Composite energy storage system, operation method thereof and distributed energy system

Abstract

This application relates to a composite energy storage system, its operation method, and a distributed energy system. The composite energy storage system includes a compressed air energy storage system, a flow battery energy storage system, and a cold and hot circulation system. The cold and hot circulation pipelines of the cold and hot circulation system connect the electrolyte storage tanks of the compressed air energy storage system and the flow battery energy storage system. The energy generated by the compressed air energy storage system during gas compression energy storage and compressed gas release is used by the flow battery energy storage system through the cold and hot circulation system, which can significantly reduce energy consumption and improve overall energy utilization efficiency. The compressed air generated by the compressed air energy storage system is used as raw material to prepare compressed inert gas, and the compressed inert gas forms a two-phase flow with the electrolyte, participating in the multiphase flow electrocatalytic reaction in the stack, which helps to improve the electrochemical reaction rate and the charge and discharge efficiency of the flow battery.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a composite energy storage system, its operation method, and a distributed energy system. Background Technology

[0002] As the penetration rate of renewable energy sources such as wind power and photovoltaics in the power grid increases, the requirements for the operational stability of the power system are higher. Long-term energy storage technology (referring to the storage of electrical energy for several hours to several months) has become a major technology for ensuring grid security and improving the capacity for new energy consumption because it can achieve energy transfer and balance across time periods.

[0003] Currently, most long-term energy storage technologies have their limitations. For example, while compressed air energy storage has advantages such as large capacity and long lifespan, its efficiency is limited by geological conditions and the energy conversion process; flow batteries, while featuring separate power and capacity designs and high safety, suffer from low energy density, system complexity, and hydrogen evolution safety risks; and thermal energy storage technology, while having lower costs, suffers from bottlenecks such as large heat loss and low heat-to-electricity conversion efficiency.

[0004] It is evident that existing long-term energy storage technologies all have technical limitations and low energy utilization efficiency. Therefore, it is necessary to leverage the strengths of each technology and compensate for their weaknesses through technological integration to amplify the technological advantages of long-term energy storage. Summary of the Invention

[0005] Therefore, it is necessary to provide a composite energy storage system, its operation method, and a distributed energy system to address the problems in the existing technology.

[0006] In a first aspect, this application provides a composite energy storage system, including: a compressed air energy storage system, a flow battery energy storage system, a cold cycle system, and a hot cycle system;

[0007] The compressed air energy storage system is used to store electrical energy through compressed gas and to drive power generation by releasing the compressed gas.

[0008] The flow battery energy storage system includes a stack and a flow circulation system. The flow battery energy storage system is used to store and release electrical energy through the electrochemical reaction of electrolytes of respective polarities in the stack, and the energy is stored in the corresponding electrolyte tank of the flow circulation system.

[0009] The cold circulation system includes a cold flow circulation pipeline, which connects the compressed air energy storage system and the flow battery energy storage system. The cold flow circulation pipeline transfers the cold energy generated by the compressed air energy storage system during the expansion and / or phase change of the compressed gas to the electrolyte storage tank of the flow battery energy storage system to cool and / or control the temperature of the electrolyte in the electrolyte storage tank.

[0010] The thermal circulation system includes a heat flow circulation pipeline that connects the compressed air energy storage system and the flow battery energy storage system. The heat flow circulation pipeline transfers the compression heat energy generated by the compressed air energy storage system during gas compression and / or phase change to the electrolyte storage tank of the flow battery energy storage system to raise and / or control the temperature of the electrolyte in the electrolyte storage tank.

[0011] In one embodiment, the cold and hot flow circulation pipelines exchange heat with the electrolyte storage tank in one of the following ways:

[0012] A portion of the cold and hot flow circulation pipelines is located inside the electrolyte storage tank and is wound into a coil.

[0013] And / or, a portion of the cold and hot flow circulation pipeline is disposed on the outer wall of the electrolyte storage tank and wound into a coil;

[0014] And / or, the electrolyte storage tank has a sandwich space that forms part of the cold and hot flow circulation pipeline;

[0015] And / or, a phase change material energy storage layer is provided between the outer wall of the electrolyte storage tank and the insulation layer, and the phase change material energy storage layer is connected to a part of the cold and hot flow circulation pipeline.

[0016] In one embodiment, the compressed air energy storage system includes a compressor unit driven by an electric motor, a heat storage device, a cold storage device, a gas storage device, and an expander unit connected by pipelines, and further drives a generator unit; the heat storage device is connected to the compressor unit and / or the gas storage device to collect and store the heat energy generated by the gas during compression and / or phase change.

[0017] The cold storage device is connected to the gas storage device and / or the expander unit, and is used to collect and store the cold energy generated by the compressed gas during expansion and / or phase change.

[0018] The hot flow circulation pipeline is connected to the heat storage device, and the cold flow circulation pipeline is connected to the cold storage device.

[0019] In one embodiment, the liquid circulation system includes the electrolyte storage tank, the electrolyte circulation pump, and the electrolyte circulation pipeline; the electrolyte storage tank is connected to the fuel cell stack through the electrolyte circulation pipeline and the electrolyte circulation pump to form an electrolyte circulation loop;

[0020] The fuel cell stack includes:

[0021] Multiple flow battery units, each flow battery unit including a positive electrode reaction chamber and a negative electrode reaction chamber that are isolated from each other, and a membrane assembly disposed between the positive and negative electrode reaction chambers;

[0022] Distribution channels and / or branch channels are used to guide electrolytes of their respective polarities to the positive and negative electrode reaction chambers of the multiple flow battery cells;

[0023] In this process, electrolytes of their respective polarities come into contact with the positive and negative electrodes in the positive and negative electrode reaction chambers and undergo electrochemical reactions. The electrolytes of their respective polarities also undergo selective ion migration between the positive and negative electrode reaction chambers through the diaphragm assembly.

[0024] In one embodiment, the flow battery cell further includes an electrolyte injection device, the electrolyte injection device comprising:

[0025] A nozzle array, disposed within the positive electrode reaction chamber and / or the negative electrode reaction chamber, is used to spray electrolyte onto the positive electrode and / or the negative electrode and / or the positive electrode side and / or the negative electrode side surface of the diaphragm assembly;

[0026] The nozzle array includes multiple nozzles connected in parallel and / or in series. The nozzle array is embedded in the positive electrode side and / or negative electrode side of the separator assembly, and / or the positive electrode reaction chamber, and / or the negative electrode reaction chamber, and is spaced at a predetermined distance from the battery separator and the positive and negative electrodes.

[0027] In one embodiment, the flow battery energy storage system further includes:

[0028] A gas-liquid mixing mechanism is used to mix compressed inert gas with electrolytes of their respective polarities to form an atomized mixture that is delivered to the corresponding electrolyte inlet of the nozzle array or the fuel cell stack. The atomized mixture enters the fuel cell stack through the nozzle array or the electrolyte inlet and participates in the electrochemical reaction.

[0029] The gas-liquid mixing mechanism includes a gas input interface, a liquid input interface, and a gas-liquid mixing outlet. The gas input interface is connected to a compressed inert gas source, the liquid input interface is connected to an electrolyte delivery pipeline, and the gas-liquid mixing outlet is connected to the corresponding electrolyte inlet of the nozzle array or the fuel cell stack.

[0030] In one embodiment, a gas management system is also included, the gas management system including a nitrogen generator and a gas delivery pipeline;

[0031] The nitrogen generator is connected to the compressed air energy storage system, and uses the compressed air generated by the compressed air energy storage system as raw material to prepare compressed inert gas;

[0032] The gas delivery pipeline connects the nitrogen generator to the flow battery energy storage system. The gas delivery pipeline includes a first branch, which is connected to the top space inside the electrolyte storage tank to introduce compressed inert gas into the electrolyte storage tank to replace and remove the hydrogen gas accumulated in the electrolyte storage tank.

[0033] In one embodiment, the gas delivery line further includes a second branch connected to the fuel cell stack for introducing compressed inert gas into the fuel cell stack, wherein the compressed inert gas and the electrolyte form a first type of flow state and carry out a multiphase electrocatalytic reaction within the fuel cell stack.

[0034] In one embodiment, the gas management system further includes a third branch connected to a gas-liquid mixing mechanism of the flow battery energy storage system, for introducing compressed inert gas into the gas-liquid mixing mechanism, wherein the compressed inert gas and electrolyte form a second type of flow state, and are jointly introduced into the stack of the flow battery energy storage system to carry out a multiphase electrocatalytic reaction.

[0035] In one embodiment, the cold cycle system includes:

[0036] The first refrigeration device utilizes the expansion of compressed air in the compressed air energy storage system under conditions of performing work and / or throttling, converting the gas's internal energy into mechanical energy to lower the temperature; and,

[0037] The first cold storage device is used to collect and store the cold energy generated by the first refrigeration device, and transfer the cold energy to the electrolyte storage tank through the cold flow circulation pipeline.

[0038] In one embodiment, the cold cycle system further includes:

[0039] The second refrigeration unit utilizes the processed compressed gas from the compressed air energy storage system as the refrigerant, and forms a refrigerant phase change cycle through a compressor, condenser, expansion valve, and evaporator connected sequentially via pipelines, absorbing latent heat during the phase change process; and

[0040] The second cold storage device is used to collect and store the cold energy generated by the second refrigeration device, and transfer the cold energy to the electrolyte storage tank through the cold flow circulation pipeline.

[0041] In a second aspect, this application provides a distributed energy system, including a composite energy storage system as described in the first aspect, wherein the composite energy storage system is connected to one or more of a power grid, a wind power generation system, a photovoltaic thermal power system, and / or a gas turbine.

[0042] In one embodiment, it further includes:

[0043] Solar thermal utilization systems, including solar collectors;

[0044] The solar collector is connected to the heat storage device of the compressed air energy storage system through a heat exchange pipeline to form a heat replenishment circuit.

[0045] Thirdly, this application provides a method for operating a composite energy storage system, comprising the following steps:

[0046] The compressed heat energy generated by the compressed air energy storage system during gas compression and / or phase change is transferred to the electrolyte storage tank of the flow battery energy storage system through a thermal circulation system to raise and / or control the temperature of the electrolyte in the electrolyte storage tank.

[0047] The cold energy generated by the compressed air energy storage system during the expansion and / or phase change of compressed gas is transferred to the electrolyte storage tank of the flow battery energy storage system through a cold circulation system to cool and / or control the temperature of the electrolyte in the electrolyte storage tank.

[0048] In one embodiment, it further includes:

[0049] The compressed air generated by the compressed air energy storage system is prepared into a compressed inert gas, and the compressed inert gas is introduced into the top space inside the electrolyte storage tank to replace and remove the hydrogen gas accumulated in the electrolyte storage tank.

[0050] And / or, a compressed inert gas is introduced into the stack of the flow battery energy storage system, and forms a first type of flow state with the electrolyte in the stack to carry out a multiphase electrocatalytic reaction;

[0051] And / or, compressed inert gas is introduced into the gas-liquid mixing mechanism of the flow battery energy storage system, and the compressed inert gas and electrolyte form a second type of flow state, which is then introduced into the stack of the flow battery energy storage system to carry out a multiphase electrocatalytic reaction.

[0052] This application discloses a composite energy storage system, its operation method, and a distributed energy system. The composite energy storage system includes a compressed air energy storage system, a flow battery energy storage system, and a hot and cold cycle system. The hot circulation pipeline of the hot cycle system connects the electrolyte tanks of the compressed air energy storage system and the flow battery energy storage system, transferring the heat energy generated by the compressed air energy storage system during gas compression and / or phase change to the electrolyte tank for heating and / or temperature control of the electrolyte. The cold circulation pipeline of the cold cycle system connects the electrolyte tanks of the compressed air energy storage system and the flow battery energy storage system, transferring the cold energy generated by the compressed air energy storage system during gas expansion and / or phase change to the electrolyte tank of the flow battery energy storage system for cooling and / or temperature control of the electrolyte in the electrolyte tank. Using the heat energy generated by the compressed air energy storage system during gas compression and / or phase change as a stable heat source for the flow battery energy storage system, replacing electric heating, can significantly reduce energy consumption and improve overall energy utilization efficiency. Similarly, using the cold energy generated by the compressed air energy storage system during gas expansion and / or phase change as a stable cold source for the flow battery energy storage system, replacing forced convection cooling or independent air conditioning systems, can significantly reduce energy consumption and improve overall energy utilization efficiency. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a block diagram of a composite energy storage system provided in one embodiment;

[0055] Figure 2 This is a schematic diagram of heat exchange between a compressed air energy storage system and a thermal cycle system provided in one embodiment.

[0056] Figure 3 This is a schematic diagram of the combination method of the composite energy storage system provided in one embodiment;

[0057] Figure 4 This is a schematic diagram of a portion of a heat flow circulation pipeline coiled inside an electrolyte storage tank, as provided in one embodiment.

[0058] Figure 5 This is a schematic diagram of a portion of a heat flow circulation pipeline coiled around the outer wall of an electrolyte storage tank in one embodiment;

[0059] Figure 6 This is a schematic diagram of an electrolyte storage tank with a sandwich space provided in one embodiment;

[0060] Figure 7 This is a schematic diagram of a phase change heat storage layer provided between the outer wall of the electrolyte storage tank and the insulation layer in one embodiment;

[0061] Figure 8a This is a schematic diagram of the structure of a flow battery stack provided in one embodiment;

[0062] Figure 8b This is a schematic diagram of the structure of a flow battery stack provided in another embodiment;

[0063] Figure 8c A cross-sectional view of a flow battery stack provided in one embodiment;

[0064] Figure 8d A cross-sectional view of a flow battery stack and its cross-section provided in another embodiment;

[0065] Figure 9 This is a schematic diagram of a beaded curtain nozzle array provided in one embodiment;

[0066] Figure 10a This is a schematic diagram of a gas-liquid mixing mechanism provided in one embodiment;

[0067] Figure 10b This is a schematic diagram of a gas-liquid mixing mechanism provided in one embodiment;

[0068] Figure 11 This is a schematic diagram of a flow battery stack with a gas-liquid mixing mechanism provided in one embodiment;

[0069] Figure 12 This is a schematic diagram of the circulation of a flow battery system provided in one embodiment;

[0070] Figure 13 This is a schematic diagram of the circulation of a flow battery system provided in one embodiment;

[0071] Figure 14 This is a schematic diagram of the circulation of a flow battery system provided in one embodiment;

[0072] Figure 15 This is a schematic diagram of the circulation of a flow battery system provided in one embodiment;

[0073] Figure 16 This is a block diagram of a composite energy storage system provided in one embodiment;

[0074] Figure 17 This is a schematic diagram of a distributed energy system provided in one embodiment;

[0075] Figure 18 This is a schematic diagram of a distributed energy system provided in another embodiment;

[0076] Figure 19 This is a schematic diagram of a distributed energy system provided in yet another embodiment;

[0077] Figure 20 This is a flowchart of an operation method for a composite energy storage system provided in one embodiment.

[0078] Explanation of reference numerals in the attached figures:

[0079] 6-9. Cooler; 10. Compressed air energy storage system; 11. Electric motor unit; 12. Compressor unit; 12-1. Low-pressure air compressor; 12-2. High-pressure air compressor; 13. Heat flow storage tank; 14. Gas storage device; 15. Expander unit; 16. Generator unit; 17. Second heat exchanger; 18. Heat storage device; 19. First heat exchanger; 101. First gas control valve; 102. Second gas control valve; 103. Pressure regulating valve;

[0080] 20. Flow battery energy storage system; 21. Stack; 211. Positive electrode reaction chamber; 212. Negative electrode reaction chamber; 213. Separator assembly; 214. Solid phase functional layer; 23. Electrolyte storage tank; 23-1. First electrolyte storage tank; 23-2. Second electrolyte storage tank; 23-3. First electrolyte replenishment tank; 23-4. Second electrolyte replenishment tank; 24. Electrolyte injection device; 25. Gas-liquid mixing mechanism; 251. Gas input interface; 252. Liquid input interface; 253. Gas-liquid mixing outlet; 26. Phase change thermal storage layer; 27. Insulation layer; 28. Electrolyte 28-1, First electrolyte circulation pump; 28-2, Second electrolyte circulation pump; 28-3, First electrolyte replenishment circulation pump; 28-4, Second electrolyte replenishment circulation pump; 29, Electrolyte circulation pipeline; 29-1, First electrolyte circulation pipeline; 29-2, Second electrolyte circulation pipeline; 29-3, First electrolyte replenishment pipeline; 29-4, Second electrolyte replenishment pipeline; 201-1, First electrolyte filter; 201-2, Second electrolyte filter; 202, Liquid pressure transmitter; 203, Liquid control valve; 204, Liquid flow transmitter;

[0081] 206. Electrolyte neutralization and desalination device; 207. Gas-liquid separator (corrosion resistant);

[0082] 30. Heat circulation system; 31. Heat flow circulation piping; 32. Heat flow circulation pump; 33. Temperature monitoring module; 34. Heat flow control valve;

[0083] 40. Cold circulation system; 41. Cold flow circulation piping;

[0084] 50. Gas management system; 51. Nitrogen generator; 52. Gas delivery pipeline; 54. (Nitrogen) storage tank; 54-1. First (nitrogen) storage tank; 54-2. Second (nitrogen) storage tank; 55. Gas-liquid separator; 56. Gas purification device; 57. Pressure regulating valve; 58. Gas control valve; 59. Gas flow transmitter;

[0085] 201-1, First electrolyte filter; 201-2, Second electrolyte filter;

[0086] 88. Electric heater; 89. Thermocouple temperature sensor; 90. Liquid level sensor; 91. Pressure relief valve (safety valve); 92. Pressure gauge; 93. Gas pressure regulator; 94. Gas flow regulator; 95. Dryer filter; 205. Circulating air compressor; 98. Gas phase blocker; 99. Liquid phase blocker. Detailed Implementation

[0087] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate preferred embodiments of the application. However, this application may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0088] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0089] Currently, large-scale energy storage technologies mainly include pumped hydro storage and compressed air storage (CASS). Among these, CASS systems offer advantages such as large storage capacity, long cycle life, and low unit cost. CASS systems utilize electricity during off-peak grid periods, compressing gas to high pressure using a compressor driven by an electric motor and storing it in underground caverns or pressure vessels. During peak load periods, the high-pressure air is released and used by an expander to drive a generator to produce electricity. However, traditional CASS systems are limited by geological conditions and have relatively low overall efficiency. The release process typically requires the combustion of fossil fuels to reheat the air. While advanced adiabatic CASS systems recover the heat generated during compression and use it to heat the air during release, eliminating the need for a combustion chamber and achieving higher efficiency and zero carbon emissions, the large amount of low-temperature compression heat generated during compression still requires optimization in terms of overall energy efficiency during storage and subsequent utilization.

[0090] Flow batteries offer advantages such as independent design of power and capacity, long cycle life, and high intrinsic safety. However, their energy and power densities are generally low. Under overcharge or over-discharge conditions, hydrogen and oxygen evolution side reactions can occur within the stack of flow batteries (especially aqueous flow battery systems). The resulting flammable and explosive gases can flow back into the electrolyte storage tank with the electrolyte and accumulate in the top space, easily forming an explosive gas mixture and posing a serious safety hazard. Currently, flow batteries use various active and passive hydrogen removal systems to remove hydrogen, which not only increases system complexity and cost but also affects system reliability. Furthermore, the electrolyte in flow batteries needs to operate within a specific temperature range. Traditional temperature control methods often use immersion heaters, which pose risks of localized overheating of the electrolyte and dry burning of the heater, affecting its chemical and system stability, increasing system energy consumption and heating element replacement costs, and reducing overall system efficiency and lifespan.

[0091] From a practical perspective, compressed air energy storage contains a significant amount of unutilized low- and medium-temperature thermal energy, while flow battery energy storage requires additional energy to maintain its operating temperature. Furthermore, the inert gas resources generated in compressed air energy storage systems could potentially address the gas evolution safety hazards inherent in flow battery energy storage systems. However, current large-scale energy storage technologies have not yet combined compressed air energy storage with flow battery energy storage to achieve complementary energy utilization and synergistic efficiency, thereby fully leveraging the advantages of each technology.

[0092] According to an exemplary embodiment, this embodiment provides a composite energy storage system, referring to... Figures 1-3As shown, the composite energy storage system includes a compressed air energy storage system 10, a flow battery energy storage system 20, a cold cycle system 40, and a thermal cycle system 30. The compressed air energy storage system 10 stores electrical energy through compressed gas and drives power generation by releasing the compressed gas. The flow battery energy storage system 20 includes a fuel cell stack 21 and a flow circulation system (not labeled in the figure). The flow battery energy storage system 20 stores and releases electrical energy through electrochemical reactions of electrolytes of their respective polarities within the fuel cell stack 21, and stores the energy in the corresponding electrolyte tank 23 of the flow circulation system. The cold cycle system 40 includes a cold flow circulation pipeline 41, which connects the compressed air energy storage system 10 and the flow battery energy storage system 30. The flow battery energy storage system 20 includes a cold flow circulation pipeline 41 that transfers the cold energy generated by the compressed air energy storage system 10 during the expansion and / or phase change of compressed gas to the electrolyte storage tank 23 of the flow battery energy storage system 20, so as to cool and / or control the temperature of the electrolyte in the electrolyte storage tank 23; the thermal circulation system 30 includes a thermal flow circulation pipeline 31 that connects the compressed air energy storage system 10 and the flow battery energy storage system 20, and the thermal flow circulation pipeline 31 transfers the heat energy generated by the compressed air energy storage system 10 during the gas compression and / or phase change to the electrolyte storage tank of the flow battery energy storage system 20, so as to heat and / or control the temperature of the electrolyte in the electrolyte storage tank.

[0093] In this embodiment of the composite energy storage system, the thermal circulation system 30 includes a thermal circulation pipeline 31, which connects the compressed air energy storage system 10 and the electrolyte storage tank 23 of the flow battery energy storage system 20. The thermal energy generated by the compressed air energy storage system 10 during gas compression and / or phase change is used as a stable heat source for the flow battery energy storage system 20, replacing electric heating, which can significantly reduce energy consumption and improve overall energy utilization efficiency. The cold circulation system 40 includes a cold circulation pipeline 41, which connects the compressed air energy storage system 10 and the electrolyte storage tank 23 of the flow battery energy storage system 20. The cold energy generated by the compressed air energy storage system 10 during compressed gas expansion and / or phase change is used as a stable cold source for the flow battery energy storage system 20, replacing forced convection cooling or independent air conditioning system cooling, which can significantly reduce energy consumption and improve overall energy utilization efficiency.

[0094] Specifically, refer to Figure 2 , Figure 3 As shown, the compressed air energy storage system 10 includes a compressor unit 12 driven by an electric motor unit 11, a heat storage device 18, a gas storage device 14, and an expander unit 15 connected by pipelines, and further drives a generator unit 16; the heat storage device 18 is connected to the compressor unit 12 and / or the gas storage device 14, and is used to collect and store the heat energy generated by the gas during compression and / or phase change; the heat flow circulation pipeline 31 is connected to the heat storage device 18.

[0095] The heat exchanger located in the electrolyte storage tank 23 of the flow battery energy storage system 20 can exchange heat with the heat exchanger in the heat storage device 18 of the compressed air energy storage system 10. The heat generated during gas compression and / or phase change is first stored in the heat storage device 18, and then transferred between the two energy storage systems via the heat exchanger and connecting pipes. The heat storage device 18 belongs to the compressed air energy storage system 10, while the heat exchanger is present in both systems. Since the gas compression and / or phase change process naturally generates heat, the rational utilization of this heat helps improve the energy efficiency of the combined flow battery energy storage system 20.

[0096] The compressed air energy storage system 10 operates in two stages: energy storage and energy release. During the energy storage stage, when the grid load is low or when there is a surplus of renewable energy generation, the external power supply drives the compressor unit 12 via the electric motor unit 11 to perform multi-stage compression of the air and store it in the air storage device 14. A large amount of heat energy generated during the compression and / or phase change of the gas is collected and stored by the heat storage device 18. Additionally, the compressor unit can be cooled by a cooler (see reference...). Figure 3 As shown, some heat is transferred, collected, and stored in the thermal storage device 18; during the energy release phase, when power generation is needed, the compressed gas in the gas storage device 14 is released, and the cold storage device ( Figure 2 , Figure 3 (Not shown) Collects and stores the cold energy generated by the compressed gas during expansion and / or phase change. At the same time, the compressed gas can enter the expander unit 15 through the pressure reducing valve 103 to expand and do work, driving the generator unit 16 to generate electricity.

[0097] For example, refer to Figure 2 and Figure 3 As shown, the compressor unit 12 may include a low-pressure air compressor 12-1 and a high-pressure air compressor 12-2 connected in sequence. For example, sensible heat storage materials such as molten salt or latent heat storage materials (phase change materials) may be used in the thermal storage device 18. For example, the external power supply can be the power grid or a new energy power plant. For example, the electrical energy generated by the generator set 16 can be transmitted to the power grid or the user-side load through power conversion devices such as power converters and transformers.

[0098] Reference Figure 2 and Figure 3 As shown, a first gas control valve 101 and a pressure regulating valve 103 are sequentially installed in the pipeline between the gas outlet of the compressor unit 12 and the expander unit 15. A second gas control valve 102 is installed in the pipeline between the gas outlet of the compressor unit 12 and the heat storage device 18 and the gas storage device 14.

[0099] In this embodiment, a heat storage device 18 is used to collect and store the heat energy generated by the gas during compression and / or phase change. This not only theoretically increases the energy storage efficiency of the compressed air energy storage system 10 to over 70%, but also provides a stable and efficient heat source for the flow battery energy storage system 20, thereby improving the energy utilization level of the composite energy storage system in this embodiment.

[0100] From a functional module perspective, the flow battery energy storage system 20 includes a stack 21 and a flow circulation system. The flow circulation system stores and releases electrical energy through electrochemical reactions of electrolytes of respective polarities within the stack 21, storing the energy in corresponding electrolyte tanks 23 within the flow circulation system. The flow circulation system includes the electrolyte tank 23, an electrolyte circulation pump 28, and electrolyte circulation pipelines 29. The electrolyte tank 23 is connected to the stack 21 via the electrolyte circulation pipelines 29 and the electrolyte circulation pump 28, forming an electrolyte circulation loop.

[0101] The thermal circulation system 30 includes a heat flow circulation pipe 31, which connects the compressed air energy storage system 10 and the flow battery energy storage system 20. The heat flow circulation pipe 31 is connected to the heat storage device 18 and transfers the compression heat energy generated by the compressed air energy storage system 10 during gas compression and / or phase change to the electrolyte storage tank 23 of the flow battery energy storage system 20 to heat and / or control the temperature of the electrolyte in the electrolyte storage tank 23.

[0102] Further reference Figure 2 and Figure 3 As shown, the thermal circulation system 30 also includes a heat flow tank 35, a heat flow circulation pump 32, at least one heat flow control valve 34, a first heat exchanger 19 disposed in the heat storage device 18, and a second heat exchanger 17 disposed at the electrolyte storage tank 23 of the flow battery energy storage system 20. The heat flow medium (e.g., water or other heat-conducting fluid) in the heat flow tank 35, driven by the heat flow circulation pump 32, flows through the first heat exchanger 19, absorbing the compressive heat stored in the heat storage device 18 and transforming it into a high-temperature heat flow. This high-temperature heat flow is then transported to the flow battery energy storage system 20, where it transfers heat to the electrolyte via the second heat exchanger 17.

[0103] This embodiment improves the energy storage efficiency of the compressed air energy storage system 10 by exchanging heat energy between the thermal circulation system 30 and the compressed air energy storage system 10, and also provides a stable and efficient heat source for the flow battery energy storage system 20, realizing multi-level utilization of energy and collaborative work between the two (multiple) energy storage systems.

[0104] Furthermore, the thermal cycling system 30 also includes a temperature control module and a temperature monitoring module 33 (see reference). Figures 4-7 The temperature monitoring module 33 may include thermocouple thermometers installed in the heat storage device 18 and the electrolyte storage tank 23 (see reference). Figure 13 The temperature control module is a functional module of the composite energy storage system in this embodiment. Based on the real-time monitoring data of the heat source (heat flow) and electrolyte temperature, it can control the heat flow rate (velocity) and / or pressure in the thermal circulation system 30, and control the heat exchange between the heat source (heat flow) and the electrolyte in real time, thereby realizing closed-loop management of temperature control.

[0105] It should be noted that, Figure 2 The specific locations of the two modules mentioned above are not shown. Figures 4 to 7 The image shows one type of location for the temperature monitoring module 33. In actual systems, the temperature monitoring module 33 and the corresponding temperature control module can be set in multiple locations as needed, so they will not be labeled one by one here.

[0106] The temperature control module is connected to the temperature monitoring module via signal connection, and is also connected to the heat flow circulation pump 32 and the heat flow control valve 34 via control connection. The temperature control module receives the temperature signal from the temperature monitoring module and sends control commands to at least one heat flow circulation pump 32 and / or at least one heat flow control valve 34 according to the preset temperature control logic, thereby driving and adjusting the flow rate (velocity) and / or pressure of the heat flow medium in the heat flow circulation pipeline 31, thereby achieving precise temperature control of the electrolyte.

[0107] This embodiment introduces an integrated temperature monitoring and control module to achieve temperature management of the heat source (heat flow) and electrolyte, so that the flow battery always operates within the optimal temperature range; at the same time, it improves the energy efficiency of the entire thermal cycle system 30 and reduces operating costs.

[0108] In some embodiments, refer to Figures 4-7 As shown, the heat source (heat flow) exchanges heat with the electrolyte storage tank 23 through the heat flow circulation pipe 31 in one of the following ways: a part of the heat flow circulation pipe 31 is disposed inside the electrolyte storage tank 23 and is wound into a coil; and / or, a part of the heat flow circulation pipe 31 is disposed on the outer wall of the electrolyte storage tank 23 and is wound into a coil; and / or, the electrolyte storage tank 23 has an interlayer space, which constitutes a part of the heat flow circulation pipe 31; and / or, a phase change heat storage layer 26 is disposed between the outer wall of the electrolyte storage tank 23 and the insulation layer 27, and the phase change heat storage layer 26 is connected to a part of the heat flow circulation pipe 31.

[0109] In one embodiment, reference is made to Figure 4 A portion of the heat flow circulation pipeline 31 is located inside the electrolyte storage tank 23 (first electrolyte storage tank 23-1 and / or second electrolyte storage tank 23-2) and is wound into a coil.

[0110] In this embodiment, a portion of the heat flow circulation pipeline 31 is made of corrosion-resistant polymer plastic tubing, which does not chemically react with the electrolyte. This portion of the polymer plastic tubing is spatially wound and shaped into a coil using a support assembly. The coil is evenly arranged inside the electrolyte storage tank 23 to ensure sufficient heat exchange area between the heat flow circulation pipeline 31 and the electrolyte. To achieve higher reliability and heat exchange efficiency, the coil portion inside the electrolyte storage tank 23 is a single, long tube without any welds or mechanical joints, thus structurally minimizing the risk of leakage. During operation, the heat transfer medium (such as hot water or other heat-conducting fluids) flows in a predetermined direction within the coil, and its heat is directly transferred to the electrolyte through the plastic tube wall, resulting in efficient and uniform heating.

[0111] In another embodiment, reference is made to Figure 5 A portion of the heat flow circulation pipeline 31 is disposed on the outer wall of the electrolyte storage tank 23 (first electrolyte storage tank 23-1 and / or second electrolyte storage tank 23-2) and is wound into a coil.

[0112] A portion of the heat flow circulation pipe 31 utilizes a metal coil with a high heat transfer coefficient. The metal coil is spatially wound and shaped using a support assembly, tightly coiled and adhered to the outer wall of the electrolyte storage tank 23, ensuring good heat transfer (conduction) characteristics between the heat flow circulation pipe 31 and the tank wall of the electrolyte storage tank 23. In this embodiment, during operation, the heat flow medium (such as hot water or other heat transfer (conduction) fluid) flows within the metal coil, and heat is sequentially transferred through the metal pipe wall, the tank wall of the electrolyte storage tank 23, and finally to the electrolyte inside the electrolyte storage tank 23. To further improve heat transfer efficiency and reliability, the coil portion located outside the electrolyte storage tank 23 is a single, continuous long pipe without any welds or mechanical joints. In this embodiment, the metal coil is positioned on the outer wall of the electrolyte storage tank 23, preventing the heat flow medium from leaking into the electrolyte storage tank 23.

[0113] The metal coil can be structurally matched with the outer wall of the electrolyte storage tank 23 and nested together, which can enhance the structural strength of the electrolyte storage tank 23 and reduce the risk of tank deformation after electrolyte is injected.

[0114] In yet another embodiment, reference is made to... Figure 6 The electrolyte storage tank 23 has a jacketed space, which forms part of the heat flow circulation pipeline 31. The heat flow medium (such as hot water or other heat transfer fluids) forms a heat flow bath in the jacket, which uniformly heats and / or controls the temperature of the internal electrolyte.

[0115] The electrolyte storage tank 23 has a sandwiched space in its shell, which consists of inner and outer layers, forming a sandwiched space between them. The electrolyte is stored in the inner layer of the electrolyte storage tank 23. The sandwiched space includes a heat inlet and a heat outlet, which are connected to the heat circulation pipeline 31. During operation, the heat medium enters from the heat inlet and flows out from the heat outlet, forming a uniform heat bath in the entire sandwiched space. Heat is transferred to the electrolyte through the inner wall of the electrolyte storage tank 23, achieving large-area, uniform heating and / or temperature control of the electrolyte.

[0116] For example, the heat inlet can be located at the bottom of the electrolyte storage tank 23 and the heat outlet can be located at the top of the electrolyte storage tank 23. This can prolong the time that the heat medium flows in the interlayer space and improve the heat exchange efficiency.

[0117] In this embodiment, the interlayer space is incorporated into the heat flow circulation pipeline 31, which can prevent the heat flow medium from leaking in the electrolyte and ensure high reliability. At the same time, the heat transfer area of ​​the interlayer space is larger, which can achieve uniform and efficient heating and / or temperature control of the electrolyte.

[0118] In one embodiment, reference is made to Figure 7 A phase change heat storage layer 26 is disposed between the outer wall of the electrolyte storage tank 23 and the insulation layer 27. The phase change heat storage layer 26 is filled with latent heat storage material (i.e., phase change material). When the thermal circulation system 30 is working, in addition to directly heating the electrolyte, some heat is fully absorbed and stored by the phase change heat storage layer 26, and the latent heat storage material undergoes a phase change (the phase change material melts from a solid state to a liquid state), storing the heat in the form of latent heat. When the flow battery energy storage system 20 circulates the liquid, causing the electrolyte temperature to drop, the heat stored in the phase change heat storage layer 26 is released (the phase change material condenses from a liquid state to a solid state), and is continuously and stably transferred to the electrolyte through the outer wall of the electrolyte storage tank 23, thereby suppressing its downward temperature fluctuation.

[0119] This embodiment utilizes the characteristics of phase change materials, such as high heat storage density, small temperature variation range, and stable temperature during heat release, to reduce the load on the heat flow circulation heating system, thereby further achieving energy saving and ensuring that the flow battery energy storage system 20 operates in the optimal and stable temperature range.

[0120] It is understandable that the combination of the heat flow circulation pipeline 31 and the electrolyte storage tank 23 is not limited to a single application method; it can be combined with the above two or more application methods. For example, the phase change heat storage layer 26 provided between the outer wall of the electrolyte storage tank 31 and the insulation layer 27 can be used in combination with the internal coil, the external coil, or the interlayer space.

[0121] The insulation layer 27 of the electrolyte storage tank 23 of the flow battery energy storage system 20 can isolate the electrolyte in the electrolyte storage tank 23 from the heat exchange with the external environment, reduce heat loss, and improve the thermal management efficiency of the entire energy storage system.

[0122] Furthermore, the flow battery energy storage system 20 includes a first electrolyte storage tank 23-1 (positive electrolyte storage tank) and a second electrolyte storage tank 23-2 (negative electrolyte storage tank), used to store the first electrolyte (positive electrolyte) and the second electrolyte (negative electrolyte), respectively. In this embodiment, the heat flow circulation pipeline 31 is combined with the electrolyte storage tank 23, which can be combined with either the positive electrolyte storage tank or the negative electrolyte storage tank. The combination method of the heat flow circulation pipeline 23 with the positive electrolyte storage tank and the negative electrolyte storage tank can be the same or different, and this application does not limit this.

[0123] In some embodiments, refer to Figures 4-7 The flow battery energy storage system 20 includes a first electrolyte tank 23-1 (positive electrolyte tank) and a second electrolyte tank 23-2 (negative electrolyte tank). The first electrolyte tank 23-1 is connected to the positive electrode reaction chamber of the battery stack via a first electrolyte circulation pipeline 29-1 and a first electrolyte circulation pump 28-1. The second electrolyte tank 23-2 is connected to the negative electrode reaction chamber of the battery stack 21 via a second electrolyte circulation pipeline 29-2 and a second electrolyte circulation pump 28-2. This forms two independent and closed electrolyte circulation loops, enabling continuous circulation of the positive and negative electrolytes and electrochemical reactions related to flow battery energy storage.

[0124] Reference Figure 3 The first electrolyte circulation pipeline 29-1 and the second electrolyte circulation pipeline 29-2 are also equipped with corresponding first electrolyte filter 201-1 and second electrolyte filter 201-2, liquid pressure transmitter 202, liquid control valve 203 and liquid flow transmitter 204.

[0125] In some embodiments, refer to Figure 8a , 8b As shown in 8c and 8d, the integrated flow battery stack 21 includes multiple flow battery units. Each flow battery unit includes a positive electrode reaction chamber 211 and a negative electrode reaction chamber 212 that are isolated from each other, and a membrane assembly 213 disposed between the positive and negative electrode reaction chambers. A distribution channel is provided to guide electrolytes of their respective polarities to the positive and negative electrode reaction chambers of the multiple flow battery units. The electrolytes of their respective polarities come into contact with the positive and negative electrodes in the positive and negative electrode reaction chambers and undergo electrochemical reactions. The electrolytes of their respective polarities undergo selective ion migration between the positive and negative electrode reaction chambers through the membrane assembly 213.

[0126] The diaphragm assembly 213 is disposed in the fuel cell substrate. The diaphragm assembly 213 separates multiple positive electrode reaction chambers 211 and multiple negative electrode reaction chambers 212 that are isolated from each other in the fuel cell substrate. A solid phase functional layer 214 is disposed on the inner wall of the positive electrode reaction chambers 211 and the negative electrode reaction chambers 212.

[0127] Reference Figure 8a The integrated flow battery structure enables the co-current flow of the first electrolyte solution and the second electrolyte solution. The first electrolyte and inert gas I are uniformly mixed outside the stack 21 and then uniformly distributed in the bottom distribution chamber of the stack 21. They then flow upwards through the integrated stack 21 and the top separation chamber, before returning together to the first electrolyte storage tank 23-1. The separated inert gas I passes through the top exhaust outlet of the first electrolyte storage tank 23-1 via a gas circulation pipeline, is treated, and then returned to the gas storage tank for storage and recycling. Similarly, the second electrolyte and inert gas II are uniformly mixed outside the stack 21 and uniformly distributed in the bottom distribution chamber of the stack 21. They then flow upwards through the integrated stack 21 and the bottom separation chamber, before returning together to the second electrolyte storage tank 23-2. The separated inert gas II passes through the top exhaust outlet of the second electrolyte storage tank 23-2 via a gas circulation pipeline, is treated, and then returned to the gas storage tank for storage and recycling.

[0128] Reference Figure 8b Another type of integrated flow battery stack achieves co-current flow of the first electrolyte solution and the second electrolyte solution. The first electrolyte and inert gas I enter the stack, are mixed and evenly distributed in the bottom mixing chamber and distribution chamber, and then flow upwards through the integrated stack 21 and the top separation chamber before returning to the first electrolyte storage tank 23-1. The separated inert gas I can be discharged to the atmosphere or a gas recovery device after treatment via a pressure relief valve at the top of the first electrolyte storage tank 23-1. Similarly, the second electrolyte and inert gas II enter the stack, are mixed and evenly distributed in the bottom mixing chamber, and then flow upwards through the integrated stack 21 and the top separation chamber before returning to the second electrolyte storage tank 23-2. The separated inert gas II can be discharged to the atmosphere or a gas recovery device after treatment via a pressure relief valve at the top of the second electrolyte storage tank 23-2.

[0129] Reference Figure 8a , 8b As shown, the integrated flow battery stack is equipped with an inert gas channel that accompanies the first and second electrolyte solutions as they enter and exit the flow battery stack 21, thereby forming a gas-liquid-solid three-phase electrocatalytic reaction environment inside the stack 21 to improve the charge and discharge performance and efficiency of the flow battery stack 21.

[0130] The part (mixing chamber and / or distribution chamber) used to connect the inlet and outlet of the first and second electrolytes and inert gas to the integral structure of the fuel cell stack has the functions of gas / liquid mixing, buffering and / or uniform distribution; the channels of this part do not interfere with each other and maintain a complete seal at the connection with the gas / liquid inlet and outlet and the integral structure; the sealing methods include, but are not limited to: using sealing lines or sealing surfaces to pressurize and clamp seal, using sealing adhesive to seal at the structural connection interface, and heating and melting at the structural connection interface and then pressurizing and heat sealing.

[0131] In this embodiment, the stack substrate can adopt an integral structure, made of integrally sintered ceramic material or integrally stretched thermoplastic material. The stack substrate material is resistant to the electrolyte system of the flow battery (such as strongly acidic or strongly alkaline electrolyte) and is non-conductive. The material is integrally dense, without through holes, and airtight, ensuring the long-term stability and safety of the stack. The stack substrate contains multiple positive electrode reaction chambers 211 and multiple negative electrode reaction chambers 212, which are isolated from each other and arranged in parallel within the stack substrate. The reaction chambers (positive electrode reaction chamber 211 / negative electrode reaction chamber 212) can be designed as a straight structure or a fin-like irregular cross-sectional geometry. The cross-sectional shape, cross-sectional area, length, and height of the reaction chambers can be flexibly adjusted according to the power and capacity requirements of the flow battery energy storage system 20. For example, by adjusting the volume and cross-sectional area of ​​the channels, the electrolyte flow and reaction efficiency can be optimized. For example, the cross-section of the reaction chamber can be designed as trapezoidal or rectangular, combined with a corrugated interface, to enhance turbulence and improve the mass transfer level of the electrolyte. (Refer to...) Figure 8c , 8d As shown, for example, the number of reaction chambers can be 12×12, and their cross-sectional area and the height of the integral structure can be designed according to the power and capacity requirements of the energy storage system; the structure ensures that the reaction chambers of different polarities are sealed to each other while meeting the ion exchange requirements during the charging and discharging process.

[0132] A solid-phase functional layer 214 is formed on the channel wall of the positive electrode reaction chamber 211 / negative electrode reaction chamber 212. It is electrically connected to the positive and negative polarity main current collectors at corresponding positions in the fuel cell stack 21 to realize the exchange of electrical energy between the fuel cell stack 21 and the external power system / external load.

[0133] In this embodiment, the solid functional layer 214 includes at least a catalyst layer, which includes an electrocatalyst, such as platinum, palladium, or non-precious metals and their oxides. In other embodiments, the solid functional layer 214 may further include a current collector layer, which includes a conductive material, such as a carbon-based material, a metal-based material, or other composite conductive material. After the first and second electrolyte solutions enter the flow battery stack 21 along a predetermined flow direction, they come into contact with the solid functional layer 214 (catalyst) on the inner wall and undergo an electrochemical reaction. Wires of different polarities leading from the solid functional layer 214 of each reaction chamber are connected in series and / or parallel to an external DC power supply system / external load, thereby realizing the storage and release of electrical energy.

[0134] In this embodiment, a current collector layer and a catalyst layer can be sequentially prepared on the channel wall to form a solid functional layer 214. For example, the solid functional layer 214 can be sequentially formed by spraying, sputtering, evaporative chemical vapor deposition, electrochemical deposition and other preparation and curing processes.

[0135] For example, a large fuel cell stack can use an external integrated process to prepare the solid functional layer 214. First, the solid functional layer 214 is made on the outside of the fuel cell stack substrate, and then the solid functional layer 214 is assembled and implanted into the reaction chamber of the fuel cell stack 21.

[0136] A removable diaphragm assembly 213 is assembled within the fuel cell stack substrate. The diaphragm assembly 213 separates the positive electrode reaction chamber 211 from the adjacent negative electrode reaction chamber 212. The diaphragm assembly 213 is removable, replaceable, and reassembleable. The diaphragm assembly 213 is made of an ion exchange membrane (such as a perfluorosulfonic acid membrane) or other selectively permeable membrane materials. It separates the electrolytes of different polarities in the positive electrode reaction chamber 211 and the negative electrode reaction chamber 212, preventing cross-contamination. Simultaneously, it enables the necessary ion exchange during charging and discharging, facilitating the subsequent maintenance and management of the fuel cell stack 21. In this embodiment, the diaphragm assembly is configured according to the spatial layout and planar projection of the positive and negative electrode reaction chambers.

[0137] Based on the spatial layout and planar projection of the positive and negative electrode reaction chambers, a diaphragm region is set on the fuel cell stack substrate. The diaphragm assembly 213 is integrated with the integral structure through an assembly method, achieving a sealed mounting (assembly) interface, and features detachability, replaceability, and reassembly capability. The diaphragm assembly 213 is made of an ion exchange membrane (such as a perfluorosulfonic acid membrane) or other selective diaphragm materials, effectively separating the positive and negative electrode electrolytes while simultaneously achieving ion exchange during charging and discharging. The detachable design of the diaphragm assembly 213 facilitates maintenance and replacement, reducing long-term operating costs.

[0138] The fuel cell stack 21 in this embodiment has good heat transfer and mass transfer characteristics, low pressure loss, and can operate in semi-intermittent or continuous mode. The positive and negative electrolytes can be supplied in a co-current manner as needed (see reference). Figure 8a , 8b (as shown) or countercurrent (refer to) Figure 8c , 8d The electrolytes flow through their respective reaction chambers in the manner shown. Furthermore, when using three-phase electrocatalytic reaction technology, the positive and negative electrolytes and compressed inert gas can flow in parallel, exhibiting slug flow or fully mixed flow characteristics as they co-flow through their respective reaction chambers, achieving high flow rates and rapid response to meet the operational requirements of instantaneous reactions. After feeding is stopped, the channels can be quickly emptied, reducing the risk of side reactions caused by residual electrolyte.

[0139] The integral substrate of the fuel cell stack 21 has a dense structure and no through holes, reducing the risk of electrolyte leakage. The assembly of the fuel cell stack 21, the integration of the solid phase functional layer 214 and the diaphragm assembly 213 ensure the sealing of the installation interface, effectively improving the problem of electrolyte leakage. In this embodiment, the seal between the substrate of the fuel cell stack 21 and the mixing chamber (distribution chamber) uses high-performance sealing materials (such as elastic sealing materials represented by fluororubber or high-performance engineering plastics represented by polytetrafluoroethylene) to ensure long-term sealing performance under high pressure and highly corrosive environments.

[0140] The fuel cell stack 21 in this embodiment has dimensional consistency during pilot-scale, pilot-scale and mass production processes, and can achieve large-scale production through similar scaling principles, taking into account capacity, performance and efficiency. The manufacturing of the integral structure of the fuel cell stack 21, the integrated preparation of the solid phase functional layer 214 and the detachable design of the diaphragm assembly 213 improve the overall maintenance efficiency of the fuel cell stack 21 and reduce maintenance costs.

[0141] In some embodiments, refer to Figure 8c As shown, the diaphragm assembly 213 is located inside the fuel cell stack 21, and has a partially linear structure with a simple, non-bent interface, facilitating manufacturing and maintenance; (Refer to...) Figure 8d As shown, the separator assembly 213 is located inside the fuel cell stack 21, and has a partially bow-shaped structure with a tortuous and complex interface. The separator material is an ion exchange membrane (such as a perfluorosulfonic acid membrane), which has good ion conductivity and chemical stability. The separator assembly 213 divides the fuel cell stack 21 into several positive electrode reaction chambers 211 and negative electrode reaction chambers 212 (in this embodiment, 12×12 cells, i.e., 144 reaction chambers). The cross-sectional area of ​​the reaction chambers and the height of the integral structure can be set according to the power and capacity requirements of the flow battery energy storage system 20. For example, by adjusting the size or number of reaction chambers, different power levels (e.g., 10kW to 1MW) and capacity requirements (e.g., 100kWh to 10MWh) can be met.

[0142] The inner walls of the positive electrode reaction chamber 211 and the negative electrode reaction chamber 212 are provided with a solid-phase functional layer 214. The solid-phase functional layer 214 includes a current collector layer (such as a carbon-based material represented by graphite or a metal-based material represented by stainless steel) and a catalyst layer (such as a carbon-coated catalyst or a metal oxide-coated catalyst). The current collector layer is used to collect current, and the catalyst layer is used to promote electrochemical reactions. The first electrolyte solution (positive electrode electrolyte, such as vanadium ion solution) from the first electrolyte storage tank 23-1 and the second electrolyte solution (negative electrode electrolyte, such as vanadium ion solution) from the second electrolyte storage tank 23-2 enter the stack along a set flow direction and flow rate, forming a countercurrent flow on both sides of the membrane, and undergoing an electrochemical reaction (redox reaction during charging and discharging) with the solid-phase functional layer 214. The countercurrent flow design of the electrolyte on both sides of the membrane can enhance the ion exchange efficiency and help alleviate the concentration polarization phenomenon on both sides of the membrane.

[0143] In this embodiment, the positive electrode reaction chamber 211 and the negative electrode reaction chamber 212 are mutually sealed by a diaphragm assembly 213 to prevent cross-contamination of the electrolyte. The sealing method can be, but is not limited to, the following: applying mechanical pressure to the assembly and sealing interface; using a tenon or labyrinth structure and corrosion-resistant sealing material for pressure clamping and sealing; or using corrosion-resistant sealing materials such as silicone, epoxy resin, or magnetorheological fluid to fully fill the assembly and sealing interface; to ensure the reliability and safety of the fuel cell stack during long-term operation.

[0144] Wires of different polarities (such as positive and negative wires) drawn from each positive electrode reaction chamber 211 and each negative electrode reaction chamber 212 are connected in series and parallel. For example, refer to Figure 8c As shown, the solid-phase functional layer 214 containing 12 reaction chambers of the same vertical polarity can be connected in series to form one pole of a charge / discharge module. Multiple charge / discharge modules can be connected in parallel to the positive and negative poles of an external DC power supply system / external load. The electrical connection method is optimized according to the input / output power requirements (such as voltage and current range) and power conversion mode (such as DC / AC inverter efficiency) of the energy storage system to maximize energy conversion efficiency.

[0145] In this embodiment, during the charging process of the flow battery energy storage system 20, an external DC power supply system supplies power to the stack 21. The first electrolyte solution undergoes an oxidation reaction on the positive electrode side, and the second electrolyte solution undergoes a reduction reaction on the negative electrode side, converting electrical energy into chemical energy, which is then stored in the electrolyte solution. During the discharging process, the electrolyte solutions of their respective polarities undergo a reverse reaction, converting chemical energy into electrical energy, which is then output to an external load through wires.

[0146] In some other embodiments, the flow battery energy storage system 20 employs three-phase electrocatalytic reaction technology, in which the positive and negative electrolytes and compressed inert gas can form a co-flow, flowing through their respective reaction chambers with slug flow or fully mixed flow characteristics. This can enhance the electrocatalytic activity of the reaction interface within the stack and improve charge and discharge efficiency.

[0147] In this embodiment, the flow battery energy storage system 20 features an integrated structure design for the stack 21, reducing manufacturing complexity. The reverse flow of electrolytes of different polarities and the optimized diaphragm design improve selective ion migration efficiency. The size and number of reaction chambers are adjustable to accommodate different power and capacity requirements. Multiple sealing methods are employed in the positive electrode reaction chamber 211 and the negative electrode reaction chamber 212 to ensure long-term operational stability. This embodiment's flow battery energy storage system 20 operates at current densities up to 100 mA / cm². 2 Under operating conditions, the energy efficiency of the fuel cell stack can exceed 80%, and it has a long cycle life, making it suitable for fields such as grid energy storage and renewable energy smoothing.

[0148] The electrolyte spraying device 24 is based on jet electrodeposition technology. By spraying the electrolyte at high speed and directionally to the electrochemical reaction interface, it effectively reduces the thickness of the diffusion layer on the electrode surface, promotes the mass transfer efficiency of active materials on the electrode surface, and thus significantly improves the limiting current density and reaction rate of the electrochemical reaction.

[0149] In some embodiments, each flow battery cell in the stack 21 further includes an electrolyte injection device 24. The electrolyte injection device 24 includes a nozzle array disposed in the positive electrode reaction chamber 211 and / or the negative electrode reaction chamber 212 for spraying electrolyte onto the positive electrode and / or the negative electrode and / or the positive electrode side and / or the negative electrode side surface of the separator assembly 213. The nozzle array includes multiple nozzles connected in parallel and / or in series. The nozzle array is embedded in the positive electrode side and / or the negative electrode side of the separator assembly 213, and / or the positive electrode reaction chamber 211 and / or the negative electrode reaction chamber 212, and maintains a certain distance from the battery separator and the positive and negative electrodes.

[0150] In some embodiments, refer to Figure 9 As shown, the nozzle array has a beaded curtain structure, consisting of multiple nozzles connected in parallel and / or in series, and is pre-embedded in the diaphragm assembly 213. The nozzles connected in parallel and / or in series are connected to each other through liquid conduits to form a dense and wide-coverage spray surface.

[0151] In the fabrication of the separator assembly, the nozzle array can be integrally formed with the membrane frame, i.e., pre-embedded on the positive and negative electrode sides of the separator assembly. This integrated design allows two sets of nozzle arrays to be located in the positive and negative electrode reaction chambers of the flow battery unit, respectively. The electrolytes on the positive and negative electrode sides can be precisely sprayed through their corresponding nozzle arrays to the positive and negative electrode interfaces and the positive and negative electrode interfaces of the ion exchange membrane within their respective reaction chambers.

[0152] It is understandable that, in order to optimize the spraying effect, the distance between the nozzle and the electrode surface and the ion exchange membrane surface in each reaction chamber should be adjusted and appropriately reduced, thereby improving the mass transfer efficiency of the reaction interface and coordinating and realizing a high level of coupling between the electrode / electrolyte / membrane three-phase interface in the electrochemical reaction process.

[0153] In some embodiments, the gas-liquid mixing process can occur in a nozzle inside the fuel cell stack. Within the flat structure of the nozzle, compressed inert gas comes into contact with and mixes with the electrolyte, and is then atomized and ejected at high speed at the nozzle outlet.

[0154] The nozzle orifice can be designed with an inwardly tapered structure to create a confluence and throttling effect of the electrolyte near the orifice, and to precisely control the spray angles (α and β) on both sides of the nozzle. The selectable range of spray angles is typically between 15° and 120°, depending on the surface area of ​​the electrode plates and / or battery separator that the nozzle unit needs to cover and its distance from the surface of the electrode plates and / or battery separator.

[0155] To achieve effective coverage of the electrode and / or battery separator surfaces, the nozzle's jet body is a solid cone. The nozzle diameter and jet angle on both sides can be designed to be the same or different, thereby flexibly adjusting the initial velocity, direction, flow rate, and flow pattern of the jet to meet different operating conditions and functional requirements.

[0156] The nozzle can be an internal mixing type, where the compressed inert gas and electrolyte are mixed before leaving the nozzle tip (conical structure) and exit the nozzle orifice together to form an atomized mixture. The nozzle can also be an external mixing type, where the compressed inert gas and electrolyte are mixed after leaving the nozzle tip (conical structure) separately, forming an atomized mixture in the space outside the nozzle.

[0157] In other embodiments, the gas-liquid mixing process can occur outside the fuel cell stack 21. Compressed inert gas passes at high speed through the gas-liquid mixing mechanism 25, for example, through the local vacuum suction (negative pressure) generated inside a venturi tube (at the intersection of a T-shaped or cross-shaped pipe), introducing the electrolyte and mixing it with the compressed inert gas. The optimized gas-liquid mixing mechanism can generate uniform, fine droplets with a diameter of less than 50 μm, which are then delivered to the nozzle array inside the fuel cell stack 21 through small-diameter pipes embedded in the membrane frame.

[0158] In some embodiments, the flow battery energy storage system 20 further includes a gas-liquid mixing mechanism 25, which is used to mix compressed inert gas (such as compressed nitrogen or compressed argon) with electrolyte to form an atomized mixture that is delivered to the corresponding electrolyte inlet of the nozzle array or the stack, enters the stack, and participates in the electrochemical reaction. In the gas-liquid mixing mechanism 25, the electrolyte and compressed inert gas (such as compressed nitrogen or compressed argon) are fully mixed, and the kinetic energy of the compressed gas breaks the electrolyte into fine droplets to form an atomized jet, which can obtain a higher initial velocity of electrolyte injection and achieve an atomization effect.

[0159] Reference Figure 10a , Figure 10b As shown, the gas-liquid mixing mechanism 25 includes: a compressed inert gas input interface 251, a liquid input interface 252, and a gas-liquid mixing outlet 253. The gas input interface 251 is connected to a compressed inert gas source, the liquid input interface 253 is connected to an electrolyte delivery pipeline, and the gas-liquid mixing outlet 253 is connected to the corresponding electrolyte inlet of the nozzle array or fuel cell stack.

[0160] In other embodiments, the gas-liquid mixing mechanism 25 can employ a working principle similar to that of a jet aeration pump, utilizing the viscosity between the high-speed jet and the inert gas to achieve gas intake and gas-liquid mixing. After the jet carrying the inert gas enters the throat, its flow process can be divided into two stages: in the first half of the throat (the jet section), both liquid and gas maintain a continuous flow state, and energy exchange occurs only between the gas and liquid phases at their contact surfaces; the gas is not cut, and the gas transfer rate is relatively limited at this stage. In the latter half of the throat, due to the combined effect of the kinetic energy of the jet and the back pressure at the end of the gas-liquid mixing mechanism 25, the gas and liquid phases form a mixing shock wave, and intense energy exchange occurs in the shock wave region. The gas is broken into an emulsion, forming a homogeneous emulsion with bubble diameters reaching approximately 100 μm. Subsequently, the gas-liquid mixed flow enters the diffuser, where the flow head is converted into a pressure head, further compressing the bubbles. Therefore, in this gas-liquid mixing mechanism 25, the gas transfer rate and the level of gas-liquid mixing are significantly improved.

[0161] To control the atomization characteristics of the gas-liquid mixture, the flow rate and pressure of the compressed inert gas can be regulated using a needle valve, metering screw, or adjustable pressure regulator. Simultaneously, an electrolyte delivery system based on pressure characteristics can control the electrolyte flow rate using a metering screw, rapid pulse width modulation valve, needle valve, or adjustable pressure regulator. Precise spray control can be achieved by carefully adjusting the flow rates of the compressed inert gas and electrolyte.

[0162] Reference Figure 11As shown in Figure a, a conventional fuel cell stack 21 employing a plate-type stacked structure includes positive and negative electrode assemblies (containing a solid-phase functional layer 214) and a membrane assembly 213. A positive electrode reaction chamber 211 is formed between the positive electrode assembly and the membrane assembly 213, and a negative electrode reaction chamber 212 is formed between the negative electrode assembly and the membrane assembly; (Refer to...) Figure 11 As shown in Figure b, within the same structural framework, the battery stack 21, which integrates an electrolyte injection device 24, provides bidirectional injection functionality to both the electrode interface and the ion exchange membrane interface in each reaction chamber. The electrolyte injection device 24 includes a nozzle array disposed within the positive electrode reaction chamber 211 and / or the negative electrode reaction chamber 212, for injecting electrolyte onto the positive and / or negative electrode and / or the positive and / or negative electrode surfaces of the separator assembly 213. During charging and discharging, this promotes uniform distribution of active materials within the diffusion layer at the electrode-electrolyte interface and accelerates the ion exchange process at the electrolyte-ion exchange membrane interface, thereby significantly improving the limiting current density and overall performance of the flow battery.

[0163] Among them, reference Figure 13 As shown, the electrolyte injection device 24 can use a dedicated electrolyte storage container (divided into positive and negative electrode sides) and can be independently replenished through electrolyte delivery sub-pipelines (divided into positive and negative electrode sides); see reference Figure 12 As shown, the electrolyte injection device 24 can also use the electrolyte storage tank 23 in the liquid circulation system and deliver it synchronously through the electrolyte delivery pipeline (divided into positive and negative sides).

[0164] In some embodiments, the electrolyte injection device 24 uses dedicated electrolyte storage containers (separate for positive and negative electrodes) for independent replenishment. The electrolyte is delivered to the nozzle arrays within the positive and negative electrode reaction chambers via electrolyte delivery sub-pipelines (separate for positive and negative electrodes). The electrolyte delivery sub-pipelines are equipped with electrolyte replenishment and circulation pumps. This facilitates stable electrolyte injection and compensates for capacity decay caused by incomplete reversibility of electrochemical reactions after multiple charge-discharge cycles, thereby extending the maintenance-free period and lifespan of the flow battery.

[0165] In some embodiments, refer to Figure 13As shown, the flow battery energy storage system 20 also includes an electrolyte replenishment system; the electrolyte replenishment system includes an electrolyte replenishment tank and an electrolyte replenishment circulation pump, used to replenish electrolyte to the electrolyte circulation loop or electrolyte injection device. The electrolyte replenishment system is used to maintain the long-term stable operation of the flow battery energy storage system and extend its lifespan. It can be understood that the electrolyte replenishment system includes a first electrolyte replenishment tank and a first electrolyte replenishment circulation pump, as well as a second electrolyte replenishment tank and a second electrolyte replenishment circulation pump. The first electrolyte replenishment tank is used to store a first electrolyte (positive electrode electrolyte) with a specified active material concentration, and the second electrolyte replenishment tank is used to store a second electrolyte (negative electrode electrolyte) with a specified active material concentration. The electrolyte replenishment and circulation pump can pump electrolyte with a specified active substance concentration from the electrolyte replenishment tank into the main electrolyte circulation loop (e.g., by merging into the main circulation loop through a designated interface or directly injecting into the corresponding electrolyte tank) to replenish electrolyte losses caused by evaporation, leakage, membrane migration, or side reactions, maintaining the stability and balance of electrolyte volume and active substance quantity in the main circulation loop. Alternatively, the electrolyte replenishment and circulation pump can also directly deliver electrolyte with a specified active substance concentration to the electrolyte injection device. This provides an independent and stable electrolyte source for the high-speed injection of electrolyte by the electrolyte injection device, ensuring the injection atomization effect and avoiding interference from flow fluctuations in the main circulation loop. By spraying, electrolyte with a specified concentration of active material is directly and quickly replenished to the electrode and membrane reaction interface. This can effectively compensate for the significant decrease in active material concentration caused by incomplete and reversible reactions after multiple charge-discharge cycles, as well as the imbalance of the electrolyte system caused by water migration. It effectively restores the concentration of active material and rebalances the electrolyte system, thereby extending the maintenance-free cycle and service life of the flow battery.

[0166] This embodiment introduces an independent electrolyte replenishment system, which can replenish the electrolyte of the flow battery energy storage system 20, improve the reliability and stability of the flow battery energy storage system 20 during long-term operation, and improve the mass transfer efficiency of the internal reaction interface of the stack by directional replenishment of electrolyte, which is beneficial to maintaining the long-term energy storage characteristics of the composite energy storage system.

[0167] In some embodiments, compressed inert gas is prepared using compressed air generated by the compressed air energy storage system 10 as raw material. With the assistance of the gas management system, the flow battery energy storage system 20 can effectively utilize the compressed inert gas. For example, the compressed inert gas is delivered to the top space within the electrolyte storage tank 23 and / or delivered to the reaction chamber of the stack 21 via the gas-liquid mixing mechanism 25 and / or the electrolyte injection device 24.

[0168] Specifically, compressed inert gas can be introduced into the top space of the electrolyte storage tank 23 for trickle purging, which can displace and remove accumulated hydrogen gas; and / or compressed inert gas can be introduced into the gas-liquid mixing mechanism 25 for mixing and atomizing with electrolytes of their respective polarities. For example, the gas-liquid mixing mechanism can be a jet pump; and / or compressed inert gas can be introduced into the electrolyte injection device 24 in the reaction chamber of the fuel cell stack 21 to form a gas-liquid two-phase flow with the electrolytes of their respective polarities, and sprayed onto the electrode interface and / or the membrane interface to participate in and enhance the electrocatalytic reaction. This improves the electrochemical reaction rate and the charge / discharge efficiency of the flow battery.

[0169] In some embodiments, refer to Figure 8b , Figure 14 As shown, before the compressed inert gas and electrolytes of their respective polarities are introduced into the reaction chambers of the fuel cell stack 21, they first pass through a structural chamber with buffering and distribution functions to ensure uniform gas and electrolyte distribution and avoid local hot spots or blockages. The inlet and outlet of the compressed inert gas and electrolyte do not interfere with each other, and the connection with the structural chamber is completely sealed. The structural chamber connecting the inlet and outlet of the first electrolyte, the second electrolyte, and the compressed inert gas adopts a porous distributor or guide plate design to achieve gas / liquid buffering and uniform distribution. This structure is made of corrosion-resistant material and is connected to the integral fuel cell stack 21 through the above-mentioned sealing method to ensure no leakage.

[0170] In some embodiments, refer to Figure 3 and Figure 16 As shown, the composite energy storage system also includes a gas management system 50, which includes a nitrogen generation device 51 and a gas delivery pipeline 52.

[0171] The nitrogen generator 51 is connected to the gas storage device 14 of the compressed air energy storage system 10 to prepare compressed inert gas using compressed air generated by the compressed air energy storage system 10 as raw material. The gas delivery pipeline 25 connects the nitrogen generator 51 to the gas inlet of the flow battery energy storage system 20. The gas delivery pipeline 52 includes a first branch, which is connected to the top space inside the electrolyte storage tank 23 for introducing compressed inert gas into the electrolyte storage tank 23 to replace and remove the hydrogen gas accumulated in the electrolyte storage tank 23.

[0172] In some embodiments, the gas delivery line 52 further includes a second branch connected to the fuel cell stack 21 for introducing compressed inert gas into the fuel cell stack 21, wherein the compressed inert gas and the electrolyte form a gas-liquid mixture to form a first type of flow state, and a multiphase electrocatalytic reaction is carried out in the fuel cell stack 21.

[0173] In some embodiments, the gas management system 50 further includes a third branch connected to the gas-liquid mixing mechanism 25 of the flow battery energy storage system 20, for introducing compressed inert gas into the gas-liquid mixing mechanism 25, wherein the compressed inert gas and electrolyte form a second type of flow state and are jointly introduced into the stack of the flow battery energy storage system 20 to carry out a multiphase electrocatalytic reaction.

[0174] In this embodiment, refer to Figure 3 The inlet of the nitrogen generator 51 is connected to the compressed air outlet of the gas storage device 14. The compressed air output from the compressed air outlet of the gas storage device 14 passes sequentially through a gas-liquid separator 55 and a gas purification device 56 before entering the nitrogen generator 51. The nitrogen generator 51 employs physical separation methods, such as membrane air separation, cryogenic air separation, or molecular sieve air separation, to separate oxygen and nitrogen from the compressed air, thereby obtaining high-purity compressed nitrogen. Furthermore, a pressure-reducing valve 57 is installed at the compressed air outlet of the gas storage device 14.

[0175] In a preferred embodiment, the nitrogen generator 51 employs membrane air separation. Compressed air undergoes deep purification and drying by sequentially passing through a gas-liquid separator, a pre-filter, a refrigerated dryer, a precision filter, an ultrafilter, and an activated carbon filter, reducing the oil content to below 0.01 mg / L and removing solid particles larger than 0.01 μm in diameter. The purified compressed air is then heated to 40°C~50°C by a heater before entering the membrane separator for oxygen-nitrogen separation, ultimately yielding a compressed inert gas (high-pressure, high-purity nitrogen) with a pressure up to 35 MPa and a concentration between 95% and 99%. Thus, the gas management system 50 is connected to the compressed air energy storage system 10, eliminating the need for an external gas source and reducing operating costs.

[0176] The compressed inert gas produced by the nitrogen generator 51 is stored in a dedicated nitrogen storage tank 54. For example, the compressed inert gas produced by the nitrogen generator 51 can be stored in a second (negative electrode side) nitrogen storage tank 54-2 and a first (positive electrode side) nitrogen storage tank 54-1, respectively. In this embodiment, both the second (negative electrode side) nitrogen storage tank 54-2 and the first (positive electrode side) nitrogen storage tank 54-1 are equipped with a pressure relief valve 91 and a pressure gauge 92. The gas delivery pipeline 52 delivers the compressed inert gas in the nitrogen storage tank 54 to multiple locations in the flow battery energy storage system 20. The gas delivery pipeline 52 is equipped with a pressure regulator 93 and a flow regulator 94.

[0177] In this embodiment, the gas delivery pipeline 52 includes at least three branches: a first branch, a second branch, and a third branch. In this embodiment, the gas delivery pipeline 52 may be made of pressure-resistant and corrosion-resistant seamless stainless steel pipe.

[0178] The first branch is a hydrogen purging branch, connected to the top space inside the electrolyte storage tank 23. It is used to continuously or intermittently introduce compressed nitrogen into the electrolyte storage tank 23, forming a trickle purging process to displace and remove the hydrogen accumulated in the electrolyte storage tank 23, fundamentally eliminating the risk of explosion and improving system safety. The trickle purging can be in continuous mode or in an intermittent pulse mode based on feedback data from the hydrogen concentration sensor in the electrolyte storage tank 23.

[0179] It is understandable that under overcharge or over-discharge conditions, hydrogen evolution (H2) and oxygen evolution (O2) side reactions will occur within the flow battery stack. The resulting hydrogen gas accumulates in the top space of the electrolyte storage tank 23, posing a safety hazard. The gas management system 50 continuously or intermittently introduces compressed nitrogen gas into the top space of the first electrolyte storage tank 23-1 and the second electrolyte storage tank 23-2 through the first branch of the gas delivery pipeline 52, forming a trickle purging. This actively and continuously replaces and clears the accumulated hydrogen and other flammable and explosive gases in the electrolyte storage tank 23, keeping the minimum volume concentration of hydrogen and other flammable and explosive gases controlled at 25% or below their lower explosive limit. This can replace traditional active and passive hydrogen purging systems, improving the system's safety.

[0180] The second branch is a gas-liquid mixing branch, connected to the inlet of the reaction chamber of the flow battery stack 21. It is used to introduce compressed nitrogen gas into the stack, causing it to form a gas-liquid two-phase flow with the electrolyte. This gas-liquid two-phase flow can form Taylor flow or slug flow within the tubular channels of each reaction chamber of the stack. Under this flow pattern, the gas phase acts like a piston, pushing the liquid slug along the channel, forming a piston flow. Simultaneously, there is a strong circulating flow inside the liquid slug. The gas phase is separated from the solid functional layer 214 on the channel wall by only a very thin liquid film, optimizing the radial and axial mass transfer efficiency. Its mass transfer rate can be increased by an order of magnitude compared to single-phase liquid flow. The gas-liquid two-phase flow and the solid functional layer 214 (catalytic layer) on the channel wall together constitute a gas-liquid-solid three-phase catalytic system, enhancing the mass transfer process and improving the electrochemical reaction rate of the stack 21 and the charge / discharge efficiency of the flow battery.

[0181] In this embodiment, the flow battery stack 21 is designed to support a gas-liquid-solid three-phase electrocatalytic reaction. For example, the stack 21 may have a tubular bushing structure or an integral structure. Thus, compressed nitrogen gas is introduced into the positive electrode reaction chamber and the negative electrode reaction chamber of the stack 21 through the second branch of the gas delivery pipeline 52, forming a gas-liquid two-phase flow with the electrolyte of their respective polarities.

[0182] In this embodiment, the second branch introduces compressed nitrogen into the reaction chamber of the flow battery stack 21. Compressed nitrogen has higher kinetic energy and diffusion rate. When compressed nitrogen enters the liquid phase and diffuses, it can accelerate the mass transfer process from the liquid phase active material to the solid phase catalyst interface.

[0183] Compressed nitrogen and electrolyte form a plug flow in the tubular channel of the reaction chamber, reducing backmixing in the reactor and resulting in a more uniform distribution of potential and current. This improves the electrochemical reaction kinetics at the liquid-solid catalyst interface, thereby increasing the efficiency of the electrochemical reaction per unit time, achieving process intensification, and enhancing the power density and charge-discharge efficiency of the flow battery.

[0184] The third branch is another type of gas-liquid mixing, connected to the gas-liquid mixing mechanism 25 (such as a jet pump or venturi tube) in the electrolyte injection device 24. The third branch is used to provide compressed nitrogen gas required for electrolyte atomization. The nitrogen gas can be mixed and atomized with the electrolyte outside the stack through the gas-liquid mixing mechanism 25 or other devices, or directly mixed and atomized at the nozzle, breaking the electrolyte into micron-sized droplets to form a high-speed atomized jet, further optimizing its mass transfer process on the electrode surface.

[0185] In some embodiments, refer to Figures 12-15 As shown, compressed nitrogen gas delivered to the flow battery energy storage system 20 via the gas delivery pipeline 25 participates in the reaction and then circulates back to the first electrolyte storage tank 23-1 and the second electrolyte storage tank 23-2 with the liquid flow. Due to its low density, it accumulates in the top space within the electrolyte storage tank 23. In this embodiment, a pressure relief valve 91 and a pressure gauge 92 are installed at the top of the electrolyte storage tanks 23 (first electrolyte storage tank 23-1 and second electrolyte storage tank 23-2). When the pressure displayed by the pressure gauge 92 exceeds a certain threshold, the pressure relief valve 91 automatically opens and releases the mixed gas to the atmosphere or a gas recovery and treatment device, preventing excessive accumulation of gas in the electrolyte storage tank 23.

[0186] In some embodiments, the gas recovery and treatment device includes an electrolyte neutralization and desalination device 206, a dry gas-liquid separator 207, a circulating compressor 205, and a drying filter 95. The mixed gas leaves the storage tank and enters the gas recovery and treatment device. After passing through the electrolyte neutralization and desalination device 206 and the gas-liquid separator 207, the electrolyte entrained in the mixed gas is separated and returned to the electrolyte storage tank. It should be noted that since the mixed gas contains electrolyte components, the gas-liquid separator 207 must be resistant to the electrolyte system. Subsequently, the mixed gas is pressurized by the circulating air compressor 205, and then further removed by the drying filter 95 to remove moisture and any potentially carried electrolyte (mist), and stored in the gas storage tank 54. Since this portion of compressed gas is intended for recycling, cross-contamination during mixing with the electrolyte should be avoided. Therefore, a first gas storage tank 54-1 and a second gas storage tank 54-2 should be used separately. When using the compressed gas in the storage tanks, it should first be purified by the gas purification device 56. The purified compressed gas is separated from other gases by a nitrogen generator 51. The final compressed nitrogen is mixed with the electrolyte along the gas delivery pipeline 52 and participates in the multiphase electrocatalytic reaction within the fuel cell stack. This process allows for the recycling of the mixed gas, reducing the operating cost of the composite energy storage system.

[0187] In some embodiments, refer to Figures 12-14 The diagram shows a circulation schematic of a flow battery system 20 in a composite energy storage system. Compressed gas in the gas storage tank 54, after further purification and nitrogen preparation, is then supplied to the flow battery energy storage system 20 via a gas delivery pipeline 52. The gas delivery pipeline 52 is equipped with a gas flow regulator 94 and a gas pressure regulator 93 to control and monitor the nitrogen delivery flow rate and pressure. After the compressed nitrogen enters the flow battery energy storage system 20, it is directed to... Figure 10a , Figure 10b As shown, the gas enters the gas-liquid mixing mechanism 25 through the gas input interface 251, mixes with the electrolyte in the gas-liquid mixing mechanism 25, and then flows out through the gas-liquid mixing outlet 253 to participate in the electrochemical reaction of the fuel cell stack 21; in some embodiments, refer to Figures 12-14 As shown, the compressed gas stored in the gas storage tank 54 can come from the atmosphere. After being pressurized by the circulating air compressor 205, the gas can be further dehydrated by the dryer filter 95 before being stored in the gas storage tank 54. When using the compressed gas in the gas storage tank, it is first purified by the gas purification device 56. The purified compressed gas is then separated from other gases by the nitrogen generator 51 to obtain the compressed nitrogen required by the flow battery energy storage system 20; in other embodiments, refer to Figure 3 and Figures 12-14As shown, the compressed gas stored in the gas storage tank 54 can come from the compressed air energy storage system 10. The compressed air output from the compressed air outlet of the gas storage device 14 passes sequentially through the gas-liquid separator 55 and the gas purification device 56 before being stored in the gas storage tank 54. When using the compressed gas in the gas storage tank, it is first purified by the gas purification device 56. The purified compressed gas is then separated from other gases by the nitrogen generator 51 to obtain the compressed nitrogen required by the flow battery energy storage system 20.

[0188] In some embodiments, reference Figure 3 and Figure 15 As shown, the compressed gas can come from the compressed air energy storage system 10. The compressed air output from the compressed air outlet of the gas storage device 14 passes through the gas-liquid separation device 55 and the gas purification device 56 in sequence, and then enters the nitrogen generation device 51. The compressed inert gas generated by the nitrogen generation device 51 is stored in a dedicated (nitrogen) storage tank 54, thereby obtaining the compressed nitrogen required by the flow battery energy storage system 20.

[0189] In some embodiments, refer to Figures 12-14 As shown, the gas reacted with the electrolyte flows back to the electrolyte storage tank 23 via the electrolyte circulation pipeline 29. In this embodiment, the electrolyte storage tank 23 includes a first electrolyte storage tank 23-1 and a second electrolyte storage tank 23-2, which store the first electrolyte and the second electrolyte, respectively. The electrolyte circulation pipeline 29 is equipped with an electrolyte circulation pump 28 (including a first electrolyte circulation pump 28-1 and a second electrolyte circulation pump 28-2), electrolyte filters 201-1 and 201-2 (for the first electrolyte and the second electrolyte, respectively), a liquid control valve 203, a liquid pressure transmitter 202, and a liquid flow transmitter 204, which are used to realize the circulation and transportation of the electrolyte, process filtration, and process monitoring.

[0190] Because nitrogen and other gases are less dense than the electrolyte, they gradually accumulate in the top space of the electrolyte storage tank 23. Pressure gauges 92 and pressure relief valves 91 are respectively installed at the top of the first electrolyte storage tank 23-1 and the second electrolyte storage tank 23-2. Pressure gauge 92 continuously monitors and displays the gas pressure in the top space of the tank. When the pressure exceeds a preset safety threshold, the pressure relief valve 91 automatically opens, discharging the accumulated mixed gas in the top space to the atmosphere or a gas recovery and treatment device. Therefore, the mixed gas entering the gas recovery and treatment device initiates a gas recycling process.

[0191] In some embodiments, refer to Figures 9-13As shown, the flow battery energy storage system 20 employs a plate-stacking structure for the battery stack 21. Each flow battery unit in the battery stack 21 includes an electrolyte injection device 24, which comprises a nozzle array disposed within the positive electrode reaction chamber 211 and / or the negative electrode reaction chamber 212. The nozzle array is used to spray electrolyte onto the positive electrode and / or negative electrode and / or the positive electrode side and / or negative electrode side surface of the separator assembly 213. During electrolyte injection, another portion of electrolyte enters the battery stack 21 through a conventional inlet. After participating in the reaction, the gas-liquid mixture returns to the storage tank along with the liquid circulation system. The flow battery energy storage system 20 may include a gas-liquid mixing mechanism 25, which mixes compressed nitrogen with the electrolyte to form an atomized mixture that is delivered to the nozzle array and participates in the electrochemical reaction within the battery stack 21.

[0192] In some embodiments, refer to Figure 8a , Figure 8b , Figure 8c , Figure 8d and Figure 14As shown, the flow battery energy storage system 20 adopts an integral structure of the fuel cell stack 21. The fuel cell stack 21 includes multiple flow battery cells, each of which includes a positive electrode reaction chamber 211 and a negative electrode reaction chamber 212 that are isolated from each other, and a separator assembly 213 disposed between the positive and negative electrode reaction chambers; a distribution channel is provided to guide the electrolyte to the positive and negative electrode reaction chambers of the multiple flow battery cells; wherein, the electrolyte of each polarity comes into contact with the positive and negative electrodes in the positive and negative electrode reaction chambers and undergoes an electrochemical reaction, and the electrolyte of each polarity undergoes selective ion migration between the positive and negative electrode reaction chambers through the separator assembly 213. The flow battery energy storage system 20 includes a gas phase blocker 98 and a liquid phase blocker 99, used to coordinate the flow rate ratio, timing sequence, and interval of the gas and liquid phase fluids entering the stack 21. This allows the introduced compressed nitrogen gas and electrolyte to flow in parallel, exhibiting slug flow characteristics as they co-flow through their respective reaction chambers, thereby enhancing the mass transfer process and improving the electrochemical reaction rate of the stack 21 and the charge / discharge efficiency of the flow battery. The integrally structured stack 21 includes a distribution chamber (partition chamber) connecting the inlet and outlet of the first and second electrolytes and inert gas to the integral structure of the stack, providing gas / liquid buffering and uniform distribution. The channels in this part do not interfere with each other, thus creating a gas-liquid-solid three-phase electrocatalytic reaction environment inside the stack 21 to improve the charge / discharge performance and efficiency of the flow battery stack 21. In this process, the first electrolyte and compressed nitrogen I are mixed in the bottom mixing chamber, and then pass from bottom to top through the integrated fuel cell stack 21 and the top separation chamber, before returning together to the first electrolyte storage tank 23-1. Compressed nitrogen I can be processed through the exhaust outlet at the top of the first electrolyte storage tank 23-1 and then returned to the gas storage tank for storage and recycling. Similarly, the second electrolyte and compressed nitrogen II are mixed in the bottom mixing chamber, and then pass from bottom to top through the integrated fuel cell stack 21 and the top separation chamber, before returning together to the second electrolyte storage tank 23-2. Compressed nitrogen II can be processed through the exhaust outlet at the top of the second electrolyte storage tank 23-2 and then returned to the gas storage tank for storage and recycling.

[0193] In some embodiments, refer to Figure 8a , Figure 8b , Figure 8c , Figure 8d and Figure 15As shown, the flow battery energy storage system 20 employs an integrally structured stack 21. The integrally structured stack 21 includes sections (mixing chamber and distribution chamber) for connecting the inlet and outlet of the first and second electrolytes and the inert gas to the integral structure of the stack, providing gas / liquid mixing, buffering, and uniform distribution functions. Preferably, a gas-liquid mixing mechanism 25 can be provided outside the stack 21, allowing the positive and negative electrolytes and compressed inert gas to flow together through their respective reaction chambers in a fully mixed flow pattern, thereby further enhancing the mass transfer process and improving the electrochemical reaction rate of the stack 21 and the charge / discharge efficiency of the flow battery. The channels in this section do not interfere with each other, thus forming a gas-liquid-solid three-phase electrocatalytic reaction environment inside the stack 21 to improve the charge / discharge performance and efficiency of the flow battery stack 21. In this process, the first electrolyte and compressed nitrogen I are mixed in the bottom mixing chamber, and then pass from bottom to top through the integrated fuel cell stack 21 and the top separation chamber, before returning together to the first electrolyte storage tank 23-1. Compressed nitrogen I can be discharged to the atmosphere or a gas recovery treatment device after treatment through the pressure relief valve at the top of the first electrolyte storage tank 23-1. Similarly, the second electrolyte and compressed nitrogen II are mixed in the bottom mixing chamber, and then pass from bottom to top through the integrated fuel cell stack 21 and the top separation chamber, before returning together to the second electrolyte storage tank 23-2. Compressed nitrogen II can be discharged to the atmosphere or a gas recovery treatment device after treatment through the pressure relief valve at the top of the second electrolyte storage tank 23-2.

[0194] Reference Figure 16 As shown, the gas management system 50 of this embodiment uses compressed air from the compressed air energy storage system 10 to prepare compressed inert gas, and continuously or intermittently introduces the compressed inert gas into the top space of the electrolyte storage tank 23 in the flow battery energy storage system 20 to form a trickle purging. It can actively and continuously replace and remove hydrogen and other flammable and explosive gases accumulated in the tank, and / or introduce the compressed inert gas into the gas-liquid mixing mechanism 25 for mixing and atomizing with the electrolyte of its respective polarity, and / or introduce the compressed inert gas into the reaction chamber of the fuel cell stack 21 for forming a gas-liquid two-phase flow with the electrolyte of its respective polarity. Therefore, the composite energy storage system of this embodiment not only utilizes the cold and heat energy generated by the compressed air energy storage system 10 during energy storage and release to reduce the energy consumption of the flow battery energy storage system during operation, but also utilizes the compressed gas stored in the compressed air energy storage system 10 to prepare compressed inert gas, which is used to improve the operational stability and charge-discharge performance of the flow battery energy storage system 20. This improves the energy utilization level of the composite energy storage system composed of the compressed air energy storage system 10 and the flow battery energy storage system 20, and enhances the coupling characteristics of energy flow and material flow between the two long-term energy storage systems and the overall stability of the system.

[0195] In this embodiment, in the composite energy storage system, the compressed air energy storage system 10, in accordance with the peak-valley characteristics of the power grid, achieves "energy storage during off-peak hours and energy release during peak hours." When the system is in energy storage mode, the power grid drives the motor and compressor units to convert electrical energy into compressed air and store it. At this time, the nitrogen generator 51 of the gas management system operates, converting part of the compressed air into compressed nitrogen and storing it for use in the flow battery energy storage system 20. During the charging and discharging of the flow battery energy storage system 20, the first branch can be used for purging and hydrogen removal; the second and third branches can be selected and activated in a timely manner according to the structural requirements and charging and discharging power requirements of the flow battery energy storage system 20 to improve the reaction rate and charging and discharging efficiency. Throughout the process, the compressed nitrogen can be recycled within the composite energy storage system. At the same time, the heat and cold energy stored in the compressed air energy storage system 10 during energy storage and release can also be transferred to the flow battery energy storage system 20 through the thermal cycle system 30 and the cold cycle system 40 to ensure that the electrolyte and the compressed inert gas participating in the electrochemical reaction process are at the optimal operating temperature.

[0196] In some embodiments, reference Figure 16 As shown, the composite energy storage system includes a cold cycle system 40, comprising a first refrigeration device that utilizes compressed air in the compressed air energy storage system 10 to expand under conditions of external work and / or throttling, converting the gas's internal energy into mechanical energy, thus forming a physical device with a significantly reduced temperature; and a first cold storage device and a cold flow circulation pipeline, used to collect and store the cold energy generated by the first refrigeration device, and transfer the cold energy to the electrolyte storage tank 23 through the cold flow circulation pipeline to cool and / or control the temperature of the electrolyte in the electrolyte storage tank. For example, the cold cycle system 40 utilizes the characteristic that compressed air's temperature drops significantly (up to tens of degrees below zero Celsius) after expansion and work, directly using the exhaust gas from the expansion outlet as a low-temperature refrigerant and industrial cold source.

[0197] The first cold storage device utilizes the compressed air energy storage system 10 to expand under conditions of external work and / or throttling, generating low-temperature exhaust gas that can be directly used for refrigeration. For example, the first cold storage device can directly introduce the low-temperature exhaust gas into the cooling-required location (such as a data center, cold chain warehouse, or building air conditioning system) through a cold flow circulation pipeline, providing cold air or chilled water to the user side via a gas-to-gas or gas-to-liquid heat exchanger, achieving direct cooling. Alternatively, the first cold storage device utilizes the low-temperature exhaust gas generated by the compressed air energy storage system 10 to exchange heat with the evaporator in the refrigeration cycle. Through a refrigeration cycle using an industrial refrigerant (such as carbon dioxide, ammonia, etc.), the temperature is further reduced or the cooling capacity is increased, thereby driving and enhancing an independent evaporative refrigeration cycle to provide cooling energy for scenarios with greater distances or higher requirements.

[0198] In this embodiment, the cold energy generated by the compressed air energy storage system 10 during the expansion and / or phase change of compressed gas is collected, stored and utilized through the cold cycle system 40. The composite energy storage system composed of the compressed air energy storage system 10 has a cooling function while releasing energy to generate electricity, realizing combined power and cooling, improving the comprehensive energy utilization level and economic benefits of the system, and is suitable for various large-scale power and cooling places such as cold chain distribution hubs or data centers with combined cooling and electricity needs.

[0199] In some embodiments, the cold cycle system 40 further includes a second refrigeration device and a second energy storage device; a refrigerant phase change cycle is formed by using compressed gas processed in the compressed air energy storage system as a refrigerant and a compressor, condenser, expansion valve and evaporator connected in sequence through pipelines, and a physical device that absorbs latent heat during the phase change process; the second cold storage device is used to collect and store the cold energy generated by the second refrigeration device and transfer the cold energy to the electrolyte storage tank through a cold flow circulation pipeline.

[0200] According to an exemplary embodiment, this embodiment provides a distributed energy system, referring to... Figure 17 , Figure 18 , Figure 19 As shown, the distributed energy system includes the composite energy storage system of the above embodiments. This composite energy storage system is connected to one or more of the following: the power grid, wind power generation system, photovoltaic thermal power system, and / or gas turbine. The distributed energy system integrates the composite energy storage system of any of the aforementioned embodiments, serving as the hub for energy storage / release and energy exchange within the system. This distributed energy system integrates wind power generation, photovoltaic power generation / heating, energy storage, and gas turbines, simultaneously meeting the comprehensive needs of users / loads for electricity, heating, and cooling. The energy input side of the composite energy storage system can be connected to one or more of the following: the power grid, wind power generation device, photovoltaic power generation / heating device, and / or gas turbine, to receive electricity and heat from the power grid, intermittent new energy sources, and traditional fossil fuels; simultaneously, the composite energy storage system can provide one or more forms of energy supply to users / loads, including electricity, heating, and cooling.

[0201] In this embodiment of the distributed energy system, the composite energy storage system utilizes the long-duration, large-capacity energy storage characteristics of the compressed air energy storage system 10 and the rapid response and flexible power regulation characteristics of the flow battery energy storage system to form a complementary advantage. The flow battery energy storage system 20 can absorb the minute-level and hour-level power input fluctuations of new energy sources such as wind power and photovoltaics, and can achieve smooth power output and frequency regulation to meet the high power quality requirements of the grid side and the user side. The compressed air energy storage system 10 can achieve peak-valley arbitrage over a longer time span. For example, it can store excess new energy power on weekends for use during weekday peak hours. The compressed air energy storage system 10 (especially when using underground caverns) can even use its huge energy storage capacity to balance energy supply and demand in different seasons. For example, it can store abundant photovoltaic power in summer for use during the peak heating season in winter.

[0202] The distributed energy system in this embodiment achieves peak shaving and valley filling across multiple time scales, enabling charge-discharge cycles across days, months, and even seasons, thus responding to changes in electricity demand at different time scales. Through the scheduling of composite energy storage, the intermittency and instability issues of wind and solar power are resolved, increasing the proportion of new energy sources in the energy structure. It can cope with electricity demand changes at different time scales, from second-level fluctuations to seasonal differences, improving the overall distributed energy system's resilience to extreme weather and sudden failures.

[0203] The distributed energy system of this embodiment can integrate wind power generation, photovoltaic power generation / heating, energy storage, gas turbines, and other equipment to improve energy utilization efficiency and meet diverse user energy needs. For example, the composite energy storage system and the gas turbine work together as a reliable power source to ensure power supply when renewable energy output is insufficient. The composite energy storage system, through the thermal cycle system 30, transfers the heat energy generated by the compressed air energy storage system 10 during gas compression and / or phase change to the electrolyte storage tank of the flow battery energy storage system 20 for heating and / or temperature control of the electrolyte; or, after heat exchange, directly provides industrial process heat or district heating to the user / load side; it can also, through the refrigeration cycle, use the cold energy generated by the compressed air energy storage system 10 during compressed gas expansion and / or phase change to directly supply cooling or further increase the cooling capacity through low-temperature exhaust, providing a cold source for building air conditioning or industrial cooling. Therefore, the above-mentioned distributed energy system can simultaneously meet the electricity, heating, and cooling needs of the user / load side, achieving efficient energy utilization and energy conservation and emission reduction.

[0204] In one embodiment, combined with append Figure 17The distributed energy system shown includes an energy output side and a composite energy storage system. The energy output side includes wind farms, solar farms, and the power grid. Among them, wind farms and solar farms serve as intermittent renewable energy generation units; the power grid can serve as both an input and output source of electricity; the composite energy storage system often serves as a backup and auxiliary power source for the operation of the distributed energy system, storing electricity from the power grid and / or new energy sources, and releasing electricity when needed to meet the demands of the grid side and the user side.

[0205] In other embodiments, the energy output side may further include a combustion chamber for supplying fossil fuels to supplement heat to the expander unit of the compressed air energy storage system 10, and a gas turbine for supplying fossil fuels and its driven generator set, which can serve as an emergency backup power source. The compressed air energy storage system 10 of the composite energy storage system includes a compressor unit (including a low-pressure air compressor and a high-pressure air compressor) driven by an electric motor, a heat storage device, a cold storage device, a gas storage device, an expander unit, and further drives a generator set. The gas storage device can be a gas storage tank or an underground gas storage cavern; the expander unit may include a high-pressure turbine and a low-pressure turbine, which can jointly drive a generator set.

[0206] The flow battery energy storage system 20 of the composite energy storage system includes a fuel cell stack 21 and an electrolyte storage tank 23. Most of the compressed air generated by the compressed air energy storage system 10 is stored in a gas storage device (gas tank or underground gas storage cavern) for subsequent power generation. A small portion can be transported to a nitrogen generation device in the gas management system (not shown in the figure) to prepare compressed inert gas (compressed nitrogen in this embodiment), which is then further stored in a nitrogen storage tank for transport to the flow battery energy storage system 20, where it mixes with the electrolyte and forms a liquid electrolyte. The gas flows in two phases and participates in the electrochemical reaction in the fuel cell stack 23. The heat generated during the gas compression and / or phase change process of the compressed air energy storage system 10 is transferred to the electrolyte storage tank 23 of the flow battery energy storage system 20 to heat up and / or control the temperature of the electrolyte in the electrolyte storage tank 23. The cold energy generated during the expansion and / or phase change process of the compressed gas in the compressed air energy storage system 10 is transferred to the electrolyte storage tank 23 of the flow battery energy storage system 205 to cool down and / or control the temperature of the electrolyte in the electrolyte storage tank 23.

[0207] When wind and solar power generation is excessive and / or the grid is at a low load, electrical energy from the energy output side can be used to drive the compressor unit of the compressed air energy storage system 10, compressing the gas and storing it in the gas storage device. Simultaneously, the thermal storage device collects and stores the heat energy generated during gas compression and / or phase change. Excess electrical energy can also be stored in the form of chemical energy in the flow battery energy storage system 20. When electricity demand is at its peak and / or wind and solar power generation is insufficient, the high-pressure air stored in the compressed air energy storage system 10 absorbs heat through the thermal storage device (or, if the compressed air energy storage system 10 lacks a thermal storage device, it is heated by the combustion chamber), becoming high-temperature, high-pressure air. This heat drives the expander unit to rotate, thereby powering the generator set. The flow battery energy storage system 20 can also respond quickly, working together with the compressed air energy storage system 10 to supply power to the user / load side, providing stable power support. The compressed air energy storage system 10 provides continuous and stable base load power, while the flow battery energy storage system 20 provides rapid peak-shaving response and power frequency regulation, forming a complementary cycle and function.

[0208] The distributed energy system of this embodiment transforms fluctuating wind and solar resources into stable power sources that are dispatchable and reliable by the power grid through composite energy storage; it achieves integrated wind, solar, energy storage and transmission, peak shaving and valley filling, and enhances the stability and reliability of the power grid; at the same time, the distributed energy system of this embodiment can realize the rational storage and release of electrical energy, thermal energy and cold energy, and utilize them efficiently, and also convert some compressed air into compressed nitrogen and store it for later use, thereby realizing the diversified utilization of energy and materials in the system.

[0209] In another embodiment, as shown in the appendix Figure 18 As shown, this embodiment provides a distributed energy system. The difference between this distributed energy system and the above embodiments is that the distributed energy system in this embodiment adds a solar thermal power system, including a solar thermal collector (such as a parabolic trough or tower collector) and / or a solar thermal power device. The solar thermal power system is connected to the heat storage device of the compressed air energy storage system 10 through a heat exchange pipeline to form a heat replenishment loop, which can serve as a supplementary heat source and / or one of the important heat sources for the heat storage device.

[0210] In this embodiment of the distributed energy system, when there is sufficient sunshine, the heat energy collected by the solar thermal power system can be transported and stored in the heat storage device of the compressed air energy storage system 10, thereby enhancing the heat storage capacity and heat source supply capacity of the compressed air energy storage system 10. During the energy release phase, the compressed air released by the air storage device in the compressed air energy storage system 10 can absorb more heat, thereby driving the expander unit to generate more electricity, improving the energy release efficiency and power output capacity of the compressed air energy storage system 10.

[0211] The distributed energy system of this embodiment can achieve solar supplementation by utilizing a solar thermal source, thereby improving the cycle energy storage efficiency of the compressed air energy storage system 10 and making the overall energy utilization efficiency and economy of the entire composite energy storage system reach a higher level. At the same time, the distributed energy system of this embodiment can reduce or replace the reliance of the compressed air energy storage system 10 on fossil fuel supplementation, further reducing the carbon emissions of the entire system and making it more environmentally friendly.

[0212] In another embodiment, as shown in the appendix Figure 19 As shown, this embodiment provides a distributed energy system. The difference between this distributed energy system and the previous embodiments is that this system integrates a cold cycle system 40 and a hot cycle system 30. This allows for active cooling and heating of the electrolyte system in the flow battery energy storage system 20, forming a bidirectional temperature control system for more precise temperature management of the flow battery energy storage system 20. This distributed energy system not only stores and releases electrical energy but also stably stores and releases cold and hot energy, achieving combined power, cooling, and heating. It is suitable for industrial parks, commercial complexes, food processing centers, and data centers with stable demands for cold and hot energy 20.

[0213] In a distributed energy system, a refrigeration device can utilize the compressed air in the compressed air energy storage system 10 to expand under conditions of doing work and / or throttling, converting the internal energy of the gas into mechanical energy, resulting in a significant temperature reduction. The cold storage device is used to collect and store the cold energy generated during the expansion and / or phase change of the compressed gas. In this embodiment of the distributed energy system, during the energy release and power generation process of the compressed air energy storage system 10, the refrigeration device utilizes the expansion of the compressed air energy storage system 10 under the condition of external work and / or throttling, and the generated low-temperature exhaust gas can be directly used for refrigeration; the cold storage device collects and stores the cold energy generated in this process, and introduces the low-temperature exhaust gas directly into the place requiring cooling (such as data center, cold chain cold storage or building air conditioning system) through heat exchanger and cold flow circulation pipeline, or provides cold air or cold water to the user side through gas-to-gas or gas-to-liquid heat exchanger to achieve direct cooling; or the cold energy can be transferred to the electrolyte storage tank 23 through the cold flow circulation pipeline to cool and / or control the temperature of the electrolyte in the electrolyte storage tank, ensuring that the electrolyte system of the flow battery energy storage system 20 operates in the optimal temperature range.

[0214] In distributed energy systems, refrigeration devices can also use compressed gas processed in compressed air energy storage systems as refrigerant. The refrigerant phase change cycle is formed by connecting a compressor, condenser, expansion valve and evaporator in sequence through pipelines, and latent heat is absorbed during the phase change process. The cold storage device collects and stores the cold energy generated in this process, and can transfer the cold energy to various places that need cooling through cold flow circulation pipelines and heat exchangers.

[0215] In this embodiment, the distributed energy system includes multiple heat exchangers installed in the compressed air energy storage system 15 and the flow battery energy storage system 20, used for temperature management of the electrolyte system in the flow battery energy storage system 20. Specifically, during the compression energy storage stage of the compressed air energy storage system 10, the thermal circulation system 30 is activated to circulate the hot flow medium. After absorbing heat energy through the first heat exchanger in the thermal storage device, it becomes a high-temperature hot flow medium. The high-temperature hot flow medium then flows through the second heat exchanger installed at the electrolyte storage tank, transferring heat to the electrolyte to achieve temperature heating and / or temperature control of the electrolyte. During the expansion energy release stage of the compressed air energy storage system 10, the cold circulation system 40 is activated to circulate the cold flow medium. After absorbing cold energy through the third heat exchanger in the cold storage device, it becomes a low-temperature cold flow medium. The low-temperature cold flow medium then flows through the fourth heat exchanger installed at the electrolyte storage tank, transferring cold energy to the electrolyte to achieve temperature cooling and / or temperature control of the electrolyte. In distributed energy systems, when the ambient temperature is too high or the electrolyte system temperature in the flow battery energy storage system 20 rises too rapidly, the refrigeration device can also utilize the low-temperature exhaust gas generated by the compressed air energy storage system 10 to exchange heat with the evaporator in the refrigeration cycle. Through the refrigeration cycle using industrial refrigerants (such as carbon dioxide, ammonia, etc.), the temperature can be further reduced or the cooling capacity increased. The cold energy storage device collects and stores the cold energy generated during this process, and can transfer it to various locations with greater cooling demands through cold flow circulation pipelines and heat exchangers.

[0216] Therefore, the distributed energy system in this embodiment can utilize the cold energy generated by the compressed air energy storage system 10 during the expansion and / or phase change of compressed gas to transfer to the electrolyte storage tank of the flow battery energy storage system 20, providing the flow battery energy storage system 20 with a stable and active cooling capability that is not limited by the ambient temperature; the distributed energy system can utilize the heat energy generated by the compressed air energy storage system 10 during the gas compression and / or phase change to transfer to the electrolyte storage tank 23 of the flow battery energy storage system 20, providing the flow battery energy storage system 20 with a stable and active heating capability that is not limited by the ambient temperature.

[0217] According to an exemplary embodiment, this embodiment provides an operation method for a composite energy storage system, referring to... Figure 19 As shown, it includes the following steps:

[0218] Step S101: The heat energy generated by the compressed air energy storage system 10 during gas compression and / or phase change is transferred to the electrolyte storage tank of the flow battery energy storage system 20 through the thermal circulation system 30, so as to raise and / or control the temperature of the electrolyte in the electrolyte storage tank.

[0219] Step S102: The cold energy generated by the compressed air energy storage system 10 during the expansion and / or phase change of compressed gas is transferred to the electrolyte storage tank of the flow battery energy storage system 20 through the cold circulation system 40 to cool and / or control the temperature of the electrolyte in the electrolyte storage tank.

[0220] In this embodiment, during the compression energy storage stage of the compressed air energy storage system 10, the thermal circulation system 30 is activated to circulate the hot flow medium. After absorbing heat energy through the first heat exchanger in the heat storage device, the hot flow medium becomes a high-temperature hot flow medium. The high-temperature hot flow medium then flows through the second heat exchanger located at the electrolyte storage tank, transferring heat to the electrolyte to achieve heating and / or temperature control of the electrolyte. During the expansion energy release stage of the compressed air energy storage system 10, the cold circulation system 40 is activated to circulate the cold flow medium. After absorbing cold energy through the third heat exchanger in the cold storage device, the cold flow medium becomes a low-temperature cold flow medium. The low-temperature cold flow medium then flows through the fourth heat exchanger located at the electrolyte storage tank, transferring cold energy to the electrolyte to achieve cooling and / or temperature control of the electrolyte.

[0221] The operation method of the composite energy storage system in this embodiment involves a hot flow circulation pipeline connecting the electrolyte tanks of the compressed air energy storage system 10 and the flow battery energy storage system 20. The heat energy generated by the compressed air energy storage system 10 during gas compression and / or phase change is used as a stable heat source for the flow battery energy storage system 20, replacing electric heating, which significantly reduces energy consumption and improves overall energy efficiency. Similarly, a cold flow circulation pipeline connecting the compressed air energy storage system 10 and the electrolyte tanks of the flow battery energy storage system 20 uses the cold energy generated by the compressed gas energy storage system 10 during compressed gas expansion and / or phase change as a stable cold source for the flow battery energy storage system 20, replacing forced convection cooling or independent air conditioning systems, which also significantly reduces energy consumption and improves overall energy efficiency.

[0222] In some embodiments, the operation method of the composite energy storage system further includes the following steps:

[0223] Step S103: Prepare compressed air from compressed air energy storage system 10 into compressed inert gas, and introduce the compressed inert gas into the top space inside the electrolyte storage tank to replace and remove the hydrogen gas accumulated in the electrolyte storage tank.

[0224] In this embodiment, a portion of the compressed air from the compressed air energy storage system 10 is led to the nitrogen generator of the gas management system to prepare compressed inert gas (high-purity compressed nitrogen). Through the first branch of the gas delivery pipeline, the high-purity compressed nitrogen, at a pressure slightly higher than the top space inside the storage tank, is continuously or intermittently introduced into the top space inside the electrolyte storage tank, forming a trickle purging effect. This actively and safely removes hydrogen from the electrolyte storage tank, reducing the risk of explosion.

[0225] In some embodiments, the operation method of the composite energy storage system further includes the following steps:

[0226] Step S104: Compressed inert gas is introduced into the stack of the flow battery energy storage system 20, and forms a first type of flow state with the electrolyte in the stack to carry out a multiphase flow electrocatalytic reaction.

[0227] In this embodiment, a portion of compressed inert gas (high-purity compressed nitrogen) is injected into the electrolyte pipeline leading to the fuel cell stack through the second branch of the gas delivery pipeline. The flow ratio of compressed inert gas to electrolyte is controlled so that the two mix in the straight pipes of each reaction chamber in the fuel cell stack, forming a slug flow or Taylor flow. Together with the catalyst layer on the channel wall of each reaction chamber, they form a gas-liquid-solid three-phase catalytic system, thereby enhancing the mass transfer process and improving the electrochemical reaction rate and the charge and discharge efficiency of the flow battery.

[0228] In some embodiments, the operation method of the composite energy storage system further includes the following steps:

[0229] Step S105: A portion of compressed inert gas (high-purity compressed nitrogen) is introduced into the gas-liquid mixing mechanism 25 of the flow battery energy storage system 20. The compressed inert gas and electrolyte form a second type of flow state therein and are introduced into the stack of the flow battery energy storage system 20 to carry out a multiphase electrocatalytic reaction.

[0230] In this embodiment, compressed inert gas (high-purity compressed nitrogen) is delivered to a gas-liquid mixing mechanism (such as a jet pump or venturi tube) via a third branch of the gas delivery pipeline. Here, the high-purity compressed nitrogen is thoroughly mixed with the electrolyte, breaking the electrolyte into micron-sized droplets to form a high-speed atomized jet. This jet is then uniformly sprayed onto the electrode surface and / or the battery separator surface via a nozzle array, further optimizing the electrochemical reaction interface, enhancing the mass transfer process, and improving the electrochemical reaction rate and the charge / discharge efficiency of the flow battery.

[0231] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0232] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A hybrid energy storage system, characterized by, include: Compressed air energy storage system, flow battery energy storage system, cold cycle system and hot cycle system; The compressed air energy storage system is used to store electrical energy through compressed gas and to drive power generation by releasing the compressed gas. The flow battery energy storage system includes a stack and a flow circulation system. The flow battery energy storage system is used to store and release electrical energy through the electrochemical reaction of electrolytes of respective polarities in the stack, and the energy is stored in the corresponding electrolyte tank of the flow circulation system. The cold circulation system includes a cold flow circulation pipeline, which connects the compressed air energy storage system and the flow battery energy storage system. The cold flow circulation pipeline transfers the cold energy generated by the compressed air energy storage system during the expansion and / or phase change of the compressed gas to the electrolyte storage tank of the flow battery energy storage system to cool and / or control the temperature of the electrolyte in the electrolyte storage tank. The thermal circulation system includes a heat flow circulation pipeline that connects the compressed air energy storage system and the flow battery energy storage system. The heat flow circulation pipeline transfers the compression heat energy generated by the compressed air energy storage system during gas compression and / or phase change to the electrolyte storage tank of the flow battery energy storage system to raise and / or control the temperature of the electrolyte in the electrolyte storage tank.

2. The composite energy storage system of claim 1, wherein, The cold and hot flow circulation pipelines exchange heat with the electrolyte storage tank using one of the following methods: A portion of the cold and hot flow circulation pipelines is located inside the electrolyte storage tank and is wound into a coil. And / or, a portion of the cold and hot flow circulation pipeline is disposed on the outer wall of the electrolyte storage tank and wound into a coil; And / or, the electrolyte storage tank has a sandwich space that forms part of the cold and hot flow circulation pipeline; And / or, a phase change material energy storage layer is provided between the outer wall of the electrolyte storage tank and the insulation layer, and the phase change material energy storage layer is connected to a part of the cold and hot flow circulation pipeline.

3. The composite energy storage system of claim 1, wherein, The compressed air energy storage system includes a compressor unit driven by an electric motor, a heat storage device, a cold storage device, a gas storage device, and an expander unit connected by pipelines, and further drives a generator unit; the heat storage device is connected to the compressor unit and / or the gas storage device, and is used to collect and store the heat energy generated by the gas during compression and / or phase change. The cold storage device is connected to the gas storage device and / or the expander unit, and is used to collect and store the cold energy generated by the compressed gas during expansion and / or phase change. The hot flow circulation pipeline is connected to the heat storage device, and the cold flow circulation pipeline is connected to the cold storage device.

4. The composite energy storage system of claim 1, wherein, The liquid circulation system includes the electrolyte storage tank, the electrolyte circulation pump, and the electrolyte circulation pipeline; The electrolyte storage tank is connected to the fuel cell stack via the electrolyte circulation pipeline and the electrolyte circulation pump, forming an electrolyte circulation loop; The fuel cell stack includes: Multiple flow battery units, each flow battery unit including a positive electrode reaction chamber and a negative electrode reaction chamber that are isolated from each other, and a membrane assembly disposed between the positive and negative electrode reaction chambers; Distribution channels and / or branch channels are used to guide electrolytes of their respective polarities to the positive and negative electrode reaction chambers of the multiple flow battery cells; In this process, electrolytes of their respective polarities come into contact with the positive and negative electrodes in the positive and negative electrode reaction chambers and undergo electrochemical reactions. The electrolytes of their respective polarities also undergo selective ion migration between the positive and negative electrode reaction chambers through the diaphragm assembly.

5. The composite energy storage system of claim 4, wherein, The flow battery unit further includes an electrolyte injection device, which includes: A nozzle array, disposed within the positive electrode reaction chamber and / or the negative electrode reaction chamber, is used to spray electrolyte onto the positive electrode and / or the negative electrode and / or the positive electrode side and / or the negative electrode side surface of the diaphragm assembly; The nozzle array includes multiple nozzles connected in parallel and / or in series. The nozzle array is embedded in the positive electrode side and / or negative electrode side of the separator assembly, and / or the positive electrode reaction chamber, and / or the negative electrode reaction chamber, and is spaced at a predetermined distance from the battery separator and the positive and negative electrodes.

6. The composite energy storage system of claim 5, wherein, The flow battery energy storage system also includes: A gas-liquid mixing mechanism is used to mix compressed inert gas with electrolytes of their respective polarities to form an atomized mixture that is delivered to the corresponding electrolyte inlet of the nozzle array or the fuel cell stack. The atomized mixture enters the fuel cell stack through the nozzle array or the electrolyte inlet and participates in the electrochemical reaction. The gas-liquid mixing mechanism includes a gas input interface, a liquid input interface, and a gas-liquid mixing outlet. The gas input interface is connected to a compressed inert gas source, the liquid input interface is connected to an electrolyte delivery pipeline, and the gas-liquid mixing outlet is connected to the corresponding electrolyte inlet of the nozzle array or the fuel cell stack.

7. The composite energy storage system of claim 4, wherein, It also includes a gas management system, which includes a nitrogen generator and a gas delivery pipeline; The nitrogen generator is connected to the compressed air energy storage system, and uses the compressed air generated by the compressed air energy storage system as raw material to prepare compressed inert gas; The gas delivery pipeline connects the nitrogen generator to the flow battery energy storage system. The gas delivery pipeline includes a first branch, which is connected to the top space inside the electrolyte storage tank to introduce compressed inert gas into the electrolyte storage tank to replace and remove the hydrogen gas accumulated in the electrolyte storage tank.

8. The composite energy storage system according to claim 7, characterized in that, The gas delivery pipeline also includes a second branch connected to the fuel cell stack, used to introduce compressed inert gas into the fuel cell stack, wherein the compressed inert gas and the electrolyte form a first type of flow state and carry out a multiphase electrocatalytic reaction within the fuel cell stack.

9. The composite energy storage system according to claim 7, characterized in that, The gas management system also includes a third branch connected to the gas-liquid mixing mechanism of the flow battery energy storage system, which is used to introduce compressed inert gas into the gas-liquid mixing mechanism. The compressed inert gas and electrolyte form a second type of flow state therein and are jointly introduced into the stack of the flow battery energy storage system to carry out a multiphase electrocatalytic reaction.

10. The composite energy storage system according to claim 1, characterized in that, The cold cycle system includes: The first refrigeration device utilizes the compressed air in the compressed air energy storage system to expand under conditions of doing work and / or throttling, converting the gas's internal energy into mechanical energy, thereby lowering the temperature; and, The first cold storage device is used to collect and store the cold energy generated by the first refrigeration device, and transfer the cold energy to the electrolyte storage tank through the cold flow circulation pipeline.

11. The composite energy storage system according to claim 1, characterized in that, The cold cycle system also includes: The second refrigeration unit utilizes the processed compressed gas from the compressed air energy storage system as the refrigerant, and forms a refrigerant phase change cycle through a compressor, condenser, expansion valve, and evaporator connected sequentially via pipelines, absorbing latent heat during the phase change process; and The second cold storage device is used to collect and store the cold energy generated by the second refrigeration device, and transfer the cold energy to the electrolyte storage tank through the cold flow circulation pipeline.

12. A distributed energy system, characterized in that, Includes the composite energy storage system as described in any one of claims 1 to 11, wherein the composite energy storage system is connected to one or more of a power grid, a wind power generation system, a photovoltaic thermal power system, and / or a gas turbine.

13. The distributed energy system according to claim 12, characterized in that, Also includes: Solar thermal utilization systems, including solar collectors; The solar collector is connected to the heat storage device of the compressed air energy storage system through a heat exchange pipeline to form a heat replenishment circuit.

14. An operation method for a composite energy storage system, characterized in that, Includes the following steps: The compressed heat energy generated by the compressed air energy storage system during gas compression and / or phase change is transferred to the electrolyte storage tank of the flow battery energy storage system through a thermal circulation system to raise and / or control the temperature of the electrolyte in the electrolyte storage tank. The cold energy generated by the compressed air energy storage system during the expansion and / or phase change of compressed gas is transferred to the electrolyte storage tank of the flow battery energy storage system through a cold circulation system to cool and / or control the temperature of the electrolyte in the electrolyte storage tank.

15. The operation method of the composite energy storage system according to claim 14, characterized in that, Also includes: The compressed air generated by the compressed air energy storage system is prepared into a compressed inert gas, and the compressed inert gas is introduced into the top space inside the electrolyte storage tank to replace and remove the hydrogen gas accumulated in the electrolyte storage tank. And / or, a compressed inert gas is introduced into the stack of the flow battery energy storage system, and forms a first type of flow state with the electrolyte in the stack to carry out a multiphase electrocatalytic reaction; And / or, compressed inert gas is introduced into the gas-liquid mixing mechanism of the flow battery energy storage system, and the compressed inert gas and electrolyte form a second type of flow state, which is then introduced into the stack of the flow battery energy storage system to carry out a multiphase electrocatalytic reaction.

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