A compressed air energy storage system sharing a heat exchanger and an energy storage and energy release method

Abstract

The present invention relates to the technical field of compressed air energy storage, and particularly relates to a compressed air energy storage system sharing a heat exchanger and an energy storage and energy release method. The compressed air energy storage system includes an energy storage circuit formed by sequentially connecting a first air compressor, a first heat exchange unit, a second air compressor, a second heat exchange unit, a third air compressor, a third heat exchange unit and a gas storage unit, and an energy release circuit formed by sequentially connecting the third heat exchange unit, the second heat exchange unit, a first air expander, the first heat exchange unit and a second air expander and being opposite to the energy storage circuit. The present invention performs multi-stage compression on the air introduced from the outside of the environment, can reduce the amplitude of the decline of the compressed heat grade in the system, stores the high-temperature compressed heat by using molten salt working medium, and stores the low-temperature compressed heat by using pressurized water working medium to fully store the compressed heat in each stage. By sharing the heat exchanger in the energy storage circuit and the energy release circuit, the area of the heat exchanger that needs to be configured in the conventional energy storage system can be greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of compressed air energy storage, and in particular to a compressed air energy storage system sharing a heat exchanger and an energy storage and energy release method thereof. Background Art

[0002] Energy storage systems have the capabilities of energy time-shifting and rapid response, and can effectively solve many problems brought by large-scale new energy access to the power system. Compressed air energy storage systems have the advantages of large capacity, long life, low cost, flexible siting, high safety, etc., and have attracted more and more extensive attention from the academic and industrial circles, and have broad application prospects.

[0003] An air compressor with a large compression ratio can raise the compression heat to above 350°C. In order to better store this part of heat, molten salt coupled with pressurized water is usually used as the heat storage working medium of the system. Among them, molten salt stores high-temperature compression heat, and pressurized water stores low-temperature compression heat. This will result in a large number of heat exchangers being required to be configured in the heat storage and heat exchange subsystem of the system, thereby increasing the system cost and floor area. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide a compressed air energy storage system sharing a heat exchanger and an energy storage and energy release method thereof, so as to solve the problem that the existing energy storage system needs to configure a large-area heat exchanger, resulting in an increase in system cost and floor area.

[0005] The present invention discloses a compressed air energy storage system sharing a heat exchanger, including:

[0006] An air compression module, including a first air compressor, a second air compressor, a third air compressor and a gas storage unit, and an air inlet is provided on the first air compressor;

[0007] A heat exchange and energy storage module, including a first heat exchange unit, a second heat exchange unit and a third heat exchange unit. The first air compressor, the first heat exchange unit, the second air compressor, the second heat exchange unit, the third air compressor, the third heat exchange unit and the gas storage unit are connected in sequence to form an energy storage circuit. Both the first heat exchange unit and the second heat exchange unit exchange heat and store the compression heat of the compressed air through molten salt coupled with pressurized water working medium, and the third heat exchange unit exchanges heat and stores the residual heat of the compressed air through pressurized water working medium;

[0008] The air work module includes a first air expander and a second air expander. An air discharge port is provided on the second air expander. The third heat exchange unit, the second heat exchange unit, the first air expander, the first heat exchange unit, and the second air expander are connected in sequence and form an energy release line that is reverse to the energy storage line. The third heat exchange unit also releases the stored compressed heat and compensation heat to the compressed air through a pressurized water working medium. The second heat exchange unit and the first heat exchange unit also release the stored compressed heat to the compressed air through molten salt coupled with a pressurized water working medium.

[0009] Optionally, the first heat exchange unit includes a first molten salt heat exchange component and a first pressurized water heat exchange component, and the second heat exchange unit includes a second molten salt heat exchange component and a second pressurized water heat exchange component;

[0010] The first molten salt heat exchange component includes a first common heat exchanger, a first high-temperature storage tank, and a first low-temperature storage tank. A first working medium flow channel is provided in the first common heat exchanger. The first high-temperature storage tank is connected to one end of the first working medium flow channel, and the first low-temperature storage tank is connected to the other end of the first working medium flow channel. A low-temperature working medium is pre-stored in the first low-temperature storage tank;

[0011] A first air flow channel for heat exchange with the first working medium flow channel is also provided in the first common heat exchanger. A first air interface communicating with one end of the first air flow channel and a second air interface communicating with the other end of the first air flow channel are provided on the first common heat exchanger;

[0012] The compositional structures of the first pressurized water heat exchange component, the second molten salt heat exchange component, and the second pressurized water heat exchange component are all the same as the compositional structure of the first molten salt heat exchange component.

[0013] Optionally, a first working medium pump is provided between the first low-temperature storage tank and the first working medium flow channel. The first low-temperature storage tank, the first working medium pump, and the first working medium flow channel are connected in sequence. A first solenoid valve is provided on the inlet pipeline of the first working medium pump, and a second solenoid valve is provided on the outlet pipeline of the first working medium pump. A first bypass is connected between the first high-temperature storage tank and the first working medium flow channel, so that after the first working medium pump extracts the low-temperature working medium in the first low-temperature storage tank for heat exchange, it is stored in the first high-temperature storage tank along the first bypass. A third solenoid valve is provided on the first bypass;

[0014] A second working medium pump is provided between the first high-temperature storage tank and the first working medium flow channel. The first high-temperature storage tank, the second working medium pump, and the first working medium flow channel are connected in sequence. A fourth solenoid valve is provided on the inlet pipeline of the second working medium pump, and a fifth solenoid valve is provided on the outlet pipeline of the second working medium pump. A second bypass is connected between the first low-temperature storage tank and the first working medium flow channel, so that after the second working medium pump extracts the high-temperature working medium in the first high-temperature storage tank for heat exchange, it flows back into the first low-temperature storage tank along the second bypass, and a sixth solenoid valve is provided on the second bypass.

[0015] Optionally, a first energy storage gas pipeline is connected between the outlet of the first air compressor and the first air interface included in the first molten salt heat exchange module, and a seventh solenoid valve is provided on the first energy storage gas pipeline. The second air interface included in the first molten salt heat exchange module is connected to the first air interface included in the first pressurized water heat exchange module;

[0016] A second energy storage gas pipeline is connected between the second air interface included in the first pressurized water heat exchange module and the inlet of the second air compressor. An eighth solenoid valve is provided on the second energy storage gas pipeline. A third energy storage gas pipeline is connected between the outlet of the second air compressor and the first air interface included in the second molten salt heat exchange module, and a ninth solenoid valve is provided on the third energy storage gas pipeline;

[0017] The second air interface included in the second molten salt heat exchange module is connected to the first air interface included in the second pressurized water heat exchange module. A fourth energy storage gas pipeline is connected between the second air interface included in the second pressurized water heat exchange module and the inlet of the third air compressor. A tenth solenoid valve is provided on the fourth energy storage gas pipeline. A fifth energy storage gas pipeline is connected between the outlet of the third air compressor and the third heat exchange unit, and an eleventh solenoid valve is provided on the fifth energy storage gas pipeline;

[0018] A sixth energy storage gas pipeline is provided between the third heat exchange unit and the gas storage unit, and a twelfth solenoid valve is provided on the sixth energy storage gas pipeline.

[0019] Optionally, a pressurized water heat exchanger is provided on the fourth energy storage gas pipeline. The tenth solenoid valve is located on the outlet side of the pressurized water heat exchanger, and a thirteenth solenoid valve is provided on the fourth energy storage gas pipeline on the inlet side of the pressurized water heat exchanger.

[0020] Optionally, the third heat exchange unit includes a third pressurized water heat exchange assembly, which includes a second shared heat exchanger, a hot water storage tank, a cold water storage tank, a high-temperature compensation storage tank, and a low-temperature recovery storage tank. A second working fluid flow channel is provided in the second shared heat exchanger. The hot water storage tank is connected to one end of the second working fluid flow channel, and the cold water storage tank is connected to the other end of the second working fluid flow channel. Cold water is pre-stored in the cold water storage tank. The high-temperature compensation storage tank is connected to one end of the second working fluid flow channel, and the low-temperature recovery storage tank is connected to the other end of the second working fluid flow channel. High-temperature water is pre-stored in the high-temperature compensation storage tank;

[0021] A second air flow channel heat-exchanged with the second working fluid flow channel is further provided in the second shared heat exchanger. A third air interface communicating with one end of the second air flow channel and a fourth air interface communicating with the other end of the second air flow channel are provided on the second shared heat exchanger.

[0022] Optionally, a third working fluid pump is provided between the cold water storage tank and the second working fluid flow channel. The cold water storage tank, the third working fluid pump, and the second working fluid flow channel are connected in sequence. A fourteenth solenoid valve is provided on the inlet pipeline of the third working fluid pump, and a fifteenth solenoid valve is provided on the outlet pipeline of the third working fluid pump. A third bypass is connected between the hot water storage tank and the second working fluid flow channel, so that after the third working fluid pump extracts the cold water in the cold water storage tank for heat exchange, it is stored in the hot water storage tank along the third bypass. A sixteenth solenoid valve is provided on the third bypass.

[0023] Optionally, a fourth working fluid pump is provided between the high-temperature compensation storage tank and the second working fluid flow channel. The high-temperature compensation storage tank, the fourth working fluid pump, and the second working fluid flow channel are connected in sequence. A seventeenth solenoid valve is provided on the inlet pipeline of the fourth working fluid pump, and an eighteenth solenoid valve is provided on the outlet pipeline of the fourth working fluid pump. A nineteenth solenoid valve is provided on the connecting pipeline between the low-temperature recovery storage tank and the second working fluid flow channel, so that after the fourth working fluid pump extracts the high-temperature water in the high-temperature compensation storage tank for heat exchange, it flows back to the low-temperature recovery storage tank.

[0024] Optionally, a first energy-releasing gas transmission pipeline is connected between the second air interface included in the second pressurized water heat exchange assembly and the third air interface included in the third pressurized water heat exchange assembly. A twentieth solenoid valve is provided on the first energy-releasing gas transmission pipeline;

[0025] A second energy release gas transmission pipeline is connected between the inlet of the first air expander and the first air interface included in the second molten salt heat exchange assembly, and a twenty-first electromagnetic valve is arranged on the second energy release gas transmission pipeline. A third energy release gas transmission pipeline is connected between the outlet of the first air expander and the second air interface included in the first pressurized water heat exchange assembly, and a twenty-second electromagnetic valve is arranged on the third energy release gas transmission pipeline;

[0026] A fourth energy release gas transmission pipeline is connected between the inlet of the second air expander and the first air interface included in the first molten salt heat exchange assembly, and a twenty-third electromagnetic valve is arranged on the fourth energy release gas transmission pipeline.

[0027] The present invention also provides an energy storage and energy release method applied to the above compressed air energy storage system. The energy storage and energy release method includes:

[0028] In response to the energy storage power station performing energy storage, controlling the ambient air to enter through the air inlet on the first air compressor, and the first air compressor compresses the entered air to obtain primary compressed air;

[0029] Controlling the primary compressed air to enter the first heat exchange unit for primary compressed heat storage, then controlling the heat-exchanged compressed air to enter the second air compressor for compression to obtain secondary compressed air, controlling the secondary compressed air to enter the second heat exchange unit for secondary compressed heat storage, then controlling the heat-exchanged compressed air to enter the third air compressor for compression to obtain tertiary compressed air, controlling the tertiary compressed air to enter the third heat exchange unit for tertiary compressed heat storage, and then controlling the heat-exchanged compressed air to enter the gas storage unit for storage;

[0030] In response to the energy storage power station performing energy release, controlling the compressed air stored in the gas storage unit to be released, the third heat exchange unit exchanges the stored compressed heat and compensation heat to the released compressed air, and the second heat exchange unit exchanges the stored compressed heat to the compressed air, and controlling the heat-exchanged compressed air to enter the first air expander to perform primary work on the outside;

[0031] Controlling the compressed air after work to enter the first heat exchange unit, the first heat exchange unit continues to exchange the stored compressed heat to the compressed air, and controlling the heat-exchanged compressed air to enter the second air expander to perform secondary work on the outside, and controlling the compressed air after secondary work to be discharged from the air discharge port on the second air expander.

[0032] Compared with the prior art, the beneficial effects of the compressed air energy storage system and the energy storage and energy release method with a shared heat exchanger provided by the embodiments of the present invention are as follows:

[0033] By setting up a multi-stage compression form composed of a first air compressor, a second air compressor, and a third air compressor, the air introduced from outside the environment is compressed in multiple stages to continuously generate high-temperature compressed air, which can effectively reduce the degree of decline in the compression heat grade in the system. At the same time, the first heat exchange unit, the second heat exchange unit, and the third heat exchange unit are used to exchange heat with the compressed air at the outlet of each stage of the air compressor respectively, and molten salt coupled with pressurized water is used as the heat storage working medium. The molten salt working medium stores high-temperature compression heat, and the pressurized water working medium stores low-temperature compression heat to fully store the compression heat at each stage and ensure the energy storage efficiency. In addition, based on the principle of cascaded utilization of energy, an energy release line opposite to the energy storage line is arranged, so that the first heat exchange unit, the second heat exchange unit, and the third heat exchange unit are heat exchangers shared by energy storage and energy release, to ensure the efficiency of the round trip of energy storage and energy release in the system, and greatly reduce the area of the heat exchanger that needs to be configured in the conventional energy storage system, thereby effectively reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The technical solutions of the present invention will be further described in detail below with reference to the drawings and embodiments. In the drawings:

[0035] Figure 1 is a schematic block diagram of the overall structure of the compressed air energy storage system provided by the embodiment of the present invention;

[0036] Figure 2 is a schematic structural diagram of the first molten salt heat exchange component provided by the embodiment of the present invention;

[0037] Figure 3 is a schematic structural diagram of the third pressurized water heat exchange component provided by the embodiment of the present invention.

[0038] Each reference numeral in the figure is:

[0039] 1. Air compression module; 11. First air compressor; 111. First energy storage gas pipeline; 112. Seventh solenoid valve; 12. Second air compressor; 121. Second energy storage gas pipeline; 122. Eighth solenoid valve; 123. Third energy storage gas pipeline; 124. Ninth solenoid valve; 13. Third air compressor; 131. Fourth energy storage gas pipeline; 132. Tenth solenoid valve; 133. Fifth energy storage gas pipeline; 134. Eleventh solenoid valve; 14. Gas storage unit; 141. Sixth energy storage gas pipeline; 142. Twelfth solenoid valve; 2. Heat exchange and energy storage module; 21. First heat exchange unit; 211. First molten salt heat exchange component; 212. First pressurized water heat exchange component; 213. First common heat exchanger; 2131. First air interface; 2132. Second air interface; 214. First high-temperature storage tank; 2141. First bypass; 2142. Third solenoid valve; 2143. Second working medium pump; 2144. Fourth solenoid valve; 2145. Fifth solenoid valve; 215. First low-temperature storage tank; 2151. First working medium pump; 2152. First solenoid valve; 2153. Second solenoid valve; 2154. Second bypass; 2155. Sixth solenoid valve; 22. Second heat exchange unit; 221. Second molten salt heat exchange component; 222. Second pressurized water heat exchange component; 23. Third heat exchange unit; 231. Second common heat exchanger; 2311. Third air interface; 2312. Fourth air interface; 232. Hot water storage tank; 2321. Third bypass; 2322. Sixteenth solenoid valve; 233. Cold water storage tank; 2331. Third working medium pump; 2332. Fourteenth solenoid valve; 2333. Fifteenth solenoid valve; 234. High-temperature compensation storage tank; 2341. Fourth working medium pump; 2342. Seventeenth solenoid valve; 2343. Eighteenth solenoid valve; 235. Low-temperature recovery storage tank; 2351. Nineteenth solenoid valve; 3. Air work module; 31. First air expander; 311. Second energy release gas pipeline; 312. Twenty-first solenoid valve; 313. Third energy release gas pipeline; 314. Twenty-second solenoid valve; 32. Second air expander; 321. Fourth energy release gas pipeline; 322. Twenty-third solenoid valve; 33. First energy release gas pipeline; 331. Twentieth solenoid valve; 4. Pressurized water heat exchanger; 41. Thirteenth solenoid valve. Specific embodiments

[0040] 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. Now, in conjunction with the drawings, the preferred embodiments of the present invention will be described in detail.

[0041] The present invention discloses a compressed air energy storage system with a common heat exchanger, as Figure 1As shown in the figure, it includes an air compression module 1, a heat exchange and energy storage module 2, and an air work module 3. The air compression module 1 includes a first air compressor 11, a second air compressor 12, a third air compressor 13, and a gas storage unit 14. An air inlet is provided on the first air compressor 11. The heat exchange and energy storage module 2 includes a first heat exchange unit 21, a second heat exchange unit 22, and a third heat exchange unit 23. The first air compressor 11, the first heat exchange unit 21, the second air compressor 12, the second heat exchange unit 22, the third air compressor 13, the third heat exchange unit 23, and the gas storage unit 14 are connected in sequence to form an energy storage circuit. Both the first heat exchange unit 21 and the second heat exchange unit 22 exchange heat and store the compression heat of the compressed air through molten salt coupled with pressurized water working medium. The third heat exchange unit 23 exchanges heat and stores the residual heat of the compressed air through pressurized water working medium. The air work module 3 includes a first air expander 31 and a second air expander 32. An air outlet is provided on the second air expander 32. The third heat exchange unit 23, the second heat exchange unit 22, the first air expander 31, the first heat exchange unit 21, and the second air expander 32 are connected in sequence to form an energy release circuit that is reverse to the energy storage circuit. The third heat exchange unit 23 also releases the stored compression heat and compensation heat to the compressed air through pressurized water working medium. The second heat exchange unit 22 and the first heat exchange unit 21 also release the stored compression heat to the compressed air through molten salt coupled with pressurized water working medium.

[0042] Through the implementation of the above embodiments of the compressed air energy storage system, a multi-stage compression form composed of the first air compressor 11, the second air compressor 12, and the third air compressor 13 is set up to perform multi-stage compression on the air introduced from outside the environment, so as to continuously generate high-temperature compressed air, which can effectively reduce the decline amplitude of the compressed heat grade in the system. At the same time, the first heat exchange unit 21, the second heat exchange unit 22, and the third heat exchange unit 23 are respectively used to immediately exchange heat with the compressed air at the outlet of each stage of the air compressor, and molten salt coupled with pressurized water is used as the heat storage working medium. The molten salt working medium stores high-temperature compressed heat, and the pressurized water working medium stores low-temperature compressed heat, so as to fully exchange heat and store energy for the compressed heat at each stage, thereby ensuring the energy storage efficiency. In addition, based on the principle of cascaded utilization of energy, an energy release line opposite to the energy storage line is arranged, so that the first heat exchange unit 21, the second heat exchange unit 22, and the third heat exchange unit 23 are heat exchangers shared by energy storage and energy release. Since the air is multi-stage compressed, as the grade of the compressed heat decreases, the grade of the compressed heat stored by heat exchange in the third heat exchange unit 23 is relatively low. Therefore, when the system releases compressed air, the third heat exchange unit 23 uses the pressurized water working medium to release the stored compressed heat and the pre-stored compensation heat to the compressed air, and then introduces the heat-exchanged compressed air into the second heat exchange unit 22 for heat exchange, so as to ensure that the grade of the compressed heat of the released compressed air is increased to the preset standard before doing work, so as to fully utilize the compressed heat of this part. Similarly, the grade of the compressed heat stored in the first heat exchange unit 21 is the highest. Therefore, the compressed air after doing work in the first air expander 31 is directly introduced into the first heat exchange unit 21 for heat exchange. The first heat exchange unit 21 uses the molten salt coupled with the pressurized water working medium to release the stored compressed heat to the compressed air, and then introduces the heat-exchanged compressed air into the second air expander 32 for doing work. The compressed air after doing work is directly discharged to the outside of the environment, so as to ensure the efficiency of the energy storage and release cycle in the system, and greatly reduce the area of the heat exchanger required in the conventional energy storage system, thereby effectively reducing the cost.

[0043] Further, in combination with Figure 2As shown, the first heat exchange unit 21 includes a first molten salt heat exchange component 211 and a first pressurized water heat exchange component 212, and the second heat exchange unit 22 includes a second molten salt heat exchange component 221 and a second pressurized water heat exchange component 222. The first molten salt heat exchange component 211 includes a first common heat exchanger 213, a first high-temperature storage tank 214, and a first low-temperature storage tank 215. A first working medium flow channel is provided in the first common heat exchanger 213. The first high-temperature storage tank 214 is connected to one end of the first working medium flow channel, and the first low-temperature storage tank 215 is connected to the other end of the first working medium flow channel. A low-temperature working medium is pre-stored in the first low-temperature storage tank 215. A first air flow channel heat-exchanged with the first working medium flow channel is further provided in the first common heat exchanger 213. A first air interface 2131 communicating with one end of the first air flow channel and a second air interface 2132 communicating with the other end of the first air flow channel are provided on the first common heat exchanger 213.

[0044] The composition structures of the first pressurized water heat exchange component 212, the second molten salt heat exchange component 221, and the second pressurized water heat exchange component 222 are all the same as that of the first molten salt heat exchange component 211. That is, the first pressurized water heat exchange component 212, the second molten salt heat exchange component 221, and the second pressurized water heat exchange component 222 are all connected and composed of components such as the first common heat exchanger 213, the first high-temperature storage tank 214, and the first low-temperature storage tank 215. So that the energy storage and energy release of each heat exchange component can be independently controlled, thereby enabling the dynamic adjustment of the energy storage efficiency of each heat exchange component.

[0045] Through the implementation of the above embodiments of the compressed air energy storage system, since the compressed heat grade of the air is relatively high after being compressed by the first air compressor 11 and the second air compressor 12. Therefore, both the first heat exchange unit 21 and the second heat exchange unit 22 first use the low-temperature molten salt working medium to store the high-temperature compressed heat of the compressed air, and then use the low-temperature pressurized water working medium to store the low-temperature compressed heat of the compressed air to fully exchange heat and store energy to ensure the energy storage efficiency. In addition, using the heat exchange component structure composed of the first common heat exchanger 213, the first high-temperature storage tank 214, and the first low-temperature storage tank 215, the first air interface 2131 or the second air interface 2132 on the first common heat exchanger 213 is connected to adjacent equipment to facilitate the transportation of the compressed air. When storing energy, the low-temperature working medium in the first low-temperature storage tank 215 enters the first working medium flow channel to exchange heat with the compressed air and then is stored in the first high-temperature storage tank 214. When releasing energy, the high-temperature working medium in the first high-temperature storage tank 214 enters the first working medium flow channel to exchange heat with the compressed air and then is stored in the first low-temperature storage tank 215.

[0046] Preferably, the first common heat exchanger 213 included in the first molten salt heat exchange assembly 211 shares the same first high-temperature storage tank 214 and the same first low-temperature storage tank 215 with the first common heat exchanger 213 included in the second molten salt heat exchange assembly 221, so that both the first molten salt heat exchange assembly 211 and the second molten salt heat exchange assembly 221 exchange heat with air through the molten salt working medium, and the heated molten salt working medium in both the first molten salt heat exchange assembly 211 and the second molten salt heat exchange assembly 221 is stored in the same first high-temperature storage tank 214, or the cooled molten salt working medium flows back to the same first low-temperature storage tank 215. Thereby, the first molten salt heat exchange assembly 211 and the second molten salt heat exchange assembly 221 perform centralized energy storage to improve the energy storage efficiency.

[0047] The first common heat exchanger 213 included in the first pressurized water heat exchange assembly 212 shares the same other first high-temperature storage tank 214 and the same first low-temperature storage tank 215 with the first common heat exchanger 213 included in the second pressurized water heat exchange assembly 222, so that both the first pressurized water heat exchange assembly 212 and the second pressurized water heat exchange assembly 222 exchange heat with air through the pressurized water working medium, and the heated pressurized water working medium in both the first pressurized water heat exchange assembly 212 and the second pressurized water heat exchange assembly 222 is stored in the same first high-temperature storage tank 214, or the cooled pressurized water working medium flows back to the same first low-temperature storage tank 215. Thereby, the first pressurized water heat exchange assembly 212 and the second pressurized water heat exchange assembly 222 perform centralized energy storage to improve the energy storage efficiency.

[0048] Further, a first working medium pump 2151 is provided between the first low-temperature storage tank 215 and the first working medium flow path, and the first low-temperature storage tank 215, the first working medium pump 2151, and the first working medium flow path are connected in sequence. A first solenoid valve 2152 is provided on the inlet pipeline of the first working medium pump 2151, and a second solenoid valve 2153 is provided on the outlet pipeline of the first working medium pump 2151. A first bypass 2141 is connected between the first high-temperature storage tank 214 and the first working medium flow path, so that after the first working medium pump 2151 extracts the low-temperature working medium in the first low-temperature storage tank 215 for heat exchange, it is stored in the first high-temperature storage tank 214 along the first bypass 2141. A third solenoid valve 2142 is provided on the first bypass 2141. A second working medium pump 2143 is provided between the first high-temperature storage tank 214 and the first working medium flow path, and the first high-temperature storage tank 214, the second working medium pump 2143, and the first working medium flow path are connected in sequence. A fourth solenoid valve 2144 is provided on the inlet pipeline of the second working medium pump 2143, and a fifth solenoid valve 2145 is provided on the outlet pipeline of the second working medium pump 2143. A second bypass 2154 is connected between the first low-temperature storage tank 215 and the first working medium flow path, so that after the second working medium pump 2143 extracts the high-temperature working medium in the first high-temperature storage tank 214 for heat exchange, it flows back to the first low-temperature storage tank 215 along the second bypass 2154. A sixth solenoid valve 2155 is provided on the second bypass 2154.

[0049] Through the implementation of the above embodiments of the compressed air energy storage system, when the first molten salt heat exchange component 211, the first pressurized water heat exchange component 212, the second molten salt heat exchange component 221, and the second pressurized water heat exchange component 222 perform energy storage, the sixth solenoid valve 2155 is closed, and the first solenoid valve 2152 and the second solenoid valve 2153 are opened. The low-temperature molten salt or pressurized working fluid in the first low-temperature storage tank 215 is pressurized and transported to the first working fluid flow channel by the first working fluid pump 2151; the third solenoid valve 2142 is opened, and the fourth solenoid valve 2144 and the fifth solenoid valve 2145 are turned off. After the low-temperature molten salt or pressurized working fluid exchanges heat with the passing compressed air in the first working fluid flow channel, it enters the first high-temperature storage tank 214 through the first bypass 2141, thereby realizing the storage process of air compression heat.

[0050] Similarly, when the first molten salt heat exchange component 211, the first pressurized water heat exchange component 212, the second molten salt heat exchange component 221, and the second pressurized water heat exchange component 222 perform energy release, the third solenoid valve 2142 is closed, and the fourth solenoid valve 2144 and the fifth solenoid valve 2145 are opened. The high-temperature molten salt or pressurized working fluid in the first high-temperature storage tank 214 is pressurized and transported to the first working fluid flow channel by the second working fluid pump 2143; the sixth solenoid valve 2155 is opened, and the first solenoid valve 2152 and the second solenoid valve 2153 are turned off. After the high-temperature molten salt or pressurized working fluid exchanges heat with the passing compressed air in the first working fluid flow channel, it enters the first low-temperature storage tank 215 through the second bypass 2154, thereby realizing the energy release process of the stored compressed heat.

[0051] Further, looking back Figure 1, a first energy storage gas pipeline 111 is connected between the outlet of the first air compressor 11 and the first air interface 2131 included in the first molten salt heat exchange assembly 211, and a seventh electromagnetic valve 112 is arranged on the first energy storage gas pipeline 111. The second air interface 2132 included in the first molten salt heat exchange assembly 211 is connected to the first air interface 2131 included in the first pressurized water heat exchange assembly 212. A second energy storage gas pipeline 121 is connected between the second air interface 2132 included in the first pressurized water heat exchange assembly 212 and the inlet of the second air compressor 12. An eighth electromagnetic valve 122 is arranged on the second energy storage gas pipeline 121. A third energy storage gas pipeline 123 is connected between the outlet of the second air compressor 12 and the first air interface 2131 included in the second molten salt heat exchange assembly 221, and a ninth electromagnetic valve 124 is arranged on the third energy storage gas pipeline 123. The second air interface 2132 included in the second molten salt heat exchange assembly 221 is connected to the first air interface 2131 included in the second pressurized water heat exchange assembly 222. A fourth energy storage gas pipeline 131 is connected between the second air interface 2132 included in the second pressurized water heat exchange assembly 222 and the inlet of the third air compressor 13. A tenth electromagnetic valve 132 is arranged on the fourth energy storage gas pipeline 131. A fifth energy storage gas pipeline 133 is connected between the outlet of the third air compressor 13 and the third heat exchange unit 23, and an eleventh electromagnetic valve 134 is arranged on the fifth energy storage gas pipeline 133. A sixth energy storage gas pipeline 141 is arranged between the third heat exchange unit 23 and the gas storage unit 14, and a twelfth electromagnetic valve 142 is arranged on the sixth energy storage gas pipeline 141.

[0052] By implementing the above embodiments of the compressed air energy storage system, control all the seventh electromagnetic valve 112 to the twelfth electromagnetic valve 142 to be opened to conduct the energy storage line, so that the air outside the environment sequentially passes through the first air compressor 11, the first heat exchange unit 21, the second air compressor 12, the second heat exchange unit 22, the third air compressor 13, and the third heat exchange unit 23, and then enters the gas storage unit 14 for storage. Similarly, control all the seventh electromagnetic valve 112 to the twelfth electromagnetic valve 142 to be closed to close the energy storage line and facilitate the conduction of the energy release line to be switched, so as to realize the rapid switching of the system energy storage and energy release, and further ensure the system energy storage and energy release efficiency.

[0053] Furthermore, a pressurized water heat exchanger 4 is arranged on the fourth energy storage gas pipeline 131. The tenth electromagnetic valve 132 is located on the outlet side of the pressurized water heat exchanger 4, and a thirteenth electromagnetic valve 41 is arranged on the fourth energy storage gas pipeline 131 on the inlet side of the pressurized water heat exchanger 4.

[0054] Through the implementation of the above embodiments of the compressed air energy storage system, since the compressed air at the outlet of the second air compressor 12 is compressed to a relatively high pressure and temperature. After passing through the second molten salt heat exchange assembly 221 and the second pressurized water heat exchange assembly 222 in sequence for sufficient heat exchange, it will enter the third air compressor 13 for final compression. As the last stage of compression, the third air compressor 13 only needs to compress the compressed air to generate low-temperature compression heat, without requiring a large amount of power consumption. Therefore, before the compressed air enters the third air compressor 13, the pressurized water heat exchanger 4 is used to further cool the compressed air after heat exchange by the second pressurized water heat exchange assembly 222, ensuring that the compressed air after heat exchange by the pressurized water heat exchanger 4 meets the inlet temperature requirements of the third air compressor 13, so as to reduce the energy consumption of the third air compressor 13 and improve the compression efficiency. Among them, the pressurized water heat exchanger 4 only acts on the heat exchange of the compressed air at the inlet of the third air compressor 13 and does not participate in the shared heat exchange of energy storage and energy release.

[0055] Further, as shown in Figure 3 FIG. 5, the third heat exchange unit 23 includes a third pressurized water heat exchange assembly. The third pressurized water heat exchange assembly includes a second shared heat exchanger 231, a hot water storage tank 232, a cold water storage tank 233, a high-temperature compensation storage tank 234, and a low-temperature recovery storage tank 235. A second working medium flow channel is provided in the second shared heat exchanger 231. The hot water storage tank 232 is connected to one end of the second working medium flow channel, and the cold water storage tank 233 is connected to the other end of the second working medium flow channel. Cold water is pre-stored in the cold water storage tank 233. The high-temperature compensation storage tank 234 is connected to one end of the second working medium flow channel, and the low-temperature recovery storage tank 235 is connected to the other end of the second working medium flow channel. High-temperature water is pre-stored in the high-temperature compensation storage tank 234. A second air flow channel arranged for heat exchange with the second working medium flow channel is further provided in the second shared heat exchanger 231. A third air interface 2311 communicating with one end of the second air flow channel and a fourth air interface 2312 communicating with the other end of the second air flow channel are provided on the second shared heat exchanger 231.

[0056] Through the implementation of the above embodiments of the compressed air energy storage system, the compressed heat grade of the compressed air after being compressed by the third air compressor 13 has been reduced to a low temperature. Therefore, the third heat exchange unit 23 only needs to store the low-temperature compressed heat of the compressed air by using a pressurized water working medium. That is, an exchanger structure composed of the second common heat exchanger 231, the hot water storage tank 232, the cold water storage tank 233, the high-temperature compensation storage tank 234, and the low-temperature recovery storage tank 235 is used. The third air interface 2311 or the fourth air interface 2312 on the second common heat exchanger 231 is connected to adjacent equipment to facilitate the transportation of the compressed air. When storing energy, the cold water working medium in the cold water storage tank 233 enters the second working medium flow channel to exchange heat with the compressed air and is then stored in the hot water storage tank 232. When releasing energy, since the compressed heat grade stored in the hot water storage tank 232 is relatively low and cannot meet the heat exchange temperature requirements of the released air. Therefore, in addition to controlling the low-temperature water working medium in the hot water storage tank 232 to enter the second working medium flow channel to exchange heat with the compressed air and then be stored in the cold water storage tank 233, at the same time, the high-temperature water working medium pre-stored in the high-temperature compensation storage tank 234 is controlled to enter the second working medium flow channel to exchange heat with the compressed air and then be stored in the low-temperature recovery storage tank 235 to achieve temperature compensation, so as to ensure that when the third pressurized water heat exchange assembly performs energy release heat exchange, it can meet the heat exchange temperature requirements of the released compressed air.

[0057] Further, a third working medium pump 2331 is provided between the cold water storage tank 233 and the second working medium flow channel. The cold water storage tank 233, the third working medium pump 2331, and the second working medium flow channel are connected in sequence. A fourteenth solenoid valve 2332 is provided on the inlet pipeline of the third working medium pump 2331, and a fifteenth solenoid valve 2333 is provided on the outlet pipeline of the third working medium pump 2331. A third bypass 2321 is connected between the hot water storage tank 232 and the second working medium flow channel, so that after the third working medium pump 2331 extracts the cold water in the cold water storage tank 233 for heat exchange, it is stored in the hot water storage tank 232 along the third bypass 2321. A sixteenth solenoid valve 2322 is provided on the third bypass 2321.

[0058] Further, a fourth working medium pump 2341 is provided between the high-temperature compensation storage tank 234 and the second working medium flow channel. The high-temperature compensation storage tank 234, the fourth working medium pump 2341, and the second working medium flow channel are connected in sequence. A seventeenth solenoid valve 2342 is provided on the inlet pipeline of the fourth working medium pump 2341, and an eighteenth solenoid valve 2343 is provided on the outlet pipeline of the fourth working medium pump 2341. A nineteenth solenoid valve 2351 is provided on the connecting pipeline between the low-temperature recovery storage tank 235 and the second working medium flow channel, so that after the fourth working medium pump 2341 extracts the high-temperature water in the high-temperature compensation storage tank 234 for heat exchange, it flows back to the low-temperature recovery storage tank 235.

[0059] Through the implementation of the above embodiments of the compressed air energy storage system, when the third pressurized water heat exchange component stores energy, the nineteenth solenoid valve 2335 is closed, the fourteenth solenoid valve 2332 and the fifteenth solenoid valve 2333 are opened, and the cold water working medium in the cold water storage tank 233 is pressurized and conveyed to the second working medium flow path by the third working medium pump 2331; the sixteenth solenoid valve 2322 is opened, the seventeenth solenoid valve 2324 and the eighteenth solenoid valve 2325 are shut off. After the cold water working medium exchanges heat with the passing compressed air in the second working medium flow path, it enters the hot water storage tank 232 through the third bypass 2321, thereby realizing the storage process of air compression heat.

[0060] When the third pressurized water heat exchange component releases energy, since the pressurized water working medium stored in the hot water storage tank 232 after continuous compression and heat exchange in the energy storage circuit has a relatively low temperature, its thermal energy cannot meet the requirement of heating the released air. Therefore, control the sixteenth solenoid valve 2322 to close, and control the seventeenth solenoid valve 2342 and the eighteenth solenoid valve 2343 to open. The high-temperature water working medium pre-supplemented in the high-temperature compensation storage tank 234 is pressurized and conveyed to the second working medium flow path by the fourth working medium pump 2341; the nineteenth solenoid valve 2351 is opened. After the high-temperature water working medium heats the passing released air in the second working medium flow path, it returns to the low-temperature recovery storage tank 235, thereby using additional thermal energy to ensure that the released air in the gas storage unit can be heated to a certain temperature at the initial stage to meet the subsequent heat exchange and external work requirements.

[0061] Furthermore, looking back Figure 1 , the outlet of the third air compressor 13 is connected to the third air interface 2311 included in the third pressurized water heat exchange component through the fifth energy storage gas pipeline 133, and a first energy release gas pipeline 33 is connected between the second air interface 2132 included in the second pressurized water heat exchange component 222 and the third air interface 2311 included in the third pressurized water heat exchange component. A twentieth solenoid valve 331 is provided on the first energy release gas pipeline 33;

[0062] A second energy release gas pipeline 311 is connected between the inlet of the first air expander 31 and the first air interface 2131 included in the second molten salt heat exchange component 221, and a twenty-first solenoid valve 312 is provided on the second energy release gas pipeline 311. A third energy release gas pipeline 313 is connected between the outlet of the first air expander 31 and the second air interface 2132 included in the first pressurized water heat exchange component 212, and a twenty-second solenoid valve 314 is provided on the third energy release gas pipeline 313. A fourth energy release gas pipeline 321 is connected between the inlet of the second air expander 32 and the first air interface 2131 included in the first molten salt heat exchange component 211, and a twenty-third solenoid valve 322 is provided on the fourth energy release gas pipeline 321.

[0063] Through the implementation of the above embodiments of the compressed air energy storage system, control the twelfth solenoid valve 142, and fully open the twentieth solenoid valve 331 to the twenty-third solenoid valve 322 to conduct the energy release line, so that the compressed air in the gas storage unit 14 sequentially passes through the third heat exchange unit 23, the second heat exchange unit 22, the first air expander 31, the first heat exchange unit 21, and the second air expander 32, and then is discharged to the outside of the environment. Similarly, control the twentieth solenoid valve 331 to the twenty-third solenoid valve 322 to be fully closed to close the energy release line and facilitate the switching of the energy storage line to be conducted, so as to realize the rapid switching of the system's energy storage and energy release, and further ensure the energy storage and energy release efficiency of the system.

[0064] The present invention also provides an energy storage and energy release method, which is applied to the above-mentioned compressed air energy storage system. The energy storage and energy release method includes:

[0065] In response to the energy storage of the energy storage power station, control the ambient air to enter through the air inlet on the first air compressor 11, and the first air compressor 11 compresses the entering air to obtain primary compressed air;

[0066] Control the primary compressed air to enter the first heat exchange unit 21 for primary compression heat storage, then control the heat-exchanged compressed air to enter the second air compressor 12 for compression to obtain secondary compressed air, control the secondary compressed air to enter the second heat exchange unit 22 for secondary compression heat storage, then control the heat-exchanged compressed air to enter the third air compressor 13 for compression to obtain tertiary compressed air, control the tertiary compressed air to enter the third heat exchange unit 23 for tertiary compression heat storage, and then control the heat-exchanged compressed air to enter the gas storage unit 14 for storage;

[0067] In response to the energy release of the energy storage power station, control the release of the compressed air stored in the gas storage unit 14. The third heat exchange unit 23 exchanges the stored compression heat and compensation heat to the released compressed air, and the second heat exchange unit 22 exchanges the stored compression heat to the compressed air, and control the heat-exchanged compressed air to enter the first air expander 31 to perform primary work on the outside world;

[0068] Control the compressed air after work to enter the first heat exchange unit 21. The first heat exchange unit 21 continues to exchange the stored compression heat to the compressed air, and control the heat-exchanged compressed air to enter the second air expander 32 to perform secondary work on the outside world. Control the compressed air after secondary work to be discharged from the air discharge port on the second air expander 32.

[0069] Through the implementation of the embodiments of the above energy storage and energy release method, the first air compressor 11, the second air compressor 12, and the third air compressor 13 are used to perform multi-stage compression on the air introduced from outside the environment to continuously generate high-temperature compressed air. At the same time, the first heat exchange unit 21, the second heat exchange unit 22, and the third heat exchange unit 23 are respectively used to immediately exchange heat with the compressed air at the outlet of each stage of the air compressor. The molten salt working medium stores the high-temperature compressed heat, and the pressurized water working medium stores the low-temperature compressed heat to fully exchange heat and store energy for the compressed heat at each stage, thereby ensuring the energy storage efficiency. In addition, based on the principle of cascaded utilization of energy, the first heat exchange unit 21, the second heat exchange unit 22, and the third heat exchange unit 23 are heat exchangers shared by energy storage and energy release. When the system releases compressed air, the third heat exchange unit 23 uses the pressurized water working medium to release the stored compressed heat and the pre-stored compensation heat to the compressed air. After the heat-exchanged compressed air is introduced into the second heat exchange unit 22 for heat exchange, it is introduced into the first air expander 31 to do work externally. Then, the compressed air after doing work in the first air expander 31 is directly introduced into the first heat exchange unit 21 for heat exchange, and the heat-exchanged compressed air is introduced into the second air expander 32 to do work externally. The compressed air after doing work is directly discharged to the outside of the environment to ensure the efficiency of the energy storage and energy release cycle in the system, and greatly reduce the area of the heat exchanger required in the conventional energy storage system, thereby effectively reducing the cost.

[0070] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Those skilled in the art can modify the technical solutions described in the above embodiments or equivalently replace some of the technical features; and all such modifications and replacements should fall within the protection scope of the appended claims of the present invention.

Claims

1. A compressed air energy storage system with a shared heat exchanger, characterized in that, The compressed air energy storage system includes: An air compression module, including a first air compressor, a second air compressor, a third air compressor, and a gas storage unit, wherein an air inlet is provided on the first air compressor; A heat exchange and energy storage module, including a first heat exchange unit, a second heat exchange unit, and a third heat exchange unit. The first air compressor, the first heat exchange unit, the second air compressor, the second heat exchange unit, the third air compressor, the third heat exchange unit, and the gas storage unit are connected in sequence to form an energy storage circuit. The first heat exchange unit and the second heat exchange unit both exchange heat and store the compression heat of the compressed air through molten salt coupled with pressurized water working medium, and the third heat exchange unit exchanges heat and stores the residual heat of the compressed air through pressurized water working medium; The first heat exchange unit includes a first molten salt heat exchange component and a first pressurized water heat exchange component. The second heat exchange unit includes a second molten salt heat exchange component and a second pressurized water heat exchange component. The first molten salt heat exchange component includes a first common heat exchanger, a first high-temperature storage tank, and a first low-temperature storage tank. A first working medium flow channel is provided in the first common heat exchanger, and a first air flow channel is arranged for heat exchange with the first working medium flow channel. A first air interface communicating with one end of the first air flow channel and a second air interface communicating with the other end of the first air flow channel are provided on the first common heat exchanger. The composition structures of the first pressurized water heat exchange component, the second molten salt heat exchange component, and the second pressurized water heat exchange component are all the same as the composition structure of the first molten salt heat exchange component; A fourth energy storage gas pipeline is connected between the second air interface included in the second pressurized water heat exchange component and the inlet of the third air compressor, and a pressurized water heat exchanger is provided on the fourth energy storage gas pipeline; The third heat exchange unit includes a third pressurized water heat exchange component. The third pressurized water heat exchange component includes a second common heat exchanger, a hot water storage tank, a cold water storage tank, a high-temperature compensation storage tank, and a low-temperature recovery storage tank. A second working medium flow channel is provided in the second common heat exchanger. The hot water storage tank is connected to one end of the second working medium flow channel, and the cold water storage tank is connected to the other end of the second working medium flow channel, and cold water is pre-stored in the cold water storage tank. The high-temperature compensation storage tank is connected to one end of the second working medium flow channel, and the low-temperature recovery storage tank is connected to the other end of the second working medium flow channel, and high-temperature water is pre-stored in the high-temperature compensation storage tank. A second air flow channel is also provided in the second common heat exchanger for heat exchange with the second working medium flow channel. A third air interface communicating with one end of the second air flow channel and a fourth air interface communicating with the other end of the second air flow channel are provided on the second common heat exchanger; The air work module includes a first air expander and a second air expander. An air discharge port is provided on the second air expander. The third heat exchange unit, the second heat exchange unit, the first air expander, the first heat exchange unit, and the second air expander are connected in sequence and form an energy release line that is reverse to the energy storage line. The third heat exchange unit also releases the stored compression heat and compensation heat to the compressed air through a pressurized water working medium. The second heat exchange unit and the first heat exchange unit also release the stored compression heat to the compressed air through molten salt coupling with the pressurized water working medium.

2. The compressed air energy storage system with a shared heat exchanger according to claim 1, wherein: The first high-temperature storage tank is connected to one end of the first working medium flow channel, and the first low-temperature storage tank is connected to the other end of the first working medium flow channel. A low-temperature working medium is pre-stored in the first low-temperature storage tank.

3. The compressed air energy storage system with a shared heat exchanger according to claim 2, wherein: A first working medium pump is provided between the first low-temperature storage tank and the first working medium flow channel. The first low-temperature storage tank, the first working medium pump, and the first working medium flow channel are connected in sequence. A first solenoid valve is provided on the inlet pipeline of the first working medium pump, and a second solenoid valve is provided on the outlet pipeline of the first working medium pump. A first bypass is connected between the first high-temperature storage tank and the first working medium flow channel, so that after the first working medium pump extracts the low-temperature working medium in the first low-temperature storage tank for heat exchange, it is stored in the first high-temperature storage tank along the first bypass. A third solenoid valve is provided on the first bypass; A second working medium pump is provided between the first high-temperature storage tank and the first working medium flow channel. The first high-temperature storage tank, the second working medium pump, and the first working medium flow channel are connected in sequence. A fourth solenoid valve is provided on the inlet pipeline of the second working medium pump, and a fifth solenoid valve is provided on the outlet pipeline of the second working medium pump. A second bypass is connected between the first low-temperature storage tank and the first working medium flow channel, so that after the second working medium pump extracts the high-temperature working medium in the first high-temperature storage tank for heat exchange, it flows back to the first low-temperature storage tank along the second bypass. A sixth solenoid valve is provided on the second bypass.

4. The compressed air energy storage system with a shared heat exchanger according to claim 2 or 3, characterized in that: A first energy storage gas pipeline is connected between the outlet of the first air compressor and the first air interface included in the first molten salt heat exchange assembly, and a seventh solenoid valve is provided on the first energy storage gas pipeline. The second air interface included in the first molten salt heat exchange assembly is connected to the first air interface included in the first pressurized water heat exchange assembly; A second energy storage gas pipeline is connected between the second air interface included in the first pressurized water heat exchange assembly and the inlet of the second air compressor. An eighth solenoid valve is provided on the second energy storage gas pipeline. A third energy storage gas pipeline is connected between the outlet of the second air compressor and the first air interface included in the second molten salt heat exchange assembly, and a ninth solenoid valve is provided on the third energy storage gas pipeline; The second air interface included in the second molten salt heat exchange component is connected to the first air interface included in the second pressurized water heat exchange component. A fourth energy storage gas pipeline is connected between the second air interface included in the second pressurized water heat exchange component and the inlet of the third air compressor. A tenth solenoid valve is provided on the fourth energy storage gas pipeline. A fifth energy storage gas pipeline is connected between the outlet of the third air compressor and the third heat exchange unit, and an eleventh solenoid valve is provided on the fifth energy storage gas pipeline; A sixth energy storage gas pipeline is provided between the third heat exchange unit and the gas storage unit, and a twelfth solenoid valve is provided on the sixth energy storage gas pipeline.

5. The compressed air energy storage system with a shared heat exchanger according to claim 4, wherein: The tenth solenoid valve is located on the outlet side of the pressurized water heat exchanger, and a thirteenth solenoid valve is provided on the fourth energy storage gas pipeline on the inlet side of the pressurized water heat exchanger.

6. The compressed air energy storage system with a shared heat exchanger according to claim 1, wherein: A third working medium pump is provided between the cold water storage tank and the second working medium flow channel. The cold water storage tank, the third working medium pump, and the second working medium flow channel are connected in sequence. A fourteenth solenoid valve is provided on the inlet pipeline of the third working medium pump, and a fifteenth solenoid valve is provided on the outlet pipeline of the third working medium pump. A third bypass is connected between the hot water storage tank and the second working medium flow channel, so that after the third working medium pump extracts the cold water in the cold water storage tank for heat exchange, it is stored in the hot water storage tank along the third bypass. A sixteenth solenoid valve is provided on the third bypass.

7. The compressed air energy storage system with a shared heat exchanger according to claim 6, wherein: A fourth working medium pump is provided between the high-temperature compensation storage tank and the second working medium flow channel. The high-temperature compensation storage tank, the fourth working medium pump, and the second working medium flow channel are connected in sequence. A seventeenth solenoid valve is provided on the inlet pipeline of the fourth working medium pump, and an eighteenth solenoid valve is provided on the outlet pipeline of the fourth working medium pump. A nineteenth solenoid valve is provided on the pipeline connecting the low-temperature recovery storage tank and the second working medium flow channel, so that after the fourth working medium pump extracts the high-temperature water in the high-temperature compensation storage tank for heat exchange, it flows back to the low-temperature recovery storage tank.

8. The compressed air energy storage system with a shared heat exchanger according to any one of claims 6-7, characterized in that: A first energy release gas pipeline is connected between the second air interface included in the second pressurized water heat exchange component and the third air interface included in the third pressurized water heat exchange component. A twentieth solenoid valve is provided on the first energy release gas pipeline; A second energy release gas pipeline is connected between the inlet of the first air expander and the first air interface included in the second molten salt heat exchange component, and a twenty-first solenoid valve is provided on the second energy release gas pipeline. A third energy release gas pipeline is connected between the outlet of the first air expander and the second air interface included in the first pressurized water heat exchange component, and a twenty-second solenoid valve is provided on the third energy release gas pipeline; A fourth energy release gas pipeline is connected between the inlet of the second air expander and the first air interface included in the first molten salt heat exchange component, and a twenty-third solenoid valve is provided on the fourth energy release gas pipeline.

9. A method for energy storage and release, characterized in that, For a compressed air energy storage system using the common heat exchanger according to any one of claims 1-8, the energy storage and energy release method includes: In response to the energy storage of the energy storage power station, control the ambient air to enter through the air inlet on the first air compressor, and the first air compressor compresses the entering air to obtain primary compressed air; Control the primary compressed air to enter the first heat exchange unit for primary compression heat storage, then control the compressed air after heat exchange to enter the second air compressor for compression to obtain secondary compressed air, control the secondary compressed air to enter the second heat exchange unit for secondary compression heat storage, then control the compressed air after heat exchange to enter the third air compressor for compression to obtain tertiary compressed air, control the tertiary compressed air to enter the third heat exchange unit for tertiary compression heat storage, and then control the compressed air after heat exchange to enter the gas storage unit for storage; In response to the energy release of the energy storage power station, control the release of the compressed air stored in the gas storage unit. The third heat exchange unit exchanges the stored compression heat and compensation heat to the released compressed air, and the second heat exchange unit exchanges the stored compression heat to the compressed air, and control the compressed air after heat exchange to enter the first air expander to perform primary work on the outside world; Control the compressed air after work to enter the first heat exchange unit. The first heat exchange unit continues to exchange the stored compression heat to the compressed air, and control the compressed air after heat exchange to enter the second air expander to perform secondary work on the outside world. Control the compressed air after secondary work to be discharged from the air outlet on the second air expander.

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