A compound heat-exchange compressed air energy storage system and energy storage method

Abstract

The application belongs to the technical field of compressed air energy storage, and particularly relates to a compressed air energy storage system with compound heat exchange and an energy storage method. The compressed air energy storage system with compound heat exchange is characterized in that: the outlet air of the first compressor is sequentially cooled by the high-temperature heat storage mechanism, the medium-temperature heat storage mechanism and the water heat storage mechanism; the outlet air of the second compressor is sequentially cooled by the medium-temperature heat storage mechanism and the water heat storage mechanism; the inlet air of the first turbine is sequentially heated by the water heat storage mechanism and the medium-temperature heat storage mechanism; the inlet air of the second turbine is sequentially heated by the water heat storage mechanism, the medium-temperature heat storage mechanism and the high-temperature heat storage mechanism; the heat storage capacity of the high-temperature heat storage mechanism is greater than that of the medium-temperature heat storage mechanism, and the heat storage capacity of the medium-temperature heat storage mechanism is greater than that of the water heat storage mechanism. The application realizes heat exchange and heating by setting three heat exchange mechanisms, solves the problem of excessively large end difference of the heat exchanger caused by using a single heat exchange medium, and enables the water in the water heat storage mechanism to remain in a liquid state.

Description

A compressed air energy storage system and energy storage method with dual heat exchange Technical Field

[0001] This invention belongs to the field of compressed air energy storage technology, specifically relating to a compressed air energy storage system and energy storage method with a dual heat exchange. Background Technology

[0002] Compressed air energy storage technology offers advantages over pumped hydro storage, gravity storage, and electrochemical storage technologies, including wider applicability, lower construction costs, and longer service life. Compressed air energy storage technologies can be categorized into traditional compressed air energy storage, advanced adiabatic compressed air energy storage, heat exchange compressed air energy storage, isothermal compressed air energy storage, liquid air energy storage, supercritical compressed air energy storage, underwater compressed air energy storage, and compressed air energy storage coupled with an external heat source. Among these, advanced adiabatic compressed air energy storage systems store the large amount of heat generated during compression and then use this stored heat to reheat the compressed air during energy release, thereby driving a turbine to perform work.

[0003] Increasing the thermal storage temperature can improve the electro-electric conversion efficiency of the adiabatic compressed air energy storage system. However, to maintain the stored water in a liquid state at high temperatures, the pressure of the stored water needs to be increased, leading to higher costs for the storage tank. Using heat transfer oil as the heat exchange medium can achieve high-temperature thermal storage at atmospheric pressure; however, using a single heat exchange medium can result in excessive temperature differences between the heat exchanger terminals, reducing system efficiency.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a compressed air energy storage system and energy storage method with a duplex heat exchange. The present invention achieves heat exchange and heating by setting up a three-stage heat exchange mechanism, which solves the problem of excessive heat exchanger terminal difference caused by using a single heat exchange medium, and at the same time enables the water in the water storage mechanism to be kept in a liquid state.

[0006] This invention includes the following technical solutions:

[0007] The present invention provides a compressed air energy storage system with a dual heat exchange, comprising: a first compressor, a second compressor, an air storage tank, a first turbine, and a second turbine connected in sequence; and further comprising a high-temperature heat storage mechanism, a medium-temperature heat storage mechanism, and a water heat storage mechanism;

[0008] The outlet air of the first compressor is cooled sequentially by passing through the high-temperature heat storage mechanism, the medium-temperature heat storage mechanism, and the water heat storage mechanism.

[0009] The outlet air of the second compressor is cooled sequentially by the medium-temperature heat storage mechanism and the water heat storage mechanism;

[0010] The inlet air of the first turbine is heated sequentially by the water heat storage mechanism and the medium-temperature heat storage mechanism; the inlet air of the second turbine is heated sequentially by the water heat storage mechanism, the medium-temperature heat storage mechanism and the high-temperature heat storage mechanism.

[0011] Among them, the heat storage capacity of high-temperature heat storage mechanism > heat storage capacity of medium-temperature heat storage mechanism > heat storage capacity of water heat storage mechanism.

[0012] Furthermore, the high-temperature heat storage mechanism includes a first high-temperature tank for heat exchange medium, a first low-temperature tank for heat exchange medium, a first high-temperature heat exchanger, and a second high-temperature heat exchanger.

[0013] The first high-temperature heat exchanger is connected to the inlet of the first high-temperature heat exchange medium tank, the outlet of the first high-temperature heat exchange medium tank is connected to the second high-temperature heat exchanger, the second high-temperature heat exchanger is connected to the inlet of the first low-temperature heat exchange medium tank, and the outlet of the first low-temperature heat exchange medium tank is connected to the first high-temperature heat exchanger.

[0014] The first high-temperature heat exchanger is installed on the outlet pipe of the first compressor, and the second high-temperature heat exchanger is installed on the inlet pipe of the second turbine.

[0015] Furthermore, the high-temperature heat storage mechanism also includes a third high-temperature heat exchanger and a fourth high-temperature heat exchanger, wherein the second high-temperature heat exchanger is connected to the inlet of the first heat exchange medium high-temperature tank and the second high-temperature heat exchanger is connected to the outlet of the first heat exchange medium low-temperature tank.

[0016] The third high-temperature heat exchanger is installed on the outlet pipe of the second compressor, and a first shut-off valve is installed between the second compressor and the third high-temperature heat exchanger.

[0017] A second shut-off valve is provided in parallel with the first shut-off valve and the third high-temperature heat exchanger;

[0018] The fourth high-temperature heat exchanger is installed on the inlet pipe of the first turbine.

[0019] Furthermore, the heat exchange medium of the high-temperature heat storage mechanism is molten salt.

[0020] Furthermore, the medium-temperature heat storage mechanism includes a second high-temperature heat exchange medium tank, a second low-temperature heat exchange medium tank, a first medium-temperature heat exchanger, a second medium-temperature heat exchanger, a third medium-temperature heat exchanger, and a fourth medium-temperature heat exchanger.

[0021] The first medium-temperature heat exchanger is installed on the outlet pipe of the first compressor, and the second medium-temperature heat exchanger is installed on the outlet pipe of the second compressor; the first medium-temperature heat exchanger and the second medium-temperature heat exchanger are connected in parallel between the inlet of the second heat exchange medium high-temperature tank and the outlet of the second heat exchange medium low-temperature tank.

[0022] The third medium-temperature heat exchanger is installed on the inlet pipe of the first turbine, and the fourth medium-temperature heat exchanger is installed on the inlet pipe of the second turbine; the third medium-temperature heat exchanger and the fourth medium-temperature heat exchanger are connected in parallel between the outlet of the second heat exchange medium high-temperature tank and the inlet of the second heat exchange medium low-temperature tank.

[0023] Furthermore, the heat exchange medium of the medium-temperature heat storage mechanism is heat transfer oil.

[0024] Furthermore, the water heat storage mechanism includes a hot water tank, a cold water tank, and a first low-temperature heat exchanger, a second low-temperature heat exchanger, a third low-temperature heat exchanger, and a fourth low-temperature heat exchanger.

[0025] The first low-temperature heat exchanger is installed on the outlet pipe of the first compressor, and the second low-temperature heat exchanger is installed on the outlet pipe of the second compressor; the first low-temperature heat exchanger and the second low-temperature heat exchanger are connected in parallel between the inlet of the hot water tank and the outlet of the cold water tank.

[0026] The third low-temperature heat exchanger is installed on the inlet pipe of the first turbine, and the fourth low-temperature heat exchanger is installed on the inlet pipe of the second turbine; the third low-temperature heat exchanger and the fourth low-temperature heat exchanger are connected in parallel between the outlet of the hot water tank and the inlet of the cold water tank.

[0027] Furthermore, a first valve is provided at the inlet end of the gas storage tank; and / or a second valve is provided at the outlet end of the gas storage tank.

[0028] Furthermore, a first circulation pump is connected to the outlet pipe of the first high-temperature heat exchange medium tank, and a second circulation pump is connected to the outlet pipe of the first low-temperature heat exchange medium tank; and / or a third circulation pump is connected to the outlet pipe of the second high-temperature heat exchange medium tank, and a fourth circulation pump is connected to the outlet pipe of the second low-temperature heat exchange medium tank; and / or a fifth circulation pump is connected to the outlet pipe of the hot water tank, and a sixth circulation pump is connected to the outlet pipe of the cold water tank.

[0029] A second aspect of the present invention provides a method for compressed air energy storage with a dual heat exchange system, comprising the above-described dual heat exchange compressed air energy storage system, including the following steps:

[0030] When energy storage begins, when the pressure inside the gas storage tank is at the first preset pressure value, the first valve and the second shut-off valve are opened, the first shut-off valve is closed, and the second circulation pump, the fourth circulation pump and the sixth circulation pump are started, so that the first compressor and the second compressor start working and the gas storage tank stores gas.

[0031] When the pressure inside the gas storage tank reaches the second preset pressure value, the first shut-off valve is opened and then closed until the pressure inside the gas storage tank reaches the third preset pressure value. Then the first compressor and the second compressor stop working and the energy storage is completed.

[0032] Wherein: First preset pressure value < Second preset pressure value < Third preset pressure value.

[0033] By adopting the above technical solution, the present invention has the following advantages:

[0034] 1. This invention achieves heat exchange and heating by setting up a three-stage heat exchange mechanism, which solves the problem of excessive temperature difference at the heat exchanger terminals caused by using a single heat exchange medium, and at the same time enables the water in the water storage mechanism to remain in a liquid state.

[0035] 2. This invention achieves cascaded heat transfer by arranging multi-stage heat exchangers, thereby increasing the heat exchange temperature and improving system efficiency.

[0036] 3. This invention avoids the problem of excessive temperature difference at the ends of a heat exchanger with a single heat exchange medium by using different heat exchange media in heat exchangers in different temperature ranges, thereby reducing heat exchange losses and improving system efficiency.

[0037] 4. The heat exchange medium of the present invention is stored at atmospheric pressure, which reduces the cost of the storage tank.

[0038] 5. The energy storage method of the present invention is not only simple to operate, but also improves heat exchange efficiency and avoids heat loss. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 is a schematic diagram of a compressed air energy storage system with a compound heat exchange in an embodiment of the present invention;

[0041] Figure 2 is a schematic diagram of the structure of a compressed air energy storage system with a duplex heat exchange in an embodiment of the present invention;

[0042] In the attached diagram: 10-First compressor, 20-Second compressor, 30-Gas storage tank, 40-First turbine, 50-Second turbine, 60-High-temperature heat storage mechanism, 61-First high-temperature heat exchange medium tank, 62-First low-temperature heat exchange medium tank, 63-First high-temperature heat exchanger, 64-Second high-temperature heat exchanger, 651-Third high-temperature heat exchanger, 652-Fourth high-temperature heat exchanger, 66-First shut-off valve, 67-Second shut-off valve, 68-First circulating pump, 69-Second circulating pump, 70-Medium-temperature heat storage mechanism, 71-Second heat exchange medium 72-Second low-temperature heat exchange medium tank, 73-First medium-temperature heat exchanger, 74-Second medium-temperature heat exchanger, 75-Third medium-temperature heat exchanger, 76-Fourth medium-temperature heat exchanger, 77-Third circulating pump, 78-Fourth circulating pump, 80-Water heat storage mechanism, 81-Hot water tank, 82-Cold water tank, 83-First low-temperature heat exchanger, 84-Second low-temperature heat exchanger, 85-Third low-temperature heat exchanger, 86-Fourth low-temperature heat exchanger, 87-Fifth circulating pump, 88-Sixth circulating pump, 91-First valve, 92-Second valve. Detailed Implementation

[0043] The following description provides many different embodiments or examples for implementing various features of the invention. The elements and arrangements described in the specific examples below are only for concise expression of the invention and are merely examples, not intended to limit the invention.

[0044] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means a plurality or more, unless otherwise explicitly specified.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of multiple components or the interaction between multiple components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Example 1

[0048] This embodiment provides a compressed air energy storage system with a compound heat exchange, as shown in Figure 1, including: a first compressor 10, a second compressor 20, an air storage tank 30, a first turbine 40 and a second turbine 50 connected in sequence; it also includes a high-temperature heat storage mechanism 60, a medium-temperature heat storage mechanism 70 and a water heat storage mechanism 80.

[0049] The outlet air of the first compressor 10 is cooled by passing through the high-temperature heat storage mechanism 60, the medium-temperature heat storage mechanism 70 and the water heat storage mechanism 80 in sequence.

[0050] The outlet air of the second compressor 20 is cooled sequentially by the medium-temperature heat storage mechanism 70 and the water heat storage mechanism 80;

[0051] The inlet air of the first turbine 40 is heated sequentially by the water heat storage mechanism 80 and the medium-temperature heat storage mechanism 70; the inlet air of the second turbine is heated sequentially by the water heat storage mechanism 80, the medium-temperature heat storage mechanism 70 and the high-temperature heat storage mechanism 60.

[0052] Among them, the heat storage capacity of the high-temperature heat storage mechanism 60 is greater than that of the medium-temperature heat storage mechanism 70, which is greater than that of the water heat storage mechanism 80.

[0053] The high-temperature heat storage mechanism 60 has a higher heat storage capacity than the medium-temperature heat storage mechanism 70, which in turn has a higher heat storage capacity than the water heat storage mechanism 80. This allows for multi-stage heat exchange, reducing heat loss. Furthermore, based on this structure, the device achieves a thermal balance effect, meaning the heat exchanged exceeds the usage, while maintaining turbine efficiency.

[0054] Furthermore, the high-temperature heat storage mechanism 60 includes a first heat exchange medium high-temperature tank 61, a first heat exchange medium low-temperature tank 62, and a high-temperature heat exchanger;

[0055] The high-temperature heat exchanger includes a first high-temperature heat exchanger 63 and a second high-temperature heat exchanger 64. The first high-temperature heat exchanger 63 is connected to the inlet of the first high-temperature heat exchange medium tank 61, the outlet of the first high-temperature heat exchange medium tank 61 is connected to the second high-temperature heat exchanger 64, the second high-temperature heat exchanger 64 is connected to the inlet of the first low-temperature heat exchange medium tank 62, and the outlet of the first low-temperature heat exchange medium tank 62 is connected to the first high-temperature heat exchanger 63.

[0056] The first high-temperature heat exchanger 63 is installed on the outlet pipe of the first compressor 10, and the second high-temperature heat exchanger 64 is installed on the inlet pipe of the second turbine 50.

[0057] The air in the outlet pipe of the second compressor 20 is cooled by the medium-temperature heat storage mechanism 70 and the water heat storage mechanism 80. When the first compressor 10 and the second compressor 20 are initially working, the heat exchange efficiency can be guaranteed. However, after the first compressor 10 and the second compressor 20 have been working for a period of time, since the second compressor 20 is connected to the air storage tank 30, and the air storage tank 30 is already filled with high-pressure or high-temperature high-pressure air, it will affect the pressure and temperature of the air at the outlet of the second compressor 20. That is, the temperature will rise. Only the medium-temperature heat storage mechanism 70 and the water heat storage mechanism 80 are used for cooling, resulting in low heat exchange efficiency and correspondingly increased requirements on the air storage tank 30.

[0058] Furthermore, as shown in Figure 2, the high-temperature heat exchanger also includes a third high-temperature heat exchanger 651, the second high-temperature heat exchanger 64 is connected to the inlet of the first heat exchange medium high-temperature tank 61, and the second high-temperature heat exchanger 64 is connected to the outlet of the first heat exchange medium low-temperature tank 62.

[0059] The third high-temperature heat exchanger 651 is installed on the outlet pipe of the second compressor 20, and a first shut-off valve 66 is installed between the second compressor 20 and the third high-temperature heat exchanger 651.

[0060] A second shut-off valve 67 is provided in parallel with the first shut-off valve 66 and the third high-temperature heat exchanger 651.

[0061] Based on this, the problem of poor heat exchange efficiency of the outlet air of the second compressor 20 after the first compressor 10 and the second compressor 20 have been working for a period of time has been solved.

[0062] Meanwhile, both the first turbine 40 and the second turbine 50 are heated three times, resulting in the highest enthalpy drop efficiency and thus the highest system heating efficiency.

[0063] Furthermore, the heat exchange medium of the high-temperature heat storage mechanism 60 is molten salt.

[0064] Furthermore, the medium-temperature heat storage mechanism 70 includes a second high-temperature heat exchange medium tank 71, a second low-temperature heat exchange medium tank 72, a first medium-temperature heat exchanger 73, a second medium-temperature heat exchanger 74, a third medium-temperature heat exchanger 75, and a fourth medium-temperature heat exchanger 76.

[0065] The first medium-temperature heat exchanger 73 is installed on the outlet pipe of the first compressor 10, and the second medium-temperature heat exchanger 74 is installed on the outlet pipe of the second compressor 20; the first medium-temperature heat exchanger 73 and the second medium-temperature heat exchanger 74 are connected in parallel between the inlet of the second heat exchange medium high-temperature tank 71 and the outlet of the second heat exchange medium low-temperature tank 72.

[0066] The third medium-temperature heat exchanger 75 is installed on the inlet pipe of the first turbine 40, and the fourth medium-temperature heat exchanger 76 is installed on the inlet pipe of the second turbine 50; the third medium-temperature heat exchanger 75 and the fourth medium-temperature heat exchanger 76 are connected in parallel between the outlet of the second high-temperature heat exchange medium tank 71 and the inlet of the second low-temperature heat exchange medium tank 72.

[0067] Furthermore, the heat exchange medium of the medium-temperature heat storage mechanism 70 is heat transfer oil.

[0068] Furthermore, the water heat storage mechanism 80 includes a hot water tank 81, a cold water tank 82, a first low-temperature heat exchanger 83, a second low-temperature heat exchanger 84, a third low-temperature heat exchanger 85, and a fourth low-temperature heat exchanger 86.

[0069] The first low-temperature heat exchanger 83 is installed on the outlet pipe of the first compressor 10, and the second low-temperature heat exchanger 84 is installed on the outlet pipe of the second compressor 20; the first low-temperature heat exchanger 83 and the second low-temperature heat exchanger 84 are connected in parallel between the inlet of the hot water tank 81 and the outlet of the cold water tank 82.

[0070] The third low-temperature heat exchanger 85 is installed on the inlet pipe of the first turbine 40, and the fourth low-temperature heat exchanger 86 is installed on the inlet pipe of the second turbine 50; the third low-temperature heat exchanger 85 and the fourth low-temperature heat exchanger 86 are connected in parallel between the outlet of the hot water tank 81 and the inlet of the cold water tank 82.

[0071] Furthermore, a first valve 91 is provided at the inlet end of the gas storage tank 30; and / or a second valve 92 is provided at the outlet end of the gas storage tank 30. This facilitates the control of the energy storage system and improves its safety.

[0072] Furthermore, a first circulation pump 68 is connected to the outlet pipe of the first high-temperature heat exchange medium tank 61, and a second circulation pump 69 is connected to the outlet pipe of the first low-temperature heat exchange medium tank 62; and / or a third circulation pump 77 is connected to the outlet pipe of the second high-temperature heat exchange medium tank 71, and a fourth circulation pump 78 is connected to the outlet pipe of the second low-temperature heat exchange medium tank 72; and / or a fifth circulation pump 87 is connected to the outlet pipe of the hot water tank 81, and a sixth circulation pump 88 is connected to the outlet pipe of the cold water tank 82. Based on this, heat exchange efficiency and heating efficiency can be improved.

[0073] It should be noted that the first compressor 10 is connected to motor 1, and the second compressor 20 is connected to motor 2. Air enters the first compressor 10 after passing through an air filter.

[0074] Example 2

[0075] This embodiment provides a compressed air energy storage method with compound heat exchange, including the compressed air energy storage system with compound heat exchange described in Embodiment 1, comprising the following steps:

[0076] When energy storage begins, when the pressure inside the gas storage tank 30 is the first preset pressure value, the first valve 91 and the second shut-off valve 67 are opened, the first shut-off valve 66 is closed, and the second circulation pump 69, the fourth circulation pump 78 and the sixth circulation pump 88 are started, so that the first compressor 10 and the second compressor 20 start working and the gas storage tank 30 stores gas.

[0077] When the pressure inside the gas storage tank 30 reaches the second preset pressure value, the first shut-off valve 66 is opened and the first shut-off valve 66 is closed until the pressure inside the gas storage tank 30 reaches the third preset pressure value, at which point the first compressor 10 and the second compressor 20 stop working and the energy storage is completed.

[0078] Wherein: First preset pressure value < Second preset pressure value < Third preset pressure value.

[0079] Taking a gas storage pressure of 23MPa and a rated operating power of 50MW as an example, the energy storage method process is as follows:

[0080] At the start of energy storage, the pressure in the storage tank is 9 MPa (i.e., the first preset pressure value). The first valve 91 and the second shut-off valve 67 are opened, and the second circulation pump 69, the fourth circulation pump 78, and the sixth circulation pump 88 are started. The motors 1 and 2 are started, and the motor 1 drives the first compressor 10 and the motor 2 drives the second compressor 20. Normal temperature and pressure air enters the first compressor 10 through an air filter. The high temperature and high pressure air from the first compressor is cooled by passing through the high temperature heat storage mechanism 60, the medium temperature heat storage mechanism 70, and the water heat storage mechanism 80. The cooled normal temperature and high pressure air enters the second compressor 20 and is compressed to a high temperature and high pressure state. The high temperature and high pressure air from the second compressor 20 is cooled by passing through the medium temperature heat storage mechanism 70 and the water heat storage mechanism 80. The cooled normal temperature and high pressure air enters the storage tank 30 for storage.

[0081] When the pressure inside the gas storage tank 30 reaches 16MPa (i.e., the second preset pressure value), the first shut-off valve 66 is opened and the second shut-off valve 67 is closed. The high-temperature and high-pressure air from the second compressor 20 is cooled sequentially by the high-temperature heat storage mechanism 60, the medium-temperature heat storage mechanism 70, and the water heat storage mechanism 80. The cooled room-temperature and high-pressure air enters the gas storage tank 30 for storage. When the pressure inside the gas storage tank 30 reaches 23MPa (i.e., the third preset pressure value), the motor 1 and the motor are turned off, and the first shut-off valve 66 and the first valve 91 are closed, and the energy storage is completed.

[0082] When releasing energy, the second valve 92 is opened, and the first circulation pump 68, the third circulation pump 77, and the fifth circulation pump 87 are started. The normal temperature high-pressure gas from the gas storage tank 30 is heated sequentially through the water heat storage mechanism 80, the medium temperature heat storage mechanism 70, and the high temperature heat storage mechanism 60. The heated high temperature high-pressure air enters the first turbine 40 and expands, doing work. The exhaust gas from the first turbine 40 is heated sequentially through the water heat storage mechanism 80, the medium temperature heat storage mechanism 70, and the high temperature heat storage mechanism 60. The heated high temperature high-pressure air enters the second turbine 50 and expands, doing work.

[0083] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

Claims

1. A method for compressed air energy storage with a complex heat exchange system, characterized in that, The energy storage method is implemented through an energy storage system, which includes a first compressor (10), a second compressor (20), a gas storage tank (30), a first turbine (40), and a second turbine (50) connected in sequence; it also includes a high-temperature heat storage mechanism (60), a medium-temperature heat storage mechanism (70), and a water heat storage mechanism (80); the outlet air of the first compressor (10) is cooled by passing through the high-temperature heat storage mechanism (60), the medium-temperature heat storage mechanism (70), and the water heat storage mechanism (80) in sequence; the outlet air of the second compressor (20) is cooled by passing through the medium-temperature heat storage mechanism (70) and the water heat storage mechanism (80) in sequence; the inlet air of the first turbine (40) is cooled by passing through the high-temperature heat storage mechanism (60), the medium-temperature heat storage mechanism (70), and the water heat storage mechanism (80) in sequence. The second turbine inlet air is heated by the water heat storage mechanism (80) and the medium-temperature heat storage mechanism (70); the second turbine inlet air is heated by the water heat storage mechanism (80), the medium-temperature heat storage mechanism (70) and the high-temperature heat storage mechanism (60) in sequence; wherein, the heat storage capacity of the high-temperature heat storage mechanism (60) > the heat storage capacity of the medium-temperature heat storage mechanism (70) > the heat storage capacity of the water heat storage mechanism (80); the high-temperature heat storage mechanism (60) includes a first heat exchange medium high-temperature tank (61), a first heat exchange medium low-temperature tank (62), a first high-temperature heat exchanger (63) and a second high-temperature heat exchanger (64), the first high-temperature heat exchanger (63) is connected to the inlet of the first heat exchange medium high-temperature tank (61), the first heat exchanger... The outlet of the high-temperature medium tank (61) is connected to the second high-temperature heat exchanger (64), the second high-temperature heat exchanger (64) is connected to the inlet of the first low-temperature medium tank (62), and the outlet of the first low-temperature medium tank (62) is connected to the first high-temperature heat exchanger (63); the first high-temperature heat exchanger (63) is installed on the outlet pipe of the first compressor (10), and the second high-temperature heat exchanger (64) is installed on the inlet pipe of the second turbine (50); the high-temperature heat storage mechanism (60) also includes a third high-temperature heat exchanger (651) and a fourth high-temperature heat exchanger (652), the third high-temperature heat exchanger (651) being connected to the first high-temperature medium tank. (61) inlet, and the third high temperature heat exchanger (651) is connected to the outlet of the first heat exchange medium low temperature tank (62); the third high temperature heat exchanger (651) is set on the outlet pipe of the second compressor (20), and a first shut-off valve (66) is set between the second compressor (20) and the third high temperature heat exchanger (651); a second shut-off valve (67) is set in parallel with the first shut-off valve (66) and the third high temperature heat exchanger (651); the fourth high temperature heat exchanger (652) is set on the inlet pipe of the first turbine (40); the method includes the following steps: when energy storage starts, when the pressure in the gas storage tank (30) is a first preset pressure value;Open the first valve (91) and the second shut-off valve (67), close the first shut-off valve (66), start the second circulation pump (69), the fourth circulation pump (78), and the sixth circulation pump (88) to start the first compressor (10) and the second compressor (20) to start working, and store gas in the gas storage tank (30); when the pressure in the gas storage tank (30) reaches the second preset pressure value, open the first shut-off valve (66), close the first shut-off valve (66), and continue until the pressure in the gas storage tank (30) reaches the third preset pressure value, at which point the first compressor (10) and the second compressor (20) stop working and the energy storage is complete; wherein: the first preset pressure value < the second preset pressure value < the third preset pressure value.

2. The compressed air energy storage method with compound heat exchange according to claim 1, characterized in that, The heat exchange medium of the high-temperature heat storage mechanism (60) is molten salt.

3. A compressed air energy storage method with compound heat exchange according to any one of claims 1-2, characterized in that, The intermediate-temperature heat storage mechanism (70) includes a second high-temperature heat exchange medium tank (71), a second low-temperature heat exchange medium tank (72), a first intermediate-temperature heat exchanger (73), a second intermediate-temperature heat exchanger (74), a third intermediate-temperature heat exchanger (75), and a fourth intermediate-temperature heat exchanger (76); the first intermediate-temperature heat exchanger (73) is installed on the outlet pipe of the first compressor (10), and the second intermediate-temperature heat exchanger (74) is installed on the outlet pipe of the second compressor (20); the first intermediate-temperature heat exchanger (73) and the second intermediate-temperature heat exchanger (75) are installed on the outlet pipe of the second compressor (20); 74) The third medium-temperature heat exchanger (75) is installed in parallel between the inlet of the second high-temperature heat exchange medium tank (71) and the outlet of the second low-temperature heat exchange medium tank (72); the third medium-temperature heat exchanger (75) is installed on the inlet pipe of the first turbine (40), and the fourth medium-temperature heat exchanger (76) is installed on the inlet pipe of the second turbine (50); the third medium-temperature heat exchanger (75) and the fourth medium-temperature heat exchanger (76) are installed in parallel between the outlet of the second high-temperature heat exchange medium tank (71) and the inlet of the second low-temperature heat exchange medium tank (72).

4. The compressed air energy storage method with compound heat exchange according to claim 3, characterized in that, The heat exchange medium of the medium-temperature heat storage mechanism (70) is heat transfer oil.

5. The compressed air energy storage method with compound heat exchange according to claim 3, characterized in that, The water storage mechanism (80) includes a hot water tank (81), a cold water tank (82), a first low-temperature heat exchanger (83), a second low-temperature heat exchanger (84), a third low-temperature heat exchanger (85), and a fourth low-temperature heat exchanger (86). The first low-temperature heat exchanger (83) is located on the outlet pipe of the first compressor (10), and the second low-temperature heat exchanger (84) is located on the outlet pipe of the second compressor (20). The first low-temperature heat exchanger (83) and the second low-temperature heat exchanger (84) are connected in parallel between the inlet of the hot water tank (81) and the outlet of the cold water tank (82). The third low-temperature heat exchanger (85) is located on the inlet pipe of the first turbine (40), and the fourth low-temperature heat exchanger (86) is located on the inlet pipe of the second turbine (50). The third low-temperature heat exchanger (85) and the fourth low-temperature heat exchanger (86) are connected in parallel between the outlet of the hot water tank (81) and the inlet of the cold water tank (82).

6. The compressed air energy storage method with compound heat exchange according to claim 1, characterized in that, The gas storage tank (30) is provided with a first valve (91) at its inlet end; and / or the gas storage tank (30) is provided with a second valve (92) at its outlet end.

7. The compressed air energy storage method with compound heat exchange according to claim 5, characterized in that, A first circulating pump (68) is connected to the outlet pipe of the first heat exchange medium high temperature tank (61), and a second circulating pump (69) is connected to the outlet pipe of the first heat exchange medium low temperature tank (62); and / or a third circulating pump (77) is connected to the outlet pipe of the second heat exchange medium high temperature tank (71), and a fourth circulating pump (78) is connected to the outlet pipe of the second heat exchange medium low temperature tank (72); and / or a fifth circulating pump (87) is connected to the outlet pipe of the hot water tank (81), and a sixth circulating pump (88) is connected to the outlet pipe of the cold water tank (82).

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