Integrated methane production and co2 solar thermal power generation energy storage and supply system

Abstract

The application discloses an energy storage and supply system integrating methane preparation and carbon dioxide solar heat power generation, which is used for hydrogen production through solar photovoltaic and wind complementary power generation, and is used for reaction of hydrogen and carbon dioxide generated in a biomass fuel manufacturing process to generate methane to realize energy storage; high-temperature solar energy is used as a high-temperature heat source of a supercritical carbon dioxide cycle to realize efficient utilization of solar light heat; the generated methane is used as an auxiliary heat source of the supercritical carbon dioxide cycle to ensure that the supercritical carbon dioxide power generation system can work stably and continuously. The system uses heat released during methane manufacturing as a low-temperature heat source of the supercritical carbon dioxide cycle, improves the power generation efficiency of the carbon dioxide cycle, promotes the methanation reaction to proceed in a positive direction, and improves the methane yield. The system uses renewable energy as an energy source, realizes zero emission of carbon dioxide on the basis of efficient energy storage and supply, and has good environmental protection benefits.

Description

Technical Field

[0001] This invention belongs to the field of energy storage and power supply technology, specifically relating to an energy storage and power supply system that integrates methane production and carbon dioxide solar thermal power generation. Background Technology

[0002] With societal progress and technological advancements, humanity's demand for energy is increasing. Traditional fossil fuels are no longer sufficient to meet this demand, leading to energy crises. The utilization of renewable energy is crucial for the entire world. As research into new energy development continues, technologies for utilizing renewable energy sources such as solar, wind, and geothermal energy have been proposed. Among these, solar energy is the most widely distributed and abundant permanent renewable energy source. Developing efficient solar energy utilization technologies is one of the effective ways to solve humanity's energy problems. Solar photovoltaic power generation and solar thermal power generation are important solar energy utilization technologies and will occupy a vital position in the future development of the energy industry in my country and the world.

[0003] The application of supercritical carbon dioxide Brayton cycle in Generation 4 advanced nuclear reactor systems has been extensively studied. This is because supercritical carbon dioxide has a high density near the critical point, which reduces compression work. Furthermore, power system equipment such as compressors and turbines using supercritical carbon dioxide as the working fluid has a compact structure, reducing equipment costs. The supercritical carbon dioxide cycle achieves high cycle thermal efficiency at its highest temperature of 500–800℃, a temperature achievable with current solar thermal power generation concentrators and solar thermal receivers using existing technology. Moreover, the performance of the supercritical carbon dioxide cycle is significantly higher than that of commercial steam power cycles, making its application in concentrated solar thermal power generation systems a promising prospect.

[0004] However, due to the inherent instability and discontinuity of solar energy, solar concentrators and solar thermal receivers alone cannot continuously power the supercritical carbon dioxide cycle. Under high temperature and high pressure conditions, fluctuations in the operating parameters of carbon dioxide before entering the turbine can cause significant damage to the equipment. Solar energy storage technology can reduce energy waste and improve energy utilization efficiency, but currently, the cost of storing solar energy using heat transfer oil or molten salt is relatively high, and the utilization of stored energy is somewhat limited. Therefore, how to economically and effectively store solar energy and flexibly utilize the stored energy, while ensuring the stable and continuous operation of the supercritical carbon dioxide power generation system, is a prerequisite for the widespread application of this system. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an energy storage and power supply system that integrates methane production and carbon dioxide solar thermal power generation, in order to address the shortcomings of the existing supercritical carbon dioxide cycle for continuous energy supply and the technical problem that carbon dioxide operating parameters cause damage to equipment under high temperature and high pressure conditions.

[0006] The present invention adopts the following technical solution:

[0007] An integrated energy storage and supply system combining methane production and carbon dioxide solar thermal power generation includes:

[0008] The biomass energy production subsystem utilizes the reaction of hydrogen with carbon dioxide produced during the biomass fuel manufacturing process to generate methane.

[0009] The methane production subsystem uses a combination of solar photovoltaic and wind power to generate hydrogen, and hydrogen and carbon dioxide undergo a strongly exothermic reaction in the presence of a catalyst to produce methane.

[0010] The supercritical carbon dioxide cycle subsystem uses high-temperature solar energy as a high-temperature heat source and methane produced by the biomass energy production subsystem and the methane production subsystem as an auxiliary heat source to drive the methanation reaction in the forward direction.

[0011] A concentrating solar thermal collector subsystem is used to heat the carbon dioxide in the supercritical carbon dioxide cycle subsystem.

[0012] Specifically, the biomass energy production subsystem includes a biomass fuel production system, which is connected to a biomass fuel storage tank and a carbon dioxide storage tank. The carbon dioxide storage tank is connected to the methane production unit of the methane production subsystem and the auxiliary compressor of the supercritical carbon dioxide cycle subsystem.

[0013] Specifically, the methane production subsystem includes a wind turbine and solar photovoltaic panels. The wind turbine and solar photovoltaic panels complement each other in generating electricity. The generated electricity is directly supplied to users or connected to the power grid. Excess electricity is sent to an electrolyzer to store the produced oxygen and hydrogen in oxygen and hydrogen storage tanks, respectively. The oxygen storage tank is connected to the auxiliary combustion chamber of the supercritical carbon dioxide cycle subsystem, and the hydrogen storage tank is connected to the methane production unit of the supercritical carbon dioxide cycle subsystem.

[0014] Specifically, the supercritical carbon dioxide cycle subsystem includes an auxiliary combustion chamber. One end of the auxiliary combustion chamber is connected to the oxygen storage tank of the methane production subsystem. The other end passes sequentially through a waste heat recovery device, a carbon dioxide separator, a carbon dioxide storage tank, an auxiliary compressor, an auxiliary cooler, and a compressor before splitting into two paths. One path connects to the low-temperature side inlet of the high-temperature regenerator via the methane production device, and the other path connects to the low-temperature side inlet of the high-temperature regenerator via the low-temperature side of the low-temperature regenerator. The low-temperature side outlet of the high-temperature regenerator splits into two paths via a concentrating solar collector subsystem. One path connects to the turbine, and the other path connects to the turbine via the auxiliary combustion chamber. The turbine is connected to a generator. The turbine connects to the compressor via the high-temperature side of the high-temperature regenerator, the high-temperature side of the low-temperature regenerator, and the cooler.

[0015] Furthermore, the carbon dioxide separator is connected to the electrolyzer of the methane preparation subsystem.

[0016] Furthermore, the concentrating solar thermal collector subsystem includes a solar collector, and several heliostats are installed on one side of the solar collector.

[0017] Furthermore, a first three-way valve is installed on the connecting pipe between the low-temperature side outlet of the high-temperature regenerator and the inlet of the solar collector, and a second three-way valve is installed on the connecting pipe between the outlet of the solar collector and the auxiliary combustion chamber. The first three-way valve and the second three-way valve are connected.

[0018] Furthermore, a third three-way valve is installed at the outlet of the solar collector. One path of the third three-way valve is connected to the turbine via a fourth three-way valve, and the other path is connected to the turbine via a second three-way valve, an auxiliary combustion chamber, and a fourth three-way valve.

[0019] Furthermore, the upper fluid treatment chamber of the carbon dioxide separator is used to adsorb carbon dioxide. A hot fluid is introduced below to exchange heat with the upper fluid and desorb the carbon dioxide. After the carbon dioxide flows out, it is split into two paths through the gas output end of the waste heat recovery device. One path is connected to the input end of the upper fluid treatment chamber of the first carbon dioxide separator and the input end of the lower fluid treatment chamber of the second carbon dioxide separator; the other path is connected to the hot fluid input end of the lower fluid treatment chamber of the first carbon dioxide separator. The lower fluid output end of the first carbon dioxide separator is connected to the input end of the upper fluid treatment chamber of the second carbon dioxide separator.

[0020] Furthermore, a carbon dioxide outlet is provided at the top of the upper fluid treatment chamber of the carbon dioxide separator, a suitable temperature fluid inlet is provided on one side of the upper fluid treatment chamber of the carbon dioxide separator, and a suitable temperature fluid outlet is provided on the other side. A porous adsorption medium baffle on which metal-organic framework compounds are attached is provided inside the upper fluid treatment chamber of the carbon dioxide separator. A heat exchange baffle is provided between the upper fluid treatment chamber and the lower fluid treatment chamber, and a hot fluid inlet is provided on one side of the lower fluid treatment chamber, and a cold fluid outlet is provided on the other side.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] This integrated energy storage and supply system combines methane production with carbon dioxide solar thermal power generation. It utilizes high-temperature solar energy as a high-temperature heat source for the supercritical carbon dioxide cycle to achieve efficient utilization of solar thermal energy. It also uses solar photovoltaic and wind power to generate hydrogen, which reacts with carbon dioxide produced during biomass fuel manufacturing to produce methane for energy storage. The generated methane serves as an auxiliary heat source for the supercritical carbon dioxide cycle, ensuring the stable and continuous operation of the supercritical carbon dioxide power generation system. Using renewable energy as its energy source, it achieves zero carbon dioxide emissions based on efficient energy storage and supply, demonstrating significant environmental benefits.

[0023] Furthermore, when the solar irradiance intensity causes the temperature of the solar collector to be higher than the temperature of the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator, and is sufficient to heat the carbon dioxide to the required turbine inlet temperature, the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator only flows through the solar collector; when the solar irradiance intensity causes the temperature of the solar collector to be higher than the temperature of the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator, but is insufficient to heat the carbon dioxide to the required turbine inlet temperature, the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator first flows through the solar collector, and then flows through the auxiliary combustion chamber to be heated to the required turbine inlet temperature; when the solar irradiance intensity causes the temperature of the solar collector to be lower than or equal to the temperature of the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator, the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator only flows through the auxiliary combustion chamber to be heated to the required turbine inlet temperature, and the solar subsystem stops working.

[0024] Furthermore, using the heat released during methane production as a low-temperature heat source for the supercritical carbon dioxide cycle improves the power generation efficiency of the carbon dioxide cycle and promotes the methanation reaction in the positive direction, thereby increasing methane production.

[0025] Furthermore, the biomass energy production subsystem can generate carbon dioxide while producing renewable biomass fuel, supplementing the supercritical carbon dioxide cycle subsystem with raw materials, promoting the continuous operation of the supercritical carbon dioxide cycle, and improving the efficiency of energy utilization.

[0026] Furthermore, the carbon dioxide flowing out of the reactor's carbon dioxide outlet maintains the same temperature as the carbon dioxide after heat exchange, allowing it to directly merge into the next heat exchanger. The electricity required for water electrolysis is provided by renewable energy generation, reducing carbon emissions. The methane production subsystem utilizes hydrogen produced from water electrolysis to generate water, which, after separation, returns to the water electrolysis unit to form a recycling system. The methane produced by this subsystem can be stored and utilized, or used to provide an auxiliary heat source for the supercritical carbon dioxide recycling subsystem, improving energy utilization efficiency.

[0027] Furthermore, the supercritical carbon dioxide cycle subsystem utilizes high-temperature solar energy as a high-temperature heat source to generate electricity and provide heat for the methanation reaction through a heat exchanger and expander. When solar energy is insufficient to heat carbon dioxide to a suitable temperature, methane produced by the biomass energy preparation subsystem and the methane preparation subsystem can be used as an auxiliary heat source through an auxiliary combustion chamber to propel the methanation reaction in the forward direction.

[0028] Furthermore, in the concentrating solar thermal collector subsystem, the heliostat can change its angle according to the sun's position to reflect as much light as possible onto the collector. The collector can then work with the auxiliary combustion chamber to provide heat to the supercritical carbon dioxide cycle subsystem, depending on the situation.

[0029] Furthermore, the carbon dioxide separation device is equipped with two carbon dioxide absorbers that can adsorb carbon dioxide from the gas stream cooled to a suitable temperature. When the adsorption medium exchanges heat with the lower fluid and rises to a certain temperature, it desorbs. The hot fluid becomes a cold fluid after passing through the lower fluid treatment chamber of one reactor. The cold fluid can then enter the upper part of the other absorber for adsorption, forming a gas and energy recycling structure, which greatly reduces energy consumption and improves adsorption efficiency. In the absorber, metal organic framework (MOF) materials are used to absorb carbon dioxide, and folded baffles are added to establish a highly efficient heat exchange structure.

[0030] In summary, this invention uses renewable energy as its energy source and achieves zero carbon dioxide emissions based on efficient energy storage and supply, thus demonstrating significant environmental benefits.

[0031] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the process flow of the system of the present invention;

[0033] Figure 2 This is a schematic diagram illustrating the working principle of a carbon dioxide separator.

[0034] The components include: 1. Wind turbine; 2. Solar photovoltaic panel; 3. Electrolyzer; 4. Oxygen storage tank; 5. Hydrogen storage tank; 6. Biomass fuel production system; 7. Biomass fuel storage tank; 8. Carbon dioxide storage tank; 9. Methane production unit; 10. Methane separator; 11. Methane storage tank; 12. Auxiliary combustion chamber; 13. Solar collector; 14. Heliostat; 15. Turbine; 16. Generator; 17. High-temperature regenerator; 18. Low-temperature regenerator; 19. Cooler; 20. Compressor; 21. Auxiliary... 21. Compressor; 22. Auxiliary cooler; 23. Waste heat recovery device; 24. Carbon dioxide separator; 25. First three-way valve; 26. Second three-way valve; 27. Third three-way valve; 28. Fourth three-way valve; 29. ​​Methane compressor; 30. Suitable temperature fluid inlet; 31. Porous adsorption medium baffle; 32. Heat exchange baffle; 33. Carbon dioxide outlet; 34. Suitable temperature fluid outlet; 35. Hot fluid inlet; 36. Cold fluid outlet; 37. First carbon dioxide separator; 38. Second carbon dioxide separator. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "one side," "one end," and "one side," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0037] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0039] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0040] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0041] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0042] This invention provides an integrated energy storage and supply system for methane production and carbon dioxide solar thermal power generation. It utilizes a combination of solar photovoltaic and wind power to produce hydrogen, which is then reacted with carbon dioxide generated during biomass fuel production to generate methane for energy storage. High-temperature solar energy serves as the high-temperature heat source for the supercritical carbon dioxide cycle, achieving efficient utilization of solar thermal energy. The generated methane is used as an auxiliary heat source for the supercritical carbon dioxide cycle, ensuring stable and continuous operation of the supercritical carbon dioxide power generation system. The system uses the heat released during methane production as a low-temperature heat source for the supercritical carbon dioxide cycle, improving the power generation efficiency of the carbon dioxide cycle and promoting the methanation reaction in the positive direction, thus increasing methane production. This system uses renewable energy as its energy source, achieving zero carbon dioxide emissions while providing efficient energy storage and supply, resulting in significant environmental benefits.

[0043] Please see Figure 1 The present invention discloses an energy storage and supply system integrating methane production and carbon dioxide solar thermal power generation, comprising a biomass energy production subsystem, a methane production subsystem, a supercritical carbon dioxide cycle subsystem, and a concentrating solar thermal collection subsystem.

[0044] The biomass energy production subsystem uses the reaction of hydrogen with carbon dioxide produced during the biomass fuel manufacturing process to generate methane for energy storage. The generated methane is used as an auxiliary heat source for the supercritical carbon dioxide cycle subsystem to ensure the stable and continuous operation of the supercritical carbon dioxide cycle subsystem.

[0045] The methane production subsystem generates hydrogen by combining solar photovoltaic and wind power. The generated electricity is used by users or fed into the grid. Excess electricity is sent to electrolyzer 3 to electrolyze water to produce oxygen and hydrogen, which are stored in oxygen storage tank 4 and hydrogen storage tank 5, respectively. Hydrogen and carbon dioxide undergo a strongly exothermic reaction under the action of a catalyst to produce methane and water. The generated methane serves as an auxiliary heat source for the supercritical carbon dioxide cycle subsystem, ensuring the stable and continuous operation of the supercritical carbon dioxide cycle subsystem.

[0046] The supercritical carbon dioxide cycle subsystem uses high-temperature solar energy as a high-temperature heat source to achieve efficient utilization of solar thermal energy, improve the power generation efficiency of the carbon dioxide cycle, and promote the methanation reaction in the positive direction to increase methane production.

[0047] The concentrating solar thermal collector subsystem is used to heat the carbon dioxide in the supercritical carbon dioxide cycle subsystem.

[0048] The biomass energy production subsystem includes a biomass fuel production system 6, a biomass fuel storage tank 7, and a carbon dioxide storage tank 8.

[0049] Biomass raw materials are fed into the biomass fuel preparation system 6, where they undergo a series of processing steps to produce biomass fuel and carbon dioxide. After separation, they are stored in the biomass fuel storage tank 7 and the carbon dioxide storage tank 8, respectively.

[0050] The methane production subsystem includes a wind turbine 1, a solar photovoltaic panel 2, an electrolyzer 3, an oxygen storage tank 4, a hydrogen storage tank 5, a methane production device 9, a methane separator 10, a methane compressor 29, and a methane storage tank 11.

[0051] The wind turbine 1 and the solar photovoltaic panel 2 complement each other to generate electricity. The generated electricity is directly supplied to users or connected to the grid, while the excess electricity is sent to the electrolyzer 3 to electrolyze water to produce oxygen and hydrogen, which are stored in the oxygen storage tank 4 and the hydrogen storage tank 5, respectively. The hydrogen in the hydrogen storage tank 5 and the carbon dioxide in the carbon dioxide storage tank 8 are mixed in a certain proportion and then enter the methane preparation device 9. Under the action of a catalyst, a strong exothermic reaction occurs to produce methane and water. After the mixture of methane and water is separated by the methane separator 10, the water is sent to the electrolyzer 3 for recycling, and the methane is compressed by the methane compressor 29 and sent to the methane storage tank 11. A portion of the methane is used as an auxiliary heat source for the supercritical carbon dioxide cycle, and the remainder is used for other purposes.

[0052] The supercritical carbon dioxide cycle subsystem includes an auxiliary combustion chamber 12, a turbine 15, a generator 16, a high-temperature regenerator 17, a low-temperature regenerator 18, a cooler 19, a compressor 20, an auxiliary compressor 21, an auxiliary cooler 22, a waste heat recovery device 23, a carbon dioxide separator 24, a first three-way valve 25, a second three-way valve 26, a third three-way valve 27, and a fourth three-way valve 28.

[0053] Supercritical carbon dioxide near its critical point is compressed by compressor 20 and then split. One part flows into the low-temperature side of the low-temperature regenerator 18, where it exchanges heat with the carbon dioxide flowing out from the high-temperature side of the high-temperature regenerator 17. The other part flows through the methane preparation unit 9, absorbing the heat released during methane preparation. The two streams of carbon dioxide merge before the inlet of the low-temperature side of the high-temperature regenerator 17 and then flow into the low-temperature side of the high-temperature regenerator 17, where they exchange heat with the carbon dioxide flowing out from turbine 15. The first three-way valve 25, the second three-way valve 26, the third three-way valve 27, and the fourth three-way valve 28 are adjusted according to the solar irradiance intensity to allow the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17 to exchange heat. Carbon dioxide can flow only through the solar collector 13, or only through the auxiliary combustion chamber 12, or it can flow through the solar collector 13 first and then through the auxiliary combustion chamber 12. The high-temperature carbon dioxide flowing out of the solar collector 13 or the auxiliary combustion chamber 12 is heated to the required turbine inlet temperature, and then enters the turbine 15 to expand and do work, driving the generator 16 to generate electricity. The carbon dioxide flowing out of the turbine 15 passes sequentially through the high-temperature side of the high-temperature regenerator 17 and the high-temperature side of the low-temperature regenerator 18, transferring heat to the carbon dioxide on the low-temperature side. The carbon dioxide flowing out of the high-temperature side of the low-temperature regenerator 18 enters the cooler 19 and is cooled to a state near the critical point, starting the next cycle.

[0054] When there is a carbon dioxide leak in the supercritical carbon dioxide cycle, part of the carbon dioxide in the carbon dioxide storage tank 8 is compressed by the auxiliary compressor 21 and then cooled by the auxiliary cooler 22. It is then combined with the carbon dioxide flowing out of the cooler 19 before the compressor 20 inlet to replenish the carbon dioxide leaked from the system.

[0055] The concentrating solar thermal collector subsystem is a tower-type solar thermal collector system, including a solar collector 13 and a heliostat 14; the heliostat 14 reflects sunlight into the solar collector 13 to directly heat the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17.

[0056] When the solar irradiance makes the temperature of the solar collector 13 higher than the temperature of the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17, and can heat the carbon dioxide to the required turbine inlet temperature, the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17 only flows through the solar collector 13.

[0057] When the solar irradiance causes the temperature of the solar collector 13 to be higher than the temperature of the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17, but cannot heat the carbon dioxide to the required turbine inlet temperature, the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17 first flows through the solar collector 13, and then flows through the auxiliary combustion chamber 12 to be heated to the required turbine inlet temperature.

[0058] When the solar irradiance causes the temperature of the solar collector 13 to be lower than or equal to the temperature of the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17, the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17 only flows through the auxiliary combustion chamber 12 and is heated to the required turbine inlet temperature, and the solar subsystem stops working.

[0059] When solar irradiance is insufficient, some oxygen from oxygen storage tank 4 and some methane from methane storage tank 11 enter the auxiliary combustion chamber 12 for combustion to heat carbon dioxide. If the oxygen supply is insufficient, air is introduced from the outside. The exhaust gas after combustion is processed by the waste heat recovery device 23 for waste heat recovery. After that, the exhaust gas enters the carbon dioxide separator 24, and the separated carbon dioxide and water enter the carbon dioxide storage tank 8 and the electrolysis cell 3 for recycling, respectively.

[0060] The oxygen storage tank 4, hydrogen storage tank 5, and methane storage tank 11 respectively store sufficient reserves of oxygen, hydrogen, and methane to prevent the system from shutting down when solar and wind power are insufficient at the same time.

[0061] When both solar and wind power are insufficient, electricity can be obtained from the external power grid and input into electrolyzer 3 to produce hydrogen through water electrolysis, in order to prevent the system from stopping.

[0062] The carbon dioxide flowing out from the low-temperature side of the low-temperature regenerator 18 has the same temperature and pressure as the carbon dioxide flowing out from the methane preparation unit 9.

[0063] The carbon dioxide flowing out of the auxiliary cooler 22 has the same temperature and pressure as the carbon dioxide flowing out of the cooler 19.

[0064] The electrical energy generated by generator 16 can be used by users or connected to the grid; it can also be input into electrolyzer 3 for electrolysis of water to produce hydrogen when solar and wind energy are insufficient, in order to prevent the system from stopping.

[0065] Waste heat recovery device 23 includes, but is not limited to, transcritical carbon dioxide cycle, Rankine cycle, lithium bromide absorption chiller, ammonia absorption chiller and jacketed water heat exchanger.

[0066] Please see Figure 2 The upper fluid treatment chamber of the carbon dioxide separator 24 is provided with a carbon dioxide outlet 33 at the top. A suitable temperature fluid inlet 30 is provided on one side of the upper fluid treatment chamber, and a suitable temperature fluid outlet 34 is provided on the other side. A porous adsorption medium baffle 31 for attaching metal-organic framework compounds is provided inside the upper fluid treatment chamber. A heat exchange baffle 32 is provided between the upper fluid treatment chamber and the lower fluid treatment chamber. A hot fluid inlet 35 is provided on one side of the lower fluid treatment chamber, and a cold fluid outlet 36 is provided on the other side.

[0067] The upper fluid treatment chamber adsorbs carbon dioxide, and the lower part introduces hot fluid to exchange heat with the upper part, which can desorb carbon dioxide. The carbon dioxide flows out from the carbon dioxide outlet 33. The gas output end of the waste heat recovery device 23 is divided into two paths. One path is connected to the input end of the upper fluid treatment chamber of the first carbon dioxide separator 37 and the input end of the lower fluid treatment chamber of the second carbon dioxide separator 38. The other path is connected to the hot fluid input end of the lower fluid treatment chamber of the first carbon dioxide separator 37. The lower fluid output end of the first carbon dioxide separator 37 is connected to the input end of the upper fluid treatment chamber of the second carbon dioxide separator 38.

[0068] The specific workflow is as follows:

[0069] Biomass raw materials are fed into the biomass fuel preparation system 6, and after a series of processing steps, biomass fuel and carbon dioxide are generated. After separation, they are stored in the biomass fuel storage tank 7 and the carbon dioxide storage tank 8, respectively.

[0070] At the same time, the wind turbine 1 and the solar photovoltaic panel 2 complement each other to generate electricity. The generated electricity is directly supplied to users or connected to the grid, while the excess electricity is sent to the electrolyzer 3 to electrolyze water to produce oxygen and hydrogen, which are stored in the oxygen storage tank 4 and the hydrogen storage tank 5 respectively.

[0071] Hydrogen in hydrogen storage tank 5 and carbon dioxide in carbon dioxide storage tank 8 are mixed in a certain proportion and then enter methane preparation device 9. Under the action of catalyst, a strong exothermic reaction occurs to produce methane and water. The mixture of methane and water is separated by methane separator 10. The water is transported to electrolyzer 3 for recycling. The methane is compressed by methane compressor 29 and then transported to methane storage tank 11. A portion of the methane is used as an auxiliary heat source for supercritical carbon dioxide cycle, and the remainder is used for other purposes.

[0072] Supercritical carbon dioxide near the critical point is compressed by compressor 20 and then split. One part flows into the low-temperature side of low-temperature regenerator 18 to exchange heat with carbon dioxide flowing out from the high-temperature side of high-temperature regenerator 17. The other part flows through methane preparation device 9 to absorb the heat released during methane preparation, promote the methanation reaction in the forward direction, and increase the methane yield. The two streams of carbon dioxide are heated to the same temperature and merge before the inlet of the low-temperature side of high-temperature regenerator 17. Then they flow into the low-temperature side of high-temperature regenerator 17 to exchange heat with carbon dioxide flowing out from turbine 15.

[0073] When the solar irradiance makes the temperature of the solar collector 13 higher than the temperature of the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17, and can heat the carbon dioxide to the required turbine inlet temperature, the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17 only flows through the solar collector 13 for direct heating.

[0074] When the solar irradiance causes the temperature of the solar collector 13 to be higher than the temperature of the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17, but the carbon dioxide cannot be heated to the required turbine inlet temperature, the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17 first flows through the solar collector 13 for direct heating, and then flows through the auxiliary combustion chamber 12 to be heated to the required turbine inlet temperature.

[0075] When the solar irradiance causes the temperature of the solar collector 13 to be lower than or equal to the temperature of the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17, the carbon dioxide flowing out from the low-temperature side of the high-temperature regenerator 17 only flows through the auxiliary combustion chamber 12 and is heated to the required turbine inlet temperature, and the solar subsystem stops working.

[0076] High-temperature carbon dioxide flowing out of the solar collector 13 or the auxiliary combustion chamber 12 is heated to the required turbine inlet temperature, and then enters the turbine 15 to expand and do work, driving the generator 16 to generate electricity.

[0077] The carbon dioxide flowing out of turbine 15 passes sequentially through the high-temperature side of high-temperature regenerator 17 and the high-temperature side of low-temperature regenerator 18, transferring heat to the carbon dioxide on the low-temperature side.

[0078] The carbon dioxide flowing out from the high-temperature side of the low-temperature regenerator 18 enters the cooler 19 and is cooled to a state near the critical point, and then the next cycle begins.

[0079] When solar irradiance is insufficient, some oxygen from oxygen storage tank 4 and some methane from methane storage tank 11 enter the auxiliary combustion chamber 12 to burn and heat carbon dioxide. If the oxygen supply is insufficient, air is introduced from the outside to ensure complete combustion of methane in the auxiliary combustion chamber 12. The exhaust gas after combustion is processed by the waste heat recovery device 23 for waste heat recovery, and then the exhaust gas enters the carbon dioxide separator 24. The separated carbon dioxide and water are recycled into the carbon dioxide storage tank 8 and the electrolytic cell 3, respectively.

[0080] The exhaust gas entering the carbon dioxide separator 24 is divided into two paths. One path of gas is cooled and enters the upper fluid treatment chamber of the first carbon dioxide separator 37 and the lower fluid treatment chamber of the second carbon dioxide separator 38. The second path of fluid enters the lower fluid treatment chamber of the first carbon dioxide separator 37. The fluid treated in the upper fluid treatment chamber of the first carbon dioxide separator 37 enters the upper fluid treatment chamber of the second carbon dioxide separator 38. Water is output from the upper fluid treatment chambers of the first carbon dioxide separator 37 and the second carbon dioxide separator 38, respectively.

[0081] When there is a carbon dioxide leak in the supercritical carbon dioxide cycle, part of the carbon dioxide in the carbon dioxide storage tank 8 is compressed by the auxiliary compressor 21 and then cooled by the auxiliary cooler 22. It then merges with the carbon dioxide flowing out of the cooler 19 before the compressor 20 inlet to replenish the leaked carbon dioxide in the system.

[0082] In summary, this invention provides an energy storage and supply system integrating methane production and carbon dioxide solar thermal power generation. It utilizes a combination of solar photovoltaic and wind power to generate hydrogen, and then reacts the hydrogen with carbon dioxide produced during biomass fuel production to generate methane for energy storage. High-temperature solar energy serves as the high-temperature heat source for the supercritical carbon dioxide cycle, achieving efficient utilization of solar thermal energy. The generated methane acts as an auxiliary heat source for the supercritical carbon dioxide cycle, ensuring stable and continuous operation of the supercritical carbon dioxide power generation system. Furthermore, the heat released during methane production serves as the low-temperature heat source for the supercritical carbon dioxide cycle, improving the power generation efficiency of the carbon dioxide cycle and promoting the methanation reaction in the positive direction, thus increasing methane production. Using renewable energy as the energy source, it achieves zero carbon dioxide emissions based on efficient energy storage and supply, demonstrating significant environmental benefits.

[0083] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. An integrated energy storage and power supply system for methane production and carbon dioxide solar thermal power generation, characterized in that, include: The biomass energy production subsystem utilizes the reaction of hydrogen with carbon dioxide produced during the biomass fuel manufacturing process to generate methane. The methane production subsystem uses a combination of solar photovoltaic and wind power to generate hydrogen, and hydrogen and carbon dioxide undergo a strongly exothermic reaction in the presence of a catalyst to produce methane. The supercritical carbon dioxide cycle subsystem uses high-temperature solar energy as a high-temperature heat source and methane produced by the biomass energy production subsystem and the methane production subsystem as an auxiliary heat source to drive the methanation reaction in the forward direction. The supercritical carbon dioxide cycle subsystem includes an auxiliary combustion chamber (12). One end of the auxiliary combustion chamber (12) is connected to the oxygen storage tank (4) of the methane production subsystem. The other end passes through the waste heat recovery device (23), carbon dioxide separator (24), carbon dioxide storage tank (8), auxiliary compressor (21), auxiliary cooler (22), and compressor (20) in sequence before splitting into two paths. One path passes through the methane... The preparation device (9) is connected to the low-temperature side inlet of the high-temperature regenerator (17), and another path is connected to the low-temperature side inlet of the high-temperature regenerator (17) via the low-temperature side of the low-temperature regenerator (18). The low-temperature side outlet of the high-temperature regenerator (17) is split into two paths after passing through the concentrating solar thermal collector subsystem. One path is connected to the turbine (15), and the other path is connected to the turbine (15) via the auxiliary combustion chamber (12). The turbine (15) is connected to the generator (16). The turbine (15) is connected to the compressor (20) after passing through the high-temperature side of the high-temperature regenerator (17), the high-temperature side of the low-temperature regenerator (18), and the cooler (19). A concentrating solar thermal collector subsystem is used to heat the carbon dioxide in the supercritical carbon dioxide cycle subsystem.

2. The integrated methane production and carbon dioxide solar thermal power generation energy storage and supply system according to claim 1, characterized in that, The biomass energy production subsystem includes a biomass fuel production system (6), which is connected to a biomass fuel storage tank (7) and a carbon dioxide storage tank (8), respectively. The carbon dioxide storage tank (8) is connected to a methane production device (9) of the methane production subsystem and an auxiliary compressor (21) of the supercritical carbon dioxide cycle subsystem.

3. The integrated methane production and carbon dioxide solar thermal power generation energy storage and supply system according to claim 1, characterized in that, The methane production subsystem includes a wind turbine (1) and a solar photovoltaic panel (2). The wind turbine (1) and the solar photovoltaic panel (2) generate electricity in a complementary manner. The generated electricity is directly supplied to users or connected to the power grid. The excess electricity is transported to the electrolyzer (3). The oxygen and hydrogen produced are stored in the oxygen storage tank (4) and the hydrogen storage tank (5), respectively. The oxygen storage tank (4) is connected to the auxiliary combustion chamber (12) of the supercritical carbon dioxide cycle subsystem, and the hydrogen storage tank (5) is connected to the methane production device (9) of the supercritical carbon dioxide cycle subsystem.

4. The integrated methane production and carbon dioxide solar thermal power generation energy storage and supply system according to claim 1, characterized in that, The carbon dioxide separator (24) is connected to the electrolyzer (3) of the methane preparation subsystem.

5. The integrated methane production and carbon dioxide solar thermal power generation energy storage and supply system according to claim 1, characterized in that, The concentrating solar thermal collector subsystem includes a solar collector (13), and several heliostats (14) are installed on one side of the solar collector (13).

6. The integrated methane production and carbon dioxide solar thermal power generation energy storage and supply system according to claim 5, characterized in that, A first three-way valve (25) is installed on the connecting pipe between the low-temperature side outlet end of the high-temperature regenerator (17) and the inlet end of the solar collector (13), and a second three-way valve (26) is installed on the connecting pipe between the outlet end of the solar collector (13) and the auxiliary combustion chamber (12). The first three-way valve (25) and the second three-way valve (26) are connected.

7. The integrated methane production and carbon dioxide solar thermal power generation energy storage and supply system according to claim 6, characterized in that, A third three-way valve (27) is installed at the outlet of the solar collector (13). One path of the third three-way valve (27) is connected to the turbine (15) via the fourth three-way valve (28), and the other path is connected to the turbine (15) via the second three-way valve (26), the auxiliary combustion chamber (12), and the fourth three-way valve (28).

8. The integrated methane production and carbon dioxide solar thermal power generation energy storage and supply system according to claim 1, characterized in that, The upper fluid treatment chamber of the carbon dioxide separator (24) is used to adsorb carbon dioxide. A hot fluid is introduced below to exchange heat with the upper part and desorb the carbon dioxide. After the carbon dioxide flows out, it is divided into two paths through the gas output end of the waste heat recovery device (23). One path is connected to the input end of the upper fluid treatment chamber of the first carbon dioxide separator and the input end of the lower fluid treatment chamber of the second carbon dioxide separator; the other path is connected to the hot fluid input end of the lower fluid treatment chamber of the first carbon dioxide separator. The lower fluid output end of the first carbon dioxide separator is connected to the input end of the upper fluid treatment chamber of the second carbon dioxide separator.

9. The integrated methane production and carbon dioxide solar thermal power generation energy storage and supply system according to claim 8, characterized in that, A carbon dioxide outlet (33) is provided at the top of the upper fluid treatment chamber of the carbon dioxide separator (24). A suitable temperature fluid inlet (30) is provided on one side of the upper fluid treatment chamber of the carbon dioxide separator (24), and a suitable temperature fluid outlet (34) is provided on the other side. A porous adsorption medium baffle (31) on which metal-organic framework compounds are attached is provided inside the upper fluid treatment chamber of the carbon dioxide separator (24). A heat exchange baffle (32) is provided between the upper fluid treatment chamber and the lower fluid treatment chamber. A hot fluid inlet (35) is provided on one side of the lower fluid treatment chamber, and a cold fluid outlet (36) is provided on the other side.

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