energy storage, fuel cells, etc. Pumped hydro storage and compressed air energy storage have the characteristics of high energy storage density and high output power, and have been used on a large scale. However, pumped storage power stations must build dams, which consume a lot of water and cause certain damage to the ecology. The compressed air energy storage system does not consume water and has no impact on the ecological environment. It has the advantages of low initial investment cost, high efficiency, non-toxicity, and long life, and has great development prospects. In addition, the current utilization rate of low-grade heat sources such as industrial waste heat is low, and the operating range of compressed air energy storage systems is limited due to the low utilization rate of renewable energy sources due to fluctuations and intermittency.

SUMMARY OF THE INVENTION

In view of the above-mentioned defects and deficiencies of the prior art, the present invention aims to provide a compressed air energy storage system for efficiently utilizing low-grade heat energy and a control method thereof, by adding a low-grade heat source input part in the existing compressed air energy storage system And the high-temperature heat energy utilization part, the low-grade heat source is used to heat the inlet air entering the energy storage compressor unit, thereby increasing the compressed air temperature of the outlet gas of the energy storage compressor unit, and the heat of the outlet part of the energy storage compressor unit is used as a heat engine. The heat source of the gas working medium, the heat engine can provide power for the energy storage compressor and the heat engine side compressor at the same time. By adopting this coupling system, the low-grade heat energy is converted into high-grade heat energy, and the efficient utilization of low-grade heat energy can be realized. The system has the characteristics of energy saving, high efficiency, and strong application of renewable energy.

The technical scheme adopted by the present invention for realizing its technical purpose is:

A compressed air energy storage system for efficiently utilizing low-grade thermal energy, comprising a compressed air energy storage unit, the compressed air energy storage unit comprising an energy storage compressor unit, an energy storage expansion unit, a high-pressure air storage chamber, and a motor and a generator, wherein the low-pressure intake line of the energy storage compressor unit is communicated with the atmosphere, the high-pressure exhaust line of the energy storage compressor unit is communicated with the air inlet of the high-pressure air storage chamber, and the energy storage The high-pressure air intake line of the expansion unit is communicated with the exhaust port of the high-pressure air storage chamber, the electric motor unit is drivingly connected with the power input end of the energy storage compressor unit, and the power output end of the energy storage expansion unit is connected to the The generator set drive connection is characterized in that,

The system also includes a low-grade thermal energy input unit and a high-temperature thermal energy utilization unit, wherein,

--The low-grade heat energy input unit includes a low-temperature heat storage device and a first heat exchanger, wherein the low-temperature heat storage device is provided with a heat storage material and a structure for introducing low-grade heat energy, the The low temperature heat storage device is also provided with a heat exchange coil, and the hot side of the first heat exchanger is communicated with the heat exchange coil in the low temperature heat storage device through a pipeline to form a low temperature heat energy circulation loop. The cold side of the heater is arranged on the low pressure intake line of the energy storage compressor unit;

--The high-temperature thermal energy utilization unit includes a heat engine, a second heat exchanger, a high-temperature heat storage device, and a heat engine side compressor unit, wherein the high-pressure exhaust line of the energy storage compressor unit passes through the first heat exchanger in sequence. The hot side of the second heat exchanger and the first heat exchange coil of the high temperature heat storage device are connected to the air inlet of the high pressure gas storage chamber, and the cold side of the second heat exchanger is arranged on the heat engine On the gas working medium inlet line of the heat engine, the first output shaft of the heat engine is drivingly connected to the heat engine side compressor unit, the second output shaft of the heat engine is driven and connected to the energy storage compressor unit through a clutch, and the heat engine side The air inlet of the compressor unit is communicated with the atmosphere, and the exhaust port is communicated with the air inlet of the high-pressure air storage chamber through the pipeline through the second heat exchange coil of the high-temperature heat storage device, and the high-temperature heat storage At least one pressure regulating valve is arranged on the communication pipeline between the second heat exchange coil of the device and the air inlet of the high-pressure air storage chamber, and the exhaust port of the high-pressure air storage chamber passes through the high-temperature storage chamber through the pipeline. The third heat exchange coil of the heat device is communicated with the high-pressure intake line of the energy storage expansion unit, and at least one control valve is arranged on the exhaust line of the high-pressure gas storage chamber.

In the above system of the present invention, a first heat exchanger is arranged in front of the energy storage compressor unit, and the first heat exchanger exchanges heat with the low-temperature heat storage device, and the low-temperature heat storage device introduces and stores low-grade heat The heat energy is utilized by preheating the air entering the energy storage compressor unit to realize the utilization of the heat in the low-grade heat source. Since the low-grade heat source is used to heat the inlet air entering the energy storage compressor unit, the compressed air temperature of the outlet gas of the energy storage compressor unit is also increased, and the utilization of low-grade heat energy into high-grade heat energy is realized.

In the above-mentioned system of the present invention, a second heat exchanger is arranged on the gas working medium inlet line of the heat engine, and through heat exchange with the high-temperature and high-pressure compressed air discharged from the energy storage compressor unit, the gas entering the heat engine is increased. The inlet temperature of the working medium provides a heat source for the heat engine, and at the same time reduces the temperature of the air stored in the high-pressure gas storage chamber.

In the above system of the present invention, the heat engine drives the heat engine side compressor group, and the heat engine side compressor group compresses the air to the temperature near the high temperature heat storage device and the near pressure of the high pressure gas storage chamber. The high temperature and high pressure The air is stored in the high-pressure air storage chamber after being stored in the high-temperature heat storage device, so as to realize the storage of more air.

In the above system of the present invention, a clutch is provided on the second output shaft of the heat engine, the clutch connects the energy storage compressor unit and the heat engine, and the change of access load is realized by opening and closing the clutch.

In the above system of the present invention, a pressure regulating valve is provided on the communication pipeline between the second heat exchange coil of the high temperature heat storage device and the air inlet of the high pressure gas storage chamber, which is used to adjust the flow rate from the heat engine. The pressure of the compressed air of the side compressor unit.

Preferably, the heat engine is a gas turbine, a piston internal combustion engine, a Rankine cycle heat engine or a Stirling engine.

Preferably, the low-grade thermal energy comes from solar low-temperature thermal storage, industrial waste heat or inter-season thermal storage.

Preferably, the heat storage material in the low temperature heat storage device and the high temperature heat storage device is water, sand or soil.

Preferably, the energy storage compressor unit, the heat engine side compressor unit, and the expansion unit are one or a combination of a piston type, a centrifugal type, an axial flow type, a screw type or a rotor type.

Preferably, the first heat exchanger and the second heat exchanger are one of shell and tube type, plate fin type, plate type, spiral tube type, casing type, plate and shell type, tube-fin type and heat pipe type or several combinations.

Preferably, the electric power of the electric motor comes from one or more combinations of wind power generation, solar power generation, and power grid.

Preferably, the energy storage compressor unit and the expansion unit are single-stage or multi-stage.

Preferably, the high temperature thermal storage device and the low temperature thermal storage device are double-tank indirect thermal storage, packed bed thermal storage or molten salt single-tank thermal storage.

Preferably, the system includes an energy storage working mode and an energy releasing working mode.

Further, when the system is in the energy storage working mode, start the electric motor, the energy storage compressor unit, the heat engine, and the heat engine side compressor unit, close the control valve on the exhaust line of the high-pressure gas storage chamber, and the low-temperature storage The low-grade heat energy in the thermal device is transmitted to the inlet air of the energy storage compressor unit through the first heat exchanger, and the high temperature and high pressure compressed air discharged from the energy storage compressor unit is released in the second heat exchanger The heat is used to heat the gas working medium entering the heat engine, and then enters the high temperature heat storage device to further release heat and store it in the high pressure gas storage chamber in a state close to normal temperature; at the same time, the heat engine drives the heat engine side compressor unit The high-temperature and high-pressure compressed air discharged from the heat engine side compressor unit enters the high-temperature heat storage device to release heat, and is then stored in the high-pressure air storage chamber after being pressure-regulated by the pressure regulating valve.

Further, when the input power of the electric motor cannot meet the demand, the clutch is closed, so that the heat engine provides part of the work for the energy storage compressor group to meet the energy storage demand.

Further, when the system is in the energy release mode, open the control valve on the exhaust line of the high-pressure gas storage chamber, close the electric motor, the energy storage compressor unit, the heat engine, and the heat engine side compressor unit, and the high-pressure gas storage unit is closed. The high-pressure compressed air in the chamber enters the high-temperature heat storage device to absorb heat and then flows into the expansion unit to expand and perform work, driving the generator to work and output electric energy to the outside.

According to another aspect of the present invention, a control method for the above system is also provided, characterized in that when energy storage is required, the electric motor, the energy storage compressor unit, the heat engine, and the heat engine side compressor unit are started, and the high-voltage unit is turned off. The control valve on the exhaust line of the air storage chamber, the low-grade heat energy in the low-temperature heat storage device is transmitted to the inlet air of the energy storage compressor unit through the first heat exchanger, and the energy storage compressor unit discharges The high-temperature and high-pressure compressed air releases heat in the second heat exchanger to heat the gaseous working medium entering the heat engine, and then enters the high-temperature heat storage device to further release heat and stores it in the high-pressure gas storage in a state close to normal temperature At the same time, the high-temperature and high-pressure compressed air discharged from the heat-engine-side compressor set by the heat engine drives the heat-engine side compressor set to enter the high-temperature heat storage device to release heat, and is then stored in the in the high pressure air chamber.

Further, when the input power of the electric motor cannot meet the demand, the clutch is closed, so that the heat engine provides part of the work for the energy storage compressor group to meet the energy storage demand.

Further, when it is necessary to release energy, open the control valve on the exhaust pipeline of the high-pressure air storage chamber, close the electric motor, the energy storage compressor unit, the heat engine, and the heat-engine side compressor unit, and the high pressure in the high-pressure air storage chamber is closed. The compressed air enters the high-temperature heat storage device to absorb heat and then passes into the expansion unit to expand and perform work, driving the generator to work and output electric energy to the outside.

The working principle of the compressed air energy storage system for efficiently utilizing low-grade thermal energy of the present invention is as follows:

When storing energy, the air absorbs low-grade heat energy in the first heat exchanger and enters the energy storage compressor unit. Driven by excess electric energy, the air is compressed to a high temperature and high pressure state, and the compressed gas is compressed in the second heat exchanger. Cooling and heating the gas working medium of the heat engine at the same time, the cooled air is cooled again in the high temperature heat storage device, and finally stored in the high pressure storage room in the form of normal temperature and high pressure. At the same time, the heated gas working medium enters the heat engine with the efficiency of the heat engine, and the work done by the heat engine drives the compressor unit on the heat engine side to compress the air, and the compressed high-temperature and high-pressure air enters the high-temperature heat storage device to release heat and then enters the high-pressure gas storage chamber for storage. When the load needs to be changed, by closing the clutch, the heat engine can provide part of the work for the energy storage compressor unit to reduce the external load. When releasing energy, the gas in the high-pressure gas storage chamber is heated by the high-temperature heat storage device, and then sent to the expansion unit for expansion to do work.

It can be seen from the above technical solutions that the beneficial effects of the present invention are: on the basis of the compressed air energy storage system, the compressed air energy storage, waste heat utilization and heat engine are combined, and low-grade heat energy is used to add air in front of the compressor inlet, The utilization of low-grade energy is realized, and the compressed air energy storage is combined with the heat engine, which improves the energy utilization efficiency of the system and broadens the working range of the system.

Description of drawings

FIG. 1 is a schematic diagram of a compressed air energy storage system for efficiently utilizing low-grade thermal energy according to the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

As shown in FIG. 1 , the compressed air energy storage system for efficiently utilizing low-grade thermal energy of the present invention includes a compressed air energy storage unit, and the compressed air energy storage unit includes an energy storage compressor unit C1, an energy storage expansion unit 12, and a compressed air energy storage unit. The high-pressure air storage chamber 10, an electric motor 3 and a generator 13, wherein the low-pressure air intake line of the energy storage compressor group C1 is communicated with the atmosphere, and the high-pressure exhaust line of the energy storage compressor group C1 is connected with the air intake of the high-pressure air storage chamber 10. The high-pressure intake line of the energy storage expansion unit 12 is connected with the exhaust port of the high-pressure air storage chamber 10, the motor unit 3 is connected to the power input end of the energy storage compressor unit C1, and the power output end of the energy storage expansion unit 12 is connected. Drive connection with generator set 13. As a preference, the electric power of the motor set 3 comes from one or more combinations of renewable energy sources such as wind power generation and solar power generation, power grids, and the like. The energy storage compressor unit C1 may be a single-stage or multi-stage compressor, and the energy storage expansion unit 12 may be a single-stage or multi-stage expander. The energy storage compressor unit C1 can be one or a combination of piston, centrifugal, axial, screw or rotor compressors, and the energy storage expansion unit 12 can be piston, axial, centrifugal , one of screw or hybrid expanders.

In order to realize the efficient utilization of low-grade thermal energy, the compressed air energy storage system for efficiently utilizing low-grade thermal energy of the present invention is further provided with a low-grade thermal energy input unit and a high-temperature thermal energy utilization unit.

Referring to Figure 1, the low-grade heat energy input unit includes a low-temperature heat storage device TS1 and a first heat exchanger H1. The low-temperature heat storage device TS1 is provided with heat storage materials such as water, sand, soil, etc., and uses double-tank indirect heat storage. , packed bed heat storage, molten salt single tank heat storage and other similar structures to store low-grade heat energy, low-grade heat energy comes from solar low-temperature heat storage, industrial waste heat, and cross-season heat storage. The low-grade heat energy can be input into the low-temperature heat storage device TS1 in various ways. For example, it can be fed into the low-temperature heat storage device TS1 by means of a hot water coil, and the hot water is used as the carrier of low-grade heat energy. The thermal storage material in the device TS1 performs heat exchange, transfers heat to the thermal storage material for thermal storage, or inputs low-grade thermal energy into the low-temperature thermal storage device TS1 through other direct or indirect means, all of which belong to the scope of the prior art. , the present invention will not be expanded in detail here. The low temperature heat storage device TS1 is also provided with a heat exchange coil (not shown in the figure), and the hot side of the first heat exchanger H1 forms a low temperature heat energy circulation loop with the heat exchange coil in the low temperature heat storage device TS1 through pipelines , the cold side of the first heat exchanger H1 is arranged on the low-pressure intake line of the energy storage compressor group C1, and the low-grade heat energy accumulated in the low-temperature heat storage device TS1 is transported to the first heat exchanger H1 through the low-temperature heat energy circulation loop. In the hot side, the air entering the energy storage compressor group C1 through the cold side of the first heat exchanger H1 is heated, so as to realize the utilization of low-grade thermal energy.

Referring to FIG. 1, the high temperature thermal energy utilization unit includes a heat engine 6, a second heat exchanger H2, a high temperature heat storage device TS2 and a heat engine side compressor group C2, wherein the high pressure exhaust line of the energy storage compressor group C1 passes through the first The hot side of the second heat exchanger H2 and the first heat exchange coil of the high temperature heat storage device TS2 are communicated with the air inlet of the high-pressure gas storage chamber 10 , and the cold side of the second heat exchanger H2 is arranged on the gas working part of the heat engine 6 . On the mass air inlet line, the first output shaft of the heat engine 6 is driven to connect to the heat engine side compressor group C2, the second output shaft of the heat engine 6 is driven to connect to the energy storage compressor group C1 through a clutch 15, and the air inlet of the heat engine side compressor group C2 is connected to the compressor group C1. The atmosphere is communicated, and the exhaust port is communicated with the air inlet of the high-pressure gas storage chamber 10 through the second heat exchange coil of the high-temperature heat storage device TS2 through the pipeline, and the second heat exchange coil of the high-temperature heat storage device TS2 is connected to the high-pressure gas storage chamber 10. At least one pressure regulating valve 9 is arranged on the communication pipeline between the air inlets of the gas storage chamber 10, and the exhaust port of the high pressure gas storage chamber 10 passes through the pipeline through the third heat exchange coil of the high temperature heat storage device TS2 and the storage. The high-pressure intake line of the expandable unit 12 is communicated, and at least one control valve is arranged on the exhaust line of the high-pressure gas storage chamber 10 . Similar to the low-temperature thermal storage device TS1, the high-temperature thermal storage device TS2 can also choose thermal storage materials such as water, sand, soil, etc., and adopts a double-tank indirect thermal storage, packed bed thermal storage, molten salt single-tank thermal storage and other similar structures form to store high-grade high-temperature thermal energy. The heat engine 6 can be a gas turbine, a piston internal combustion engine, a Rankine cycle heat engine, a Stirling engine, etc. When these types of heat engines are working, a gaseous working medium such as air is required to participate in the work to improve the intake of the gaseous working medium. The temperature can improve the overall working efficiency of the heat engine. For this reason, when the heat engine 6 in the present invention is working, because its gas working medium inlet line passes through the cold side of the second heat exchanger H2, and the second heat exchanger H2 The hot side is fed with high-temperature and high-pressure compressed air discharged from the energy storage compressor group C1, so the gas working medium of the heat engine 6 is discharged through the second heat exchanger H2 and the energy storage compressor group C1 before entering the heat engine. The high temperature and high pressure compressed air conducts heat exchange, which can increase the inlet temperature of the gas working medium of the heat engine, provide a heat source for the heat engine, and also reduce the temperature of the air stored in the subsequent high-pressure gas storage chamber 10 . In addition, the heat engine 6 drives the heat engine side compressor group C2, and the heat engine side compressor group C2 compresses the air to the near temperature of the high temperature heat storage device TS2 and the near pressure of the high pressure air storage chamber 10, and the high temperature and high pressure air is stored in the high temperature heat storage device TS2 after being stored in the In the high-pressure air storage chamber 10, more compressed air is stored. Further, the second output shaft of the heat engine 6 is driven and connected to the energy storage compressor group C1 through the clutch 15 , and the change of the access load of the energy storage compressor group C1 is realized by opening and closing the clutch 15 . The pressure regulating valve 9 is at least set on the communication pipeline between the second heat exchange coil of the high temperature heat storage device TS2 and the air inlet of the high pressure gas storage chamber 10, which is used to adjust the pressure of the compressed air from the heat engine side compressor group C2 .

The compressed air energy storage system for efficiently utilizing low-grade thermal energy of the present invention includes an energy storage working mode and an energy releasing working mode in the working process. When the whole system is in the energy storage working mode, the air 1 enters the compressor group C1 to be compressed after absorbing low-grade heat energy in the first heat exchanger H1, and the compressed high-temperature and high-pressure gas releases heat in the second heat exchanger H2 and enters the The high temperature heat storage device TS2, after the high temperature and high pressure air is cooled, is stored in the high pressure gas storage chamber 10 in a state close to normal temperature; at the same time, the gas working medium of the heat engine 6 enters the heat engine 6 after absorbing heat in the second heat exchanger H2 to participate in the work, and the heat engine 6 The work drives the compressor group C2 on the heat engine side, and the air 7 is compressed in the compressor group C2 on the heat engine side. After the compressed gas enters the high temperature heat storage device TS2 to release heat, it is regulated by the pressure regulating valve 9 and stored in the high pressure gas storage chamber. 10 out of 10. When the input power of the motor 3 (ie, the external load) is not large, the clutch 15 is closed, and the heat engine 6 provides part of the work for the energy storage compressor group C1 to meet the energy storage demand.

When the whole system is in the energy release mode, the high-pressure compressed air in the high-pressure gas storage chamber 10 enters the high-temperature heat storage device TS2 to absorb heat and then enters the expansion unit 12 to expand and perform work, and the exhaust 14 is communicated with the atmosphere.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of the present invention. within.

Claims (10)

1. A compressed air energy storage system for efficiently utilizing low-grade thermal energy, comprising a compressed air energy storage unit, the compressed air energy storage unit comprising an energy storage compressor unit, an energy storage expansion unit, a high-pressure air storage chamber, A motor and a generator, wherein the low-pressure intake line of the energy storage compressor unit is communicated with the atmosphere, the high-pressure exhaust line of the energy storage compressor unit is communicated with the air inlet of the high-pressure air storage chamber, and the The high-pressure intake line of the energy storage expansion unit is communicated with the exhaust port of the high-pressure air storage chamber, the motor unit is drivingly connected with the power input end of the energy storage compressor unit, and the power output end of the energy storage expansion unit Driven connection with the generator set, characterized in that: The system also includes a low-grade thermal energy input unit and a high-temperature thermal energy utilization unit, wherein, --The low-grade heat energy input unit includes a low-temperature heat storage device and a first heat exchanger, wherein the low-temperature heat storage device is provided with a heat storage material and a structure for introducing low-grade heat energy, the The low temperature heat storage device is also provided with a heat exchange coil, and the hot side of the first heat exchanger is communicated with the heat exchange coil in the low temperature heat storage device through a pipeline to form a low temperature heat energy circulation loop. The cold side of the heater is arranged on the low pressure intake line of the energy storage compressor unit; --The high-temperature thermal energy utilization unit includes a heat engine, a second heat exchanger, a high-temperature heat storage device, and a heat engine side compressor unit, wherein the high-pressure exhaust line of the energy storage compressor unit passes through the first heat exchanger in sequence. The hot side of the second heat exchanger and the first heat exchange coil of the high temperature heat storage device are connected to the air inlet of the high pressure gas storage chamber, and the cold side of the second heat exchanger is arranged on the heat engine On the gas working medium inlet line of the heat engine, the first output shaft of the heat engine is drivingly connected to the heat engine side compressor unit, the second output shaft of the heat engine is driven and connected to the energy storage compressor unit through a clutch, and the heat engine side The air inlet of the compressor unit is communicated with the atmosphere, and the exhaust port is communicated with the air inlet of the high-pressure air storage chamber through the pipeline through the second heat exchange coil of the high-temperature heat storage device, and the high-temperature heat storage At least one pressure regulating valve is arranged on the communication pipeline between the second heat exchange coil of the device and the air inlet of the high-pressure air storage chamber, and the exhaust port of the high-pressure air storage chamber passes through the high-temperature storage chamber through the pipeline. The third heat exchange coil of the heat device is communicated with the high-pressure intake line of the energy storage expansion unit, and at least one control valve is arranged on the exhaust line of the high-pressure gas storage chamber. 2. The compressed air energy storage system according to the preceding claim, wherein the heat engine is a gas turbine, a piston internal combustion engine, a Rankine cycle heat engine or a Stirling engine. 3 . The compressed air energy storage system according to the preceding claim, wherein the low-grade thermal energy comes from low-temperature solar thermal storage, industrial waste heat or inter-season thermal storage. 4 . 4. The compressed air energy storage system according to the preceding claim, wherein the heat storage material in the low temperature heat storage device and the high temperature heat storage device is water, sand or soil. 5. The compressed air energy storage system according to the preceding claim, wherein the energy storage compressor unit, the heat engine side compressor unit, and the expansion unit are of a piston type, a centrifugal type, an axial flow type, a screw type or a rotor type. one or a combination of several. 6. The compressed air energy storage system according to the preceding claim, wherein the first heat exchanger and the second heat exchanger are shell and tube type, plate-fin type, plate type, spiral tube type, and casing type , one or a combination of plate and shell type, tube-fin type and heat pipe type. 7. The compressed air energy storage system according to the preceding claim, wherein the electric energy of the electric motor comes from one or more combinations of wind power generation, solar power generation, and power grid. 8 . The compressed air energy storage system according to claim 8 , wherein the energy storage compressor unit and the expansion unit are single-stage or multi-stage. 9 . 9 . The compressed air energy storage system according to the preceding claim, wherein the high-temperature thermal storage device and the low-temperature thermal storage device are double-tank indirect thermal storage, packed bed thermal storage or molten salt single-tank thermal storage. 10 . 10. The compressed air energy storage system according to the preceding claim, wherein the system includes an energy storage working mode and an energy releasing working mode.

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