A gas compression energy storage device and method

Abstract

The application provides a gas compression energy storage device and an energy storage method. The gas compression energy storage device comprises a first energy storage subsystem, which comprises a low-pressure water tank and a high-pressure water tank, a first turbine assembly and a heat storage body assembly. The first turbine assembly realizes hot steam compression and power generation by expansion of the hot steam in different working conditions. The heat storage body assembly is used for generating hot steam by gasifying hot water or generating hot water by liquefying hot steam in different working conditions of the first turbine assembly. The pressure maintaining assembly is used for filling or discharging pressure maintaining gas into or out of the low-pressure water tank or the high-pressure water tank to maintain constant pressure and realize the energy storage function through the pressure maintaining process. The main energy storage equipment of the application is the high-pressure water tank and the low-pressure water tank, which store liquid water. The volume is reduced by more than 90% compared with a gas storage library, and the ground layout pressure container can be completely adopted, the site selection is flexible, and the land occupation is small. Moreover, the equipment investment cost is low, and the process flow is simple and reliable.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a gas compression energy storage device and energy storage method. Background Technology

[0002] Compressed gas energy storage technology is a type of power storage system capable of storing large-capacity, long-term electrical energy. It stores excess electricity by compressing atmospheric pressure gas to high pressure using a compressor. When electricity is needed, the high-pressure gas is released and expands to generate electricity. Compressed gas energy storage mainly includes compressed air energy storage and compressed carbon dioxide energy storage.

[0003] Compressed gas energy storage devices require large-capacity gas storage tanks to store the gas. Compressed air energy storage uses high-pressure gas storage, and the storage tanks often need to be underground caverns to meet the volume and pressure requirements; compressed carbon dioxide energy storage uses atmospheric pressure gas storage, and the storage tanks are extremely large, requiring a correspondingly large land area. These issues limit the large-scale promotion of compressed gas energy storage.

[0004] Liquefied air or liquefied carbon dioxide can solve the gas storage problem. However, liquid air has a temperature below -190℃, and the irreversible losses during the liquefaction process are large, making cold storage difficult and resulting in low energy storage efficiency. Liquid carbon dioxide exists only in the parameter range of 0.52MPa / -56℃ to 7.4MPa / 31℃, which is basically a low temperature range. Cold storage is difficult, the pressure ratio range required for energy storage is small, the energy storage capacity is limited, and the cost of carbon dioxide is high. Increasing the amount used will lead to excessively high initial investment and operation and maintenance costs. Summary of the Invention

[0005] This application aims to at least partially address one of the technical problems in related technologies. Therefore, the purpose of this application is to propose a gas compression energy storage device and method, wherein hot steam is used as the energy storage medium. Electrical energy is converted into thermal energy and pressure energy through hot steam compression, and then the thermal energy and pressure energy are converted back into electrical energy through hot steam expansion. The hot steam can transform into liquid water under constant pressure. The thermal energy can be stored through the heat storage medium and the hot water itself, eliminating the need for large-capacity gas storage facilities and reducing the need for underground space or large land use. Simultaneously, the pressure-holding component allows for the injection or output of pressure-holding gas into or from the low-pressure or high-pressure water tank during gas compression energy storage, maintaining a constant pressure and achieving energy storage through the pressure-holding process.

[0006] To achieve the above objectives, this application proposes a gas compression energy storage device, comprising:

[0007] A first energy storage subsystem includes a low-pressure water tank and a high-pressure water tank, which are interconnected and used to store hot water at different pressures, and a first turbine assembly and a thermal storage assembly connected to the low-pressure water tank and the high-pressure water tank, respectively. The first turbine assembly compresses hot steam and generates electricity by expanding the hot steam under different operating conditions. The thermal storage assembly, under different operating conditions of the first turbine assembly, is used to vaporize hot water to generate hot steam while maintaining a constant pressure, or to liquefy the hot steam to generate hot water while maintaining a constant pressure.

[0008] The pressure-holding component is used to fill or output pressure-holding gas into the low-pressure water tank or the high-pressure water tank under different operating conditions of the first turbine component, maintain constant pressure, and realize energy storage function through the pressure-holding process.

[0009] In some embodiments, the thermal storage assembly includes a low-temperature thermal storage body and a high-temperature thermal storage body; wherein the low-temperature thermal storage body is connected to the first turbine assembly and the low-pressure water tank respectively, and under different operating conditions of the first turbine assembly, it is used to vaporize the hot water in the low-pressure water tank, so that the hot water generates hot steam under constant pressure, or liquefy the hot steam output by the first turbine assembly after doing work, and so that the hot steam generates hot water under constant pressure; the high-temperature thermal storage body is connected to the first turbine assembly and the high-pressure water tank respectively, and under different operating conditions of the first turbine assembly, it is used to vaporize the hot water in the high-pressure water tank, so that the hot water generates hot steam under constant pressure, or liquefy the compressed hot steam output by the first turbine assembly, so that the hot steam generates hot water under constant pressure.

[0010] In some embodiments, the first energy storage subsystem further includes a first heat exchange and heat storage component connected to the first turbine component and the heat storage body component respectively. The heat exchange and heat storage component is located between the low-temperature heat storage body and the high-temperature heat storage body and is heat exchanged with the first turbine component. Under different operating conditions of the first turbine component, the heat exchange and heat storage component releases heat to the hot steam in the first turbine component or stores heat.

[0011] In some embodiments, the pressure-holding assembly includes a second energy storage subsystem and a third energy storage subsystem; wherein the second energy storage subsystem generates compressed air to fill the low-pressure water tank under different operating conditions, or extracts compressed air from the low-pressure water tank for expansion and work; the third energy storage subsystem generates compressed working gas to fill the high-pressure water tank under different operating conditions, or extracts compressed working gas from the high-pressure water tank for expansion and work.

[0012] In some embodiments, the first turbine assembly includes a first compressor and a first expander, wherein the first compressor compresses hot steam and the first expander expands high-pressure hot steam to generate electricity.

[0013] In some embodiments, the first heat exchange and storage assembly includes a heat storage medium circulation loop consisting of a first heat recovery unit, a first hot tank, a first reheater, and a first cold tank, wherein the heat storage medium recovers heat from the hot steam at the outlet of the first compressor in the first heat recovery unit, and uses the recovered heat in the first reheater to heat the hot steam entering the first expander; the first cold tank and the first hot tank are respectively used to store heat storage medium at different temperatures.

[0014] In some embodiments, the second energy storage subsystem includes a second turbine assembly connected to the low-pressure water tank, including a second compressor and a second expander, wherein the second compressor compresses air; and the second expander compresses air to expand and generate electricity.

[0015] In some embodiments, the third energy storage subsystem includes a third turbine assembly, a second heat exchange and thermal storage assembly, and a high-pressure storage tank; wherein the third turbine assembly compresses the working gas and uses the expansion of the working gas to generate electricity under different operating conditions; the second heat exchange and thermal storage assembly is used to release heat or store heat into the working gas in the third turbine assembly under different operating conditions; the high-pressure storage tank is connected to the third turbine assembly and is used to store the working gas.

[0016] In some embodiments, the third turbine assembly includes a third compressor and a third expander, wherein the third compressor compresses the working gas; and the third expander compresses the working gas, expands it, and generates electricity.

[0017] In some embodiments, the second heat exchange and heat storage assembly includes a heat storage medium circulation loop consisting of a second heat recovery unit, a second hot tank, a second reheater, and a second cold tank; the heat storage medium recovers the heat of the working gas output by the third compressor in the second heat recovery unit; and transfers the heat to the working gas entering the third expander in the second reheater; the second cold tank and the second hot tank are used to store heat storage medium at different temperatures.

[0018] In some embodiments, the working gas includes carbon dioxide and nitrogen. When the working gas is carbon dioxide, the third energy storage subsystem further includes a phase change component connected to the third turbine component, which is used to liquefy gaseous carbon dioxide or vaporize liquid carbon dioxide under different operating conditions of the third turbine component.

[0019] In some embodiments, this application proposes an energy storage method using a gas compression energy storage device, which stores energy using the gas compression energy storage device described in any of the above embodiments, and includes the following process:

[0020] Energy storage stage: Hot water is output from the low-pressure water tank and heated and steamed by the thermal storage component. Then, it is compressed to a high temperature and high pressure state by the first turbine component, and the latent heat of compression is released into the thermal storage component and liquefied to obtain high temperature and high pressure water. The high temperature and high pressure water is input into the high pressure water tank for storage. At the same time, the pressure-holding gas in the low-pressure water tank is input, and the pressure-holding gas in the high pressure water tank is output to do work.

[0021] Energy release stage: The high-pressure water tank outputs high-temperature and high-pressure water, which is heated and vaporized by the heat storage component. Then, the water expands and does work through the first turbine component, releasing the latent heat of compression into the heat storage component and liquefying to obtain low-pressure hot water. The low-pressure hot water is input into the low-pressure water tank for storage. At the same time, the pressure-holding gas in the high-pressure water tank is input, and the pressure-holding gas in the low-pressure water tank is output to do work.

[0022] In some embodiments, during the energy storage or energy release phase, the pressure-holding gas is compressed or expanded under different operating conditions to generate electricity and perform work into the low-pressure water tank or the high-pressure water tank.

[0023] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0024] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 This is a schematic diagram of the structure of a gas compression energy storage device according to an embodiment of this application;

[0026] Figure 2 This is a schematic diagram of the structure of a gas compression energy storage device according to an embodiment of this application;

[0027] Figure 3 This is a schematic diagram of the structure of a gas compression energy storage device according to an embodiment of this application;

[0028] Figure 4 This is a schematic diagram of the structure of a gas compression energy storage device according to an embodiment of this application;

[0029] Figure 5 This is a flowchart of a gas compression energy storage method according to an embodiment of this application;

[0030] In the diagram, 1 is the first energy storage subsystem; 11 is the low-pressure water tank; 12 is the medium-low temperature thermal storage body; 13 is the first turbine assembly; 131 is the first compressor; 132 is the first expander; 14 is the first heat exchange and thermal storage assembly; 141 is the first heat recovery unit; 142 is the first reheater; 143 is the first cold tank; 144 is the first hot tank; 15 is the high-temperature thermal storage body; and 16 is the high-pressure water tank.

[0031] 2. Second energy storage subsystem; 21. Second turbine assembly; 211. Second compressor; 212. Second expander;

[0032] 3. Third energy storage subsystem; 31. Third turbine assembly; 311. Third compressor; 312. Third expander; 32. Second heat exchange and storage assembly; 321. Second heat recovery unit; 322. Second reheater; 323. Second cold tank; 324. Second hot tank; 33. Phase change assembly; 331. Condenser; 332. Evaporator; 34. High-pressure storage tank. Detailed Implementation

[0033] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Rather, the embodiments of this application include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0034] See Figure 1 To achieve the above objectives, this application proposes a gas compression energy storage device comprising a first energy storage subsystem 1 and a pressure holding component; the first energy storage subsystem 1 includes a low-pressure water tank 11 and a high-pressure water tank 16, which are used to store hot water at different pressures and are interconnected, and a first turbine component 13 and a thermal energy storage component, which are respectively connected to the low-pressure water tank 11 and the high-pressure water tank 16; wherein the first turbine component 13 realizes the compression of hot steam and the generation of power by utilizing the expansion of hot steam under different operating conditions; the thermal energy storage component is used to vaporize hot water to generate hot steam under a constant pressure state or to liquefy hot steam to generate hot water under a constant pressure state under different operating conditions of the first turbine component 13.

[0035] The first energy storage subsystem 1 includes a low-pressure water tank 11 and a high-pressure water tank 16, a first turbine assembly 13, and a thermal storage assembly. The low-pressure water tank 11 is insulated from the environment and has a certain capacity for storing low-pressure hot water. However, to prevent flash evaporation of the hot water, a pressure-holding gas is introduced above the hot water surface using a pressure-holding assembly to maintain pressure balance. The pressure of the low-pressure water tank 11 is 0.1-0.5 MPa. Similarly, the high-pressure water tank 16 is insulated from the environment and has a certain capacity for storing high-pressure, high-temperature hot water. To prevent flash evaporation of the high-temperature hot water, a pressure-holding gas is introduced above the high-temperature hot water surface using a pressure-holding assembly to maintain pressure balance. The pressure of the example high-pressure water tank 16 is 1-5 MPa.

[0036] In this embodiment, both the first turbine assembly 13 and the heat storage assembly are disposed between and connected to the low-pressure water tank 11 and the high-pressure water tank 16. The heat storage assembly stores the condensation heat released by the vaporization of hot water in the low-pressure water tank 11 and the high-pressure water tank 16. It can use phase change cold storage materials for cold storage, or it can use a large amount of sensible heat cold storage materials for small temperature difference heat storage. Under different operating conditions of the first turbine assembly 13, it is used to vaporize hot water to generate hot steam or liquefy hot steam to generate hot water. For example, in the energy storage stage of the first turbine assembly 13, the low-pressure hot water output from the low-pressure water tank 11 is heated and vaporized by the heat storage assembly to generate hot steam. After the hot steam is compressed by the first turbine assembly 13, the heat storage assembly recovers the heat of the compressed hot steam to liquefy the hot steam to generate high-pressure hot water, which is then stored in the high-pressure water tank 16. During the energy release phase of the first turbine assembly 13, the high-pressure water tank 16 outputs high-pressure hot water, which is heated and steamed by the heat storage assembly to generate hot steam. After expanding and doing work in the first turbine assembly 13, the heat storage assembly recovers the heat of the hot steam after doing work, liquefies the hot steam to generate low-pressure hot water, and stores the low-pressure hot water in the low-pressure water tank 11.

[0037] For example, in this embodiment, the first turbine assembly 13 compresses hot steam and generates electricity by expanding the hot steam under different operating conditions. For instance, the first turbine assembly 13 includes a first compressor 131 and a first expander 132, and the heat storage assembly includes a medium-low temperature heat storage body 12 and a high temperature heat storage body 15. The first compressor 131 compresses the hot steam; the first expander 132 is used to expand the high-pressure hot steam and generate electricity. The first compressor 131 is driven by an electric motor to compress the hot steam and can be in one or more stages. The first expander 132 is used to expand the high-pressure hot steam and drive the generator to generate electricity and can also be in one or more stages. The low-temperature heat storage body 12 is connected to the first compressor 131, the first expander 132, and the low-pressure water tank 11 respectively. Under different operating conditions of the first turbine assembly 13, it is used to vaporize the hot water in the low-pressure water tank 11, so that the hot water generates hot steam under constant pressure, or liquefies the hot steam output by the first expander 132 after doing work, and generates hot water under constant pressure. The high-temperature heat storage body 15 is connected to the first compressor 131, the first expander 132, and the high-pressure water tank 16 respectively. Under different operating conditions of the first turbine assembly 13, it is used to vaporize the hot water in the high-pressure water tank 16, so that the hot water generates hot steam under constant pressure, or liquefies the compressed hot steam of the first compressor 131, and generates hot water under constant pressure.

[0038] The pressure-holding component is used to fill or output pressure-holding gas into the low-pressure water tank 11 or the high-pressure water tank 16 under different operating conditions of the first turbine component 13, maintain constant pressure, and realize energy storage function through the pressure-holding process.

[0039] For example, the pressure-holding component includes a second energy storage subsystem 2 and a third energy storage subsystem 3; wherein the second energy storage subsystem 2 generates compressed air to fill the low-pressure water tank 11 under different operating conditions, or extracts compressed air from the low-pressure water tank 11 for expansion and work; the third energy storage subsystem 3 generates compressed working gas to fill the high-pressure water tank 16 under different operating conditions, or extracts compressed working gas from the high-pressure water tank 16 for expansion and work.

[0040] The main energy storage equipment in this application consists of a high-pressure water tank 16 and a low-pressure water tank 11, which store liquid water. Their volume is reduced by more than 90% compared to gas storage facilities, allowing for the use of ground-mounted pressure vessels with flexible site selection and a small footprint. All equipment in the energy storage device of this application can be integrated using existing mature products and technologies, eliminating the need for new equipment development. This reduces investment costs and accelerates the large-scale construction of energy storage facilities. The working fluids used in this application are all commonly used natural working fluids in the industrial field, offering advantages such as safety, environmental friendliness, and low cost. The process flow of this application is simple, reliable, and has low operating and maintenance costs, facilitating unattended operation.

[0041] In some embodiments, the first energy storage subsystem 1 further includes a first heat exchange and heat storage component 14 connected to the first turbine component 13 and the heat storage body component respectively. It is located between the low-temperature heat storage body 12 and the high-temperature heat storage body 15 and is heat exchanged with the first turbine component 13. Under different operating conditions of the first turbine component 13, it releases heat or stores heat to the hot steam in the first turbine component 13.

[0042] The first heat exchange and storage assembly 14 includes a heat storage medium circulation loop consisting of a first heat recovery unit 141, a first hot tank 144, a first reheater 142, and a first cold tank 143. The heat storage medium recovers heat from the hot steam exiting the first compressor 131 in the first heat recovery unit 141, and uses the recovered heat in the first reheater 142 to heat the hot steam entering the first expander 132. The first cold tank 143 and the first hot tank 144 are used to store heat storage media at different temperatures. Figure 2 As shown, the hot-side inlet of the first heat recovery unit 141 is connected to the outlet of the first compressor 131 to recover the sensible heat of the hot steam at the outlet of the first compressor 131 and transfer the heat to the heat storage medium. After absorbing heat, the heat storage medium is stored in the first hot tank 144. As the heat storage medium circulates, it enters the first reheater 142 to heat the hot steam entering the first expander 132. After releasing heat, the heat storage medium enters the first cold tank 143. This cycle is repeated to release or store heat in the gaseous steam of the first turbine assembly 13 under different operating conditions.

[0043] In some embodiments, the pressure-holding component includes a second energy storage subsystem 2 and a third energy storage subsystem 3; wherein the second energy storage subsystem 2 generates compressed air to fill the low-pressure water tank 11 under different operating conditions, or extracts compressed air from the low-pressure water tank 11 to expand and do work; the third energy storage subsystem 3 generates compressed working gas to fill the high-pressure water tank 16 under different operating conditions, or extracts compressed working gas from the high-pressure water tank 16 to expand and do work.

[0044] In this system, the second energy storage subsystem 2 generates compressed air to fill the low-pressure water tank 11 under different operating conditions, or extracts the compressed air from the low-pressure water tank 11 to expand and do work. This can be understood as follows: during the energy storage stage of the first turbine component 13, the low-pressure water tank 11 outputs low-pressure hot water while the second energy storage subsystem 2 compresses air and fills the low-pressure water tank 11 with the generated compressed air to maintain pressure balance and prevent hot water flashing. At the same time, during the energy storage stage, the low-pressure hot water passes through the first turbine component 13 and the heat storage component to generate high-pressure hot water, which is then filled into the high-pressure water tank 16. The compressed working gas in the high-pressure water tank 16 is extracted and expanded in the third energy storage subsystem 3 to do work. During the energy release phase of the second turbine component 21, the high-pressure water tank 16 outputs high-pressure hot water while the third energy storage subsystem 3 generates compressed working gas and fills the high-pressure water tank 16 to maintain pressure balance and prevent the hot water in the high-pressure water tank 16 from flashing. At the same time, the high-pressure hot water passes through the first turbine component 13 and the heat storage component to generate low-pressure hot water, which is then filled into the low-pressure water tank 11. The compressed air in the low-pressure water tank 11 is extracted and expanded in the second energy storage subsystem 2 to do work.

[0045] Examples such as Figure 4 As shown, the second energy storage subsystem 2 includes a second turbine assembly 21 connected to a low-pressure water tank 11, and includes a second compressor 211 and a second expander 212. The second compressor 211 compresses air and is driven by an electric motor; it can be in one or more stages. The second expander 212 is used to compress air, expand it, and generate electricity; it can also be in one or more stages. The third energy storage subsystem 3 includes a third turbine assembly 31, a second heat exchange and heat storage assembly 32, and a high-pressure storage tank 34. The third turbine assembly 31 compresses the working gas and uses its expansion to generate electricity under different operating conditions. The second heat exchange and heat storage assembly 32 releases or stores heat into the working gas in the third turbine assembly 31 under different operating conditions. The high-pressure storage tank 34 is connected to the third turbine assembly 31 and is used to store the working gas.

[0046] like Figure 3As shown, the working gas includes carbon dioxide and nitrogen. The third turbine assembly 31 includes a third compressor 311 and a third expander 312. The third compressor 311 is driven by an electric motor to compress the working gas and can be used in one or more stages. The third expander 312 is used to compress the working gas, expand it, and generate electricity. It can also be used in one or more stages. The second heat exchange and storage assembly 32 includes a heat storage medium circulation loop consisting of a second heat recovery unit 321, a second hot tank 324, a second reheater 322, and a second cold tank 323. The heat storage medium recovers the heat of the working gas output from the third compressor 311 in the second heat recovery unit 321 and transfers the heat to the working gas entering the third expander 312 in the second reheater 322. The second cold tank 323 and the second hot tank 324 are used to store heat storage medium at different temperatures. Figure 3 and Figure 4 The outlet of the third compressor 311 is connected to the hot side of the second heat recovery unit 321. The sensible heat of the working gas at the outlet of the third compressor 311 is transferred to the heat storage medium. After absorbing heat, the heat storage medium is stored in the second hot tank 324. As the heat storage medium circulates, it enters the second reheater 322 to transfer the heat of the heat storage medium to the working gas entering the second expander 212. After releasing heat, the heat storage medium enters the second cold tank 323. This cycle is repeated to release or store heat to the compressed working gas in the third turbine assembly 31 under different operating conditions.

[0047] In some embodiments, when the working gas is carbon dioxide, the third energy storage subsystem 3 further includes a phase change component 33, which is connected to the third turbine component 31 and is used to liquefy gaseous carbon dioxide or vaporize liquid carbon dioxide under different operating conditions of the third turbine component 31.

[0048] The third energy storage subsystem 3 also includes a phase change component 33, such as Figure 4 The phase change assembly 33 shown includes a condenser 331 and an evaporator 332. The condenser 331 condenses the carbon dioxide gas discharged from the second heat recovery unit 321 into liquid carbon dioxide and separates water. The evaporator 332 vaporizes the liquid carbon dioxide and inputs it into the second reheater 322. Specifically, the condenser 331 is connected to the hot side of the second heat recovery unit 321, liquefying the gaseous carbon dioxide output from the second heat recovery unit 321. This liquid carbon dioxide is then connected to the high-pressure storage tank 34, allowing the ambient temperature liquid carbon dioxide to be stored. Simultaneously, the evaporator 332 is connected to the high-pressure storage tank 34. In some operating conditions, the liquid carbon dioxide output from the high-pressure storage tank 34 is vaporized by the evaporator 332. The outlet of the evaporator 332 is connected to the cold side of the second reheater 322, further heating the carbon dioxide gas.

[0049] In some embodiments, this application proposes an energy storage method for a gas compression energy storage device, such as... Figure 5As shown, energy storage using the gas compression energy storage device in any of the above embodiments includes the following process:

[0050] S1 energy storage stage: The low-pressure water tank 11 outputs hot water, which is heated and steamed by the heat storage body component. Then, it is compressed to a high temperature and high pressure state by the first turbine component 13, and the latent heat of compression is released into the heat storage body component and liquefied to obtain high temperature and high pressure water. The high temperature and high pressure water is input into the high pressure water tank 16 for storage. At the same time, the pressure-holding gas in the low-pressure water tank 11 is input, and the pressure-holding gas in the high pressure water tank 16 is output to do work.

[0051] S2 Energy Release Stage: High-temperature and high-pressure water is output from high-pressure water tank 16 and heated and vaporized by the heat storage component. Then, it expands and does work through the first turbine component 13, and releases the latent heat of compression into the heat storage component and liquefies to obtain low-pressure hot water. The low-pressure hot water is input into low-pressure water tank 11 for storage. At the same time, the pressure-holding gas in high-pressure water tank 16 is input, and the pressure-holding gas in low-pressure water tank 11 is output to do work.

[0052] In some embodiments, during the energy storage or energy release phase, the pressurized gas is compressed or expanded under different operating conditions to generate electricity and perform work in the low-pressure water tank 11 or the high-pressure water tank 16.

[0053] Specifically, taking carbon dioxide as the working gas as an example, the energy storage stage is as follows: Hot water output from low-pressure water tank 11 is heated and steamed by medium-low temperature heat storage body 12, then compressed to a high temperature and high pressure state by first compressor 131, and then the heat is transferred to the heat storage medium coming out of first cold tank 143 and entering first hot tank 144 by first heat recovery unit 141. The latent heat is then released into high temperature heat storage body 15 and liquefied. The high temperature and high pressure water is then sent to high pressure water tank 16 for storage. Low-pressure water tank 11 is pressurized by compressed air. During the energy storage stage, the air is compressed and pressurized by second compressor 211 and then sent to low-pressure water tank 11. At the same time, compressed carbon dioxide is pressurized and heated by third compressor 311, and then the heat is transferred to the heat storage medium coming out of second cold tank 323 and entering second hot tank 324 by second heat recovery unit 321. The carbon dioxide is then liquefied by condenser 331 and water is separated. The liquid carbon dioxide is sent to high pressure storage tank 34 for storage.

[0054] Energy release stage: High-temperature and high-pressure water output from high-pressure water tank 16 absorbs heat from high-temperature heat storage body 15 and vaporizes. Then, the heat from the heat storage medium that comes out of the first hot tank 144 and enters the first cold tank 143 is absorbed by the first reheater 142. Then, the water generates electricity and cools and depressurizes by the first expander 132. Then, the latent heat is released to the medium and low temperature heat storage body 12 and liquefies. Finally, the hot water is input into the low-pressure water tank 11 for storage.

[0055] Meanwhile, the high-pressure water tank 16 is pressurized by compressed carbon dioxide; the high-pressure storage tank 34 outputs liquid carbon dioxide, which is vaporized by the evaporator 332, and then absorbs the heat from the heat storage medium that comes out of the second hot tank 324 and enters the second cold tank 323 by the second reheater 322. Then, it generates electricity and cools and depressurizes by the third expander 312, and then inputs it into the high-pressure water tank 16; the low-pressure water tank 11 outputs compressed air and generates electricity by the second expander 212, and then discharges it into the atmosphere; when the low-pressure water tank 11 is at normal pressure, it is pressurized by the atmosphere.

[0056] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0057] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0058] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in at least one embodiment or example.

[0059] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A gas compression energy storage device, characterized in that, include A first energy storage subsystem includes a low-pressure water tank and a high-pressure water tank, which are connected to each other and used to store hot water at different pressures, and a first turbine assembly and a thermal storage assembly, which are respectively connected to the low-pressure water tank and the high-pressure water tank. The first turbine assembly compresses hot steam and generates electricity by expanding the hot steam under different operating conditions. The first turbine assembly includes a first compressor and a first expander. The first compressor compresses the hot steam, and the first expander expands the high-pressure hot steam to generate electricity. Under different operating conditions of the first turbine assembly, the thermal storage assembly is used to vaporize hot water to generate hot steam at a constant pressure or to liquefy the hot steam at a constant pressure to generate hot water. as well as The pressure-holding component is used to fill or output pressure-holding gas into the low-pressure water tank or the high-pressure water tank under different operating conditions of the first turbine component, maintain constant pressure, and realize energy storage function through the pressure-holding process.

2. The gas compression energy storage device according to claim 1, characterized in that, The thermal storage assembly includes a low-temperature thermal storage body and a high-temperature thermal storage body. The low-temperature thermal storage body is connected to both the first turbine assembly and the low-pressure water tank. Under different operating conditions of the first turbine assembly, it vaporizes the hot water in the low-pressure water tank, allowing the hot water to generate steam while maintaining a constant pressure, or liquefies the steam output from the first turbine assembly after work, allowing the steam to generate hot water while maintaining a constant pressure. The high-temperature thermal storage body is connected to both the first turbine assembly and the high-pressure water tank. Under different operating conditions of the first turbine assembly, it vaporizes the hot water in the high-pressure water tank, allowing the hot water to generate steam while maintaining a constant pressure, or liquefies the compressed steam output from the first turbine assembly, allowing the steam to generate hot water while maintaining a constant pressure.

3. The gas compression energy storage device according to claim 2, characterized in that, The first energy storage subsystem also includes a first heat exchange and heat storage component connected to the first turbine component and the heat storage body component respectively. It is located between the medium-low temperature heat storage body and the high temperature heat storage body and is heat exchanged with the first turbine component. Under different operating conditions of the first turbine component, it releases heat or stores heat to the hot steam in the first turbine component.

4. The gas compression energy storage device according to claim 3, characterized in that, The pressure-holding component includes a second energy storage subsystem and a third energy storage subsystem; wherein the second energy storage subsystem generates compressed air to fill the low-pressure water tank under different operating conditions, or extracts compressed air from the low-pressure water tank for expansion and work; the third energy storage subsystem generates compressed working gas to fill the high-pressure water tank under different operating conditions, or extracts compressed working gas from the high-pressure water tank for expansion and work.

5. The gas compression energy storage device according to claim 4, characterized in that, The first heat exchange and heat storage assembly includes a heat storage medium circulation loop consisting of a first heat recovery unit, a first hot tank, a first reheater, and a first cold tank. The heat storage medium recovers heat from the hot steam at the outlet of the first compressor in the first heat recovery unit, and uses the recovered heat in the first reheater to heat the hot steam entering the first expander. The first cold tank and the first hot tank are used to store heat storage medium at different temperatures.

6. The gas compression energy storage device according to claim 5, characterized in that, The second energy storage subsystem includes a second turbine assembly connected to the low-pressure water tank, comprising a second compressor and a second expander, wherein the second compressor compresses air and the second expander compresses air to expand and generate electricity.

7. The gas compression energy storage device according to claim 6, characterized in that, The third energy storage subsystem includes a third turbine assembly, a second heat exchange and thermal storage assembly, and a high-pressure storage tank. The third turbine assembly compresses the working gas and generates electricity by expanding the working gas under different operating conditions. The second heat exchange and thermal storage assembly releases or stores heat into the working gas in the third turbine assembly under different operating conditions. The high-pressure storage tank is connected to the third turbine assembly and is used to store the working gas.

8. The gas compression energy storage device according to claim 7, characterized in that, The third turbine assembly includes a third compressor and a third expander, wherein the third compressor compresses the working gas; and the third expander is used to compress the working gas, expand it, and generate electricity.

9. The gas compression energy storage device according to claim 8, characterized in that, The second heat exchange and storage component includes a heat storage medium circulation loop consisting of a second heat recovery unit, a second hot tank, a second reheater, and a second cold tank; the heat storage medium recovers the heat of the working gas output by the third compressor in the second heat recovery unit; and transfers the heat to the working gas entering the third expander in the second reheater; the second cold tank and the second hot tank are used to store heat storage medium at different temperatures.

10. The gas compression energy storage device according to claim 7, characterized in that, The working gas includes carbon dioxide and nitrogen. When the working gas is carbon dioxide, the third energy storage subsystem also includes a phase change component connected to the third turbine component. Under different operating conditions of the third turbine component, it is used to liquefy gaseous carbon dioxide or vaporize liquid carbon dioxide.

11. An energy storage method for a gas compression energy storage device, characterized in that, Energy storage is performed using the gas compression energy storage device described in any one of claims 1-10. The process includes the following: Energy storage stage: Hot water is output from the low-pressure water tank and heated and steamed by the thermal storage component. Then, it is compressed to a high temperature and high pressure state by the first turbine component, and the latent heat of compression is released into the thermal storage component and liquefied to obtain high temperature and high pressure water. The high temperature and high pressure water is input into the high pressure water tank for storage. At the same time, the pressure-holding gas in the low-pressure water tank is input, and the pressure-holding gas in the high pressure water tank is output to do work. Energy release stage: The high-pressure water tank outputs high-temperature and high-pressure water, which is heated and vaporized by the heat storage component. Then, the water expands and does work through the first turbine component, releasing the latent heat of compression into the heat storage component and liquefying to obtain low-pressure hot water. The low-pressure hot water is input into the low-pressure water tank for storage. At the same time, the pressure-holding gas in the high-pressure water tank is input, and the pressure-holding gas in the low-pressure water tank is output to do work.

12. The energy storage method according to claim 11, characterized in that, During the energy storage or energy release phase, the pressure-holding gas is compressed or expanded under different operating conditions to generate electricity and perform work into the low-pressure water tank or the high-pressure water tank.

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