Heat pump coupling compressed air energy storage system

Abstract

The utility model relates to the technical field of energy storage, in particular to a heat pump coupling compressed air energy storage system which comprises a compressed air energy storage module, a fused salt heat storage module and a heat pump module. Wherein the compressed air energy storage module comprises a compressor unit, an expansion unit and a storage part; the fused salt heat storage module comprises a cold salt tank, a hot salt tank, a fused salt heater and an air heater; the heat pump module comprises a second compressor, a second expansion machine and a heat absorber. Aiming at the technical problem that the traditional compressed air energy storage technology has defects, the heat pump module, the compressed air energy storage module and the fused salt heat storage module are combined, so that the heat storage temperature of the heat storage system is greatly improved, the power generation efficiency is improved, and the investment cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to a heat pump coupled compressed air energy storage system. Background Art

[0002] Compressed-Air Energy Storage (CAES) is a new energy storage technology that uses compressed air for energy storage. According to whether it depends on fossil fuel combustion during the energy release stage, it can be divided into combustion-complemented CAES and non-combustion-complemented CAES. Combustion-complemented CAES needs to use fossil energy such as natural gas for combustion. Under the same scale and capacity, the power conversion efficiency of non-combustion-complemented CAES is higher than that of combustion-complemented CAES, and it does not use fossil fuels and has no gas pollutant emissions. It is an environmentally friendly large-capacity energy storage technology. Non-combustion-complemented CAES is equipped with a heat storage system, which stores the heat energy obtained by air during charging in a certain medium through a heat exchanger, and then transfers this part of heat energy to the air through the heat exchanger during energy release, turning it into high-temperature and high-pressure air to do work outward through a turbine. Currently, the commonly used heat storage media for CAES are water and molten salt. Water is used for heat storage in the low-temperature section (below 190°C), and molten salt is used for heat storage in the high-temperature section (above 190°C). The main problems of the two heat storage systems are as follows: (1) The system operation is complex; (2) Pressurized water heat storage needs to maintain a saturated pressure to prevent heat transfer deterioration caused by flashing, etc.; (3) The cost of the pressurized water heat storage tank is very high; (4) The heat storage temperature is low, and the discharge efficiency is also low. Summary of the Utility Model

[0003] Aiming at the technical problem of the defects existing in the traditional compressed air energy storage technology, the utility model provides a heat pump coupled compressed air energy storage system, which combines a heat pump module, a compressed air energy storage module and a molten salt heat storage module, greatly improves the heat storage temperature of the heat storage system, improves the power generation efficiency, and reduces the investment cost.

[0004] The technical solution provided by the present utility model is as follows: A heat pump coupled compressed air energy storage system, comprising a compressed air energy storage module, a molten salt heat storage module, and a heat pump module; the compressed air energy storage module includes a compressor unit, an expander unit, and a storage part for storing gaseous or liquid gas working medium, the inlet of the compressor unit is communicated with the outside atmosphere, the outlet of the compressor unit is communicated with the inlet of the storage part, the inlet of the expander unit is communicated with the outlet of the storage part, and the outlet of the expander unit is communicated with the outside atmosphere; the compressor unit includes a plurality of first compressors that are connected in series front and back, and the expander unit includes a plurality of first expanders that are connected in series front and back; the molten salt heat storage module includes a cold salt tank, a hot salt tank, a molten salt heater, and an air heater, the air heater is arranged between adjacent first expanders and between the adjacent storage part and the first expander, the working medium flowing out of the cold salt tank absorbs heat on the low-temperature side of the molten salt heater and then flows into the hot salt tank, and the working medium flowing out of the hot salt tank is split and each independently flows through the high-temperature side of each air heater to release heat and then flows back to the cold salt tank; the heat pump module includes a second compressor, a second expander, and an absorber, the absorber is arranged between adjacent first compressors and between the adjacent first compressor and the storage part, the working medium flowing out of the second expander is split and each independently flows through the low-temperature side of each absorber to absorb heat and then flows into the second compressor, and the working medium flowing out of the second compressor flows through the high-temperature side of the molten salt heater to release heat and then flows back to the second expander.

[0005] Optionally, it further includes a heat pump recuperator, the working medium flowing out of the low-temperature side of the absorber absorbs heat on the low-temperature side of the heat pump recuperator and then flows into the second compressor, and the working medium flowing out of the high-temperature side of the molten salt heater releases heat on the high-temperature side of the heat pump recuperator and then flows into the second expander.

[0006] Optionally, it further includes an air recuperator, the working medium flowing out of the outlet of the expander unit releases heat on the high-temperature side of the air recuperator and then flows to the outside atmosphere, and the working medium flowing out of the storage part absorbs heat on the low-temperature side of the air recuperator and then flows to the low-temperature side of the air heater.

[0007] Optionally, the storage part is a gas storage chamber, the outlet of the compressor unit is communicated with the inlet of the gas storage chamber, the inlet of the expander unit is communicated with the outlet of the gas storage chamber, and the absorber is arranged between adjacent first compressors and between the adjacent first compressor and the gas storage chamber.

[0008] Optionally, the storage section includes a liquid storage chamber, a liquefier, an evaporator and a cryogenic tank, the working fluid flowing out of the outlet of the heat absorber flows through the high-temperature side of the liquefier to be liquefied and then flows into the liquid storage chamber, the liquefied working fluid in the liquid storage chamber flows through the low-temperature side of the evaporator to absorb heat and then flows into the low-temperature side of the air heater adjacent to the storage section; the high-temperature side inlet of the evaporator and the low-temperature side outlet of the liquefier are respectively connected to the circulating gas environment, the air flows through the high-temperature side of the evaporator to store cold and then flows into the cryogenic tank, the air in the cryogenic tank flows through the low-temperature side of the liquefier to absorb heat and then flows into the circulating gas environment.

[0009] Optionally, the working fluid in the heat pump module includes one or more combinations of air, argon, nitrogen and helium.

[0010] Optionally, the compressed air energy storage module further includes a first motor, the compressor unit includes a first transmission shaft, the first compressors share the first transmission shaft, and the first motor is in transmission connection with the first transmission shaft.

[0011] Optionally, the expander unit includes a second transmission shaft, the first expander shares the second transmission shaft, and the second transmission shaft is used for transmission connection with an output device.

[0012] Optionally, the heat pump module further includes a second motor and a third transmission shaft, the second compressor and the second expander share the third transmission shaft, and the second motor is in transmission connection with the third transmission shaft.

[0013] Beneficial Effects

[0014] The technical solution provided by the utility model has the following beneficial effects compared with the prior art: in order to solve the technical problems existing in the traditional compressed air energy storage technology, the utility model combines the heat pump module, the compressed air energy storage module and the molten salt heat storage module, which greatly improves the heat storage temperature of the heat storage system, improves the power generation efficiency and reduces the investment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is one of the structural schematic diagrams of a heat pump coupled compressed air energy storage system proposed in an embodiment of the utility model.

[0016] Figure 2 This is a second structural schematic diagram of a heat pump coupled compressed air energy storage system proposed in an embodiment of the utility model. DETAILED DESCRIPTION

[0017] In order to further understand the content of the utility model, the utility model is described in detail in conjunction with the accompanying drawings and embodiments.

[0018] The present application will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the relevant utility model and do not limit the utility model. Additionally, it should be noted that for the convenience of description, only the parts related to the utility model are shown in the drawings. The terms "first", "second", etc. used in the present utility model are set for the convenience of describing the technical solution of the present utility model and have no specific limiting effect. They are all general references and do not constitute a limiting effect on the technical solution of the present utility model. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Unless otherwise clearly defined and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. Multiple technical solutions in the same embodiment, as well as multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions without contradiction or conflict, and all are within the scope of protection required by the present utility model.

[0019] Combined with the attached Figure 1 and 2 , this embodiment proposes a heat pump coupled compressed air energy storage system, which includes a compressed air energy storage module, a molten salt heat storage module, and a heat pump module.

[0020] The compressed air energy storage module in this embodiment includes a compressor unit, an expander unit, and a storage part. The inlet of the compressor unit is connected to the outside atmosphere, the outlet of the compressor unit is connected to the inlet of the storage part, the inlet of the expander unit is connected to the outlet of the storage part, and the outlet of the expander unit is connected to the outside atmosphere. In an alternative embodiment, the storage part can adopt a gas storage chamber 14 that can directly store the gas working medium, or a storage device that can cool and liquefy the gas working medium.

[0021] Among them, the compressor group includes a plurality of first compressors 1 connected front to back between adjacent ones. In the present embodiment, two first compressors 1 are provided. It is conceivable that more than two first compressors 1 may be provided to form a multi-stage compressor group. In one embodiment, the compressed air energy storage module further includes a first motor 4, the compressor group includes a first transmission shaft, the first compressors 1 share the first transmission shaft, and the first motor 4 is connected to the first transmission shaft in a transmission manner, thereby achieving the synchronous operation of the multi-stage compressor group driven by a first motor 4.

[0022] The expansion unit includes a plurality of first expansion machines 3 connected front to back between adjacent ones. In this embodiment, two are set as an example. It is conceivable that more than two first expansion machines 3 can also be set to form a multi-stage expansion unit. In one embodiment, the expansion unit includes a second transmission shaft, and the first expansion machines 3 share the second transmission shaft, and the second transmission shaft is used for transmission connection with the output device 6, thereby realizing the synchronous outward work of the multi-stage expansion unit through the shared transmission shaft.

[0023] It can be understood that, taking the air storage chamber 14 as the storage unit as an example, the main function of the compressed air energy storage module in this embodiment is to compress the ambient air through the compressor unit when the power consumption is low, and the generated high-pressure air is stored in the air storage chamber 14, and the high-pressure air is released during the peak power consumption, and the expansion unit is used to generate power. Similarly, in other embodiments, if the storage unit is a device that cools and liquefies the gas working medium and stores it, the air can be cooled, liquefied and stored during the low power consumption, and the liquefied air can be released during the peak power consumption, that is, the liquefied air is evaporated and reduced to high-pressure gaseous air, and then the expansion unit is used to generate power.

[0024] The molten salt thermal storage module in this embodiment includes a cold salt tank 15, a hot salt tank 16, a molten salt heater 12 and an air heater 8. The air heater 8 is arranged between adjacent first expanders 3 and between adjacent storage parts and the first expander 3. The working fluid flowing out of the cold salt tank 15 flows through the low-temperature side of the molten salt heater 12 to absorb heat and then flows into the hot salt tank 16. The working fluid flowing out of the hot salt tank 16 is split and flows separately through the high-temperature side of each air heater 8 to release heat and then flows back to the cold salt tank 15.

[0025] The heat pump module in this embodiment includes a second compressor 11, a second expander 10, and a heat absorber 5. The heat absorber 5 is disposed between adjacent first compressors 1 and between an adjacent first compressor 1 and the storage unit. The working medium discharged from the second expander 10 is split and each separately flows through the low-temperature side of each heat absorber 5 to absorb heat and then flows into the second compressor 11. The working medium discharged from the second compressor 11 flows through the high-temperature side of the molten salt heater 12 to release heat and then flows back to the second expander 10. In an alternative embodiment, the above-mentioned working medium includes one or a combination of air, argon, nitrogen, and helium. Further, in one embodiment, the heat pump module further includes a second motor 2 and a third transmission shaft. The second compressor 11 and the second expander 10 share the third transmission shaft, and the second motor 2 is drivingly connected to the third transmission shaft.

[0026] In this embodiment, a heat pump recuperator 13 is additionally provided in the heat pump module. The working medium discharged from the low-temperature side of the heat absorber 5 flows through the low-temperature side of the heat pump recuperator 13 to absorb heat and then flows into the second compressor 11, and the working medium discharged from the high-temperature side of the molten salt heater 12 flows through the high-temperature side of the heat pump recuperator 13 to release heat and then flows into the second expander 10. It can be understood that in other embodiments, the heat pump recuperator 13 may not be provided in the heat pump module.

[0027] In addition, in this embodiment, the compressed air energy storage module further includes an air recuperator 7. The working medium discharged from the outlet of the expansion unit flows through the high-temperature side of the air recuperator 7 to release heat and then flows to the outside atmosphere, and the working medium discharged from the storage unit flows through the low-temperature side of the air recuperator 7 to absorb heat and then flows to the low-temperature side of the air heater 8.

[0028] Based on the above structural description of the heat pump-coupled compressed air energy storage system, taking the gas storage chamber 14 that stores high-pressure gas as the storage unit as an example, the working principle of the heat pump-coupled compressed air energy storage system in this embodiment is as follows: During the low electricity consumption period, the compressed air energy storage module and the heat pump module are started. The compression unit in the compressed air energy storage module consumes electric energy to generate high-temperature and high-pressure gas. At the same time, since the second compressor 11 and the second expander 10 in the heat pump module are also in the working state, that is, the heat pump module consumes electric energy to generate high-temperature and high-pressure gas while driving the second expander 10 to work. The working medium discharged from the second expander 10 will be split and each separately flows through the low-temperature side of each heat absorber 5 to absorb heat and then flows into the second compressor 11.

[0029] In this process, for two adjacent stages of the first compressor 1 in the compressor unit, the high-temperature and high-pressure gas generated by the previous stage of the first compressor 1 will have its heat exchanged to the working medium of the heat pump module through the heat absorber 5, only the pressure is retained, and then it enters the inlet of the next stage of the first compressor 1. The heat of the high-temperature and high-pressure gas at the outlet of the next stage of the first compressor 1 will also be exchanged to the working medium of the heat pump module by the heat absorber 5, only the pressure is retained, and finally it enters the gas storage chamber 14. Theoretically, after each stage of the first compressor 1 does work, its outlet temperature is 100 - 350 °C, preferably designed to be 300 °C. Based on the above process, the gas at the outlet of the previous stage of the first compressor 1 passes through the heat absorber 5 and then enters the inlet of the next stage of the first compressor 1. For the next stage of the first compressor 1, its inlet temperature will be 0 - 50 °C, preferably 30 °C. Also, the inlet of the first stage of the first compressor 1 communicating with the atmosphere is at the ambient temperature. Therefore, the inlet temperature of each stage of the first compressor 1 can be maintained between 0 - 50 °C.

[0030] It can be understood that after the working medium at the outlet of the second expander 10 in the heat pump module absorbs the compression heat of the two stages of the first compressor 1, it will further pass through the second compressor 11 to utilize the compression heat of the first compressor 1 to heat the working medium circulating inside the heat pump module, and store the heat of the working medium in the molten salt heat storage module through the molten salt heater 12. For the heat pump module, the inlet temperature of the second expander 10 is at room temperature, the outlet temperature of the second expander 10 is 0 - 50 °C, the inlet temperature of the second compressor 11 is basically the same as the outlet temperature of the aforementioned first compressor 1, around 100 - 350 °C, and the outlet temperature of the second compressor 11 can reach 400 - 600 °C.

[0031] During the peak electricity consumption period, start the first expander 3 of the compressed air energy storage module and the molten salt heat storage module. The molten salt heat storage module uses the high-temperature molten salt flowing on the high-temperature side in the molten salt heater 12, uses the air heater 8, or uses the combination of the air recuperator 7 and the air heater 8 to heat the high-pressure air in the gas storage chamber 14 in sequence, and finally realizes external power generation through the connection between the first expander 3 and the output device 6. In this case, the inlet temperature of each stage of the first expander 3 is 400 - 600 °C, preferably designed to be 550 °C; the outlet temperature of each stage of the first expander 3 is 180 - 320 °C, preferably designed to be 300 °C.

[0032] It can be understood that the main function of the heat pump module in this embodiment is to absorb the compression heat of the two-stage first compressor 1 respectively, and increase the temperature through the second compressor 11, so as to transfer the heat to the molten salt thermal energy storage module for storage and utilization. In addition, the main function of the compressed air energy storage module in this embodiment is to compress ambient air during the low electricity consumption period, store the generated high-pressure air in the air storage chamber 14, release the high-pressure air during the high electricity consumption period, and generate electricity by the first expander 3 doing work. For the molten salt thermal energy storage module of this embodiment, during charging, electrical energy and compression heat are absorbed through the heat pump module, and the generated high-temperature molten salt is stored in the hot salt tank 16; during discharging, the low-temperature molten salt after the air heater 8 will flow back to the cold salt tank 15.

[0033] Based on the setting of the heat absorber 5, the outlet working fluid temperature of each stage of the first compressor 1 can be cooled, so as to ensure that the inlet air temperature of each stage of the first compressor 1 is not higher than the ambient temperature, greatly improving the compression efficiency of the first compressor 1. Thereby reducing the specification requirements for the selection of the first compressor 1, and thus reducing the equipment cost of the compressor. At the same time, after improving the compression efficiency of the first compressor 1, higher-pressure air can be easily obtained and stored in the air storage chamber 14, improving the efficiency of the compressed air energy storage module.

[0034] Similar to the above-mentioned implementation manner, in combination with the attached Figure 2 As shown, the storage part can also adopt a storage device or system capable of cooling and liquefying the gas working fluid. The following gives an example of an implementation manner: The storage part includes a liquid storage chamber 9, a liquefier 17, an evaporator 18, and a cryogenic tank 19. The working fluid flowing out of the outlet of the heat absorber 5 flows through the high-temperature side of the liquefier 17 and is liquefied and then flows into the liquid storage chamber 9. The liquefied working fluid in the liquid storage chamber 9 flows through the low-temperature side of the evaporator 18 to absorb heat and then flows into the low-temperature side of the air heater 8 adjacent to the storage part; the high-temperature side inlet of the evaporator 18 and the low-temperature side outlet of the liquefier 17 are respectively communicated with the circulating gas environment. Air flows through the high-temperature side of the evaporator 18 to store cold and then flows into the cryogenic tank 19. The air in the cryogenic tank 19 flows through the low-temperature side of the liquefier 17 to absorb heat and then flows into the circulating gas environment. Among them, the circulating gas environment includes the outside atmosphere, or a closed air chamber, or an external gas circulation pipeline.

[0035] Different from the above case where the gas storage chamber 14 is adopted, in this embodiment, the gaseous working medium discharged from the outlet of the heat absorber 5 is condensed into a liquid state by the liquefier 17 and stored in the liquid storage chamber 9. The cooling capacity of the liquefier 17 comes from the cryogenic tank 19. The cryogenic tank 19 is provided with a cold storage medium and has an initial cooling capacity, that is, the cryogenic tank 19 can be used as the refrigeration source of the liquefier 17. During the peak electricity consumption period, the liquid working medium in the liquid storage chamber 9 will flow to the evaporator 18. The evaporator 18 relies on the heat of the external atmosphere as the heat source to convert the liquid working medium flowing through the evaporator 18 into a gaseous working medium. The gaseous working medium can then pass through the air heater 8 and finally enter the expansion unit to perform external work. Generally, the gaseous working medium is air. Conceivably, a pressure reducing valve can be provided between the liquefier 17 and the liquid storage chamber 9 to control the pressure, and a pump can be provided between the liquid storage chamber 9 and the evaporator 18 to realize the circulation of the liquid working medium.

[0036] Moreover, during the process that the evaporator 18 relies on the heat of the external atmosphere as the heat source to convert the liquid working medium flowing through the evaporator 18 into a gaseous working medium, the air flowing through the high-temperature side of the evaporator 18 will store the cooling capacity of the liquid working medium and transfer the cooling capacity to the cryogenic tank 19, thereby replenishing the cooling capacity in the cryogenic tank 19. Generally, devices such as a fan can be used to realize the flow of the gaseous working medium among the liquefier 17, the evaporator 18, and the cryogenic tank 19.

[0037] For the heat pump-coupled compressed air energy storage system of this embodiment, based on the setting of the additional air recuperator 7, during discharging, the high-pressure air or other working medium first passes through the air recuperator 7 for heat recovery, so as to first recover the heat of the first expander 3 at the end. At the same time, the working medium such as air passing through the air heater 8 is heated to a high temperature state by the molten salt in the heat salt tank 16 and enters the first expander 3 at the previous stage to do work; the low-pressure air after being cooled by doing work is heated by another air heater 8 again and enters the first expander 3 at the next stage to do work. The exhausted gas after doing work can also enter the air recuperator 7, be heated by the air recuperator 7, and then be discharged into the atmosphere.

[0038] Generally, a large amount of compression heat will be generated during the compression process of the air compressor, and its temperature is generally not higher than 200 °C. Currently, traditional equipment mainly uses pressurized water for heat storage. Pressurized water has pressure, and the high-pressure water circulation needs to control the pressure to prevent water vaporization and form a two-phase flow, resulting in deteriorated heat transfer, and thus leading to higher heat storage costs and a complex operation process. Moreover, the heat storage temperature depends on the temperature of the heat generated during the compression process. For traditional equipment, the circulating air temperature is relatively low during discharging, which will lead to a relatively low efficiency of compressed air energy storage.

[0039] In the heat pump-coupled compressed air energy storage system of this embodiment, the heat pump module raises the relatively low-temperature compressed heat to the molten salt heat storage temperature (above 400 °C). By utilizing the high heat storage temperature of the molten salt, the heat storage density is increased, and the heat storage cost is significantly reduced. At the same time, during discharging, the temperature of the high-pressure air can be significantly increased, improving the discharging efficiency. Moreover, the heat pump module can simultaneously absorb the compressed heat in the pure compressed air module, making the inlet temperature of each first compressor 1 in the multistage compression unit not higher than the ambient temperature, and the temperature can be stably controlled, greatly improving the compression efficiency of the first compressor 1. At the same time, the complexity of the operating conditions of the first compressor 1 is reduced, and the equipment cost and operating difficulty of the first compressor 1 are lowered.

[0040] In summary, in the heat pump-coupled compressed air energy storage system of this embodiment, the compressed air energy storage module is coupled with the molten salt heat storage module, enabling the system to have a high heat storage temperature, a low heat storage cost, simple system operation, and high discharging efficiency during discharging.

[0041] The above schematically describes the present invention and its implementation manners. This description is not restrictive, and only one of the implementation manners of the present invention is shown in the drawings. The actual structure is not limited thereto. Therefore, if those of ordinary skill in the art are inspired by it and design, without creative efforts, structural manners and embodiments similar to the technical solution without departing from the creative purpose of the present invention, they shall fall within the protection scope of the present invention.

Claims

1. A heat pump coupled compressed air energy storage system, characterized in that: It includes a compressed air energy storage module, a molten salt heat storage module and a heat pump module; The compressed air energy storage module comprises a compressor unit, an expansion unit and a storage unit for storing gaseous or liquid gas working medium, wherein the inlet of the compressor unit is connected to the outside atmosphere, the outlet of the compressor unit is connected to the inlet of the storage unit, the inlet of the expansion unit is connected to the outlet of the storage unit, and the outlet of the expansion unit is connected to the outside atmosphere; the compressor unit comprises a plurality of first compressors (1) connected front to back between adjacent ones, and the expansion unit comprises a plurality of first expanders (3) connected front to back between adjacent ones; The molten salt thermal storage module comprises a cold salt tank (15), a hot salt tank (16), a molten salt heater (12) and an air heater (8); the air heater (8) is arranged between adjacent first expanders (3) and between adjacent storage parts and the first expander (3); the working fluid flowing out of the cold salt tank (15) flows through the low-temperature side of the molten salt heater (12) to absorb heat and then flows into the hot salt tank (16); the working fluid flowing out of the hot salt tank (16) is split and flows through the high-temperature side of each air heater (8) to release heat and then flows back to the cold salt tank (15); The heat pump module comprises a second compressor (11), a second expander (10) and a heat absorber (5); the heat absorber (5) is arranged between adjacent first compressors (1) and between adjacent first compressors (1) and the storage unit; the working fluid discharged from the second expander (10) is split and flows through the low-temperature side of each heat absorber (5) to absorb heat before flowing into the second compressor (11); the working fluid discharged from the second compressor (11) flows through the high-temperature side of the molten salt heater (12) to release heat before flowing back to the second expander (10).

2. A heat pump coupled compressed air energy storage system according to claim 1, characterized in that: It also includes a heat pump regenerator (13), wherein the working fluid flowing out of the low-temperature side of the heat absorber (5) absorbs heat on the low-temperature side of the heat pump regenerator (13) and then flows into the second compressor (11), and the working fluid flowing out of the high-temperature side of the molten salt heater (12) releases heat on the high-temperature side of the heat pump regenerator (13) and then flows into the second expander (10).

3. A heat pump coupled compressed air energy storage system according to claim 1, characterized in that: It also includes an air reheater (7), wherein the working fluid flowing out of the outlet of the expansion unit passes through the high-temperature side of the air reheater (7) to release heat and then flows to the outside atmosphere, and the working fluid flowing out of the storage unit passes through the low-temperature side of the air reheater (7) to absorb heat and then flows to the low-temperature side of the air heater (8).

4. A heat pump coupled compressed air energy storage system according to claim 1, characterized in that: The storage section is an air storage chamber (14), the outlet of the compressor unit is connected to the inlet of the air storage chamber (14), the inlet of the expansion unit is connected to the outlet of the air storage chamber (14), and the heat absorber (5) is arranged between adjacent first compressors (1) and between adjacent first compressors (1) and the air storage chamber (14).

5. A heat pump coupled compressed air energy storage system according to claim 1, characterized in that: The storage section comprises a liquid storage chamber (9), a liquefier (17), an evaporator (18) and a cryogenic tank (19); the working fluid flowing out of the outlet of the heat absorber (5) passes through the high-temperature side of the liquefier (17) to be liquefied and then flows into the liquid storage chamber (9); the liquefied working fluid in the liquid storage chamber (9) passes through the low-temperature side of the evaporator (18) to absorb heat and then flows into the low-temperature side of the air heater (8) adjacent to the storage section; The high-temperature side inlet of the evaporator (18) and the low-temperature side outlet of the liquefier (17) are respectively connected to the circulating gas environment, and the air flows through the high-temperature side of the evaporator (18) to store cold and then flows into the cryogenic tank (19), and the air in the cryogenic tank (19) flows through the low-temperature side of the liquefier (17) to absorb heat and then flows into the circulating gas environment.

6. A heat pump coupled compressed air energy storage system according to claim 1, characterized in that: The working medium in the heat pump module includes one or more combinations of air, argon, nitrogen and helium.

7. A heat pump coupled compressed air energy storage system according to claim 1, characterized in that: The compressed air energy storage module further comprises a first motor (4), the compressor group comprises a first transmission shaft, the first compressors (1) share the first transmission shaft, and the first motor (4) is in transmission connection with the first transmission shaft.

8. A heat pump coupled compressed air energy storage system according to claim 1 or 5, characterized in that: The expansion machine group comprises a second transmission shaft, the first expansion machine (3) shares the second transmission shaft, and the second transmission shaft is used for transmission connection with the output device (6).

9. A heat pump coupled compressed air energy storage system according to claim 1, characterized in that: The heat pump module further comprises a second motor (2) and a third transmission shaft, the second compressor (11) and the second expander (10) share the third transmission shaft, and the second motor (2) is in transmission connection with the third transmission shaft.

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