Compressed air energy storage compression waste heat recovery method and system

Abstract

The invention relates to a compressed air energy storage compression waste heat recovery method and system. The system comprises a compressor unit, a compression side heat exchange system, a cooler, an expansion unit, an expansion side heat exchange system, a salt cavern, a low-temperature heat storage device, a high-temperature heat storage device, a motor, a generator and an organic working medium centripetal turbine power generation system. The compressor unit is connected to the salt cavern, the low-temperature heat storage device and the high-temperature heat storage device through the compression side heat exchange system; the expansion unit is connected to the salt cavern, the low-temperature heat storage device and the high-temperature heat storage device through the expansion side heat exchange system; and the organic working medium centripetal turbine power generation system is connected to the compressor unit through the cooler. Therefore, heat which is not utilized in the original compressed air energy storage compression process is completely used for heating the organic working medium R123 in the organic working medium centripetal turbine power generation system, efficient utilization of energy is achieved, and the overall efficiency of the compressed air energy storage system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air energy storage, and in particular to a method and system for recovering compressed waste heat of compressed air energy storage. Background Art

[0002] Compressed air energy storage is one of the most mature large-capacity new energy storage technologies currently available. It has the advantages of large scale, long life, long energy storage time, short construction period, low unit cost, flexible site selection, high social and environmental benefits, high safety and reliability. It is a large-scale, long-term energy storage technology with great development potential. It can be widely used in grid peak regulation, frequency regulation, power supply, new energy consumption and other scenarios, and has broad application prospects.

[0003] As a type of long-term energy storage, compressed air energy storage still has the problem of relatively low electricity-to-electricity conversion efficiency compared to pumped storage. At present, the maximum efficiency of the new compressed air energy storage demonstration project that has been built is about 60%, which is still far from the efficiency of 75% to 80% of 300 MW pumped storage. Especially in the energy storage process, there is a large amount of low-quality heat that cannot be fully utilized, resulting in a large amount of heat energy waste, which limits the further improvement of the efficiency of the compressed air energy storage system. The system efficiency can be effectively improved by rationally designing the thermal system. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a method and system for recovering waste heat from compression of a compressed air energy storage system, recovering the waste heat that cannot be used during the compression process of the compressed air energy storage system, and using the waste heat in an organic working fluid centripetal turbine power generation system to improve the system cycle efficiency.

[0005] To achieve the above object, the present invention provides the following technical solutions: In a first aspect, an embodiment of the present invention provides a compressed air energy storage compression waste heat recovery system, characterized in that it includes a compressor unit, a compression side heat exchange system, a cooler, an expansion unit, an expansion side heat exchange system, a salt cavern, a low temperature heat storage device, a high temperature heat storage device, a motor, a generator, and an organic working fluid centripetal turbine power generation system; The compressor unit is connected to the salt cavern, the low-temperature heat storage device, and the high-temperature heat storage device through a compression side heat exchange system and a cooler, and the motor is connected to the compressor unit through a shaft; The expansion unit is connected to the salt cavern, the low-temperature heat storage device, and the high-temperature heat storage device through an expansion-side heat exchange system, and the generator is connected to the expansion unit through a shaft; The organic working fluid centripetal turbine power generation system is connected to the compressor unit through a cooler, and uses the organic working fluid R123 as a medium to convert thermal energy into electrical energy; The compression side heat exchange system is used for heat exchange between the outlet air of the compressor unit and the cooling water of the low-temperature heat storage device; The expansion side heat exchange system is used for heat exchange between the inlet air of the expansion unit and the hot water of the high temperature heat storage device; The cooler is used for exchanging heat between the air of the compressor unit and the organic working medium cooled by the compression side heat exchange system and the organic working medium R123 of the centripetal turbine power generation system.

[0006] In a second aspect, an embodiment of the present invention provides a compressed air energy storage compression waste heat recovery system, characterized in that the compressor unit adopts four-stage compression, including a primary compressor, a secondary compressor, a third compressor, a fourth compressor, a primary compression side heat exchange system, a secondary compression side heat exchange system, a third compression side heat exchange system, a primary cooler, a secondary cooler, a third cooler, and a fourth cooler; the expansion unit adopts three-stage expansion, including a primary expander, a secondary expander, a third expander, a primary expansion side heat exchange system, a secondary expansion side heat exchange system, and a third expansion side heat exchange system; the organic working fluid centripetal turbine power generation system includes an organic working fluid centripetal turbine, an organic working fluid centripetal turbine generator, a condenser, and an organic working fluid circulating pump; The outlet of the organic working fluid circulation pump is connected to the compressor unit through the primary cooler, the secondary cooler, the tertiary cooler, and the quaternary cooler. The outlet of the quaternary cooler is connected to the inlet of the organic working fluid centripetal turbine. The organic working fluid centripetal turbine drives the organic working fluid centripetal turbine generator to generate electricity. The outlet of the organic working fluid centripetal turbine is connected to the condenser. The outlet of the condenser is connected to the organic working fluid circulation pump. The inlet of the first-stage compressor is connected to the atmosphere, the outlet of the first-stage compressor is connected to the inlet of the second-stage compressor through the first-stage compression side heat exchange system, the first-stage cooler, the outlet of the second-stage compressor is connected to the inlet of the third-stage compressor through the second-stage compression side heat exchange system, the second-stage cooler, the outlet of the third-stage compressor is connected to the inlet of the fourth-stage compressor through the third-stage compression side heat exchange system, the third-stage cooler, and the outlet of the fourth-stage compressor is connected to the salt cavern through the fourth-stage cooler, the outlet of the salt cavern is connected to the inlet of the first-stage expander through the first-stage expansion side heat exchange system, the outlet of the first-stage expander is connected to the inlet of the second-stage expander through the second-stage expansion side heat exchange system, the outlet of the second-stage expander is connected to the inlet of the third-stage expander through the third-stage expansion side heat exchange system, the outlet of the third-stage expander is discharged into the atmosphere, the first-stage expander, the second-stage expander, and the third-stage expander are connected to the generator shaft to drive the generator to generate electricity.

[0007] In a third aspect, an embodiment of the present invention provides a method for recovering compressed air energy storage and compressed waste heat, characterized in that it includes an energy storage process and an energy release process. During the energy storage process, the motor drives a first-stage compressor, a second-stage compressor, a third-stage compressor, and a fourth-stage compressor through a shaft connection. The inlet of the first-stage compressor is air, and the outlet is connected to a first-stage compression side heat exchange system. The outlet of the first-stage compression side heat exchange system is connected to a first-stage cooler, and the outlet of the first-stage cooler is connected to the inlet of the second-stage compressor, and the outlet of the second-stage compressor is connected to the second-stage compression side heat exchange system. The outlet of the second-stage compression side heat exchange system is connected to the second cooler, and the outlet of the second cooler is connected to the inlet of the third-stage compressor, and the outlet of the third-stage compressor is connected to the third-stage compression side heat exchange system. The outlet of the third-stage compression side heat exchange system is connected to the third-stage compressor. The outlet of the third-stage cooler is connected to the inlet of the fourth-stage compressor, the outlet of the fourth-stage compressor is connected to the fourth-stage cooler, and the outlet of the fourth-stage cooler is connected to the salt cavern. The organic working fluid R123 of the organic working fluid centripetal turbine power generation system is heated to 50±5℃ through the first-stage cooler, the second-stage cooler and the third-stage cooler connected in parallel, and then the organic working fluid R123 is heated to 120±5℃ through the fourth-stage cooler. The organic working fluid R123 enters the organic working fluid centripetal turbine power generation system to convert low-quality heat into electrical energy, which can provide part of the electrical energy for the plant power system of the compressed air energy storage power station and the first-stage compressor, the second-stage compressor, the third-stage compressor and the fourth-stage compressor, which can directly reduce the grid-connected power during the energy storage process, thereby effectively improving the overall efficiency of the compressed air energy storage system.

[0008] During the energy release process, air enters the first-stage expansion side heat exchange system from the salt cavern, the outlet of the first-stage expansion side heat exchange system is connected to the first-stage expander, the outlet of the first-stage expander is connected to the second-stage expansion side heat exchange system, the outlet of the second-stage expansion side heat exchange system is connected to the second-stage expander, the outlet of the second-stage expander is connected to the third-stage expansion side heat exchange system, the outlet of the third-stage expansion side heat exchange system is connected to the third-stage expander, the outlet of the third-stage expander is discharged into the atmosphere, the first-stage expander, the second-stage expander, and the third-stage expander are connected to the generator shaft to drive the generator to generate electricity.

[0009] In a fourth aspect, the compressed air energy storage compression heat recovery method as described above is applied, characterized in that the working fluid used in the organic working fluid centripetal turbine power generation system is the refrigerant R123, the Chinese name is trifluorodichloroethane, and the molecular formula is CF3CHCl2 (it has the advantage of low saturation temperature and can effectively utilize low-quality heat). The parameters of the organic working fluid R123 include mass flow rate and temperature after entering the cooler. The mass flow rate of the organic working fluid R123 is adjusted to make the temperature after the cooler meet the requirements.

[0010] In a fifth aspect, the compressed air energy storage compression waste heat recovery method as described above is applied, characterized in that it comprises the following steps: The low-quality compression heat refers to the heat of 60±5°C at the inlet of the cooler of the first-stage compressor, the second-stage compressor, and the third-stage compressor, and the heat of 130±5°C at the outlet of the fourth-stage compressor.During the energy storage process, the air enters the first-stage compressor and is compressed to produce high-temperature compressed air at 195±5℃. The high-temperature compressed air at 195±5℃ at the outlet of the first-stage compressor is cooled to 60±5℃ through the first-stage compression side heat exchange system, and then cooled to 40±5℃ through the first-stage cooler; the 40±5℃ air at the outlet of the first-stage cooler enters the inlet of the second-stage compressor and is compressed to produce high-temperature compressed air at 195±5℃. The high-temperature compressed air at 195±5℃ at the outlet of the second-stage compressor is cooled to 60±5℃ through the second-stage compression side heat exchange system, and then cooled to 40±5℃ through the second-stage cooler; the 40±5℃ air at the outlet of the second-stage cooler enters the inlet of the third-stage compressor and is compressed to produce 195±5℃ The high-temperature compressed air at the outlet of the three-stage compressor is cooled to 60±5℃ through the three-stage compression side heat exchange system, and then cooled to 40±5℃ through the three-stage cooler; the 40±5℃ air at the outlet of the three-stage cooler enters the inlet of the four-stage compressor and is compressed to produce 130±5℃ high-temperature compressed air. The 130±5℃ compressed air at the outlet of the four-stage compressor is cooled to 50±5℃ through the four-stage cooler and then enters the salt cavern; the heat exchange end difference of the first-stage compression side heat exchange system, the second-stage compression side heat exchange system, the three-stage compression side heat exchange system, the first-stage cooler, the second-stage cooler, the third-stage cooler, and the fourth-stage cooler is 10℃-15℃; the 50±5℃ cold water in the low-temperature heat storage device passes through the first-stage compressor The high-temperature hot water heated to 180±5℃ by the contraction-side heat exchange system, the secondary compression-side heat exchange system, and the tertiary compression-side heat exchange system flows into the high-temperature heat storage device for storage and is used to heat the inlet air of the expander; the organic working fluid R123 at 30±5℃ is heated to 50±5℃ by the first-stage cooler, the second-stage cooler, and the third-stage cooler connected in parallel, and then the organic working fluid R123 is heated to 120±5℃ by the fourth-stage cooler and enters the organic working fluid centripetal turbine to do work; in the energy release process, the compressed air is heated by the first-stage expansion-side heat exchange system, the second-stage expansion-side heat exchange system, and the third-stage expansion-side heat exchange system, and then enters the first-stage expander, the second-stage expander, and the third-stage expander to drive the generator to generate electricity; the organic working fluid R123 is connected in parallel The connected first-stage cooler, second-stage cooler and third-stage cooler are heated to 50±5℃, and then the organic working fluid R123 is heated to 120±5℃ through the fourth-stage cooler and enters the organic working fluid centripetal turbine to perform work, driving the organic working fluid centripetal turbine generator to generate electricity, thereby recycling the 60±5℃ low-quality heat in the first-stage compressor, second-stage compressor and third-stage compressor coolers and the 130±5℃ low-quality heat in the fourth-stage compressor outlet heat exchanger and converting them into electrical energy, which can provide part of the electricity for the compressed air energy storage power station power system and the first-stage compressor, second-stage compressor, third-stage compressor and fourth-stage compressor, which can directly reduce the grid-connected electricity in the energy storage process, thereby effectively improving the overall efficiency of the compressed air energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0012] Figure 1 It is a schematic diagram of the system structure of the present invention.

[0013] Figure 1 In the figure: 1- is a primary compressor, 2- is a secondary compressor, 3- is a tertiary compressor, 4- is a quaternary compressor, 5- is a salt cavern, 6- is a primary expander, 7- is a secondary expander, 8- is a tertiary expander, 9- is a primary cooler, 10- is a secondary cooler, 11- is a tertiary cooler, 12- is a quaternary cooler, 13- is a primary compression side heat exchange system, 14- is a secondary compression side heat exchange system, 15- is a tertiary compression side heat exchange system, 16- is a primary expansion side heat exchange system, 17- is a secondary expansion side heat exchange system, 18- is a tertiary expansion side heat exchange system, 19- is a low-temperature heat storage device, 20- is a high-temperature heat storage device, 21- is an organic working fluid circulation pump, 22- is a condenser, 23- is an organic working fluid centripetal turbine generator, 24- is an organic working fluid centripetal turbine, 25- is an electric motor, and 26- is a generator. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present invention will be described below in conjunction with the accompanying drawings in the embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0015] A typical compressed air energy storage system compresses air at normal temperature and pressure into high-pressure air. During the energy storage process of a typical compressed air energy storage system, the cold water of the low-temperature heat storage device cools the outlet air of the first-stage compressor, the second-stage compressor, and the third-stage compressor from 195±5℃ to 60±5℃ through the first-stage compression side heat exchange system, the second-stage compression side heat exchange system, and the third-stage compression side heat exchange system, and then uses external cooling water to further cool it to 40±5℃ through the cooler before entering the inlet of the next compressor; the fourth-stage compressor cannot be equipped with a heat exchanger to recover the compression heat due to the low outlet air temperature, and uses external cooling water to cool the air to 40±5℃ through the cooler before entering the salt cavern; the cold water of the low-temperature heat storage device is heated from 50±5℃ to 180±5℃ through the first-stage compression side heat exchange system, the second-stage compression side heat exchange system, and the third-stage compression side heat exchange system, and flows into the high-temperature heat storage device for storage to heat the expander inlet air temperature; however, the heat of 60±5℃ at the inlet of the cooler of the first-stage compressor, the second-stage compressor, and the third-stage compressor and the heat of 130±5℃ at the outlet of the fourth-stage compressor are not used.

[0016] The present invention improves the typical compressed air energy storage system. On the basis of the compressed air energy storage system, an organic working fluid centripetal turbine power generation system is added to recycle the unused low-quality compression heat. During the energy storage process, the air compressed by the compressor is heated to about 120±5°C through the first cooler 9, the second cooler 10, the third cooler 11 and the fourth cooler 12 after heat exchange. The organic working fluid R123 is converted into electrical energy through the organic working fluid centripetal turbine, thereby recycling the low-grade waste heat originally discharged by the first cooler 9, the second cooler 10, the third cooler 11 and the fourth cooler 12, realizing the efficient use of energy and improving the system cycle efficiency.

[0017] like Figure 1 As shown, the compressed air energy storage compression heat recovery system provided by the present invention includes a primary compressor 1, a secondary compressor 2, a three-stage compressor 3, a four-stage compressor 4, a salt cavern 5, a primary expander 6, a secondary expander 7, a three-stage expander 8, a primary cooler 9, a secondary cooler 10, a three-stage cooler 11, a four-stage cooler 12, a primary compression side heat exchange system 13, a secondary compression side heat exchange system 14, a three-stage compression side heat exchange system 15, a primary expansion side heat exchange system 16, a secondary expansion side heat exchange system 17, a three-stage expansion side heat exchange system 18, a low-temperature heat storage device 19, a high-temperature heat storage device 20, an organic working fluid circulation pump 21, a condenser 22, an organic working fluid centripetal turbine generator 23, an organic working fluid centripetal turbine 24, an electric motor 25, and a generator 26.

[0018] During the energy storage process, the motor 25 drives the first-stage compressor 1, the second-stage compressor 2, the third-stage compressor 3, and the fourth-stage compressor 4 through the shaft connection. The inlet of the first-stage compressor 1 is air, and the outlet is connected to the first-stage compression side heat exchange system 13. The outlet of the first-stage compression side heat exchange system 13 is connected to the first-stage cooler 9. The outlet of the first-stage cooler 9 is connected to the inlet of the second-stage compressor 2. The outlet of the second-stage compressor 2 is connected to the second-stage compression side heat exchange system 14. The outlet of the second-stage compression side heat exchange system 14 is connected to the second-stage cooler 10. The outlet of the second-stage cooler 10 is connected to the inlet of the third-stage compressor 3. The outlet of the third-stage compressor 3 is connected to the third-stage compression side heat exchange system 15. The outlet of the heat exchange system 15 is connected to the tertiary cooler 11, the outlet of the tertiary cooler 11 is connected to the inlet of the fourth-stage compressor 4, the outlet of the fourth-stage compressor 4 is connected to the fourth-stage cooler 12, and the outlet of the fourth-stage cooler 12 is connected to the salt cavern 5; the air enters the first-stage compressor 1 and is compressed to produce high-temperature compressed air of 195±5℃, the high-temperature compressed air of 195±5℃ at the outlet of the first-stage compressor 1 is cooled to 60±5℃ through the first-stage compression side heat exchange system 13, and then cooled to 40±5℃ through the first-stage cooler 9; the 40±5℃ air at the outlet of the first-stage cooler 9 enters the inlet of the second-stage compressor 2 and is compressed to produce high-temperature compressed air of 195±5℃, the second-stage compressor The 195±5℃ high-temperature compressed air at the outlet of the compressor 2 is cooled to 60±5℃ through the second compression side heat exchange system 14, and then cooled to 40±5℃ through the second cooler 10; the 40±5℃ air at the outlet of the second cooler 10 enters the inlet of the third compressor 3 and is compressed to produce 195±5℃ high-temperature compressed air. The 195±5℃ high-temperature compressed air at the outlet of the third compressor 3 is cooled to 60±5℃ through the third compression side heat exchange system 15, and then cooled to 40±5℃ through the third cooler 11; the 40±5℃ air at the outlet of the third cooler 11 enters the inlet of the fourth compressor 4 and is compressed to produce 130±5℃ high-temperature compressed air. The 130±5℃ compressed air at the outlet of the four-stage compressor 4 is cooled to 50±5℃ by the four-stage cooler 12 and then enters the salt cavern 5; the heat exchange end difference of the first-stage compression side heat exchange system 13, the second-stage compression side heat exchange system 14, the third-stage compression side heat exchange system 15, the first-stage cooler 9, the second-stage cooler 10, the third-stage cooler 11, and the fourth-stage cooler 12 is 10℃-15℃; the 50±5℃ cold water in the low-temperature heat storage device 19 is heated to 180±5℃ high-temperature hot water by the first-stage compression side heat exchange system 13, the second-stage compression side heat exchange system 14, and the third-stage compression side heat exchange system 15, and flows into the high-temperature heat storage device 20 for storage, and is used to heat the inlet air of the expander;The organic working fluid R123 at 30±5℃ is heated to 50±5℃ by the first-stage cooler 9, the second-stage cooler 10, and the third-stage cooler 11 connected in parallel, and then heated to 120±5℃ by the fourth-stage cooler 12, and enters the organic working fluid centripetal turbine 24 to do work, driving the organic working fluid centripetal turbine generator 23 to generate electricity, converting low-quality heat into electrical energy, which can provide part of the electrical energy for the compressed air energy storage power station power system and the first-stage compressor 1, the second-stage compressor 2, the third-stage compressor 3, and the fourth-stage compressor 4, and can directly reduce the amount of electricity off the grid during the energy storage process, thereby effectively improving the overall efficiency of the compressed air energy storage system. The outlet of the organic working fluid centripetal turbine 24 is connected to the condenser 22, and the outlet of the condenser 22 is connected to the organic working fluid circulation pump 21; During the energy release process, air enters the primary expansion side heat exchange system 16 from the salt cavern 5, the outlet of the primary expansion side heat exchange system 16 is connected to the primary expander 6, the outlet of the primary expander 6 is connected to the secondary expansion side heat exchange system 17, the outlet of the secondary expansion side heat exchange system 17 is connected to the secondary expander 7, the outlet of the secondary expander 7 is connected to the tertiary expansion side heat exchange system 18, the outlet of the tertiary expansion side heat exchange system 18 is connected to the tertiary expander 8, the outlet of the tertiary expander 8 is discharged into the atmosphere, the primary expander 6, the secondary expander 7, and the tertiary expander 8 are connected to the shaft of the generator 26, driving the generator 26 to generate electricity.

[0019] The above description is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A compressed air energy storage compression waste heat recovery system, characterized in that: It includes a compressor unit, a compression side heat exchange system, a cooler, an expansion unit, an expansion side heat exchange system, a salt cavern, a low temperature heat storage device, a high temperature heat storage device, a motor, a generator, and an organic working fluid centripetal turbine power generation system; The compressor unit is connected to the salt cavern, the low-temperature heat storage device, and the high-temperature heat storage device through a compression side heat exchange system and a cooler, and the motor is connected to the compressor unit through a shaft; The expansion unit is connected to the salt cavern, the low-temperature heat storage device, and the high-temperature heat storage device through an expansion-side heat exchange system, and the generator is connected to the expansion unit through a shaft; The organic working fluid centripetal turbine power generation system is connected to the compressor unit through a cooler, and uses the organic working fluid R123 as a medium to convert thermal energy into electrical energy; The compression side heat exchange system is used for heat exchange between the outlet air of the compressor unit and the cooling water of the low-temperature heat storage device; The expansion side heat exchange system is used for heat exchange between the inlet air of the expansion unit and the hot water of the high temperature heat storage device; The cooler is used for exchanging heat between the air of the compressor unit and the organic working medium cooled by the compression side heat exchange system and the organic working medium R123 of the centripetal turbine power generation system.

2. A compressed air energy storage and compression waste heat recovery system according to claim 1, characterized in that: The compressor unit adopts four-stage compression, including a primary compressor, a secondary compressor, a third compressor, and a fourth compressor; the compression side heat exchange system includes a primary compression side heat exchange system, a secondary compression side heat exchange system, and a third compression side heat exchange system; the cooler includes a primary cooler, a secondary cooler, a third cooler, and a fourth cooler; the expansion unit adopts three-stage expansion, including a primary expander, a secondary expander, and a third expander; the expansion side heat exchange system includes a primary expansion side heat exchange system, a secondary expansion side heat exchange system, and a third expansion side heat exchange system; the organic working fluid centripetal turbine power generation system includes an organic working fluid centripetal turbine, an organic working fluid centripetal turbine generator, a condenser, and an organic working fluid circulating pump; The outlet of the organic working fluid circulation pump is connected to the compressor unit through the primary cooler, the secondary cooler, the tertiary cooler, and the quaternary cooler. The outlet of the quaternary cooler is connected to the inlet of the organic working fluid centripetal turbine. The organic working fluid centripetal turbine drives the organic working fluid centripetal turbine generator to generate electricity. The outlet of the organic working fluid centripetal turbine is connected to the condenser. The outlet of the condenser is connected to the organic working fluid circulation pump. The inlet of the first-stage compressor is connected to the atmosphere, the outlet of the first-stage compressor is connected to the inlet of the second-stage compressor through the first-stage compression side heat exchange system, the first-stage cooler, the outlet of the second-stage compressor is connected to the inlet of the third-stage compressor through the second-stage compression side heat exchange system, the second-stage cooler, the outlet of the third-stage compressor is connected to the inlet of the fourth-stage compressor through the third-stage compression side heat exchange system, the third-stage cooler, and the outlet of the fourth-stage compressor is connected to the salt cavern through the fourth-stage cooler, the outlet of the salt cavern is connected to the inlet of the first-stage expander through the first-stage expansion side heat exchange system, the outlet of the first-stage expander is connected to the inlet of the second-stage expander through the second-stage expansion side heat exchange system, the outlet of the second-stage expander is connected to the inlet of the third-stage expander through the third-stage expansion side heat exchange system, the outlet of the third-stage expander is discharged into the atmosphere, the first-stage expander, the second-stage expander, and the third-stage expander are connected to the generator shaft to drive the generator to generate electricity.

3. A method for recovering waste heat from compressed air energy storage, characterized in that: The energy storage process includes an energy storage process and an energy release process. In the energy storage process, the motor drives a primary compressor, a secondary compressor, a tertiary compressor, and a quaternary compressor through a shaft connection. The inlet of the primary compressor is air, and the outlet is connected to a primary compression side heat exchange system. The outlet of the primary compression side heat exchange system is connected to a primary cooler. The outlet of the primary cooler is connected to the inlet of the secondary compressor. The outlet of the secondary compressor is connected to the secondary compression side heat exchange system. The outlet of the secondary compression side heat exchange system is connected to the secondary cooler. The outlet of the secondary cooler is connected to the inlet of the tertiary compressor. The outlet of the tertiary compressor is connected to the tertiary compression side heat exchange system. The outlet of the tertiary compression side heat exchange system is connected to the tertiary cooler. The outlet of the tertiary cooler is connected to the quaternary compressor. The inlet of the compressor and the outlet of the four-stage compressor are connected to the four-stage cooler, and the outlet of the four-stage cooler is connected to the salt cavern. The organic working fluid R123 of the organic working fluid centripetal turbine power generation system is heated to 50±5℃ through the first-stage cooler, the second-stage cooler and the third-stage cooler connected in parallel, and then the organic working fluid R123 is heated to 120±5℃ through the fourth-stage cooler. The organic working fluid R123 enters the organic working fluid centripetal turbine power generation system to convert low-quality heat into electrical energy, which can provide part of the electrical energy for the plant power system of the compressed air energy storage power station and the first-stage compressor, the second-stage compressor, the third-stage compressor and the fourth-stage compressor, which can directly reduce the grid-connected power during the energy storage process, thereby effectively improving the overall efficiency of the compressed air energy storage system; During the energy release process, air enters the first-stage expansion side heat exchange system from the salt cavern, the outlet of the first-stage expansion side heat exchange system is connected to the first-stage expander, the outlet of the first-stage expander is connected to the second-stage expansion side heat exchange system, the outlet of the second-stage expansion side heat exchange system is connected to the second-stage expander, the outlet of the second-stage expander is connected to the third-stage expansion side heat exchange system, the outlet of the third-stage expansion side heat exchange system is connected to the third-stage expander, the outlet of the third-stage expander is discharged into the atmosphere, the first-stage expander, the second-stage expander, and the third-stage expander are connected to the generator shaft to drive the generator to generate electricity.

4. The compressed air energy storage compression heat recovery method as claimed in claim 3 is characterized in that: The working fluid used in the organic working fluid centripetal turbine power generation system is refrigerant R123, whose Chinese name is trifluorodichloroethane and whose molecular formula is CF3CHCl2. The parameters of the organic working fluid R123 include mass flow rate and temperature after entering the cooler. The temperature after the cooler can meet the requirements by adjusting the mass flow rate of the organic working fluid R123.

5. The method for recovering waste heat from compressed air energy storage according to claim 3, characterized in that: The steps include: The low-quality compression heat refers to the heat of 60±5℃ at the inlet of the cooler of the first-stage compressor, the second-stage compressor, and the third-stage compressor, and the heat of 130±5℃ at the outlet of the fourth-stage compressor. In the energy storage process, the air enters the first-stage compressor and is compressed to generate high-temperature compressed air of 195±5℃. The high-temperature compressed air of 195±5℃ at the outlet of the first-stage compressor is cooled to 60±5℃ through the first-stage compression side heat exchange system, and then cooled to 40±5℃ through the first-stage cooler; the 40±5℃ air at the outlet of the first-stage cooler enters the inlet of the second-stage compressor and is compressed to generate high-temperature compressed air of 195±5℃. The high-temperature compressed air of 195±5℃ at the outlet of the second-stage compressor is cooled to 60±5℃ through the second-stage compression side heat exchange system, and then cooled to 40±5℃ through the second-stage cooler; the 40±5℃ air at the outlet of the second-stage cooler enters The high-temperature compressed air of 195±5℃ is generated after compression at the inlet of the three-stage compressor. The high-temperature compressed air of 195±5℃ at the outlet of the three-stage compressor is cooled to 60±5℃ through the three-stage compression side heat exchange system, and then cooled to 40±5℃ through the three-stage cooler; the 40±5℃ air at the outlet of the three-stage cooler enters the inlet of the four-stage compressor and is compressed to generate high-temperature compressed air of 130±5℃. The compressed air of 130±5℃ at the outlet of the four-stage compressor is cooled to 50±5℃ through the four-stage cooler and then enters the salt cavern; the first-stage compression side heat exchange system, the second-stage compression side heat exchange system, the third-stage compression side heat exchange system, the first-stage cooler, the second-stage cooler, the third-stage cooler The heat exchange end difference of the cooler and the four-stage cooler is 10℃-15℃; the 50±5℃ cold water in the low-temperature heat storage device is heated to 180±5℃ high-temperature hot water through the first-stage compression side heat exchange system, the second-stage compression side heat exchange system, and the third-stage compression side heat exchange system, and flows into the high-temperature heat storage device for storage, and is used to heat the inlet air of the expander; the 30±5℃ organic working fluid R123 is heated to 50±5℃ through the first-stage cooler, the second-stage cooler, and the third-stage cooler connected in parallel, and then the organic working fluid R123 is heated to 120±5℃ through the fourth-stage cooler, and enters the organic working fluid centripetal turbine to do work, driving the organic working fluid centripetal turbine generator to generate electricity, thereby the first-stage compressor The 60±5℃ low-quality heat in the cooler of the compressor, the secondary compressor, and the 3rd compressor, as well as the 130±5℃ low-quality heat at the outlet heat exchanger of the 4th compressor are recycled and converted into electrical energy, which can provide part of the electricity for the power supply system of the compressed air energy storage power station and the primary compressor, the secondary compressor, the 3rd compressor, and the 4th compressor, which can directly reduce the amount of electricity offline during the energy storage process, thereby effectively improving the overall efficiency of the compressed air energy storage system; in the energy release process, the compressed air is heated by the primary expansion side heat exchange system, the secondary expansion side heat exchange system, and the 3rd expansion side heat exchange system, and then enters the primary expander, the secondary expander, and the 3rd expander to drive the generator to generate electricity.

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