Compressed air energy storage system coupled with LNG cold energy utilization

Abstract

The invention relates to the technical field of LNG (Liquefied Natural Gas) gasification and compressed air energy storage, and discloses a compressed air energy storage system coupled with LNG cold energy utilization, which comprises an electric energy storage system, a compressed air subsystem, an LNG gasification subsystem and an organic Rankine cycle subsystem, the compressed air subsystem is used for compressing and storing external air, the LNG gasification subsystem is used for regasifying stored LNG, cold energy in the LNG gasification subsystem is converted into electric energy through the organic Rankine cycle subsystem to be output and used or stored through the compressed air subsystem, and the compressed air subsystem is used for storing external electric energy; the stored electric energy is output through the electric energy output system; and the auxiliary system comprises an auxiliary heat exchange subsystem and an auxiliary heat source subsystem which are respectively communicated with the compressed air subsystem. According to the LNG cold energy power generation system, LNG cold energy power generation is achieved, electric energy is directly used or stored in a compressed air mode, and electric energy of multiple sources of gas can be stored.

Description

Technical Field

[0001] The present invention relates to the technical field of LNG gasification and compressed air energy storage, and particularly relates to a compressed air energy storage system coupled with LNG cold energy utilization. Background Art

[0002] The invention patent with the application number CN202410354584.6 discloses a liquid compressed air energy storage system and method coupled with an LNG gasification station, belonging to the field of liquid compressed air energy storage. The system includes an air compression circuit provided with 2 compressors, 2 heat exchangers on the compression side, a cold box, a throttle valve and a gas-liquid separator, an air expansion circuit provided with a liquid air booster pump, an evaporator, 2 heat exchangers on the expansion side and 2 expanders, a heat energy storage and release circuit provided with a normal temperature water storage tank, 2 heat exchangers on the compression side, a high temperature water storage tank, 2 booster pumps, 2 heat exchangers on the expansion side and a gasification heater, a cold energy storage and release circuit provided with a low temperature storage tank, 2 pumps, a normal temperature storage tank, a cold box and an evaporator, and an LNG gasification circuit provided with an LNG gasification station, an air cooler, a gasification heater and a natural gas turbine; the method includes a heat storage period and a heat release period. This invention effectively couples an LNG gasification station with liquid compressed air technology, improving the comprehensive utilization rate of energy.

[0003] In the prior art, compressed air is liquefied using LNG cold energy, and then electrical energy is output by means of gasification expansion driving a turbine expander and a generator. Since liquefaction is involved, cold energy is required. When the flow rate of LNG does not match the time and the air liquefaction time, this system cannot store electrical energy by liquefying air. The prior art only stores the electrical energy converted from LNG cold energy.

[0004] Therefore, there is an urgent need for a compressed air energy storage system coupled with LNG cold energy utilization to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a compressed air energy storage system coupled with LNG cold energy utilization to solve the problems existing in the above prior art.

[0006] To achieve the above purpose, the present invention provides the following solution: The present invention provides a compressed air energy storage system coupled with LNG cold energy utilization, including:

[0007] An electrical energy storage system, including a compressed air subsystem, an LNG gasification subsystem and an organic Rankine cycle subsystem;

[0008] The compressed air subsystem is used to compress and store external air, and the LNG gasification subsystem is used to regasify the stored LNG. When the LNG gasification subsystem operates, the cold energy in the LNG gasification subsystem is converted into electrical energy for output use through the organic Rankine cycle subsystem or stored through the compressed air subsystem. When the LNG gasification subsystem does not operate, the compressed air subsystem is used to store external electrical energy;

[0009] The electrical energy output system. When power is needed, the electrical energy stored in the compressed air subsystem is output through the electrical energy output system;

[0010] The auxiliary system includes an auxiliary heat exchange subsystem and an auxiliary heat source subsystem, and the auxiliary heat exchange subsystem and the auxiliary heat source subsystem are respectively connected to the compressed air subsystem.

[0011] According to a compressed air energy storage system coupled with LNG cold energy utilization provided by the present invention, the compressed air subsystem includes a first compressor, a first heat exchanger, a second compressor, a second heat exchanger, a first stop valve and a compressed air storage tank arranged in sequence from left to right. External gas is stored in the compressed air storage tank after passing through the first compressor, the first heat exchanger, the second compressor, the second heat exchanger and the first stop valve in sequence.

[0012] According to a compressed air energy storage system coupled with LNG cold energy utilization provided by the present invention, the LNG gasification subsystem includes an LNG storage tank, an LNG booster pump, a fifth heat exchanger, a sixth heat exchanger and a fifth expander arranged in sequence from right to left. The LNG stored in the LNG storage tank is converted into natural gas and transported to the user end after passing through the LNG booster pump, the fifth heat exchanger, the sixth heat exchanger and the fifth expander in sequence.

[0013] According to a compressed air energy storage system coupled with LNG cold energy utilization provided by the present invention, the organic Rankine cycle subsystem includes a third expander, a first booster pump, a fourth expander and a second booster pump; the sixth heat exchanger is connected to the first heat exchanger through the first booster pump, the sixth heat exchanger and the first heat exchanger are respectively connected to the third expander, the fifth heat exchanger is connected to the second compressor through the second booster pump, and the fifth heat exchanger and the second booster pump are respectively connected to the fourth expander.

[0014] According to a compressed air energy storage system coupled with LNG cold energy utilization provided by the present invention, the electrical energy output system includes a third heat exchanger, a first expander, a fourth heat exchanger and a second expander connected in sequence from right to left, and the third heat exchanger is connected to the compressed air storage tank.

[0015] According to a compressed air energy storage system coupled with LNG cold energy utilization provided by the present invention, the first heat exchanger and the second heat exchanger are respectively communicated with the auxiliary heat exchange subsystem.

[0016] According to a compressed air energy storage system coupled with LNG cold energy utilization provided by the present invention, the third heat exchanger and the fourth heat exchanger are respectively communicated with the auxiliary heat source subsystem.

[0017] According to a compressed air energy storage system coupled with LNG cold energy utilization provided by the present invention, the auxiliary heat source subsystem is solar energy or waste heat from a power plant.

[0018] Compared with the prior art, the present invention has the following advantages and technical effects:

[0019] In a compressed air energy storage system coupled with LNG cold energy utilization provided by the present invention, the compressed air subsystem is used to compress and store external air, and the LNG gasification subsystem is used to regasify the stored LNG. When there is a need for LNG regasification and it is not during the peak electricity consumption period, the cold energy of LNG is converted into electric energy through technical means such as an organic Rankine cycle, a booster pump, and an expander, and then the electric energy is stored in the form of compressed air. When there is no need for LNG regasification, that is, when there is no cold energy of LNG provided, during the low electricity consumption period, or when there is other forms of renewable energy power generation and electricity storage demand, the excess electric energy is stored in the form of compressed air through the compressed air subsystem. When there is a need for LNG regasification and it is during the peak electricity consumption period, at this stage, the cold energy of LNG is converted into electric energy and directly output and used, instead of using compressed air for storage. During the peak electricity consumption period, the stored electric energy is output through the electric energy output system. At the same time, when the cold energy provided by the LNG gasification subsystem does not match the compressed heat energy in the compressed air subsystem, the auxiliary heat exchange subsystem is used to balance the heat exchange amount. When the electric energy is output, the air is heated through the auxiliary heat source subsystem. In this application, through the organic Rankine cycle, the cold energy of LNG in the LNG gasification subsystem and the compressor heat energy in the compressed air subsystem are converted into electric energy, and then stored in the form of compressed air, and then the electric energy is released through the electric energy output system when needed. Through the setting of several operation modes, when the LNG flow rate and usage time, and the compressed air flow rate and energy storage time do not match, the system can operate normally through the external auxiliary subsystem. This application can not only store the electric energy converted from the cold energy of LNG, but also store other sources of electric energy, such as wind power generation and grid valley electricity, promote the transformation of the energy structure and the consumption of renewable energy, and solve the problem of supply-demand mismatch. Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings:

[0021] Figure 1 Schematic diagram of the overall structure of the present invention;

[0022] Wherein, 1. First compressor; 2. First heat exchanger; 3. Second compressor; 4. Second heat exchanger; 5. First stop valve; 6. Compressed air storage tank; 7. Second stop valve; 8. Third heat exchanger; 9. First expander; 10. Fourth heat exchanger; 11. Second expander; 12. Third expander; 13. First booster pump; 14. Fourth expander; 15. Second booster pump; 16. LNG storage tank; 17. LNG booster pump; 18. Fifth heat exchanger; 19. Sixth heat exchanger; 20. Fifth expander. Detailed implementation manners

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0024] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the drawings and specific implementation manners.

[0025] Referring to Figure 1 , the present invention provides a compressed air energy storage system coupled with LNG cold energy utilization, including:

[0026] An electric energy storage system, including a compressed air subsystem, an LNG gasification subsystem, and an organic Rankine cycle subsystem;

[0027] The compressed air subsystem is used to compress and store external air, and the LNG gasification subsystem is used to regasify the stored LNG. When the LNG gasification subsystem operates, the cold energy in the LNG gasification subsystem is converted into electric energy for output and use through the organic Rankine cycle subsystem or stored through the compressed air subsystem. When the LNG gasification subsystem does not operate, the compressed air subsystem is used to store external electric energy;

[0028] An electric energy output system. When power is needed, the electric energy stored in the compressed air subsystem is output through the electric energy output system;

[0029] An auxiliary system, including an auxiliary heat exchange subsystem and an auxiliary heat source subsystem, the auxiliary heat exchange subsystem and the auxiliary heat source subsystem are respectively communicated with the compressed air subsystem.

[0030] In an embodiment of the present invention, the compressed air subsystem is used to compress and store the outside air, the LNG gasification subsystem is used to regasify the stored LNG. When there is a need for LNG regasification and it is not during the peak electricity consumption period, the cold energy of LNG is converted into electric energy through technical means such as an organic Rankine cycle, a booster pump, and an expander, and then the electric energy is stored in the form of compressed air. When there is no need for LNG regasification, that is, when there is no cold energy of LNG provided, during the low electricity consumption period, or when there is other forms of renewable energy power generation and there is a need for electric energy storage, the excess electric energy is stored in the form of compressed air through the compressed air subsystem. When there is a need for LNG regasification and it is during the peak electricity consumption period, at this stage, the cold energy of LNG is converted into electric energy and directly output and used, instead of using compressed air for storage. During the peak electricity consumption period, the stored electric energy is output through the electric energy output system. At the same time, when the cold energy provided by the LNG gasification subsystem does not match the compressed heat energy part in the compressed air subsystem, the auxiliary heat exchange subsystem is used to balance the heat exchange amount, and when the electric energy is output, the auxiliary heat source subsystem is used to heat and raise the temperature of the air.

[0031] As an alternative embodiment, the compressed air subsystem includes a first compressor 1, a first heat exchanger 2, a second compressor 3, a second heat exchanger 4, a first stop valve 5, and a compressed air storage tank 6 arranged in sequence from left to right. The outside gas is stored in the compressed air storage tank 6 after passing through the first compressor 1, the first heat exchanger 2, the second compressor 3, the second heat exchanger 4, and the first stop valve 5 in sequence.

[0032] In an embodiment of the present invention, first, the pressure is increased and the temperature is raised through the first compressor 1, then the temperature is lowered through the first heat exchanger 2, then the pressure is continuously increased and the temperature is raised through the second compressor 3, then the temperature is lowered again through the second heat exchanger 4, and then it is introduced into the compressed air storage tank 6 through the first stop valve 5 for storage. During the low electricity consumption period, or when there is other forms of renewable energy power generation and there is a need for electric energy storage, the excess electric energy is stored in the form of compressed air through the compressed air subsystem.

[0033] As an alternative embodiment, the LNG gasification subsystem includes an LNG storage tank 16, an LNG booster pump 17, a fifth heat exchanger 18, a sixth heat exchanger 19, and a fifth expander 20 arranged in sequence from right to left. The LNG stored in the LNG storage tank 16 is converted into natural gas and transported to the user end after passing through the LNG booster pump 17, the fifth heat exchanger 18, the sixth heat exchanger 19, and the fifth expander 20 in sequence.

[0034] In one embodiment of the present invention, after LNG is output from the LNG storage tank 16, its pressure is increased by the LNG booster pump 17, and then its temperature is increased to normal temperature by passing through the fifth heat exchanger 18 and the sixth heat exchanger 19 in sequence. Then, it expands and reduces pressure in the fifth expander 20 and performs power output. Finally, the natural gas at normal temperature and pressure is transported to the user side for use.

[0035] As an alternative embodiment, the organic Rankine cycle subsystem includes a third expander 12, a first booster pump 13, a fourth expander 14, and a second booster pump 15; the sixth heat exchanger 19 is connected to the first heat exchanger 2 through the first booster pump 13, and the sixth heat exchanger 19 and the first heat exchanger 2 are respectively connected to the third expander 12. The fifth heat exchanger 18 is connected to the second compressor 3 through the second booster pump 15, and the fifth heat exchanger 18 and the second booster pump 15 are respectively connected to the fourth expander 14.

[0036] In one embodiment of the present invention, the circulating working fluid in a state lower than gaseous state absorbs the cold energy of LNG and cools and liquefies after passing through the sixth heat exchanger 19, and then its pressure is increased by the first booster pump 13. Then, it enters the first heat exchanger 2 to absorb the compression heat of the compressed air in the air compression subsystem, heats up and vaporizes, and finally enters the third expander 12 to expand and reduce pressure and perform power output.

[0037] As an alternative embodiment, the power output system includes a third heat exchanger 8, a first expander 9, a fourth heat exchanger 10, and a second expander 11 that are connected in sequence from right to left. The third heat exchanger 8 is connected to the compressed air storage tank 6.

[0038] In one embodiment of the present invention, the compressed air stored in the compressed air storage tank 6 enters the third heat exchanger 8 through the second stop valve 7, and then enters the first expander 9 to reduce pressure and expand and perform power output. Then, the air continues to enter the fourth heat exchanger 10 and the second expander 11 to reduce pressure and expand and perform power output.

[0039] As an alternative embodiment, the first heat exchanger 2 and the second heat exchanger 4 are respectively connected to the auxiliary heat exchange subsystem.

[0040] In one embodiment of the present invention, both the first heat exchanger 2 and the second heat exchanger 4 exchange heat with the auxiliary heat exchange subsystems a1-a2 and b1-b2.

[0041] As an alternative embodiment, the third heat exchanger 8 and the fourth heat exchanger 10 are respectively connected to the auxiliary heat source subsystem.

[0042] In one embodiment of the present invention, the compressed air stored in the compressed air storage tank 6 enters the third heat exchanger 8 through the second stop valve 7, exchanges heat with the auxiliary heat source subsystem c1-d1 to increase the temperature, then enters the first expander 9 to expand under reduced pressure and output electric energy. Then the air continues to enter the fourth heat exchanger 10 to exchange heat with the auxiliary heat source subsystem c2-d2 again to increase the temperature, and then enters the second expander 11 to expand under reduced pressure and output electric energy.

[0043] As an alternative embodiment, the auxiliary heat source subsystem is solar energy or waste heat from a power plant.

[0044] In one embodiment of the present invention, the auxiliary heat source subsystem can select solar energy, waste heat from a power plant or other forms of heat sources.

[0045] The working mode of this application:

[0046] The first working mode:

[0047] When there is a need for LNG regasification and it is not during the peak electricity consumption period, the cold energy of LNG is converted into electric energy through technical means such as the organic Rankine cycle, booster pump, expander, etc. Then the electric energy is stored in the form of compressed air, and when there is an electricity demand, the compressed air is expanded and converted into electric energy for output.

[0048] After the air enters the compressed air subsystem, it first passes through the first compressor 1 to increase the pressure and temperature, then passes through the first heat exchanger 2 to cool down, and then passes through the second compressor 3 to continue increasing the pressure and temperature, and then enters the second heat exchanger 4 to cool down again, and then passes through the first stop valve 5 and is introduced into the compressed air storage tank 6 for storage. While the compressed air subsystem is working, the LNG regasification subsystem and the organic Rankine cycle subsystem are also operating. The working process of the LNG gasification subsystem is as follows: After the LNG is output from the LNG storage tank 16, it passes through the LNG booster pump 17 to increase the pressure, and then sequentially passes through the fifth heat exchanger 18 and the sixth heat exchanger 19 to increase the temperature to normal temperature, and then expands and reduces the pressure in the fifth expander 20, and electric energy is output. Finally, the natural gas at normal temperature and pressure is transported to the user end for use. The working process of the organic Rankine cycle subsystem is as follows: Taking the first organic Rankine cycle subsystem on the left as an example, the circulating working fluid below the gaseous state passes through the sixth heat exchanger 19, absorbs the cold energy of the LNG and cools down and liquefies, then passes through the first booster pump 13 to increase the pressure, and then enters the first heat exchanger 2 to absorb the compression heat of the compressed air in the air compression subsystem, heats up and vaporizes, and finally passes through the third expander 12 to expand and reduce the pressure, and electric energy is output. Among them, the power-consuming units are: the first compressor 1, the second compressor 3, the first booster pump 13, the second booster pump 15, and the LNG booster pump 17; the electric energy output units are: the third expander 12, the fourth expander 14, and the fifth expander 20; all the power-consuming units are supplied with electric energy by the electric energy output units. When the cold energy provided by the LNG in the LNG gasification subsystem does not match the compression heat energy in the compressed air subsystem, the auxiliary heat exchange subsystems a1-a2 and b1-b2 are used to balance the heat exchange amount.

[0049] The second working mode:

[0050] When there is no need for LNG regasification, that is, when there is no cold energy of LNG provided, during the low electricity consumption period, or when there is other forms of renewable energy power generation and electricity storage requirements, the excess electric energy is stored in the form of compressed air through the compressed air subsystem. When the LNG regasification subsystem and the organic Rankine cycle subsystem are not working, after the air enters the compressed air subsystem, it first passes through the first compressor 1 to increase the pressure and temperature, then passes through the first heat exchanger 2 to cool down, and then passes through the second compressor 3 to continue increasing the pressure and temperature, and then enters the second heat exchanger 4 to cool down again, and then passes through the first stop valve 5 and is introduced into the compressed air storage tank 6 for storage. Among them, the compressed air exchanges heat with the auxiliary heat exchange subsystems a1-a2 and b1-b2 in both the first heat exchanger 2 and the second heat exchanger 4.

[0051] The third working mode:

[0052] There is a demand for LNG regasification and it is at the peak of electricity consumption. During this stage, the cold energy of LNG is converted into electric energy for direct output and use, without using compressed air for storage. When the compressed air subsystem is not working, after the LNG is output from the LNG storage tank 16, its pressure is increased by the LNG booster pump 17, and then it sequentially passes through the fifth heat exchanger 18 and the sixth heat exchanger 19 to increase the temperature to normal temperature. Then it expands and reduces pressure in the fifth expander 20 and outputs electric energy. Finally, the natural gas at normal temperature and pressure is transported to the user side for use. Taking the first organic Rankine cycle subsystem on the left as an example, the circulating working fluid in a state lower than gaseous absorbs the cold energy of LNG and cools and liquefies after passing through the sixth heat exchanger 19, and then the pressure is increased by the first booster pump 13. Then it enters the first heat exchanger 2 to absorb the compression heat of the compressed air in the air compression subsystem, heats up and vaporizes, and finally passes into the third expander 12 to expand and reduce pressure and output electric energy. Among them, the organic Rankine cycle working fluid exchanges heat with the auxiliary heat exchange subsystems a1 - a2, b1 - b2 in both the first heat exchanger 2 and the second heat exchanger 4.

[0053] The fourth working mode:

[0054] When there is electric energy stored in the form of compressed air in the first working mode and the second working mode and there is a demand for electric energy output, this working mode starts to operate. During the peak of electricity consumption, the compressed air stored in the compressed air storage tank 6 enters the third heat exchanger 8 through the second stop valve 7, exchanges heat with the auxiliary heat source subsystem c1 - d1 to increase the temperature, and then enters the first expander 9 to expand and reduce pressure and output electric energy. Then the air continues to enter the fourth heat exchanger 10 to exchange heat with the auxiliary heat source subsystem c2 - d2 again to increase the temperature, and then enters the second expander 11 to expand and reduce pressure and output electric energy.

[0055] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention, 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 therefore cannot be understood as a limitation to the present invention.

[0056] The embodiments described above are only descriptions of the preferred modes of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. A compressed air energy storage system coupled with LNG cold energy utilization, characterized in that: include: The electrical energy storage system includes a compressed air subsystem, an LNG gasification subsystem, and an organic Rankine cycle subsystem; The compressed air subsystem is used to compress and store external air, and the LNG gasification subsystem is used to regasify the stored LNG. When the LNG gasification subsystem is in operation, the cold energy in the LNG gasification subsystem is converted into electrical energy for output and use or stored through the compressed air subsystem through the organic Rankine cycle subsystem. When the LNG gasification subsystem is not in operation, the compressed air subsystem is used to store external electrical energy. An electric energy output system, when electricity is needed, the electric energy stored in the compressed air subsystem is output through the electric energy output system; The auxiliary system comprises an auxiliary heat exchange subsystem and an auxiliary heat source subsystem, wherein the auxiliary heat exchange subsystem and the auxiliary heat source subsystem are respectively connected to the compressed air subsystem.

2. A compressed air energy storage system coupled with LNG cold energy utilization according to claim 1, characterized in that: The compressed air subsystem comprises a first compressor (1), a first heat exchanger (2), a second compressor (3), a second heat exchanger (4), a first stop valve (5) and a compressed air storage tank (6) which are arranged in sequence from left to right. External gas passes through the first compressor (1), the first heat exchanger (2), the second compressor (3), the second heat exchanger (4) and the first stop valve (5) in sequence and is then stored in the compressed air storage tank (6).

3. A compressed air energy storage system coupled with LNG cold energy utilization according to claim 2, characterized in that: The LNG gasification subsystem comprises an LNG storage tank (16), an LNG boosting pump (17), a fifth heat exchanger (18), a sixth heat exchanger (19) and a fifth expansion machine (20) which are arranged in sequence from right to left. The LNG stored in the LNG storage tank (16) passes through the LNG boosting pump (17), the fifth heat exchanger (18), the sixth heat exchanger (19) and the fifth expansion machine (20) in sequence and is converted into natural gas and transported to the user end.

4. A compressed air energy storage system coupled with LNG cold energy utilization according to claim 3, characterized in that: The organic Rankine cycle subsystem comprises a third expander (12), a first booster pump (13), a fourth expander (14) and a second booster pump (15); the sixth heat exchanger (19) is connected to the first heat exchanger (2) through the first booster pump (13), the sixth heat exchanger (19) and the first heat exchanger (2) are respectively connected to the third expander (12), the fifth heat exchanger (18) is connected to the second compressor (3) through the second booster pump (15), and the fifth heat exchanger (18) and the second booster pump (15) are respectively connected to the fourth expander (14).

5. A compressed air energy storage system coupled with LNG cold energy utilization according to claim 2, characterized in that: The electric energy output system comprises a third heat exchanger (8), a first expander (9), a fourth heat exchanger (10) and a second expander (11) which are connected in sequence from right to left, and the third heat exchanger (8) is connected to the compressed air storage tank (6).

6. A compressed air energy storage system coupled with LNG cold energy utilization according to claim 2, characterized in that: The first heat exchanger (2) and the second heat exchanger (4) are respectively connected to the auxiliary heat exchange subsystem.

7. A compressed air energy storage system coupled with LNG cold energy utilization according to claim 5, characterized in that: The third heat exchanger (8) and the fourth heat exchanger (10) are respectively connected to the auxiliary heat source subsystem.

8. A compressed air energy storage system coupled with LNG cold energy utilization according to claim 7, characterized in that: The auxiliary heat source subsystem is solar energy or waste heat from a power plant.

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