An energy storage system and method

Abstract

The application provides an energy storage system, characterized in that the energy storage system comprises an energy storage device, a first energy storage module and a second energy storage module, wherein the energy storage device comprises a liquid storage device and a gas storage device and is arranged in an underwater area; the first energy storage module comprises a first compression device for compressing a first medium and a first expansion device for expanding the first medium, and the first energy storage module is connected with the gas storage device through a first pipeline; the second energy storage module comprises an evaporation device and a condensation device, and is used for storing and releasing energy by using the gas-liquid phase change of a second medium; the second energy storage module is connected with the gas storage device through a second pipeline and is connected with the liquid storage device through a third pipeline; and the first expansion device is connected with the second energy storage module through a fourth pipeline, so as to transfer the heat of the first medium to the second energy storage module. According to the above, the first energy storage module and the second energy storage module are coupled to store energy, and in the energy releasing stage, the heat generated by the first energy storage module is transferred to the second energy storage module, so that the energy storage efficiency is improved; the space of the gas storage device is used for shared storage of the first medium and the second medium, in the energy storage stage, the first medium is input and the second medium is output, and in the energy releasing stage, the first medium is output and the second medium is input, so that the utilization rate of the underwater space is improved.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, specifically to an energy storage system and method. Background Technology

[0002] Offshore wind power is an important area of ​​renewable energy development, a vital force driving technological progress and industrial upgrading in wind power, and a crucial measure for adjusting the energy structure. To improve the utilization efficiency of electricity generated by wind farms, the use of suitable energy storage systems is extremely important. Current technologies generally employ single-type energy storage systems, which are not conducive to improving overall efficiency. Summary of the Invention

[0003] In view of this, this application provides an energy storage system that utilizes underwater space and couples a compressed air energy storage module and a compressed carbon dioxide energy storage module to improve underwater space utilization and energy storage efficiency. Furthermore, this application also provides a method applicable to the aforementioned energy storage system.

[0004] To achieve the above objectives, this application provides the following technical solution:

[0005] An energy storage system, comprising:

[0006] Energy storage devices, including liquid storage devices and gas storage devices, are installed in underwater areas;

[0007] The first energy storage module includes a first compression device for compressing a first medium and a first expansion device for expanding the first medium, so as to store and release energy by utilizing the compression and expansion process of the first medium. The first energy storage module is connected to the gas storage device through a first pipeline.

[0008] The second energy storage module includes an evaporation device and a condensation device, a second compression device for compressing the second medium, and a second expansion device for expanding the second medium, so as to store and release energy by utilizing the gas-liquid phase change of the second medium and the compression and expansion process. The second energy storage module is connected to the gas storage device through a second pipeline, and the second energy storage module is connected to the liquid storage device through a third pipeline.

[0009] The first expansion device is connected to the second energy storage module via a fourth pipeline to transfer the heat of the first medium to the second energy storage module.

[0010] Optionally, in the above energy storage system, the first energy storage module includes a first inlet pipe and a first outlet pipe, and a first heat storage device is provided between the first inlet pipe and the first outlet pipe, wherein the heat storage medium in the first heat storage device is used to store thermal energy; the second energy storage module includes a second inlet pipe and a second outlet pipe, and a second heat storage device is provided between the second inlet pipe and the second outlet pipe, wherein the heat storage medium in the second heat storage device is used to store thermal energy.

[0011] Optionally, in the above energy storage system, a first compression device, a gas cooler, and a gas-liquid separator are connected in series on the first inlet pipe.

[0012] Optionally, the above energy storage system also includes a water pump, which includes a first inlet pipe and a second inlet pipe. The first inlet pipe and the second inlet pipe can respectively draw water at different temperatures. The water pump delivers the higher-temperature water in the first inlet pipe to the evaporation device, and the water pump delivers the lower-temperature water in the second inlet pipe to the condensation device and the gas cooler, respectively.

[0013] Optionally, in the above energy storage system, the second outlet pipe is connected in series with the evaporation device, the preheating device, and the second expansion device, and the preheating device is connected to the first expansion device through a fourth pipeline.

[0014] Optionally, in the above energy storage system, a first expansion device is provided on the first outlet pipe, the first compression device includes a plurality of first compressors connected in series, and the first expansion device includes a plurality of first expanders connected in series.

[0015] Optionally, in the above energy storage system, a second compression device is provided on the second inlet pipe, the second compression device includes a plurality of second compressors connected in series, and the second expansion device includes a plurality of second expanders connected in series.

[0016] Optionally, in the above energy storage system, the gas storage device is divided into a first chamber and a second chamber by a diaphragm;

[0017] The first chamber stores the first medium, and the second chamber stores the second medium, wherein the first chamber is wrapped around the outside of the second chamber.

[0018] Optionally, in the above energy storage system, the gas storage device is a rigid structure with a bottom opening, the opening being connected to water, and the pressure inside the gas storage device (1) is a relatively constant water pressure.

[0019] Alternatively, the gas storage device is a rigid closed structure, and the pressure inside the gas storage device (1) is a relatively constant artificially controlled pressure;

[0020] Alternatively, the gas storage device may be a flexible closed structure, and the pressure inside the gas storage device (1) may be a relatively constant water pressure.

[0021] Optionally, in the above energy storage system, the second medium is carbon dioxide.

[0022] A method for an energy storage system, applicable to the energy storage system described above, the method comprising:

[0023] The first compression device is activated to pressurize the first medium and deliver the increased first medium to the first chamber through the first pipeline to realize energy storage of the first energy storage module. The first expansion device is activated and delivered to the first expansion device through the first pipeline, and the first medium expands to generate electricity, realizing energy release of the first energy storage module.

[0024] The second compression device and the condensation device are started to compress the second medium in the second chamber and condense it through the condensation device. The liquefied second medium is then transported to the storage device through the third pipeline, thus realizing the energy storage of the second energy storage module. The second expansion device and the evaporation device are started to vaporize the liquid second medium through the evaporation device. The vaporized second medium is expanded by the second expansion device to generate electricity, thus realizing the energy release of the second energy storage module.

[0025] The first medium, after expanding and generating electricity, is transported to the evaporation device via the fourth pipeline to transfer heat for the vaporization of the second medium.

[0026] This application provides an energy storage system, including an energy storage device, a first energy storage module, and a second energy storage module. Specifically, the energy storage device is installed in an underwater area and includes a liquid storage device and a gas storage device. The first energy storage module includes a first compression device and a first expansion device. The first compression device compresses a first medium into a high-pressure gas and transports it to a first chamber through a first pipeline; this process is the storage of electrical energy. The first expansion device expands the first medium in the first chamber and generates electricity; this process is the release of electrical energy. The second energy storage module includes a condensation device, an evaporation device, a second compression device for compressing a second medium, and a second expansion device for expanding the second medium. The second compression device transports the second medium from the second chamber... The first medium is compressed into a high-pressure gas and condensed into a liquid by a condenser. The liquid second medium is then transported to a storage device through a third pipeline. This process is the storage of electrical energy. The second medium in the storage device enters an evaporator through the third pipeline for vaporization. Then, the second expansion device expands the second medium into a low-pressure gas and generates electricity. This process is the release of electrical energy. After the first medium expands and does work, it heats up and is transported to the second energy storage module through a fourth pipeline to transfer the heat of the first medium to the second energy storage module, reducing energy loss and improving energy storage efficiency.

[0027] As can be seen from the above, the first energy storage module and the second energy storage module are coupled for energy storage, and during the energy release phase, the heat generated by the first energy storage module is transferred to the second energy storage module, which improves the energy storage efficiency; the space of the gas storage device is used for the shared storage of the first medium and the second medium. During energy storage, the first medium is input and the second medium is output. During energy release, the first medium is output and the second medium is input, which improves the utilization rate of the underwater space. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application 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 only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 This is a system schematic diagram of an open-structure rigid container gas storage facility provided in an embodiment of this application;

[0030] Figure 2 This is a schematic diagram of a closed-structure rigid or flexible container gas storage facility.

[0031] exist Figures 1-2 middle:

[0032] 1. Gas storage device;

[0033] 11. First chamber; 12. Second chamber;

[0034] 2. Liquid storage device;

[0035] 3. First energy storage module;

[0036] 31. First medium turbine assembly; 311. First compression device; 312. First expansion device; 32. First heat storage device; 321. First heat recovery unit; 322. First reheater; 323. First cold tank; 324. First hot tank; 33. Condensate assembly; 331. Gas cooler; 332. Gas-liquid separator; 34. Humidifier;

[0037] 4. Second energy storage module;

[0038] 41. Second medium turbine assembly; 411. Second compression device; 412. Second expansion device; 42. Second heat storage device; 421. Second heat recovery unit; 422. Second reheater; 423. Second cold tank; 424. Second hot tank; 43. Phase change assembly; 431. Condensation device; 432. Evaporation device; 433. Water pump; 434. Preheating device; 435. Liquid pump;

[0039] 5. First conduit; 51. First inlet pipe; 52. First outlet pipe;

[0040] 6. Second conduit; 61. Second inlet pipe; 62. Second outlet pipe;

[0041] 7. Third pipe; 8. Fourth pipe; 9. First inlet pipe; 10. Second inlet pipe. Detailed Implementation

[0042] This application provides an energy storage system that utilizes underwater space and couples a compressed air energy storage module and a compressed carbon dioxide energy storage module, thereby improving the utilization rate of underwater space and energy storage efficiency. Furthermore, this application also provides a method applicable to the aforementioned energy storage system.

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] like Figures 1-2As shown, this application embodiment provides an energy storage system, including an energy storage device, a first energy storage module 3, and a second energy storage module 4. Specifically, the energy storage device is located in an underwater area and includes a liquid storage device 2 and a gas storage device 1. The underwater location of the gas storage device firstly saves on construction costs, and secondly, the pressure compensation effect of water can reduce the pressure borne by the gas storage device, thus lowering the cost of the gas storage facility. It should be noted that the first medium is air. The first energy storage module 3 includes a first compression device 311 and a first expansion device 312. The first compression device 311 and the first expansion device 312 are collectively referred to as the air turbine assembly 31. The first medium turbine assembly 31 is mainly used for the compression and storage of air and the expansion of air to generate electricity, and is an indispensable part of the energy storage module. The first compression device 311 compresses the first medium into high-pressure gas and transports it to the first chamber (11) through the first pipeline 5. This process is the storage process of electrical energy. The first expansion device 312 expands the first medium in the gas storage device 1 and generates electricity. This process is the release process of electrical energy. The second energy storage module 4 includes a condensation device 431, an evaporation device 432, a second expansion device 412 for expanding the second medium, and a second compression device 411 for compressing the second medium. The second medium is located in the second chamber 12. During the energy storage stage, the second medium is extracted from the second chamber 12 and condensed into a liquid state by the condensation device 431. The medium is transported to the liquid storage device 2 through the third pipeline 7. During the energy release stage, the second medium in the liquid storage device 2 is pressurized and drawn by the liquid pump 435 and enters the evaporation device through the second pipeline 6 for vaporization. Then, the second expansion device 412 expands the second medium into a low-pressure gas and generates electricity. Thus, the second energy storage module 4 stores and releases energy through the gas-liquid phase change of the second medium. After the first medium expands and does work, the temperature of the first medium rises. To avoid energy waste, the first medium is transported to the second energy storage module 4 through the fourth pipeline 8 to transfer the heat of the first medium to the second energy storage module 4, thereby reducing the energy loss of the system and improving the energy storage efficiency.

[0045] As can be seen from the above, the first energy storage module 3 and the second energy storage module 4 are coupled for energy storage, and during the energy release phase, the heat generated by the first energy storage module 3 is transferred to the second energy storage module 4, which improves the energy storage efficiency; the space of the gas storage device 1 is used for the shared storage of the first medium and the second medium. During energy storage, the first medium is input and the second medium is output. During energy release, the first medium is output and the second medium is input, which improves the utilization rate of the underwater space.

[0046] It should be noted that after the second medium is vaporized by the evaporation device 432, most of it enters the first expansion device 312 to expand and do work. In order to maintain the pressure in the liquid storage device 2, a small portion is transported to the liquid storage device 2.

[0047] Furthermore, the first energy storage module 3 includes a first inlet pipe 51 and a first outlet pipe 52. A first heat storage device 32 is disposed between the first inlet pipe 51 and the first outlet pipe 52. The heat storage medium in the first heat storage device 32 is used to store thermal energy. Specifically, the first heat storage device 32 is disposed between the first compression device 311 and the first expansion device 312. During the energy storage stage, after the first compression device 311 compresses the first medium, the temperature of the first medium rises and flows along the first inlet pipe 51 through the first heat storage device 32 to exchange heat with the first heat storage device 32. Specifically, the first... The heat storage device 32 absorbs and stores the heat from the first medium. During the energy release phase, the first medium flows through the first outlet pipe 52, and the first heat storage device 32 exchanges heat with the first medium. Specifically, the first heat storage device 32 transfers the heat absorbed from the first medium during the energy storage phase back to the first medium. After the first medium is heated and expands by the first expander to do work, it is discharged to the second energy storage module 4 to supply energy to the second energy storage module 4. Thus, it can be seen that the first heat storage device 32 effectively recovers and utilizes the heat generated when the first compression device 311 is working, thereby improving the energy storage efficiency of the system.

[0048] It should be noted that the first thermal storage device 32 includes a first cold tank 323, a first hot tank 324, a first heat recovery unit 321, and a first reheater 322. When storing heat, the thermal storage medium flows out from the first cold tank 323 at a low temperature. It then flows through the first heat recovery unit 321 and absorbs the heat from the first medium, raising its temperature. Subsequently, it enters the first hot tank 324 to store the heat. When releasing heat, the thermal storage medium flows out from the first hot tank 324 and passes through the first reheater 322 to transfer the heat stored in the first medium during the thermal storage stage to the first medium. It then enters the first cold tank 323. The heat release stage and the thermal storage stage cycle repeatedly, effectively recovering and utilizing the heat generated by the first compression device 311. In addition, the energy storage system is a combined energy storage system composed of the first energy storage module 3, the second energy storage module 4, and the thermal storage devices (first thermal storage device 32 and second thermal storage device 42), which improves the overall energy efficiency of energy storage.

[0049] The second energy storage module 4 includes a second inlet pipe 61 and a second outlet pipe 62. A second heat storage device 42 is disposed between the second inlet pipe 61 and the second outlet pipe 62. The heat storage medium in the second heat storage device 42 is used to store thermal energy. The second heat storage device 42 includes a second cold tank 423, a second hot tank 424, a second heat recovery unit 421, and a second reheater 422. Their functions are the same as those of the first cold tank 323, the first hot tank 324, the first heat recovery unit 321, and the first reheater 322, respectively. The working principle and configuration of the second heat storage device 42 are the same as those of the first heat storage device 32. The beneficial effects brought by the second heat storage device 42 are the same as those of the first heat storage device 32, and will not be described again here.

[0050] Furthermore, a first compression device 311, a first heat storage device 32, a gas cooler 331, and a gas-liquid separator 332 are connected in series on the first inlet pipe 51; a first expansion device 312 is provided on the first outlet pipe 52. It should be noted that the first medium is air, and the first inlet pipe 51 is connected to the first pipeline 5 to form an energy storage pipeline for the first medium. Through the condensate assembly 33 arranged on the first inlet pipe 51, air-to-water production and gas-water separation are realized. The first outlet pipe 52 is connected to the first pipeline 5 to form an energy release pipeline for the first medium. During the energy storage stage, the first medium is compressed into high-pressure gas by the first compression device 311, and the heat of compression from the first compression device 311 is transferred to the first heat storage device 32 through heat exchange. After the first medium flows through the gas cooler 331, part of the first medium is liquefied, and then all the first medium enters the gas-liquid separator 332, where liquid fresh water is separated and delivered to water-requiring equipment and personnel, saving water resources. The gaseous first medium is delivered to the gas storage device 1 for energy storage. Thus, it can be seen that the first energy storage module 3 has diversified functions.

[0051] Furthermore, it also includes a water pump 433, which includes a first inlet pipe 9 and a second inlet pipe 10. The first inlet pipe 9 and the second inlet pipe 10 can respectively draw water at different temperatures. The water pump 433 delivers the water in the first inlet pipe 9 to the evaporation device 432, and the water pump 433 delivers the water in the second inlet pipe 10 to the condensation device 431 and the gas cooler 331 respectively. Because the temperature of seawater is different at different water levels, the first inlet pipe 9 and the second inlet pipe 10 of the water pump 433 draw seawater from different water levels, resulting in different temperatures of seawater in the first inlet pipe 9 and the second inlet pipe 10. In this application, the first inlet pipe 9 draws seawater from a shallower area, where the seawater temperature is relatively high, for example, 16°C. This seawater at this temperature is sent to the evaporation device 432, where it transfers heat to the liquid second medium. The second medium absorbs heat and turns into a gaseous state. Thus, it can be seen that the gas-liquid phase change of the second medium is achieved using existing sea conditions, thereby improving the energy storage efficiency of the second module; the second inlet pipe 10 draws... Seawater from deeper areas, with relatively lower temperatures (e.g., 4°C), is transported to a condenser 431 and a gas cooler 331. The condenser 431 is a device for liquefying the second medium, storing the liquid second medium in a storage device 2. The gas cooler 331 partially liquefies the water in the gaseous first medium, thus separating fresh water for use by personnel and equipment. This storage of the second medium and separation of water fully utilizes the temperature difference at different depths of seawater, using the lower-temperature seawater from deeper layers for condensation of the second medium and the higher-temperature seawater from shallower layers for evaporation of the second medium, thereby improving energy storage efficiency.

[0052] In an optional embodiment, an evaporation device 432, a preheating device 434, and a second expansion device 412 are connected in series on the second outlet pipe 62. The preheating device 434 is connected to the first expansion device 312 via a fourth pipe 8. A second compression device 411411 is provided on the second inlet pipe 61. It should be noted that the second inlet pipe 61 and the second pipe 6 form an energy storage pipeline, and the second outlet pipe 62 and the third pipe 7 form an energy release pipeline. The second energy storage module 4 realizes energy storage through the gas-liquid phase change of the second medium by means of phase change components 43 distributed on the second inlet pipe 61 and the second outlet pipe 62. The preheating device 434 is connected to the first expansion device 312 via the fourth pipe 8. Specifically, the first expansion device 312 expands the first medium, increasing its temperature. The heated first medium transfers heat to the preheating device 434 located in the second energy storage module 4 via the fourth pipe 8. Thus, the heat generated by the first energy storage module 3 is effectively recovered and utilized, improving energy storage efficiency.

[0053] In some other alternative embodiments, the first expansion device 312 may also be connected to the evaporation device 432, that is, the heat generated by the first expansion device 312 is transferred to the evaporation device 432 to assist the evaporation process of the second medium.

[0054] In an optional embodiment, the first compression device 311 includes a plurality of first compressors connected in series, and the first expansion device 312 includes a plurality of first expanders connected in series. The first medium flowing through the plurality of first compressors connected in series means that the first medium undergoes multi-stage compression. The more times the first medium is compressed, the higher its pressure, which is more conducive to energy storage, thus improving energy storage efficiency. The first expansion device 312 including a plurality of first expanders connected in series means that the first medium undergoes multi-stage expansion. The more times the first medium is expanded, the more work is done during expansion, resulting in more electricity generation, which is beneficial for the energy storage device to release and generate electricity.

[0055] In an optional embodiment, the second compression device 411 includes multiple second compressors connected in series, and the second expansion device 412 includes multiple second expanders connected in series. The second medium flows through multiple second compressors connected in series, meaning that the second medium undergoes multi-stage compression. The more times the second medium is compressed, the higher its pressure, which is more conducive to energy storage, thus improving energy storage efficiency. The second expansion device 412 includes multiple second expanders connected in series, meaning that the second medium undergoes multi-stage expansion. The more times the second medium is expanded, the more work is done during expansion, resulting in more electricity generation, which is beneficial for the energy storage device to release and generate electricity. It should be noted that the second compression device 411 and the second expansion device 412 are collectively referred to as the second medium turbine assembly 41. The second medium turbine assembly 41 is mainly used for the compression and storage of the second medium and the expansion and power generation of the second medium, and is an indispensable part of the energy storage module.

[0056] In some other alternative embodiments, taking into account the construction cost of the energy storage system, the first compression device 311 may include only one first compressor or include multiple first compressors connected in parallel, the first expansion device 312 may include only one first expander or multiple second compressors connected in parallel; the second compression device 411 may include only one second compressor or multiple second compressors connected in parallel, and the second expansion device 412 may include only one second expander or multiple second expanders connected in parallel.

[0057] In an optional embodiment, the gas storage device 1 is divided into a first chamber 11 and a second chamber 12 by a diaphragm; wherein the first chamber 11 stores a first medium, and the second chamber 12 stores a second medium, and the first chamber 11 surrounds the outside of the second chamber 12. In this application, the gas storage device 1 is located underwater, and the gas storage device 1 is divided into two gas storage chambers by a diaphragm, namely the first chamber 11 and the second chamber 12, and the first chamber 11 surrounds the outside of the second chamber 12. The first medium is stored in the first chamber 11, and the second medium is stored in the second chamber 12. That is to say, the first medium and the second medium occupy the same gas storage tank, which is a dual-purpose tank, saving the underwater space occupied by the gas storage device 1 and saving the cost of the gas storage device 1. It should be noted that the second chamber 12 is surrounded by a diaphragm, and the second chamber 12 can expand and contract.

[0058] In other alternative embodiments, the gas storage device 1 can be divided into multiple chambers by a diaphragm, and the gas storage device 1 can also include multiple gas storage tanks, which are further divided into multiple chambers by a diaphragm.

[0059] In an optional embodiment, the gas storage device 1 is a rigid structure with an opening that allows water to flow in but prevents the first medium from flowing out, and the opening is in communication with water. Specifically, the opening is located at the bottom of the gas storage device 1, which is divided into a first chamber 11 and a second chamber 12 by a diaphragm. The first chamber 11 contains the first medium, and the second chamber 12 contains the second medium. The first chamber 11 surrounds the outside of the second chamber 12, and the first chamber 11 has an opening in communication with water. It should be noted that the water in this embodiment refers to seawater. Since the second chamber 12 is divided by the diaphragm, the second chamber 12 can expand and contract.

[0060] In the initial state of energy storage, seawater is located in the first chamber 11 and occupies the space of the first medium, while the second chamber 12 contains the second medium. At this time, the pressure of the second medium is equal to the hydrostatic pressure of the seawater in the first chamber 11. During the energy storage phase, the second energy storage module 4 starts before the first energy storage module 3 to prepare for the storage of the first medium. That is, the second medium in the second chamber 12 is first transported to the liquid storage device 2, and more seawater enters the first chamber 11. The second chamber 12 is compressed by the seawater until all the second medium in the second chamber 12 is extracted. At this time, the seawater occupies the entire space of the gas storage device 1. Then, the first energy storage module 3 is activated, and it transports the first medium to the first chamber 11. As the first energy storage module 3 operates, the first medium discharges the seawater into the sea. The first medium eventually occupies the entire space of the gas storage device 1, maximizing the energy storage of the first medium and improving energy storage efficiency. At the same time, the extracted second medium is liquefied and stored, and the liquefied medium has a higher energy density.

[0061] The second energy storage module 4 can also operate simultaneously with the first energy storage module 3. In this case, the volume of the second medium extracted from the second chamber 12 must be the same as the volume of the first medium transported into the first chamber 11.

[0062] During the energy release phase, the first energy storage module 3 must operate before or simultaneously with the second energy storage module 4. In addition, the medium inside the first energy storage module 3 is air. After the air expands and does work, it still has residual heat. In order to avoid energy waste, the first medium is transported to the second energy storage module 4 through the fourth pipeline 8 to transfer heat to the second energy storage module 4.

[0063] In other alternative embodiments, the gas storage device 1 is a rigid closed structure. In this case, the pressure inside the gas storage device 1 is relatively constant and manually controlled. That is, the pressure in the first chamber and the second chamber remains constant, and the pressure magnitude is related to the amount of gas manually introduced into the gas storage device 1. Alternatively, the gas storage device 1 is a flexible closed structure, in which case the pressure inside the gas storage device 1 is a relatively constant hydrostatic pressure. The only difference between the operation of the energy storage module and the operation of the energy storage module with a rigid or flexible closed structure gas storage device 1 is that the air inside the closed structure (rigid or flexible closed structure) needs to be humidified first using a humidifier 34 to improve the air's ability to expand and do work. Therefore, the operation of the energy storage module with a rigid or flexible closed structure gas storage device 1 will not be described further here.

[0064] In an optional embodiment, the second medium is carbon dioxide. Under the dual-carbon context, vigorously developing carbon dioxide energy storage technology and turning carbon dioxide from waste into a valuable resource is of great significance. In this application, carbon dioxide is enclosed in a gas storage device 1 and a liquid storage device 2, which reduces air pollution while storing energy. Furthermore, carbon dioxide has advantages such as high energy storage efficiency, safety, environmental friendliness, and low unit cost. Therefore, using carbon dioxide for energy storage is beneficial for cost savings, environmental optimization, and overall energy storage.

[0065] A method for an energy storage system, applicable to the energy storage system described above, the method comprising:

[0066] The first compression device 311 is started to pressurize the first medium and transport the increased first medium to the first chamber 11 through the first pipeline 5 to realize the energy storage of the first energy storage module 3. The first expansion device 312 is started and transported to the first expansion device 312 through the first pipeline 5. The first medium expands to generate electricity and realizes the energy release of the first energy storage module 3.

[0067] The second compression device 411 and the condensation device 431 are activated to compress the second medium in the second chamber 12 and condense it through the condensation device 431. The liquefied second medium is then transported to the liquid storage device 2 through the third pipeline 7 for storage, thus realizing the energy storage of the second energy storage module 4. The second expansion device 412 and the evaporation device 432 are activated, and the liquid second medium flows through the evaporation device 432 to vaporize. The vaporized second medium expands through the second expansion device 412 to generate electricity, thus realizing the energy release of the second energy storage module 4.

[0068] The first medium, after expanding and generating electricity, is transported to the evaporation device 432 via the fourth pipeline 8 to transfer heat for the vaporization of the second medium.

[0069] The basic principles of this application have been described above with reference to specific embodiments. However, it should be noted that the advantages, benefits, and effects mentioned in this application are merely examples and not limitations, and should not be considered as essential features of each embodiment of this application. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations. These details do not limit the application to the necessity of employing the aforementioned specific details for implementation.

[0070] The block diagrams of devices, apparatuses, devices, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As those skilled in the art will recognize, these devices, apparatuses, devices, and systems can be connected, arranged, and configured in any manner. Words such as “comprising,” “including,” “having,” etc., are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The terms “or” and “and” as used herein refer to the terms “and / or,” and are used interchangeably with them unless the context clearly indicates otherwise. The term “such as” as used herein refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0071] It should also be noted that in the apparatus, equipment, and methods of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered as equivalent solutions of this application.

[0072] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0073] It should be understood that the qualifiers “first,” “second,” “third,” “fourth,” “fifth,” and “sixth” used in the description of the embodiments of this application are only used to more clearly illustrate the technical solutions and are not intended to limit the scope of protection of this application.

[0074] The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although numerous exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. An energy storage system, characterized in that, include: An energy storage device includes a liquid storage device (2) and a gas storage device (1). The gas storage device includes a first chamber (11) and a second chamber (12) separated by a diaphragm. The first chamber (11) stores a first medium, and the second chamber (12) stores a second medium. The first chamber (11) is wrapped around the outside of the second chamber (12). The energy storage device is located in an underwater area. The first energy storage module (3) includes a first compression device (311) for compressing the first medium and a first expansion device (312) for expanding the first medium, so as to store and release energy by utilizing the compression and expansion process of the first medium. The first energy storage module (3) is connected to the first chamber (11) through a first pipeline (5). The first energy storage module (3) also includes a first inlet pipe (51) and a first outlet pipe (52). A first heat storage device (32) is provided between the first inlet pipe (51) and the first outlet pipe (52). The heat storage medium in the first heat storage device (32) is used to store thermal energy. The first compression device (311), a gas cooler (331), and a gas-liquid separator (332) are connected in series on the first inlet pipe (51). The first expansion device (312) is provided on the first outlet pipe (52). The second energy storage module (4) includes an evaporation device (432) and a condensation device (431), a second compression device (411) for compressing the second medium, and a second expansion device (412) for expanding the second medium, so as to store and release energy by utilizing the gas-liquid phase change of the second medium and the compression and expansion process. The second energy storage module (4) is connected to the second chamber (12) through a second pipeline (6). The second energy storage module (4) is connected to the liquid storage device (2) through a third pipeline (7). The second energy storage module (4) also includes a second inlet pipe (61) and a second outlet pipe (62). A second heat storage device (42) is provided between the second inlet pipe (61) and the second outlet pipe (62). The heat storage medium in the second heat storage device (42) is used to store thermal energy. The water pump (433) includes a first inlet pipe (9) and a second inlet pipe (10). The first inlet pipe (9) and the second inlet pipe (10) can respectively draw water at different temperatures. The water pump (433) delivers the water at a higher temperature in the first inlet pipe (9) to the evaporator (432). The water pump (433) delivers the water at a lower temperature in the second inlet pipe (10) to the condenser (431) and the gas cooler (331) respectively. The first expansion device (312) is connected to the second energy storage module (4) through a fourth pipeline (8) to transfer the heat of the first medium to the second energy storage module (4).

2. The energy storage system according to claim 1, characterized in that, The second outlet pipe (62) is connected in series with the evaporation device (432), the preheating device (434) and the second expansion device (412). The preheating device (434) is connected to the first expansion device (312) through the fourth pipe (8). The second inlet pipe (61) is equipped with a second compression device (411).

3. The energy storage system according to claim 1, characterized in that, The first compression device (311) includes a plurality of first compressors connected in series, and the first expansion device (312) includes a plurality of first expanders connected in series.

4. The energy storage system according to claim 2, characterized in that, The second compression device (411) includes a plurality of second compressors connected in series, and the second expansion device (412) includes a plurality of second expanders connected in series.

5. The energy storage system according to claim 1, characterized in that, The gas storage device (1) is a rigid structure and has an opening that allows water to flow in but does not allow the first medium to flow out. The opening is connected to water, and the pressure inside the gas storage device (1) is a relatively constant water pressure. Alternatively, the gas storage device (1) is a rigid closed structure, and the pressure inside the gas storage device (1) is a relatively constant artificially controlled pressure; Alternatively, the gas storage device (1) is a flexible closed structure, and the pressure inside the gas storage device (1) is a relatively constant water pressure.

6. The energy storage system according to claim 1, characterized in that, The second medium is carbon dioxide.

7. A method for an energy storage system, characterized in that, The method, applicable to the energy storage system of claim 1, comprises: Start the first compression device (311) to pressurize the first medium and transport the increased first medium to the first chamber (11) through the first pipeline (5) to realize the energy storage of the first energy storage module (3). Start the first expansion device (312) and transport it to the first expansion device (312) through the first pipeline (5). The first medium expands to generate electricity and realize the energy release of the first energy storage module (3). The second compression device (411) and the condensation device (431) are started to compress the second medium in the second chamber (12), and condense it through the condensation device (431). The liquefied second medium is then transported to the storage device (2) through the third pipeline (7) for storage, thus realizing the energy storage of the second energy storage module (4). The second expansion device (412) and the evaporation device (432) are started to vaporize the liquid second medium through the evaporation device (432). The vaporized second medium is expanded by the second expansion device (412) to generate electricity, thus realizing the energy release of the second energy storage module (4). The first medium, after expanding and generating electricity, is transported to the evaporation device (432) via the fourth pipeline (8) to transfer heat for the vaporization of the second medium.

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