Energy storage system and method for coupling carbon dioxide power generation and high-temperature electrolytic hydrogen production

Abstract

The invention discloses an energy storage system and method for coupling carbon dioxide power generation and high-temperature electrolytic hydrogen production, and relates to the technical field of energy and chemical engineering, and the energy storage system comprises a renewable energy power generation mechanism, a high-temperature electrolytic hydrogen production system, a heat energy storage and recycling system and a carbon dioxide cycle power generation system. According to the invention, the high-temperature electrolytic hydrogen production system is started to store energy when the electric power is in a low ebb, the renewable energy is limited or the electric energy quality does not meet the on-grid requirement; the carbon dioxide cycle power generation system is started to release energy during power consumption peak, power accidents or large fluctuation of renewable energy power generation, the method has good load adjusting capacity, the load can be fully pulled from zero in a short time, and the operation process is clean, low-carbon and high in stability.

Description

Technical Field

[0001] The present invention relates to the field of energy and chemical technology, and in particular to an energy storage system and method for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production. Background Art

[0002] Hydrogen energy is clean, low-carbon and storable, and has great potential for application in absorbing renewable energy power and realizing grid peak regulation. Hydrogen energy storage is an important form of energy storage for building a new power system, and is one of the key technologies for improving renewable energy consumption, reducing wind and solar power abandonment, stabilizing grid output, and realizing the interconnection of grid and gas grid.

[0003] At present, hydrogen energy storage systems use electrolyzers to convert electrical energy into hydrogen and store it in hydrogen storage tanks through compressors. The hydrogen in the hydrogen storage tanks is converted into electricity through fuel cells to power the system. There are currently three main technical routes for hydrogen production by electrolysis of water in the energy storage process, namely alkaline electrolysis, proton exchange membrane electrolysis and solid oxide electrolysis. Among them, solid oxide electrolysis for hydrogen production works at high temperatures, and part of the electrical energy is replaced by thermal energy, which can significantly reduce the cost of hydrogen production. The energy release process is mainly achieved through fuel cells. However, the disadvantages of fuel cells such as high investment cost, poor reliability and durability, short life and low power level limit the large-scale application of hydrogen energy storage systems.

[0004] Carbon dioxide cycle power generation technology is an important transformative technology in the field of thermal power generation. This technology uses the high energy density of carbon dioxide to achieve high-efficiency power generation. It also has significant advantages such as small size of power equipment and system, easy modular assembly, good flexibility, etc. It can increase the load from zero to full in a short time, and has the characteristics of strong flexibility and fast response speed. In particular, carbon dioxide power generation technology based on oxygen-enriched combustion has higher power generation efficiency while reducing carbon emissions.

[0005] By utilizing the strong complementarity between the carbon dioxide power generation system based on oxygen-rich combustion and the high-temperature electrolysis hydrogen production system, a new hydrogen energy storage system with low cost, high overall efficiency and strong applicability is constructed. This is of great significance for increasing the proportion of renewable energy in my country's power system and building a green energy technology innovation system.

[0006] Therefore, there is an urgent need for an energy storage system and method that couples carbon dioxide power generation and high-temperature electrolysis to produce hydrogen. Summary of the invention

[0007] In view of this, the present invention provides an energy storage system and method for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production to solve the problems raised in the above background technology.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] An energy storage system coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production, comprising a renewable energy power generation mechanism, a high-temperature electrolysis hydrogen production system, a thermal energy storage and reuse system, and a carbon dioxide circulation power generation system;

[0010] The high-temperature electrolysis hydrogen production system includes a high-temperature electrolysis unit and a storage unit, and the carbon dioxide circulation power generation system includes a combustion power generation unit and a separation unit; the power generation end of the renewable energy power generation mechanism is connected to the power grid, and the energy storage end of the renewable energy power generation mechanism is connected to the driving end of the high-temperature electrolysis unit; the gas outlet of the high-temperature electrolysis unit, the electrolysis gas heat release path of the thermal energy storage and reuse system, and the gas inlet of the storage unit are connected in sequence; the gas outlet of the storage unit, the combustion gas heat absorption path of the thermal energy storage and reuse system, and the gas inlet of the power generation unit are connected in sequence; the power generation end of the power generation unit is connected to the power grid; the gas outlet of the power generation unit, the mixed gas heat release path of the thermal energy storage and reuse system, and the gas inlet of the separation unit are connected in sequence; the water outlet of the separation unit, the water heat absorption path of the thermal energy storage and reuse system, and the gas inlet of the high-temperature electrolysis unit are connected in sequence; the gas outlet of the separation unit, the carbon dioxide gas heat absorption path of the thermal energy storage and reuse system, and the carbon dioxide gas inlet of the power generation unit are connected in sequence.

[0011] Furthermore, the renewable energy power generation mechanism includes a power generation unit, a substation, a controller and a rectifier unit. The power generation unit energy storage end, the substation, the rectifier unit and the hydrogen production system drive end are connected in sequence. The rectifier unit converts the alternating current emitted by the power generation unit into direct current. The controller is electrically connected to the power generation unit for detecting the power generation power of the power generation unit and controlling the working state of the energy storage end of the power generation unit according to the power generation power.

[0012] Furthermore, the high-temperature electrolytic hydrogen production system includes a high-temperature electrolytic hydrogen production device, which includes a high-temperature electrolytic cell, wherein the high-temperature electrolytic cell is provided with a hydrogen chamber and an oxygen chamber separated by a diaphragm, wherein the hydrogen chamber is provided with a hydrogen catalytic electrode, wherein the oxygen chamber is provided with an oxygen catalytic electrode, wherein the hydrogen catalytic electrode and the oxygen catalytic electrode are both electrically connected to the energy storage end of the renewable energy power generation mechanism, wherein the end of the hydrogen chamber is provided with an electrolytic hydrogen outlet, and the end of the oxygen chamber is provided with an electrolytic oxygen outlet.

[0013] Furthermore, a hydrogen separator is provided at the outlet of the electrolytic hydrogen to separate water vapor in the mixed gas produced by electrolysis to obtain pure hydrogen; an oxygen separator is provided at the outlet of the electrolytic oxygen to separate water vapor in the mixed gas produced by electrolysis to obtain pure oxygen.

[0014] Furthermore, the thermal energy storage and reuse system includes a high-temperature thermal energy storage and reuse device, a medium-temperature thermal energy storage and reuse device, and a low-temperature thermal energy storage and reuse device; the storage unit includes an oxygen storage device, a hydrogen storage device, a first oxygen compressor, and a first hydrogen compressor; the electrolysis oxygen outlet, the high-temperature thermal energy storage and reuse device electrolysis oxygen heat release path, the medium-temperature thermal energy storage and reuse device electrolysis oxygen heat release path, the low-temperature thermal energy storage and reuse device electrolysis oxygen heat release path, the first oxygen compressor, and the oxygen storage device air inlet end are connected in sequence; the electrolysis hydrogen outlet, the high-temperature thermal energy storage and reuse device electrolysis hydrogen heat release path, the medium-temperature thermal energy storage and reuse device electrolysis hydrogen heat release path, the low-temperature thermal energy storage and reuse device electrolysis hydrogen heat release path, the first hydrogen compressor, and the hydrogen storage device air inlet end are connected in sequence.

[0015] Furthermore, the heat storage medium used by the high-temperature thermal energy storage and reuse device is one of molten salt, metal, stone, rock and concrete; the heat storage medium used by the medium-temperature thermal energy storage and reuse device is one of biomass oil, inorganic crystalline hydrated salt, molten salt, metal, organic fatty acid, stone, rock and concrete; the heat storage medium used by the low-temperature thermal energy storage and reuse device is one of water, paraffin, biomass oil, inorganic crystalline hydrated salt, stone, rock and concrete.

[0016] Furthermore, the combustion power generation unit includes a burner, a turbine expander, a second oxygen compressor and a second hydrogen compressor; the oxygen storage device outlet, the second oxygen compressor, the low-temperature thermal energy storage and reuse device combustion oxygen heat absorption path, the medium-temperature thermal energy storage and reuse device combustion oxygen heat absorption path and the burner oxygen inlet are connected in sequence; the hydrogen storage device outlet, the second hydrogen compressor, the low-temperature thermal energy storage and reuse device combustion hydrogen heat absorption path, the medium-temperature thermal energy storage and reuse device combustion hydrogen heat absorption path and the burner hydrogen inlet are connected in sequence; the burner is also provided with a carbon dioxide inlet; the burner outlet is connected to the turbine expander inlet, and the turbine expander power generation end is connected to the power grid through a generator.

[0017] Furthermore, the separation unit includes a water separation device, a water storage device, a water pump and a carbon dioxide compressor; the gas outlet of the turbine expander, the mixed gas heat release passage of the medium-temperature thermal energy storage and reuse device, the mixed gas heat release passage of the low-temperature thermal energy storage and reuse device, and the air inlet of the water separation device are connected in sequence; the gas outlet of the water separation device, the carbon dioxide compressor, the carbon dioxide heat absorption passage of the medium-temperature thermal energy storage and reuse device, and the carbon dioxide air inlet of the burner are connected in sequence; the water outlet of the water separation device, the water storage device, the water pump, the water heat absorption passage of the low-temperature thermal energy storage and reuse device, the water heat absorption passage of the medium-temperature thermal energy storage and reuse device, the water vapor heat absorption passage of the high-temperature thermal energy storage and reuse device, and the air inlet of the high-temperature electrolyzer are connected in sequence.

[0018] Furthermore, a drying and purification device is provided between the air outlet of the water separation device and the carbon dioxide compressor, which is used to remove water droplets carried in the carbon dioxide; an electric heating device is provided between the water vapor endothermic passage of the high-temperature thermal energy storage and recycling device and the air inlet end of the high-temperature electrolyzer, which is used to adjust the temperature of raw water entering the high-temperature electrolyzer, and the electric heating device is electrically connected to the energy storage end of the renewable energy power generation mechanism.

[0019] A method for energy storage for coupling carbon dioxide power generation and high-temperature electrolysis to produce hydrogen is implemented using any of the above-mentioned energy storage systems for coupling carbon dioxide power generation and high-temperature electrolysis to produce hydrogen, and comprises the following steps:

[0020] Energy storage process: The raw water of the water storage device is flow-controlled and pressure-regulated by the water pump and sequentially passes through the water heat absorption path of the low-temperature thermal energy storage and reuse device, the water heat absorption path of the medium-temperature thermal energy storage and reuse device, and the water vapor heat absorption path of the high-temperature thermal energy storage and reuse device to absorb heat and heat up, and then enters the high-temperature electrolyzer after being adjusted to the set temperature by the electric heating device. The energy storage end of the renewable energy power generation mechanism controls the hydrogen catalytic electrode and the oxygen catalytic electrode to work, so that water molecules generate hydrogen in the hydrogen chamber and oxygen in the oxygen chamber. The oxygen is dried and purified by the oxygen separator and sequentially passes through the high-temperature thermal energy storage and reuse device. The heat release path of the oxygen electrolysis of the storage and recycling device, the heat release path of the oxygen electrolysis of the medium-temperature thermal energy storage and recycling device, and the heat release path of the oxygen electrolysis of the low-temperature thermal energy storage and recycling device are used to release heat and cool down. The cooled oxygen is compressed by the first oxygen compressor and stored in the oxygen storage device; the hydrogen is first dried and purified by the hydrogen separator and then sequentially passes through the heat release path of the hydrogen electrolysis of the high-temperature thermal energy storage and recycling device, the heat release path of the hydrogen electrolysis of the medium-temperature thermal energy storage and recycling device, and the heat release path of the hydrogen electrolysis of the low-temperature thermal energy storage and recycling device to release heat and cool down. The cooled hydrogen is compressed by the first hydrogen compressor and stored in the hydrogen storage device;

[0021] Energy release state: the oxygen in the oxygen storage device is compressed by the second oxygen compressor, and then passes through the oxygen combustion heat absorption path of the low-temperature thermal energy storage and reuse device and the oxygen combustion heat absorption path of the medium-temperature thermal energy storage and reuse device in turn for heat absorption and temperature rise; the hydrogen in the hydrogen storage device is compressed by the second hydrogen compressor, and then passes through the hydrogen combustion heat absorption path of the low-temperature thermal energy storage and reuse device and the hydrogen combustion heat absorption path of the medium-temperature thermal energy storage and reuse device in turn for heat absorption and temperature rise; the heated oxygen and hydrogen enter the burner for combustion; the high-temperature gas generated by the combustion is mixed with the carbon dioxide entering from the carbon dioxide inlet end of the burner to form a high-temperature and high-pressure mixed gas mainly composed of carbon dioxide and water vapor, and enters the turbine expander from the gas outlet end of the burner to cooperate with the generator for Power is generated by doing work, and the mixed gas after doing work is discharged from the gas outlet of the turbine expander, and passes through the mixed gas heat release passage of the medium-temperature thermal energy storage and reuse device and the mixed gas heat release passage of the low-temperature thermal energy storage and reuse device in turn to release heat and cool down. The cooled mixed gas enters the water separation device and is separated into raw water and carbon dioxide. The carbon dioxide is first dried and purified by the drying and purification device and then discharged from the gas outlet of the water separation device, compressed by the carbon dioxide compressor, and then absorbed and heated by the carbon dioxide heat absorption passage of the medium-temperature thermal energy storage and reuse device. Then, it enters the burner from the carbon dioxide inlet end of the burner, mixes with the combustion products of oxygen and hydrogen and continues to circulate, and the raw water is discharged from the water outlet of the water separation device into the water storage device for use in energy storage.

[0022] The beneficial effects of the present invention are:

[0023] The present invention enables the high-temperature electrolysis hydrogen production system to store energy during power troughs, renewable energy power cuts, or when the power quality does not meet grid-connected requirements; and enables the carbon dioxide circulation power generation system to release energy during power consumption peaks, power accidents, or large fluctuations in renewable energy power generation. The present invention has excellent load regulation capabilities and can increase the load from zero to full in a short period of time. It can not only solve the problems of wind and solar power abandonment, but also improve the stability of the renewable energy power system. At the same time, the operation process is clean and low-carbon and has the characteristics of high stability, high flexibility, high economy, and is not restricted by energy storage cycles and geographical conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0025] Figure 1The schematic diagram of the structure of an energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production according to the present invention.

[0026] Among them, in the figure:

[0027] 1. Renewable energy power generation mechanism; 2. High-temperature electrolysis hydrogen production device; 3. High-temperature thermal energy storage and reuse device; 4. Medium-temperature thermal energy storage and reuse device; 5. Low-temperature thermal energy storage and reuse device; 6. First oxygen compressor; 7. First hydrogen compressor; 8. Oxygen storage device; 9. Hydrogen storage device; 10. Second oxygen compressor; 11. Second hydrogen compressor; 12. Burner; 13. Turbine expander; 14. Generator; 15. Water separation device; 16. Carbon dioxide compressor; 17. Water storage device; 18. Water pump; 19. Electric heating device. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0031] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0032] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0033] See attached Figure 1 , the present invention discloses an energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production, including a renewable energy power generation mechanism 1, a high-temperature electrolysis hydrogen production system, a thermal energy storage and reuse system, and a carbon dioxide cycle power generation system;

[0034] The high-temperature electrolysis hydrogen production system includes a high-temperature electrolysis unit and a storage unit, and the carbon dioxide circulation power generation system includes a combustion power generation unit and a separation unit; the power generation end of the renewable energy power generation mechanism 1 is connected to the power grid, and the energy storage end of the renewable energy power generation mechanism 1 is connected to the driving end of the high-temperature electrolysis unit; the gas outlet of the high-temperature electrolysis unit, the electrolysis gas heat release path of the thermal energy storage and reuse system, and the gas inlet of the storage unit are connected in sequence; the gas outlet of the storage unit, the combustion gas heat absorption path of the thermal energy storage and reuse system, and the gas inlet of the power generation unit are connected in sequence; the power generation end of the power generation unit is connected to the power grid; the gas outlet of the power generation unit, the mixed gas heat release path of the thermal energy storage and reuse system, and the gas inlet of the separation unit are connected in sequence; the water outlet of the separation unit, the water heat absorption path of the thermal energy storage and reuse system, and the gas inlet of the high-temperature electrolysis unit are connected in sequence; the gas outlet of the separation unit, the carbon dioxide gas heat absorption path of the thermal energy storage and reuse system, and the carbon dioxide gas inlet of the power generation unit are connected in sequence.

[0035] The renewable energy power generation mechanism 1 includes a power generation unit, a transformer substation, a controller and a rectifier unit. The power generation unit energy storage end, the transformer substation, the rectifier unit and the hydrogen production system drive end are connected in sequence. The rectifier unit converts the alternating current generated by the power generation unit into direct current. The controller is electrically connected to the power generation unit for detecting the power generation of the power generation unit and controlling the working state of the energy storage end of the power generation unit according to the power generation.

[0036] In this embodiment, the rectifying unit is a unidirectional rectifier.

[0037] The high-temperature electrolytic hydrogen production system includes a high-temperature electrolytic hydrogen production device 2, which includes a high-temperature electrolytic cell. In this embodiment, the high-temperature electrolytic cell is a solid oxide electrolytic cell; a hydrogen chamber and an oxygen chamber separated by a diaphragm are provided in the high-temperature electrolytic cell, a hydrogen catalytic electrode is provided in the hydrogen chamber, and an oxygen catalytic electrode is provided in the oxygen chamber. The hydrogen catalytic electrode and the oxygen catalytic electrode are both electrically connected to the energy storage end of the renewable energy power generation mechanism 1, an electrolytic hydrogen outlet is provided at the end of the hydrogen chamber, and an electrolytic oxygen outlet is provided at the end of the oxygen chamber.

[0038] In this embodiment, the preferred operating temperature of the high temperature electrolytic cell is 700-850°C.

[0039] A hydrogen separator is provided at the outlet of the electrolytic hydrogen to separate water vapor from the mixed gas produced by electrolysis to obtain pure hydrogen; an oxygen separator is provided at the outlet of the electrolytic oxygen to separate water vapor from the mixed gas produced by electrolysis to obtain pure oxygen.

[0040] The thermal energy storage and reuse system includes a high-temperature thermal energy storage and reuse device 3, a medium-temperature thermal energy storage and reuse device 4 and a low-temperature thermal energy storage and reuse device 5; the storage unit includes an oxygen storage device 8, a hydrogen storage device 9, a first oxygen compressor 6 and a first hydrogen compressor 7; the electrolytic oxygen outlet, the electrolytic oxygen heat release path of the high-temperature thermal energy storage and reuse device 3, the electrolytic oxygen heat release path of the medium-temperature thermal energy storage and reuse device 4, the electrolytic oxygen heat release path of the low-temperature thermal energy storage and reuse device 5, the first oxygen compressor 6 and the air inlet end of the oxygen storage device 8 are connected in sequence; the electrolytic hydrogen outlet, the electrolytic hydrogen heat release path of the high-temperature thermal energy storage and reuse device 3, the electrolytic hydrogen heat release path of the medium-temperature thermal energy storage and reuse device 4, the electrolytic hydrogen heat release path of the low-temperature thermal energy storage and reuse device 5, the first hydrogen compressor 7 and the air inlet end of the hydrogen storage device 9 are connected in sequence.

[0041] In this embodiment, the hydrogen storage device 9 and the oxygen storage device 8 are both heat-insulating storage tanks, and each includes one storage tank or a combination of multiple storage tanks connected in parallel.

[0042] The heat storage medium used by the high-temperature thermal energy storage and reuse device 3 is one of molten salt, metal, stone, rock and concrete; the heat storage medium used by the medium-temperature thermal energy storage and reuse device 4 is one of biomass oil, inorganic crystalline hydrated salt, molten salt, metal, organic fatty acid, stone, rock and concrete; the heat storage medium used by the low-temperature thermal energy storage and reuse device 5 is one of water, paraffin, biomass oil, inorganic crystalline hydrated salt, stone, rock and concrete.

[0043] The combustion power generation unit includes a burner 12, a turbine expander 13, a second oxygen compressor 10 and a second hydrogen compressor 11; the outlet end of the oxygen storage device 8, the second oxygen compressor 10, the low-temperature thermal energy storage and reuse device 5 combustion oxygen heat absorption path, the medium-temperature thermal energy storage and reuse device 4 combustion oxygen heat absorption path and the oxygen inlet end of the burner 12 are connected in sequence; the outlet end of the hydrogen storage device 9, the second hydrogen compressor 11, the low-temperature thermal energy storage and reuse device 5 combustion hydrogen heat absorption path, the medium-temperature thermal energy storage and reuse device 4 combustion hydrogen heat absorption path and the hydrogen inlet end of the burner 12 are connected in sequence; the burner 12 is also provided with a carbon dioxide inlet end; the outlet end of the burner 12 is connected to the inlet end of the turbine expander 13, and the power generation end of the turbine expander 13 is connected to the power grid through the generator 14.

[0044] The separation unit includes a water separation device 15, a water storage device 17, a water pump 18 and a carbon dioxide compressor 16; the gas outlet of the turbine expander 13, the mixed gas heat release passage of the medium-temperature thermal energy storage and reuse device 4, the mixed gas heat release passage of the low-temperature thermal energy storage and reuse device 5, and the air inlet of the water separation device 15 are connected in sequence; the gas outlet of the water separation device 15, the carbon dioxide compressor 16, the carbon dioxide heat absorption passage of the medium-temperature thermal energy storage and reuse device 4 and the carbon dioxide air inlet of the burner 12 are connected in sequence; the water outlet of the water separation device 15, the water storage device 17, the water pump 18, the water heat absorption passage of the low-temperature thermal energy storage and reuse device 5, the water heat absorption passage of the medium-temperature thermal energy storage and reuse device 4, the water vapor heat absorption passage of the high-temperature thermal energy storage and reuse device 3 and the air inlet of the high-temperature electrolyzer are connected in sequence.

[0045] In this embodiment, the turbine expander 13 adopts one of the piston type, axial flow type, centrifugal type, screw type and mixed type, and the pressure range is not less than 300 bar. The temperature range of the inlet end of the turbine expander 13 is 500-1200°C, the temperature range of the outlet end of the turbine expander 13 is preferably 500-600°C, the gas outlet temperature of the carbon dioxide compressor 16 is preferably in the range of 100-130°C, and the gas outlet pressure of the carbon dioxide compressor 16 is preferably in the range of 250-350 bar.

[0046] In this embodiment, the first oxygen compressor 6, the first hydrogen compressor 77, the second oxygen compressor 10 and the second hydrogen compressor 11 can all adopt one of piston type, axial flow type, centrifugal type, screw type and mixed type, and their pressure range is not less than 300 bar.

[0047] A drying and purification device is provided between the air outlet of the water separation device 15 and the carbon dioxide compressor 16, which is used to remove water droplets carried in the carbon dioxide; an electric heating device 19 is provided between the water vapor heat absorption passage of the high-temperature thermal energy storage and recycling device 3 and the air inlet end of the high-temperature electrolytic cell, which is used to adjust the temperature of the raw water entering the high-temperature electrolytic cell, and the electric heating device 19 is electrically connected to the energy storage end of the renewable energy power generation mechanism 1.

[0048] A method for energy storage by coupling carbon dioxide power generation and high-temperature electrolysis to produce hydrogen, comprising the following steps:

[0049] Energy storage process: The raw water of the water storage device 17 is flow-controlled and pressure-regulated by the water pump 18, and then passes through the water heat absorption path of the low-temperature thermal energy storage and reuse device 5, the water heat absorption path of the medium-temperature thermal energy storage and reuse device 4, and the water vapor heat absorption path of the high-temperature thermal energy storage and reuse device 3 to absorb heat and heat up. After being adjusted to the set temperature by the electric heating device 19, it enters the high-temperature electrolyzer. The energy storage end of the renewable energy power generation mechanism 1 controls the hydrogen catalytic electrode and the oxygen catalytic electrode to work, so that water molecules generate hydrogen in the hydrogen chamber and oxygen in the oxygen chamber. The oxygen is dried and purified by the oxygen separator and then passes through the high-temperature thermal energy storage and reuse in sequence. The heat release path of electrolytic oxygen in device 3, the heat release path of electrolytic oxygen in medium-temperature thermal energy storage and reuse device 4, and the heat release path of electrolytic oxygen in low-temperature thermal energy storage and reuse device 5 release heat and cool down. The cooled oxygen is compressed by the first oxygen compressor 6 and stored in the oxygen storage device 8; the hydrogen is first dried and purified by the hydrogen separator, and then passes through the heat release path of electrolytic hydrogen in high-temperature thermal energy storage and reuse device 3, the heat release path of electrolytic hydrogen in medium-temperature thermal energy storage and reuse device 4, and the heat release path of electrolytic hydrogen in low-temperature thermal energy storage and reuse device 5 to release heat and cool down. The cooled hydrogen is compressed by the first hydrogen compressor 7 and stored in the hydrogen storage device 9;

[0050] Energy release state: the oxygen in the oxygen storage device 8 is compressed by the second oxygen compressor 10, and then passes through the low-temperature thermal energy storage and reuse device 5 combustion oxygen heat absorption path and the medium-temperature thermal energy storage and reuse device 4 combustion oxygen heat absorption path in turn to absorb heat and heat up. The hydrogen in the hydrogen storage device 9 is compressed by the second hydrogen compressor 11, and then passes through the low-temperature thermal energy storage and reuse device 5 combustion hydrogen heat absorption path and the medium-temperature thermal energy storage and reuse device 4 combustion hydrogen heat absorption path in turn to absorb heat and heat up. The heated oxygen and hydrogen enter the burner 12 for combustion. The high-temperature gas generated by the combustion is mixed with the carbon dioxide entering from the carbon dioxide inlet end of the burner 12 to form a high-temperature and high-pressure mixed gas mainly composed of carbon dioxide and water vapor, and enters the turbine expander 13 from the gas outlet end of the burner 12 to cooperate with the generator 14 for combustion. Power is generated by doing work, and the mixed gas after doing work is discharged from the gas outlet of the turbine expander 13, and passes through the mixed gas heat release passage of the medium-temperature thermal energy storage and reuse device 4 and the mixed gas heat release passage of the low-temperature thermal energy storage and reuse device 5 in turn to release heat and cool down. The cooled mixed gas enters the water separation device 15 and is separated into raw water and carbon dioxide. The carbon dioxide is first dried and purified by the drying and purification device and then discharged from the gas outlet of the water separation device 15, compressed by the carbon dioxide compressor 16, and then absorbed and heated by the carbon dioxide heat absorption passage of the medium-temperature thermal energy storage and reuse device 4, and then enters the burner 12 from the carbon dioxide inlet end of the burner 12, mixed with the combustion products of oxygen and hydrogen and then continue to circulate, and the raw water is discharged from the water outlet of the water separation device 15 into the water storage device 17 for use in energy storage.

[0051] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production, characterized in that: It includes a renewable energy power generation mechanism (1), a high-temperature electrolysis hydrogen production system, a thermal energy storage and reuse system, and a carbon dioxide circulation power generation system; The high-temperature electrolysis hydrogen production system comprises a high-temperature electrolysis unit and a storage unit, and the carbon dioxide circulation power generation system comprises a combustion power generation unit and a separation unit; the power generation end of the renewable energy power generation mechanism (1) is connected to the power grid, and the energy storage end of the renewable energy power generation mechanism (1) is connected to the driving end of the high-temperature electrolysis unit; the gas outlet of the high-temperature electrolysis unit, the electrolysis gas heat release path of the thermal energy storage and reuse system, and the gas inlet of the storage unit are connected in sequence; the gas outlet of the storage unit, the combustion gas heat absorption path of the thermal energy storage and reuse system, and the gas inlet of the power generation unit are connected in sequence; the power generation end of the power generation unit is connected to the power grid; the gas outlet of the power generation unit, the mixed gas heat release path of the thermal energy storage and reuse system, and the gas inlet of the separation unit are connected in sequence; the water outlet of the separation unit, the water heat absorption path of the thermal energy storage and reuse system, and the gas inlet of the high-temperature electrolysis unit are connected in sequence; the gas outlet of the separation unit, the carbon dioxide gas heat absorption path of the thermal energy storage and reuse system, and the carbon dioxide gas inlet of the power generation unit are connected in sequence.

2. The energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production according to claim 1, characterized in that: The renewable energy power generation mechanism (1) comprises a power generation unit, a transformer substation, a controller and a rectifier unit. The power generation unit energy storage end, the transformer substation, the rectifier unit and the hydrogen production system drive end are connected in sequence. The rectifier unit converts the alternating current generated by the power generation unit into direct current. The controller is electrically connected to the power generation unit and is used to detect the power generation of the power generation unit and control the working state of the power storage end of the power generation unit according to the power generation.

3. The energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production according to claim 1, characterized in that: The high-temperature electrolytic hydrogen production system comprises a high-temperature electrolytic hydrogen production device (2), wherein the high-temperature electrolytic hydrogen production device (2) comprises a high-temperature electrolyzer, wherein a hydrogen chamber and an oxygen chamber separated by a diaphragm are provided in the high-temperature electrolyzer, wherein a hydrogen catalytic electrode is provided in the hydrogen chamber, wherein an oxygen catalytic electrode is provided in the oxygen chamber, wherein the hydrogen catalytic electrode and the oxygen catalytic electrode are both electrically connected to the energy storage end of the renewable energy power generation mechanism (1), wherein an electrolytic hydrogen outlet is provided at the end of the hydrogen chamber, and wherein an electrolytic oxygen outlet is provided at the end of the oxygen chamber.

4. The energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production according to claim 3 is characterized in that: A hydrogen separator is provided at the outlet of the electrolytic hydrogen to separate water vapor from the mixed gas produced by electrolysis to obtain pure hydrogen; an oxygen separator is provided at the outlet of the electrolytic oxygen to separate water vapor from the mixed gas produced by electrolysis to obtain pure oxygen.

5. The energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production according to claim 3, characterized in that: The thermal energy storage and reuse system comprises a high-temperature thermal energy storage and reuse device (3), a medium-temperature thermal energy storage and reuse device (4) and a low-temperature thermal energy storage and reuse device (5); the storage unit comprises an oxygen storage device (8), a hydrogen storage device (9), a first oxygen compressor (6) and a first hydrogen compressor (7); the electrolytic oxygen outlet, the electrolytic oxygen heat release path of the high-temperature thermal energy storage and reuse device (3), the electrolytic oxygen heat release path of the medium-temperature thermal energy storage and reuse device (4), the electrolytic oxygen heat release path of the low-temperature thermal energy storage and reuse device (5), the first oxygen compressor (6) and the air inlet of the oxygen storage device (8) are connected in sequence; the electrolytic hydrogen outlet, the electrolytic hydrogen heat release path of the high-temperature thermal energy storage and reuse device (3), the electrolytic hydrogen heat release path of the medium-temperature thermal energy storage and reuse device (4), the electrolytic hydrogen heat release path of the low-temperature thermal energy storage and reuse device (5), the first hydrogen compressor (7) and the air inlet of the hydrogen storage device (9) are connected in sequence.

6. The energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production according to claim 5, characterized in that: The heat storage medium used by the high-temperature thermal energy storage and reuse device (3) is one of molten salt, metal, stone, rock and concrete; the heat storage medium used by the medium-temperature thermal energy storage and reuse device (4) is one of biomass oil, inorganic crystalline hydrated salt, molten salt, metal, organic fatty acid, stone, rock and concrete; the heat storage medium used by the low-temperature thermal energy storage and reuse device (5) is one of water, paraffin, biomass oil, inorganic crystalline hydrated salt, stone, rock and concrete.

7. The energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production according to claim 5, characterized in that: The combustion power generation unit comprises a burner (12), a turbine expander (13), a second oxygen compressor (10) and a second hydrogen compressor (11); the outlet of the oxygen storage device (8), the second oxygen compressor (10), the combustion oxygen heat absorption path of the low-temperature thermal energy storage and reuse device (5), the combustion oxygen heat absorption path of the medium-temperature thermal energy storage and reuse device (4) and the oxygen inlet of the burner (12) are connected in sequence; the outlet of the hydrogen storage device (9), the second hydrogen compressor (11), the combustion hydrogen heat absorption path of the low-temperature thermal energy storage and reuse device (5), the combustion hydrogen heat absorption path of the medium-temperature thermal energy storage and reuse device (4) and the hydrogen inlet of the burner (12) are connected in sequence; the burner (12) is also provided with a carbon dioxide inlet; the outlet of the burner (12) is connected to the inlet of the turbine expander (13), and the power generation end of the turbine expander (13) is connected to the power grid via a generator (14).

8. The energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production according to claim 7, characterized in that: The separation unit comprises a water separation device (15), a water storage device (17), a water pump (18) and a carbon dioxide compressor (16); the gas outlet of the turbine expander (13), the mixed gas heat release passage of the medium-temperature thermal energy storage and reuse device (4), the mixed gas heat release passage of the low-temperature thermal energy storage and reuse device (5), and the gas inlet of the water separation device (15) are connected in sequence; the gas outlet of the water separation device (15), the carbon dioxide compressor (16), the carbon dioxide heat absorption passage of the medium-temperature thermal energy storage and reuse device (4), and the carbon dioxide gas inlet of the burner (12) are connected in sequence; the water outlet of the water separation device (15), the water storage device (17), the water pump (18), the water heat absorption passage of the low-temperature thermal energy storage and reuse device (5), the water heat absorption passage of the medium-temperature thermal energy storage and reuse device (4), the water vapor heat absorption passage of the high-temperature thermal energy storage and reuse device (3), and the gas inlet of the high-temperature electrolyzer are connected in sequence.

9. The energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production according to claim 8, characterized in that: A drying and purification device is provided between the air outlet of the water separation device (15) and the carbon dioxide compressor (16) for removing water droplets carried in the carbon dioxide; an electric heating device (19) is provided between the water vapor heat absorption passage of the high-temperature thermal energy storage and recycling device (3) and the air inlet of the high-temperature electrolytic cell for adjusting the temperature of the raw water entering the high-temperature electrolytic cell, and the electric heating device (19) is electrically connected to the energy storage end of the renewable energy power generation mechanism (1).

10. An energy storage method for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production, characterized in that: The method is implemented by using an energy storage system for coupling carbon dioxide power generation and high-temperature electrolysis hydrogen production according to any one of claims 1 to 9, comprising the following steps: Energy storage process: The raw water of the water storage device (17) is flow-controlled and pressure-regulated by the water pump (18), and then passes through the water heat absorption path of the low-temperature thermal energy storage and reuse device (5), the water heat absorption path of the medium-temperature thermal energy storage and reuse device (4), and the water vapor heat absorption path of the high-temperature thermal energy storage and reuse device (3) to absorb heat and heat up. The raw water is adjusted to a set temperature by the electric heating device (19) and then enters the high-temperature electrolyzer. The energy storage end of the renewable energy power generation mechanism (1) controls the operation of the hydrogen catalytic electrode and the oxygen catalytic electrode, so that water molecules generate hydrogen in the hydrogen chamber and oxygen in the oxygen chamber. The oxygen is dried and purified by the oxygen separator and then passes through the high-temperature thermal energy storage and reuse device (5) and the high-temperature thermal energy storage and reuse device (4) in sequence. The heat release path of the electrolytic oxygen of the device (3), the heat release path of the electrolytic oxygen of the medium-temperature thermal energy storage and reuse device (4), and the heat release path of the electrolytic oxygen of the low-temperature thermal energy storage and reuse device (5) are used to release heat and cool down. The cooled oxygen is compressed by the first oxygen compressor (6) and then stored in the oxygen storage device (8); the hydrogen is first dried and purified by the hydrogen separator and then sequentially passes through the heat release path of the electrolytic hydrogen of the high-temperature thermal energy storage and reuse device (3), the heat release path of the electrolytic hydrogen of the medium-temperature thermal energy storage and reuse device (4), and the heat release path of the electrolytic hydrogen of the low-temperature thermal energy storage and reuse device (5) to release heat and cool down. The cooled hydrogen is compressed by the first hydrogen compressor (7) and then stored in the hydrogen storage device (9); Energy release state: the oxygen in the oxygen storage device (8) is compressed by the second oxygen compressor (10), and then passes through the oxygen combustion heat absorption path of the low-temperature thermal energy storage and reuse device (5) and the oxygen combustion heat absorption path of the medium-temperature thermal energy storage and reuse device (4) to absorb heat and heat up; the hydrogen in the hydrogen storage device (9) is compressed by the second hydrogen compressor (11), and then passes through the hydrogen combustion heat absorption path of the low-temperature thermal energy storage and reuse device (5) and the hydrogen combustion heat absorption path of the medium-temperature thermal energy storage and reuse device (4) to absorb heat and heat up; the heated oxygen and hydrogen enter the burner (12) for combustion; the high-temperature gas generated by the combustion is mixed with the carbon dioxide entering from the carbon dioxide inlet end of the burner (12) to form a high-temperature and high-pressure mixed gas mainly composed of carbon dioxide and water vapor, and enters the turbine expander (13) from the outlet end of the burner (12) to cooperate with the generator (14) The mixed gas after work is discharged from the outlet of the turbine expander (13), and passes through the mixed gas heat release passage of the medium-temperature thermal energy storage and reuse device (4) and the mixed gas heat release passage of the low-temperature thermal energy storage and reuse device (5) in turn to release heat and cool down. The cooled mixed gas enters the water separation device (15) and is separated into raw water and carbon dioxide. The carbon dioxide is first dried and purified by the drying and purification device and then discharged from the outlet of the water separation device (15), compressed by the carbon dioxide compressor (16), and then absorbed and heated by the carbon dioxide heat absorption passage of the medium-temperature thermal energy storage and reuse device (4). It then enters the burner (12) from the carbon dioxide inlet end of the burner (12), is mixed with the combustion products of oxygen and hydrogen, and continues to circulate. The raw water is discharged from the water outlet of the water separation device (15) into the water storage device (17) for use in energy storage.

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