A heat pump electricity storage and solid oxide cell coupled energy storage system and an operation regulation method thereof

Abstract

The present application belongs to the technical field of thermoelectric energy storage, and particularly relates to a heat pump energy storage and solid oxide cell coupled energy storage system and an operation regulation method thereof. The energy storage system comprises a heat pump energy storage and energy storage loop, a heat pump energy storage and energy release loop, a solid oxide electrolysis hydrogen production loop, a solid oxide fuel cell power generation loop, a high-temperature heat coupling loop and an electric energy interaction loop. The heat pump energy storage and energy storage loop and the heat pump energy storage and energy release loop are coupled with the solid oxide cell through multiple flow high-temperature heat exchangers respectively. The energy storage system has an energy storage working state and an energy release working state. The present application can directly supply the high-temperature compression heat generated by the heat pump energy storage to the heat required for SOEC hydrogen production in the energy storage stage, and can use the SOFC heat release to heat the working medium of the heat pump energy storage and energy release loop in the energy release stage, thereby reducing the independent high-temperature heat storage configuration, reducing heat loss and improving the comprehensive efficiency of the system.

Description

Technical Field

[0001] This invention belongs to the field of thermoelectric energy storage technology, and particularly relates to a heat pump energy storage and solid oxide battery coupled energy storage system and its operation and control method. Background Technology

[0002] With the continuous increase in the installed capacity of renewable energy sources such as wind power and photovoltaics, the power output fluctuations on the source side of the power system have intensified, creating an urgent need for new energy storage technologies that combine large scale, long duration, low cost, and high efficiency. Meanwhile, hydrogen energy, as an important secondary energy carrier, plays a crucial role in energy regulation across time periods and scenarios. Therefore, the coupling and integration of high-temperature electrochemical hydrogen production, fuel cell power generation, and long-term thermoelectric energy storage has become an important development direction in the field of integrated energy.

[0003] Pumped Thermal Energy Storage (PTES), also known as Carnot Battery, is a novel thermoelectric energy storage technology. Its basic principle is to use a reverse cycle to convert electrical energy into high-temperature heat energy and low-temperature cold energy for storage during the energy storage phase. In the energy release phase, the stored heat energy and cold energy are converted into electrical energy for output through a heat engine cycle. This type of technology has advantages such as long energy storage time, strong scalability, low cost of heat and cold storage media, and suitability for large-scale long-term energy storage. In recent years, it has become an important development direction for new energy storage. Existing related solutions mostly focus on integrating Carnot Battery with wind and solar power generation, combined heat and power systems, or other energy storage methods. For example, some solutions propose to connect Carnot Battery to a wind-solar hybrid combined heat and power system to convert excess electrical energy into heat energy and generate electricity when needed. Other solutions propose to combine Carnot Battery with hydrogen electrolysis and fuel cells to form a physical-chemical coupled energy storage system.

[0004] Solid oxide batteries are a type of high-temperature electrochemical energy conversion device. Among them, the solid oxide electrolysis cell (SOEC) absorbs heat and electrical energy under high temperature conditions to electrolyze water vapor to produce hydrogen, while the solid oxide fuel cell (SOFC) uses hydrogen and other fuels to carry out electrochemical reactions to generate electricity at high temperatures and release high-grade heat. This type of technology has the advantages of high energy conversion efficiency, strong fuel adaptability, and the ability to achieve bidirectional conversion between electricity and hydrogen.

[0005] In existing technologies, heat pump energy storage systems, solid oxide electrolysis hydrogen production systems, and solid oxide fuel cell power generation systems are mostly configured to operate independently. Among them, heat pump energy storage systems typically require the simultaneous installation of high-temperature thermal storage units and low-temperature cold storage units. The high-temperature thermal storage section is large in volume and has high insulation requirements, resulting in large system equipment, complex piping, high investment costs, and high thermal management difficulty. At the same time, there are temperature difference losses and heat losses on the high-temperature side during the compression heat storage, transfer, and reuse process, which can easily cause a decrease in the usable temperature during the energy release stage, thereby affecting cycle efficiency and output power. In addition, high-temperature heat needs to rely on independent thermal storage media for time-series transfer during both the energy storage and energy release stages. However, solid thermal storage materials have strong thermal inertia, which limits the dynamic response capability of the system when the input power fluctuates rapidly or the output power changes rapidly. Especially in the face of scenarios with drastic fluctuations in the output of renewable energy sources such as wind power and photovoltaics, existing heat pump energy storage systems cannot achieve rapid adjustment at the second or minute level, and the flexibility of start-up, shutdown, and operation mode switching is insufficient, resulting in significant losses in the utilization of high-temperature heat.

[0006] Solid oxide battery systems still have certain shortcomings in existing technologies: 1) Solid oxide electrolysis hydrogen production systems in SOEC mode typically require stable power input and rely on high-temperature heat (700-850℃ or even higher) to convert water into high-temperature steam and maintain stack operation. If directly connected to fluctuating renewable energy sources such as wind and solar power, the electrolysis current, stack temperature, and gas flow rate are prone to large fluctuations, leading to increased thermal stress on the stack and affecting operational stability and lifespan. If the external high-temperature heat source is insufficient, additional electric heating, fuel supplementation heating, or independent thermal storage equipment is required. This increases the heating burden, complicates the configuration of heat sources, and reduces the overall energy efficiency of the system; 2) Although solid oxide fuel cell power generation systems can efficiently output electrical energy and release high-grade heat in SOFC mode, their output power is affected by fuel supply, stack temperature and thermal balance, and their operation flexibility is insufficient when used as a long-term energy storage and release unit; 3) If the high-temperature waste heat of solid oxide fuel cells cannot be directly coupled with the matching high-temperature heat use links, it can often only be cooled and discharged through waste heat boilers, radiators or other heat exchange devices or used for conventional waste heat recovery, resulting in insufficient utilization of high-grade heat energy.

[0007] Existing solutions propose SOFC cogeneration systems, RSOC coupled with external heat sources, and long-term energy storage solutions combining electrolytic hydrogen production / fuel cells with Carnot batteries in parallel. Most of these solutions still treat the two as relatively independent physical and chemical energy storage units, focusing mainly on electrical energy diversion and storage, exhaust gas combustion supplementary heating, or multi-energy cogeneration, without fully utilizing the inherent complementary relationship between SOEC heat absorption and SOFC heat release in the temperature range.

[0008] Therefore, there is a lack of effective coupling mechanism between existing heat pump energy storage systems, solid oxide electrolysis hydrogen production systems, and solid oxide fuel cell power generation systems. When each system operates independently, there are problems such as redundant high-temperature heat source configuration, insufficient waste heat utilization, poor adaptability to renewable energy fluctuations, lack of coordination between hydrogen energy storage and heat pump energy storage operations, and inconsistent energy scheduling among source, grid, load, and storage. How to couple and integrate the cold and hot energy storage characteristics of heat pump energy storage systems, the heat absorption and hydrogen production characteristics of solid oxide electrolysis hydrogen production systems, and the power generation and heat release characteristics of solid oxide fuel cell systems, and achieve coordinated operation of source, grid, load, and storage through an integrated energy management platform, is an urgent problem to be solved in the field of long-term energy storage and multi-energy complementarity. Although existing solutions have disclosed ideas such as Carnot battery integration, multi-energy complementarity, SOFC / RSOC energy supply, and physical and chemical energy storage coupling, a system solution that directly complements and couples the high-temperature side of heat pump energy storage with the high-temperature heat absorption and release process of SOEC / SOFC, thereby weakening the configuration of traditional thermal storage units, has not yet been seen.

[0009] From the perspective of thermal energy utilization mechanism, heat pump energy storage system generates high-temperature heat in the energy storage stage and requires high-temperature heat input in the energy release stage to improve expansion and work capacity. Solid oxide batteries, in SOEC mode, need high-temperature heat absorption to reduce electrolysis power consumption, and in SOFC mode, they can release high-temperature heat. The two exhibit a spatiotemporal complementary relationship between heat generation and heat utilization in both the energy storage and energy release stages.

[0010] In summary, there is currently a lack of a system scheme that deeply couples a heat pump energy storage system with a reversible solid oxide battery. Therefore, it is urgent to propose a coupled energy storage system of heat pump energy storage and solid oxide battery and its operation and control method. Summary of the Invention

[0011] In view of this, the present invention aims to provide a heat pump energy storage and solid oxide battery coupled energy storage system and its operation and control method, so as to solve the problems of large high-temperature heat storage loss in the heat pump energy storage system, insufficient heat energy utilization in the solid oxide battery system, and lack of synergistic coupling mechanism between the two in the prior art.

[0012] To achieve the above objectives, the technical solution created by this invention is implemented as follows: A heat pump energy storage and solid oxide battery coupled energy storage system, comprising: The heat pump energy storage circuit includes a drive fan, a working fluid pretreatment device, a heat pump energy storage drive unit, an energy storage compressor unit, an energy storage expander unit, and a low-temperature cold storage unit; The heat pump energy storage and release circuit includes a drive fan, a working fluid pretreatment device, a low-temperature cold storage unit, an energy release compressor unit, an energy release expander unit, and a heat pump energy storage and power generation unit. The solid oxide electrolysis hydrogen production circuit includes a solid oxide battery, a water storage tank, a water pump, a multi-stream reheater, a gas-liquid separator, a hydrogen compressor, and a hydrogen storage tank. The solid oxide fuel cell power generation circuit includes a solid oxide cell, a hydrogen storage tank, a multi-stream reheater, an air fan, an air pretreatment device, an aftercombustion chamber, and an SOFC power generation unit. High-temperature thermal coupling circuit, including multi-stream high-temperature heat exchanger and high-temperature auxiliary heat accumulator; The power interaction circuit includes a renewable energy generation unit, a grid-side interface, a user load unit, an integrated energy management platform, an SOEC drive unit, an SOFC generation unit, and a bidirectional converter; The heat pump energy storage circuit and the heat pump energy release circuit are coupled to the solid oxide battery through a multi-stream high-temperature heat exchanger. The capacity of the high-temperature auxiliary heat accumulator is smaller than the high-temperature heat storage capacity required for the independent operation of the heat pump energy storage system. The solid oxide battery is a reversible high-temperature electrochemical device that can switch between SOEC mode and SOFC mode. The energy storage system has an energy storage working state and an energy release working state. In the energy storage working state, the high-temperature compression heat of the heat pump energy storage circuit is supplied to the solid oxide battery for SOEC mode hydrogen production via a multi-stream high-temperature heat exchanger. In the energy release working state, the waste heat generated by the solid oxide battery in SOFC mode power generation is supplied to the heat pump energy storage energy release circuit via a multi-stream high-temperature heat exchanger.

[0013] Furthermore, in the energy storage stage, the energy storage compressor unit of the heat pump energy storage circuit generates high-temperature compression heat, which is transferred to the solid oxide electrolysis hydrogen production circuit through a multi-stream high-temperature heat exchanger to provide high-temperature heat for the SOEC inlet water vapor and air; the solid oxide battery operates in SOEC mode, using renewable energy power and high-temperature heat to electrolyze water to produce hydrogen, and the produced hydrogen is stored in a hydrogen storage tank after passing through a gas-liquid separator and a hydrogen compressor; the heat pump energy storage working fluid, after heat exchange by the multi-stream high-temperature heat exchanger, enters the energy storage expander unit for expansion and cooling, and the resulting low-temperature working fluid stores the cold energy in a low-temperature cold storage device.

[0014] Furthermore, during the energy release phase, hydrogen is released from the hydrogen storage tank, preheated by a multi-stream regenerator, and then fed into the anode of the solid oxide battery. Air is pretreated and then fed into the cathode of the solid oxide battery. The solid oxide battery operates in SOFC mode, converting the chemical energy of hydrogen into electrical energy output. The tail gas from the SOFC anode and cathode enters the combustion chamber and is burned to produce high-temperature flue gas. The high-temperature flue gas enters the multi-stream high-temperature heat exchanger, transferring high-grade heat to the working fluid of the heat pump energy storage and energy release circuit. The working fluid of the heat pump energy storage and energy release circuit sequentially obtains a low-temperature cold source through a low-temperature cold storage unit, is compressed by the energy release compressor unit, absorbs high-temperature heat through the multi-stream high-temperature heat exchanger, and then enters the energy release expander unit to do work, driving the heat pump energy storage and power generation unit to generate electricity.

[0015] Furthermore, the capacity of the high-temperature auxiliary heat accumulator is less than the high-temperature heat storage capacity required for the independent operation of the heat pump energy storage system; The high-temperature auxiliary heat storage device is used for heat buffering in at least one of the following operating conditions: when the heat absorption demand of SOEC is less than the high-temperature compression heat released by the heat pump energy storage circuit, it stores the excess high-temperature heat; when the heat absorption demand of SOEC is greater than the high-temperature compression heat released by the heat pump energy storage circuit, it releases the stored high-temperature heat for supplementary heating; when the heat release of SOFC does not match the heat absorption demand of the heat pump energy storage circuit, it performs auxiliary heat regulation.

[0016] Furthermore, the integrated energy management platform is electrically connected to the renewable energy power generation unit, the grid-side interface, the user load unit, the heat pump energy storage drive unit, the heat pump energy storage power generation unit, the SOEC drive unit, the SOFC power generation unit, and the bidirectional converter. The integrated energy management platform is used to receive real-time renewable energy output information, grid dispatch information, user load demand information, hydrogen storage status of hydrogen storage tanks, cold storage status of cryogenic cold storage devices, and temperature status of solid oxide batteries, and determines the system operation mode and power allocation based on the above information.

[0017] Furthermore, the circulating gas working medium in the heat pump energy storage circuit and the heat pump energy release circuit is one or more of the following mixed working media: air, nitrogen, argon, helium or carbon dioxide; the low-temperature cold accumulator is a packed bed cold accumulator, which is filled with a solid cold storage medium; the high-temperature auxiliary heat accumulator is a packed bed heat accumulator, a honeycomb ceramic heat accumulator, a solid particle heat accumulator or a phase change heat accumulator.

[0018] Furthermore, the reaction of the solid oxide battery in SOEC mode is as follows: Cathode: H₂O + 2e - = H2+O² - ; Anode: 2O² - =O2+4e - ; The response in SOFC mode is as follows: Cathode: O2 + 4e - =2O² - ; Anode: H2 + O² - =H₂O + 2e - .

[0019] Furthermore, it also includes a valve regulation and control system, which includes multiple regulating valves, each of which is connected to the integrated energy management platform. The valve regulation and control system is used to adjust the flow direction of the heat pump energy storage medium, the direction of SOEC and SOFC reactants and exhaust gas, and the distribution ratio of high-temperature flue gas according to the energy storage condition, energy release condition, SOEC hydrogen production condition, and SOFC power generation condition.

[0020] A method for operating and controlling a coupled energy storage system of heat pump energy storage and solid oxide battery, comprising the following steps: S1. Obtain renewable energy output information, user load demand information, hydrogen storage status of hydrogen storage tanks and cold storage status of cryogenic cold storage devices. S2. When the output of renewable energy exceeds the user's load demand and the hydrogen storage tank has not reached the hydrogen storage limit, the control system enters the energy storage hydrogen production mode: the surplus electrical energy is allocated to the heat pump energy storage drive unit and the SOEC drive unit. The high-temperature compression heat generated by the heat pump energy storage circuit is supplied to the solid oxide battery for SOEC mode hydrogen production through the multi-stream high-temperature heat exchanger. The low-temperature cold energy generated by the heat pump energy storage circuit is stored in the low-temperature cold storage device. When the high-temperature compression heat is excessive, the high-temperature auxiliary heat storage device buffers the heat. S3. When the output of renewable energy is insufficient or the user load demand is high and the hydrogen storage tank has hydrogen storage capacity, the control system enters the energy release power generation mode: the hydrogen storage tank releases hydrogen to power the solid oxide battery in SOFC mode. The SOFC exhaust gas is burned in the after-combustion chamber to generate high-temperature flue gas. The high-temperature flue gas is supplied to the heat pump energy storage and energy release circuit through the multi-stream high-temperature heat exchanger, driving the heat pump energy storage and power generation unit to generate electricity in combination. S4. The integrated energy management platform dynamically adjusts the allocation of heat pump energy storage power, SOEC hydrogen production power, SOFC power generation power, and heat pump energy release power based on renewable energy output fluctuations, grid dispatch instructions, and user load demands.

[0021] Furthermore, S2 also includes the following control steps: When the output of renewable energy fluctuates in the short term, the energy management platform prioritizes keeping the temperature and current change rate of the solid oxide battery within the allowable range, and absorbs the fluctuating electrical energy by adjusting the power of the heat pump energy storage drive unit. When renewable energy continues to be abundant, gradually increase the SOEC hydrogen production load and increase the hydrogen storage capacity of hydrogen storage tanks. When user load experiences short-term peaks, priority is given to using SOFC power generation units and heat pump energy storage power generation units to jointly supply power. When the heat absorption demand of SOEC does not match the heat released by the heat pump energy storage circuit, the matching is first achieved by adjusting the flow rate of the working fluid entering the multi-stream high-temperature heat exchanger, and the insufficient part is regulated by the high-temperature auxiliary heat accumulator.

[0022] Compared with the prior art, the present invention can achieve the following beneficial effects: 1. Reduce high-temperature thermal storage configuration and heat loss: This invention partially replaces the PTES independent high-temperature thermal storage unit with SOEC heat absorption modules, reducing the configuration of large-capacity high-temperature heat accumulators, and reducing equipment size, insulation requirements and high-temperature thermal storage losses.

[0023] 2. Improve overall system energy efficiency: This invention achieves high-temperature heat cascade utilization through multi-stream high-temperature heat exchangers and regenerators, which utilizes the compression heat of PTESE to SOEC heating and the waste heat of SOFC to PTESE heating. This reduces energy waste and irreversible heat exchange losses caused by independent configuration of each system. Compared with the existing reference system, the system round-trip efficiency can be significantly improved, which can greatly improve the overall system energy efficiency.

[0024] 3. Reduce dependence on external heat sources for SOEC and improve hydrogen production efficiency: This invention can provide a stable high-temperature heat source for SOEC through the compression heat of PTES during the energy storage stage, so that SOEC water electrolysis process can obtain a stable heat source, reduce the need for additional electric heating or fuel supplementation, and improve the stability of hydrogen production under fluctuating renewable energy conditions.

[0025] 4. Achieving coordinated operation of source-grid-load-storage: This invention coordinates the switching between PTEES energy storage / release and SOEC / SOFC modes through an integrated energy management platform, enabling dynamic balance between the power supply side, grid side, load side, and energy storage side. It converts electrical energy into cold and heat energy and hydrogen for storage or combined output, improving the absorption capacity of fluctuating renewable energy. At the same time, the heat pump energy storage system can buffer the fluctuations in renewable energy power, avoid frequent and large fluctuations in SOEC electrolysis current and SOFC output power, reduce the thermal and electrochemical shocks of solid oxide batteries, and improve the stability and service life of the stack. Attached Figure Description

[0026] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the overall framework structure of the energy storage system in an embodiment of the present invention.

[0027] Figure reference numerals: 1. Heat pump energy storage drive unit; 2. Energy storage compressor unit; 3. Energy storage expander unit; 4. Heat pump energy storage power generation unit; 5. Energy release expander unit; 6. Energy release compressor unit; 7. High-temperature auxiliary heat accumulator; 8. Low-temperature cold accumulator; 9. First waste heat dissipation heat exchanger; 10. Second waste heat dissipation heat exchanger; 11. Drive fan; 12. Working fluid pretreatment device; 13. Buffer tank; 14. Multi-stream high-temperature heat exchanger; 15. Water tank; 16. Water pump; 17. Multi-stream regenerator; 18. Air fan; 19. Air pretreatment device; 20. Drive power generation unit; 21. Bidirectional converter; 22. Solid oxide battery; 23. Gas-liquid separator. 24. Hydrogen compressor; 25. Hydrogen storage tank; 26. Afterburner; 27. Renewable energy power generation unit; 28. Grid-side interface; 29. ​​User load unit; 30. Energy integrated management platform; 101. First regulating three-way valve; 102. First regulating valve; 103. Second regulating three-way valve; 104. Third regulating three-way valve; 105. Fourth regulating three-way valve; 106. Fifth regulating three-way valve; 107. Third regulating valve; 108. First regulating four-way valve; 109. Sixth regulating three-way valve; 110. Seventh regulating three-way valve; 111. Eighth regulating three-way valve; 112. Ninth regulating three-way valve; 113. Detailed Implementation

[0028] To make the purpose, technical solution, and advantages of this invention clearer, the following description is provided in conjunction with the appendix. Figure 1 The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and do not constitute a limitation thereof.

[0029] This invention provides a heat pump energy storage and solid oxide battery coupled energy storage system, such as... Figure 1 As shown, it includes a heat pump energy storage circuit, a heat pump energy release circuit, a solid oxide electrolysis hydrogen production circuit, a solid oxide fuel cell power generation circuit, a high-temperature thermal coupling circuit, an electrical energy interaction circuit, a hydrogen storage circuit, a working fluid mass balance system, and a valve regulation and control system.

[0030] The heat pump energy storage circuit includes: a drive fan 11, a working fluid pretreatment device 12, a heat pump energy storage drive unit 1, an energy storage compressor unit 2, a multi-stream high-temperature heat exchanger 14, a high-temperature auxiliary heat accumulator 7, an energy storage expander unit 3, a low-temperature cold accumulator 8, and related pipelines and regulating valves. The energy storage compressor unit 2 and the energy storage expander unit 3 can be single-stage or multi-stage structures. The total pressure ratio of the compressor unit can be 3 to 20, and the total expansion ratio of the expander unit can be 3 to 20. When the energy storage compressor unit 2 and the energy storage expander unit 3 are multi-stage structures, they can be coaxial series, split-axis parallel, or multi-axis coupled.

[0031] The heat pump energy storage and release circuit includes: a drive fan 11, a working fluid pretreatment device 12, a low-temperature cold storage unit 8, an energy release compressor unit 6, a multi-stream high-temperature heat exchanger 14, an energy release expander unit 5, a heat pump energy storage and power generation unit 4, a high-temperature auxiliary heat storage unit 7, a first waste heat dissipation heat exchanger 9, a second waste heat dissipation heat exchanger 10, and related pipelines and regulating valves. The energy release compressor unit 6 and the energy release expander unit 5 can be single-stage or multi-stage structures. The energy release expander unit 5 is driven and connected to the heat pump energy storage and power generation unit 4 to convert thermal energy into mechanical work and further into electrical energy during the energy release stage.

[0032] The circulating gas working medium in the heat pump energy storage circuit and the heat pump energy release circuit is one or more of the following: air, nitrogen, argon, helium, and carbon dioxide. Air, nitrogen, or argon is preferred. To ensure stable system operation, the same gas working medium is preferably used in the same heat pump energy storage cycle.

[0033] The working fluid mass balance system includes a buffer tank 13 and related pipelines. The buffer tank 13 is used for working fluid mass balance and pressure stability in the closed heat pump energy storage cycle. Since the working fluid temperature, density and flow rate vary under different operating modes of the closed heat pump energy storage system, the buffer tank 13 can regulate the loop pressure by replenishing gas or recovering the working fluid, so as to ensure that the compressor unit and expander unit operate within a safe and stable range.

[0034] The solid oxide electrolysis hydrogen production circuit includes: a water storage tank 15, a water pump 16, a multi-stream regenerator 17, a multi-stream high-temperature heat exchanger 14, a solid oxide battery 22, a gas-liquid separator 23, a hydrogen compressor 24, a hydrogen storage tank 25, an air fan 18, an air pretreatment device 19, an SOEC drive unit 20, a bidirectional converter 21, and related pipelines and regulating valves. The reactants in the solid oxide electrolysis hydrogen production circuit include water or water vapor, and the gas on the anode side is air or oxygen dilution gas.

[0035] The solid oxide fuel cell power generation circuit includes: a hydrogen storage tank 25, a multi-stream reheater 17, an air fan 18, an air pretreatment device 19, a solid oxide cell 22, an afterburner 26, a multi-stream high-temperature heat exchanger 14, an SOFC power generation unit 20, a bidirectional converter 21, and related pipelines and regulating valves. The fuel in the solid oxide fuel cell power generation circuit is hydrogen, and the oxidant is air.

[0036] The hydrogen storage circuit includes: the cathode outlet of the solid oxide battery 22, a multi-stream reheater 17, a gas-liquid separator 23, a hydrogen compressor 24, a hydrogen storage tank 25, and connecting pipelines. This circuit is used to cool, separate, compress, and store the hydrogen generated in SOEC mode during the energy storage phase, and to supply fuel gas to SOFC mode during the energy release phase. The hydrogen storage tank 25 is a high-pressure hydrogen storage container, a metal hydride hydrogen storage device, a composite material hydrogen storage cylinder group, or other containers suitable for long-term hydrogen storage.

[0037] The high-temperature thermal coupling circuit includes: a multi-stream high-temperature heat exchanger 14, a multi-stream regenerator 17, a high-temperature auxiliary heat accumulator 7, an afterburner 26, and related pipelines. This circuit is used to realize thermal coupling between the high-temperature gas working fluid of the heat pump energy storage system, the SOEC inlet water vapor, the SOEC inlet air, the SOFC exhaust gas, and the high-temperature flue gas of the afterburner.

[0038] The high-temperature auxiliary heat storage device 7 can be a filled bed heat storage device, a honeycomb ceramic heat storage device, a solid particle heat storage device, or a phase change heat storage device. It is used to assist in heat regulation when the heat absorption of SOEC is insufficient, the high-temperature heat of the heat pump energy storage loop is excessive, or the heat release of SOFC is mismatched with the heat pump energy release demand. The capacity of the high-temperature auxiliary heat storage device 7 is smaller than the high-temperature heat storage capacity required for the independent operation of the heat pump energy storage system. That is, the high-temperature auxiliary heat storage device 7 only undertakes the function of heat buffering, rather than the independent large-capacity high-temperature heat storage function, thereby achieving the technical effect of reducing the configuration of independent high-temperature heat storage, reducing equipment volume and heat loss.

[0039] The low-temperature cold storage device 8 can be a cylindrical, spherical, or cuboid packed bed, filled with a solid cold storage medium. The cold storage medium can be one or more of the following: rock, ore, slag, concrete, ceramic balls, metal particles, refractory materials, or encapsulated phase change materials. The low-temperature cold storage device 8 is equipped with a temperature detection device, a pressure detection device, and a safety valve.

[0040] The power interaction loop includes: a renewable energy generation unit 27, a grid-side interface 28, a user load unit 29, an energy integrated management platform 30, a heat pump energy storage drive unit 1, a heat pump energy storage power generation unit 4, a drive power generation unit 20 (SOEC drive unit / SOFC power generation unit), and a bidirectional converter 21. The renewable energy generation unit 27, the grid-side interface 28, and the user load unit 29 are all connected to the energy integrated management platform 30 via electrical connection. The energy integrated management platform 30 distributes power according to the power output, grid-side instructions, load-side demand, and energy storage system status. The heat pump energy storage drive unit 1 is a drive motor or an electric motor, and its power supply can come from the renewable energy generation unit 27, the grid-side interface 28, or a combination of the two.

[0041] The drive power generation unit 20 is connected to the energy management platform 30 through the bidirectional converter 21. When the solid oxide battery 22 is running in SOEC mode, the bidirectional converter 21 supplies power to the solid oxide battery 22. When the solid oxide battery 22 is running in SOFC mode, the bidirectional converter 21 converts the DC power output by the solid oxide battery 22 into electrical energy that meets the requirements of the grid-side interface 28 or the user load unit 29.

[0042] The solid oxide battery 22 is a reversible high-temperature electrochemical device that can switch between SOEC mode and SOFC mode.

[0043] The valve regulation and control system includes: a first regulating three-way valve 101, a first regulating valve 102, a second regulating valve 103, a second regulating three-way valve 104, a third regulating three-way valve 105, a fourth regulating three-way valve 106, a fifth regulating three-way valve 107, a third regulating valve 108, a first regulating four-way valve 109, a sixth regulating three-way valve 110, a seventh regulating three-way valve 111, an eighth regulating three-way valve 112, and a ninth regulating three-way valve 113. Each regulating valve is used to switch the working fluid flow direction, regulate the flow rate, bypass control, and distribute heat under different operating modes. Each valve is connected to the energy integrated management platform 30 and is used to regulate the on / off state, flow direction, and flow rate of each circuit according to the energy storage condition, energy release condition, SOEC hydrogen production condition, and SOFC power generation condition.

[0044] Specifically, the first regulating three-way valve 101 is used to control the switching of the main circuit of the heat pump energy storage working fluid between the energy storage circuit and the energy release circuit; the first regulating valve 102 is used to regulate the replenishment and exhaust flow between the buffer tank 13 and the heat pump energy storage working fluid pipeline to maintain stable working fluid circuit pressure; the second regulating valve 103 is used to regulate the flow rate and pressure of the working fluid entering the energy storage expander unit 3; the second regulating three-way valve 104 is used to control the distribution of the high-temperature working fluid at the outlet of the energy storage compressor unit 2 between the multi-stream high-temperature heat exchanger 14 and the high-temperature auxiliary heat accumulator 7; the third regulating three-way valve 105 is used to control the switching of the flow direction of the working fluid at the lower interface of the low-temperature cold accumulator 8 between the energy storage circuit and the energy release circuit; the fourth regulating three-way valve 106 is used to control the connection or disconnection between the working fluid at the outlet of the energy storage expander unit 3 and the low-temperature cold accumulator 8; the fifth regulating three-way valve 107 is used to control the inlet and outlet flow direction of the working fluid at the upper interface of the low-temperature cold accumulator 8 to realize the switching of cold storage and cold release processes; the third regulating... Valve 108 is used to regulate the flow rate of the high-temperature working fluid entering the energy release expander unit 5; the first regulating four-way valve 109 is used to control the switching of the gas or heat exchange medium flow direction between the solid oxide battery multi-stream regenerator 17, the multi-stream high-temperature heat exchanger 14 and the solid oxide battery 22; the sixth regulating three-way valve 110 is used to control the distribution of the air-side outlet gas of the solid oxide battery 22 between the regenerator branch and the afterburner 26; the seventh regulating three-way valve 111 is used to control the switching of the flow direction of the fuel-side outlet gas of the solid oxide battery 22 between the hydrogen production processing branch, the regenerator branch and the afterburner 26; the eighth regulating three-way valve 112 is used to control the water separated by the gas-liquid separator 23 to flow back to the water storage tank 15 or enter the discharge / makeup branch; the ninth regulating three-way valve 113 is used to control the connection relationship between the hydrogen compressor 24, the hydrogen storage tank 25 and the fuel-side inlet of the solid oxide battery 22, so as to realize the switching between hydrogen production and storage and power generation and hydrogen supply.

[0045] The energy storage system uses a heat pump energy storage system as the basis for electro-thermal conversion and cold-thermal energy storage, and the reversible operation characteristics of the solid oxide battery 22 as the basis for electro-hydrogen conversion and hydrogen-electric conversion. The high-temperature thermal coupling between the heat pump energy storage system and the solid oxide battery system is achieved through a multi-stream high-temperature heat exchanger 14 and a multi-stream regenerator 17. The system has an energy storage working state and an energy release working state.

[0046] During the energy storage phase, the system prioritizes the use of fluctuating power output from the renewable energy power generation unit 27. The energy integrated management platform 30 receives the operating information from the renewable energy power generation unit 27, the grid-side interface 28, and the user load unit 29. Based on the current power surplus, the pressure of the hydrogen storage tank 25, the cold storage status of the low-temperature cold storage unit 8, the heat storage status of the high-temperature auxiliary heat storage unit 7, and the temperature status of the solid oxide battery 22, the system allocates power to the heat pump energy storage drive unit 1 and the SOEC drive unit 20, respectively.

[0047] The operation process of the heat pump energy storage circuit is as follows: after the drive fan 11 is started, the working gas enters the working gas pretreatment device 12. The working gas pretreatment device 12 dehumidifies, filters or purifies the working gas. The treated working gas enters the heat pump energy storage drive unit 1 and the energy storage compressor unit 2. The energy storage compressor unit 2 compresses the working gas under the drive of the heat pump energy storage drive unit 1, so that the working gas is heated and pressurized.

[0048] After the high-temperature, high-pressure gaseous working medium flows out of the outlet of the energy storage compressor unit 2, it enters the multi-stream high-temperature heat exchanger 14 after being regulated by valves such as the first regulating three-way valve 101 and the second regulating three-way valve 104. In the multi-stream high-temperature heat exchanger 14, the high-temperature gaseous working medium exchanges heat with the water vapor at the SOEC cathode inlet and the air at the SOEC anode inlet, transferring some of the high-temperature heat to the SOEC reactants, so that the water vapor and air reach the reaction temperature (700-850℃) required by the solid oxide battery 22.

[0049] When the heat absorption demand of SOEC is less than the high-temperature heat released by the heat pump energy storage circuit, the first regulating three-way valve 101, the first regulating valve 102 and related valves regulate the high-temperature gas working fluid to enter the high-temperature auxiliary heat accumulator 7 and store the excess heat in the high-temperature auxiliary heat accumulator 7; when the heat absorption demand of SOEC is large, the flow rate of the high-temperature gas working fluid entering the multi-stream high-temperature heat exchanger 14 is increased by regulating the valves.

[0050] After heat exchange in the multi-stream high-temperature heat exchanger 14 or the high-temperature auxiliary heat accumulator 7, the gaseous working medium enters the energy storage expander unit 3 to expand and cool down, forming a low-temperature gaseous working medium. The low-temperature gaseous working medium then enters the low-temperature cold storage unit 8 to exchange heat with the cold storage medium in the low-temperature cold storage unit 8, storing the cold energy in the low-temperature cold storage unit 8. The heat-exchanged gaseous working medium returns to the inlet of the drive fan 11, completing the heat pump electricity storage cycle.

[0051] The SOEC mode operation process of the solid oxide battery is as follows: On the SOEC cathode side, water in the water tank 15 is pressurized by the water pump 16 and enters the multi-stream regenerator 17. In the multi-stream regenerator 17, the water absorbs the waste heat of the high-temperature gas at the SOEC outlet and is preheated into medium-temperature steam or medium-temperature wet steam. Subsequently, the medium-temperature steam enters the multi-stream high-temperature heat exchanger 14 and further absorbs the heat released by the high-temperature gas working fluid in the heat pump energy storage circuit, raising the temperature to the high-temperature steam state required by the solid oxide battery 22.

[0052] High-temperature steam enters the cathode side of the solid oxide battery 22 and undergoes an electrolysis reaction under the electrical energy provided by the SOEC drive unit 20. The SOEC cathode reaction is: H₂O + 2e⁻ - =H2+O² -The cathode outlet gas mainly consists of generated hydrogen and unreacted water vapor. This high-temperature mixed gas enters the multi-stream regenerator 17 to exchange heat with the inlet water, recovering some of the waste heat to preheat the inlet water. The cooled mixed gas enters the gas-liquid separator 23, which separates the unreacted water and returns it to the water storage tank 15. The hydrogen enters the hydrogen compressor 24, and after compression, it is sent to the hydrogen storage tank 25 for storage.

[0053] SOEC anode side: Outside air is driven by air fan 18 into air pretreatment device 19. Air pretreatment device 19 filters, dehumidifies or preheats the air. The treated air enters multi-stream regenerator 17 and is preheated to medium temperature by high temperature oxygen-enriched gas at SOEC anode outlet. Subsequently, the medium temperature air enters multi-stream high temperature heat exchanger 14, absorbs heat released by high temperature gas working fluid in heat pump energy storage circuit, and is heated to high temperature before entering the anode of solid oxide battery 22.

[0054] Oxygen ions lose electrons on the anode side of SOEC, and the reaction formula is: 2O²⁻ - =O2+4e - The anode outlet is oxygen-enriched gas with a high oxygen content. This oxygen-enriched gas enters the multi-stream reheater 17, where it transfers waste heat to the inlet air before being discharged from the system or further recycled.

[0055] In this mode, the electricity output by the renewable energy generation unit 27 is prioritized for supplying the user load unit 29. When the renewable energy output exceeds the user load demand, the energy integrated management platform 30 allocates the surplus electricity to the heat pump energy storage drive unit 1 and the SOEC drive unit 20. The heat pump energy storage drive unit 1 is used to drive the energy storage compressor unit 2 to complete the storage of cold and heat energy, and the SOEC drive unit 20 is used to drive the solid oxide battery 22 to electrolyze hydrogen. When the renewable energy output is still in surplus, it can feed back electricity to the grid through the grid-side interface 28. When the renewable energy is insufficient for a short period of time, it can be supplemented by the grid-side interface 28 to maintain the stable operation of the SOEC.

[0056] The integrated energy management platform 30 smoothly controls the input power of SOEC based on the allowable load increase / decrease rate of the solid oxide battery 22, avoiding rapid fluctuations in electrolysis current caused by sudden changes in renewable energy output. At the same time, the integrated energy management platform 30 achieves dynamic matching between the heat pump energy storage process and the SOEC heat absorption process by adjusting the power of the heat pump energy storage drive unit 1, the speed of the energy storage compressor unit 2, the flow rate of the working fluid entering the multi-stream high-temperature heat exchanger 14, and the bypass flow rate entering the high-temperature auxiliary heat accumulator 7.

[0057] When the user load unit 29 has a high power demand, the renewable energy generation unit 27 has insufficient output, or the grid-side interface 28 needs the system to supply power to the outside, the energy integrated management platform 30 controls the system to enter the energy release generation mode. At this time, the solid oxide battery 22 operates in SOFC mode.

[0058] The operation process of the heat pump energy storage and release circuit is as follows: after the drive fan 11 is started, the gas working medium enters the working medium pretreatment device 12 for dehumidification and filtration. The treated gas working medium first enters the low temperature cold storage 8 and exchanges heat with the cold storage medium in the low temperature cold storage 8 to obtain a low temperature state. The low temperature gas working medium enters the energy release compressor unit 6 and is compressed to a medium and high pressure state.

[0059] After being compressed by the energy release compressor unit 6, the gaseous working medium enters the first waste heat dissipation heat exchanger 9 or the second waste heat dissipation heat exchanger 10 to regulate the gas temperature entering the subsequent high-temperature heat exchange stage. Subsequently, the gaseous working medium enters the multi-stream high-temperature heat exchanger 14 to exchange heat with the high-temperature flue gas from the after-combustion chamber 26, absorbing the high-grade heat generated by the combustion of SOFC tail gas and rising to high-temperature medium-pressure gas.

[0060] High-temperature, high-pressure gas enters the energy release expander unit 5, expands and does work, driving the heat pump energy storage and power generation unit 4 to generate electricity. The expanded gas working fluid returns to the inlet of the drive fan 11 or enters the low-temperature cold storage unit 8 to continue the cycle, thus completing the heat pump energy storage and power generation process.

[0061] The SOFC (Solid Oxide Fuel Cell) operation process is as follows: On the SOFC anode side: Hydrogen storage tank 25 releases hydrogen generated and stored during the energy storage stage. After being controlled by valves such as the ninth regulating three-way valve 113, the hydrogen enters the multi-stream regenerator 17. In the multi-stream regenerator 17, it absorbs heat from the high-temperature exhaust gas or medium-temperature flue gas at the SOFC outlet and is preheated to the required reaction temperature (700-850℃) of the solid oxide battery 22. The preheated hydrogen then enters the anode side of the solid oxide battery 22. The SOFC anode reaction is: H2 + O²⁻ - =H₂O + 2e - .

[0062] The anode outlet exhaust gas mainly consists of water vapor and unreacted hydrogen. This high-temperature anode exhaust gas is sent into the afterburner 26, where it mixes with the high-temperature cathode exhaust gas and undergoes combustion or catalytic oxidation to release high-grade heat.

[0063] SOFC cathode side: Outside air enters the air pretreatment device 19 via air fan 18, undergoes filtration and dehumidification, and then enters the multi-stream regenerator 17, where it is preheated to medium-temperature air. This medium-temperature air then enters the cathode side of the solid oxide cell 22 to participate in the electrochemical reaction. The SOFC cathode reaction is: O2 + 4e- - =2O² -.

[0064] The cathode outlet exhaust gas mainly consists of nitrogen and residual oxygen. This high-temperature cathode exhaust gas enters the after-combustion chamber 26 and mixes with the residual hydrogen in the SOFC anode exhaust gas to form high-temperature flue gas.

[0065] The high-temperature flue gas utilization process is as follows: the high-temperature flue gas generated in the post-combustion chamber 26 can reach a temperature of about 1000℃. This high-temperature flue gas first enters the multi-stream high-temperature heat exchanger 14, which transfers high-grade heat to the gas working fluid in the heat pump energy storage and release circuit, thereby increasing the inlet temperature and output power of the energy release expander unit 5. After preliminary heat exchange, the medium-temperature flue gas enters the multi-stream regenerator 17, which is used to preheat the SOFC anode inlet hydrogen and cathode inlet air, thereby realizing the cascade recovery of flue gas heat. Finally, the cooled flue gas is discharged from the system or enters the subsequent purification treatment device.

[0066] In this mode, the solid oxide battery 22 outputs electrical energy through the SOFC power generation unit 20 and the bidirectional converter 21, while the heat pump energy storage power generation unit 4 outputs electrical energy simultaneously. The energy integrated management platform 30 coordinates the SOFC power generation and the heat pump energy storage power generation based on the user load unit 29 demand, the grid-side interface 28 dispatch instructions, the remaining hydrogen storage capacity of the hydrogen storage tank 25, the cold storage status of the cryogenic cold storage unit 8, and the operating status of the heat pump energy storage release circuit.

[0067] When the demand of user load unit 29 is high, SOFC power generation unit 20 and heat pump energy storage power generation unit 4 give priority to supplying power to user load unit 29. When the power generation is greater than the user load demand, the excess power is fed back to the grid through grid-side interface 28. When the power generation is insufficient, the energy integrated management platform 30 can control grid-side interface 28 to supplement power supply or reduce non-critical user load to ensure stable system operation.

[0068] The integrated energy management platform 30 is used to receive real-time output information of renewable energy power generation unit 27, dispatch information of grid-side interface 28, electricity demand information of user load unit 29, operating status of heat pump energy storage system, temperature and power status of solid oxide battery 22, pressure and hydrogen storage capacity of hydrogen storage tank 25, cold storage status of low temperature cold storage 8 and heat storage status of high temperature auxiliary heat storage 7, and determine the system operation mode based on the above information.

[0069] When the output of the renewable energy power generation unit 27 exceeds the demand of the user load unit 29, and the hydrogen storage tank 25 has not reached the hydrogen storage limit, the energy integrated management platform 30 prioritizes the control system to enter the energy storage and hydrogen production mode, converting the surplus electrical energy into cold and heat energy and hydrogen energy for long-term storage.

[0070] When the output of the renewable energy power generation unit 27 is insufficient, the demand of the user load unit 29 is high, and the hydrogen storage tank 25 has sufficient hydrogen storage capacity, the energy integrated management platform 30 controls the system to enter the energy release power generation mode, and supplies power to the user load unit 29 or the grid-side interface 28 through SOFC power generation and heat pump energy storage energy release power generation.

[0071] When the grid-side interface 28 issues a peak-shaving, frequency-regulating, or standby command, the energy integrated management platform 30 adjusts the power distribution of the heat pump energy storage drive unit 1, the heat pump energy storage power generation unit 4, and the drive power generation unit 20 according to the command requirements. Under the demand of rapid power change, the energy integrated management platform 30 prioritizes adjusting the SOEC or SOFC electric power through the bidirectional converter 21, and coordinates the adjustment of the heat pump energy storage circulating working fluid flow rate and the heat exchange load of the multi-stream high-temperature heat exchanger 14 to achieve rapid system response.

[0072] When the heat absorption demand of SOEC is mismatched with the heat release of the heat pump energy storage circuit, the energy management platform 30 adjusts the working fluid flow ratio into the multi-stream high-temperature heat exchanger 14 and the high-temperature auxiliary heat accumulator 7 through the first regulating three-way valve 101, the first regulating valve 102, the second regulating three-way valve 104 and related valves. When the heat release of SOFC is mismatched with the heat absorption demand of the heat pump energy storage circuit, the energy management platform 30 adjusts the flow of high-temperature flue gas, regenerative gas and bypass gas through the fifth regulating three-way valve 107, the sixth regulating three-way valve 110, the seventh regulating three-way valve 111 and the first regulating four-way valve 109 to achieve stable distribution of high-temperature heat.

[0073] This invention also provides an operation control method for a heat pump energy storage and solid oxide battery coupled energy storage system, which includes the following steps for operation control of the above-mentioned energy storage system: S1. Obtain renewable energy output information, user load demand information, hydrogen storage status of hydrogen storage tank 25, and cold storage status of cryogenic cold storage device 8.

[0074] S2. When the output of renewable energy exceeds the user's load demand and the hydrogen storage tank 25 has not reached the hydrogen storage limit, the control system enters the energy storage hydrogen production mode: the surplus electrical energy is allocated to the heat pump energy storage drive unit 1 and the SOEC drive unit. The high-temperature compression heat generated by the heat pump energy storage circuit is supplied to the solid oxide battery 22 for SOEC mode hydrogen production through the multi-stream high-temperature heat exchanger 14. The low-temperature cold energy generated by the heat pump energy storage circuit is stored in the low-temperature cold storage 8. When the high-temperature compression heat is excessive, the high-temperature auxiliary heat storage 7 buffers the heat.

[0075] S2 also includes the following control steps: When the output of renewable energy fluctuates in the short term, the energy management platform 30 prioritizes keeping the temperature and current change rate of the solid oxide battery 22 within the allowable range, and absorbs the fluctuating electrical energy by adjusting the power of the heat pump energy storage drive unit 1. When renewable energy continues to be abundant, gradually increase the SOEC hydrogen production load and increase the hydrogen storage capacity of hydrogen storage tank 25. When the user load experiences a short-term peak, the SOFC power generation unit and the heat pump energy storage power generation unit 4 will be used together to supply power. When the heat absorption demand of SOEC does not match the heat released by the heat pump energy storage circuit, the matching is first achieved by adjusting the flow rate of the working fluid entering the multi-stream high-temperature heat exchanger 14, and the insufficient part is regulated by the high-temperature auxiliary heat accumulator 7.

[0076] S3. When the output of renewable energy is insufficient or the user load demand is high and the hydrogen storage tank 25 has hydrogen storage capacity, the control system enters the energy release power generation mode: the hydrogen storage tank 25 releases hydrogen to power the solid oxide battery 22 in SOFC mode. The SOFC exhaust gas is burned in the afterburner 26 to generate high-temperature flue gas. The high-temperature flue gas is supplied to the heat pump energy storage and energy release circuit through the multi-stream high-temperature heat exchanger 14 to drive the heat pump energy storage and power generation unit 4 to generate electricity. S4, Energy Integrated Management Platform 30: Based on the fluctuations in renewable energy output, grid dispatch instructions, and user load demand, dynamically adjust the allocation of heat pump energy storage power, SOEC hydrogen production power, SOFC power generation power, and heat pump energy release power.

[0077] Specifically, in S1, the energy integrated management platform 30 obtains renewable energy output information, user load demand information, hydrogen storage status of hydrogen storage tanks, and cold storage status of cryogenic cold storage devices.

[0078] In S2, when the output of renewable energy exceeds the user's load demand and the hydrogen storage tank has not reached its hydrogen storage limit, the control system enters the energy storage hydrogen production mode.

[0079] In S3, when renewable energy output is insufficient or user load demand is high and the hydrogen storage tank has hydrogen storage capacity, the control system enters the energy release and power generation mode.

[0080] In S4, the integrated energy management platform 30 dynamically adjusts the allocation of heat pump energy storage power, SOEC hydrogen production power, SOFC power generation power, and heat pump energy release power based on renewable energy output fluctuations, grid dispatch instructions, and user load demands.

[0081] In a preferred embodiment, the energy integrated management platform 30 adopts a hierarchical control method. The upper-level control determines the system target operation mode based on the predicted output of renewable energy, grid dispatch instructions, load forecasts, and hydrogen storage status. The middle-level control determines the power allocation based on the cold and heat storage status of the heat pump energy storage system, the temperature of the solid oxide battery 22, the current density, and the gas utilization rate. The lower-level control achieves specific execution by adjusting the opening of each compressor unit, expander unit, fan, water pump, bidirectional converter, and valve.

[0082] When the renewable energy generation unit 27 experiences short-term fluctuations, the energy management platform 30 prioritizes keeping the temperature and current change rate of the solid oxide battery 22 within the allowable range, and absorbs the fluctuating electrical energy by adjusting the power of the heat pump energy storage drive unit 1; when renewable energy is continuously in surplus, the SOEC hydrogen production load is gradually increased, and the hydrogen storage capacity of the hydrogen storage tank 25 is increased; when the user load unit 29 experiences short-term peaks, the energy management platform 30 prioritizes calling the SOFC power generation unit 20 and the heat pump energy storage power generation unit 4 to jointly supply power; when the peak load lasts for a long time, the energy release power is adjusted according to the hydrogen storage capacity of the hydrogen storage tank 25 and the cold storage status of the low-temperature cold storage device 8 to extend the power supply time.

[0083] When the heat absorption demand of SOEC does not match the heat released by the heat pump energy storage circuit, the matching is first achieved by adjusting the flow rate of the working fluid entering the multi-stream high-temperature heat exchanger 14, and the insufficient part is regulated by the high-temperature auxiliary heat accumulator 7.

[0084] When the system enters the energy storage hydrogen production mode from the shutdown state, the energy integrated management platform 30 first starts the air fan 18, water pump 16 and drive fan 11 to establish the basic flow in the SOEC water circuit, air circuit and heat pump energy storage working fluid circuit. Then, the multi-stream regenerator 17 and multi-stream high-temperature heat exchanger 14 are used to gradually increase the inlet water vapor and air temperature of the solid oxide battery 22. When the solid oxide battery 22 reaches the allowable electrolysis temperature, the energy integrated management platform 30 gradually increases the input current of the SOEC drive unit 20 and simultaneously increases the power of the heat pump energy storage drive unit 1 to match the SOEC electrolysis load and the heat pump energy storage heating load.

[0085] When the system switches from energy storage hydrogen production mode to energy release power generation mode, the energy integrated management platform 30 gradually reduces the input current of SOEC drive unit 20, shuts off or reduces the water supply from water tank 15 to solid oxide battery 22, and maintains air side purging. Subsequently, hydrogen storage tank 25 supplies hydrogen to the anode side of solid oxide battery 22, and solid oxide battery 22 switches from SOEC mode to SOFC mode. After the SOFC output voltage, current and temperature stabilize, the energy integrated management platform 30 starts the combustion chamber 26 to burn SOFC exhaust gas to generate high temperature flue gas, and starts the heat pump energy storage and energy release circuit. The energy release expander unit 5 drives the heat pump energy storage and power generation unit 4 to generate electricity.

[0086] When the system shuts down, the energy management platform 30 first reduces the power of SOEC or SOFC, and then gradually reduces the power of heat pump energy storage or release. It keeps the air fan 18, drive fan 11 and related cooling or purging circuits running for a period of time, so that the temperature of solid oxide battery 22, multi-stream high-temperature heat exchanger 14 and multi-stream regenerator 17 drops slowly, avoiding thermal shock of the fuel cell stack and thermal stress damage to the heat exchanger.

[0087] Through the above specific implementation methods, the present invention can realize the coordinated storage of electrical energy into thermal energy, cold energy and hydrogen energy when renewable energy is abundant, and realize the coordinated release of hydrogen energy and thermal energy into electrical energy when renewable energy is insufficient or during peak load, thereby constructing a heat pump energy storage and solid oxide battery coupling system with high efficiency, high flexibility and long-term energy storage capability.

[0088] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0089] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A heat pump energy storage and solid oxide battery coupled energy storage system, characterized in that, include: The heat pump energy storage circuit includes a drive fan, a working fluid pretreatment device, a heat pump energy storage drive unit, an energy storage compressor unit, an energy storage expander unit, and a low-temperature cold storage unit; The heat pump energy storage and release circuit includes a drive fan, a working fluid pretreatment device, a low-temperature cold storage unit, an energy release compressor unit, an energy release expander unit, and a heat pump energy storage and power generation unit. The solid oxide electrolysis hydrogen production circuit includes a solid oxide battery, a water storage tank, a water pump, a multi-stream reheater, a gas-liquid separator, a hydrogen compressor, and a hydrogen storage tank. The solid oxide fuel cell power generation circuit includes a solid oxide cell, a hydrogen storage tank, a multi-stream reheater, an air fan, an air pretreatment device, an aftercombustion chamber, and an SOFC power generation unit. High-temperature thermal coupling circuit, including multi-stream high-temperature heat exchanger and high-temperature auxiliary heat accumulator; The power interaction circuit includes a renewable energy generation unit, a grid-side interface, a user load unit, an integrated energy management platform, an SOEC drive unit, an SOFC generation unit, and a bidirectional converter; The heat pump energy storage circuit and the heat pump energy release circuit are coupled to the solid oxide battery through a multi-stream high-temperature heat exchanger. The capacity of the high-temperature auxiliary heat accumulator is smaller than the high-temperature heat storage capacity required for the independent operation of the heat pump energy storage system. The solid oxide battery is a reversible high-temperature electrochemical device that can switch between SOEC mode and SOFC mode. The energy storage system has an energy storage working state and an energy release working state. In the energy storage working state, the high-temperature compression heat of the heat pump energy storage circuit is supplied to the solid oxide battery for SOEC mode hydrogen production via a multi-stream high-temperature heat exchanger. In the energy release working state, the waste heat generated by the solid oxide battery in SOFC mode power generation is supplied to the heat pump energy storage energy release circuit via a multi-stream high-temperature heat exchanger.

2. The heat pump energy storage and solid oxide battery coupled energy storage system according to claim 1, characterized in that, During the energy storage phase, the energy storage compressor unit of the heat pump energy storage circuit generates high-temperature compression heat. This high-temperature compression heat is transferred to the solid oxide electrolysis hydrogen production circuit through a multi-stream high-temperature heat exchanger, providing high-temperature heat for the SOEC inlet water vapor and air. The solid oxide battery operates in SOEC mode, using renewable energy electricity and high-temperature heat to electrolyze water to produce hydrogen. The generated hydrogen is stored in a hydrogen storage tank after passing through a gas-liquid separator and a hydrogen compressor. The heat pump energy storage working fluid, after heat exchange by the multi-stream high-temperature heat exchanger, enters the energy storage expander unit for expansion and cooling. The resulting low-temperature working fluid stores cold energy in a low-temperature cold storage unit.

3. The heat pump energy storage and solid oxide battery coupled energy storage system according to claim 1, characterized in that, During the energy release phase, hydrogen is released from the hydrogen storage tank, preheated by a multi-stream regenerator, and then fed into the anode of the solid oxide battery. Air is pretreated and then fed into the cathode of the solid oxide battery. The solid oxide battery operates in SOFC mode, converting the chemical energy of hydrogen into electrical energy output. The tail gas from the SOFC anode and cathode enters the combustion chamber and is burned to produce high-temperature flue gas. The high-temperature flue gas enters the multi-stream high-temperature heat exchanger, which transfers high-grade heat to the working fluid of the heat pump energy storage and energy release circuit. The working fluid of the heat pump energy storage and energy release circuit obtains a low-temperature cold source through a low-temperature cold storage unit, is compressed by the energy release compressor unit, absorbs high-temperature heat through the multi-stream high-temperature heat exchanger, and then enters the energy release expander unit to do work, driving the heat pump energy storage and power generation unit to generate electricity.

4. The heat pump energy storage and solid oxide battery coupled energy storage system according to claim 1, characterized in that, The capacity of the high-temperature auxiliary heat accumulator is less than the high-temperature heat storage capacity required for the independent operation of the heat pump energy storage system. The high-temperature auxiliary heat storage device is used for heat buffering in at least one of the following operating conditions: when the heat absorption demand of SOEC is less than the high-temperature compression heat released by the heat pump energy storage circuit, it stores the excess high-temperature heat; when the heat absorption demand of SOEC is greater than the high-temperature compression heat released by the heat pump energy storage circuit, it releases the stored high-temperature heat for supplementary heating; when the heat release of SOFC does not match the heat absorption demand of the heat pump energy storage circuit, it performs auxiliary heat regulation.

5. The heat pump energy storage and solid oxide battery coupled energy storage system according to claim 1, characterized in that, The integrated energy management platform is electrically connected to the renewable energy power generation unit, the grid-side interface, the user load unit, the heat pump energy storage drive unit, the heat pump energy storage power generation unit, the SOEC drive unit, the SOFC power generation unit, and the bidirectional converter. The integrated energy management platform is used to receive real-time renewable energy output information, grid dispatch information, user load demand information, hydrogen storage status of hydrogen storage tanks, cold storage status of cryogenic cold storage devices, and temperature status of solid oxide batteries, and determines the system operation mode and power allocation based on the above information.

6. The heat pump energy storage and solid oxide battery coupled energy storage system according to claim 1, characterized in that, The circulating gas working medium in the heat pump energy storage circuit and the heat pump energy release circuit is one or more of the following mixed working media: air, nitrogen, argon, helium or carbon dioxide; the low-temperature cold accumulator is a packed bed cold accumulator, which is filled with a solid cold storage medium; the high-temperature auxiliary heat accumulator is a packed bed heat accumulator, a honeycomb ceramic heat accumulator, a solid particle heat accumulator or a phase change heat accumulator.

7. The heat pump energy storage and solid oxide battery coupled energy storage system according to claim 1, characterized in that, The reaction of the solid oxide battery in SOEC mode is as follows: Cathode: H₂O + 2e - = H2+O² - ; Anode: 2O² - =O2+4e - ; The response in SOFC mode is as follows: Cathode: O2 + 4e - =2O² - ; Anode: H2 + O² - =H₂O + 2e - .

8. The heat pump energy storage and solid oxide battery coupled energy storage system according to claim 1, characterized in that, It also includes a valve regulation and control system, which includes multiple regulating valves, each of which is connected to the energy integrated management platform. The valve regulation and control system is used to adjust the flow direction of the heat pump energy storage medium, the direction of SOEC and SOFC reactants and exhaust gas, and the distribution ratio of high-temperature flue gas according to the energy storage condition, energy release condition, SOEC hydrogen production condition, and SOFC power generation condition.

9. A method for operation control of a heat pump energy storage and solid oxide battery coupled energy storage system, wherein the energy storage system of any one of claims 1-8 is operated and controlled, characterized in that, Includes the following steps: S1. Obtain renewable energy output information, user load demand information, hydrogen storage status of hydrogen storage tanks and cold storage status of cryogenic cold storage devices. S2. When the output of renewable energy exceeds the user's load demand and the hydrogen storage tank has not reached the hydrogen storage limit, the control system enters the energy storage hydrogen production mode: the surplus electrical energy is allocated to the heat pump energy storage drive unit and the SOEC drive unit. The high-temperature compression heat generated by the heat pump energy storage circuit is supplied to the solid oxide battery for SOEC mode hydrogen production through the multi-stream high-temperature heat exchanger. The low-temperature cold energy generated by the heat pump energy storage circuit is stored in the low-temperature cold storage device. When the high-temperature compression heat is excessive, the high-temperature auxiliary heat storage device buffers the heat. S3. When the output of renewable energy is insufficient or the user load demand is high and the hydrogen storage tank has hydrogen storage capacity, the control system enters the energy release power generation mode: the hydrogen storage tank releases hydrogen to power the solid oxide battery in SOFC mode. The SOFC exhaust gas is burned in the after-combustion chamber to generate high-temperature flue gas. The high-temperature flue gas is supplied to the heat pump energy storage and energy release circuit through the multi-stream high-temperature heat exchanger, driving the heat pump energy storage and power generation unit to generate electricity in combination. S4. The integrated energy management platform dynamically adjusts the allocation of heat pump energy storage power, SOEC hydrogen production power, SOFC power generation power, and heat pump energy release power based on renewable energy output fluctuations, grid dispatch instructions, and user load demands.

10. The operation and control method of the heat pump energy storage and solid oxide battery coupled energy storage system according to claim 9, characterized in that, S2 also includes the following control steps: When the output of renewable energy fluctuates in the short term, the energy management platform prioritizes keeping the temperature and current change rate of the solid oxide battery within the allowable range, and absorbs the fluctuating electrical energy by adjusting the power of the heat pump energy storage drive unit. When renewable energy continues to be abundant, gradually increase the SOEC hydrogen production load and increase the hydrogen storage capacity of hydrogen storage tanks. When user load experiences short-term peaks, priority is given to using SOFC power generation units and heat pump energy storage power generation units to jointly supply power. When the heat absorption demand of SOEC does not match the heat released by the heat pump energy storage circuit, the matching is first achieved by adjusting the flow rate of the working fluid entering the multi-stream high-temperature heat exchanger, and the insufficient part is regulated by the high-temperature auxiliary heat accumulator.

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