Deep aquifer multi-source gas storage and fuel supply system and method

Abstract

The invention discloses a deep aquifer multi-source gas storage and fuel supply system and method. According to the system, a composite gas storage unit comprises an underground gas storage and a first injection-production well pattern; the renewable energy power generation field is mounted on the ground; the CAES power station comprises an underground gas storage space, a compressor, a combustion chamber and a turbine; the outlet end of the compressor is connected with the upper end of the compressed air injection well; the engine is coaxially connected with the compressor; a first inlet end of the combustion chamber is connected with the upper end of the compressed air injection well, and a second inlet end is connected with a second air outlet of the mixing device through a second passage; an air inlet of the turbine is connected with the outlet end of the combustion chamber; and the generator is coaxially connected with the turbine. The method comprises the steps that when wind and light are rich, power generation operation is conducted through the renewable energy power generation field, hydrogen and methane are extracted, and pre-storage of compressed air is synchronously achieved; and the methane hydrogen-doped mixture and compressed air are combusted in a combustion chamber, and a generator is driven to generate electricity. According to the invention, the power generation power and efficiency can be obviously improved, and the carbon emission can be reduced.

Description

Technical Field

[0001] This invention belongs to the field of integrated energy development and utilization technology, specifically a multi-source gas storage and fuel supply system and method for deep aquifers. Background Technology

[0002] With the global energy structure transitioning towards low-carbon and clean energy, hydrogen energy, as an ideal secondary energy carrier, has seen its large-scale storage and efficient utilization technologies become a research hotspot. Constructing gas storage facilities using deep underground aquifers is an effective solution for achieving large-scale seasonal hydrogen storage, offering advantages such as large capacity and relatively low cost. However, aquifer hydrogen storage technology faces two major challenges in practical operation: First, during the gas extraction phase, as gas is continuously extracted, the reservoir pressure continuously decreases, leading to a reduced extraction rate and even insufficient wellhead pressure. This results in a large amount of "cushion gas" remaining in the reservoir, not only reducing the gas recovery rate but also causing significant economic losses. Second, constructing a separate long-distance pipeline network for hydrogen transportation requires huge infrastructure investment and is economically inefficient. Blending hydrogen with existing natural gas (mainly methane) pipelines in a certain proportion for transportation is widely recognized as an economically feasible approach. However, existing technologies lack effective methods for the coordinated extraction, precise mixing, and integrated transportation of native methane and artificially injected hydrogen in aquifers, and especially lack key processes for maintaining reservoir pressure balance and precisely controlling the hydrogen doping ratio during extraction.

[0003] On the other hand, compressed air energy storage (CAES), as a representative of large-scale physical energy storage technology, plays an important role in smoothing renewable energy fluctuations and improving grid stability. During the energy release and power generation process in a CAES system, fuel needs to be burned to heat high-pressure air to improve power generation efficiency and prevent turbine icing. Currently, this process mainly relies on fossil fuels such as natural gas or diesel, which not only leads to carbon emissions but also makes the operating costs of power plants significantly affected by fluctuations in fossil fuel prices, thus restricting its clean development and economic benefits.

[0004] Looking at existing technologies, the development of these two fields exhibits a clear disconnect. On the one hand, research on aquifer gas storage focuses primarily on the storage and extraction of the gas itself, failing to deeply integrate it with downstream efficient and clean energy conversion scenarios (such as low-carbon power generation). On the other hand, CAES (Clean Energy Storage and Energy Conversion) power plants have long been constrained by high-carbon fuels, urgently requiring the search for stable, low-carbon, and flexible alternative fuel sources. Deep aquifer gas storage possesses the potential to provide clean fuels for CAES power plants, but how to organically integrate the two to construct a unified system capable of dynamically adjusting fuel composition (from pure methane to high-proportion hydrogen and even pure hydrogen) according to grid demand, achieving energy spatiotemporal shifting and synergistic optimization, has become an unresolved challenge in the current technological field. Therefore, there is an urgent need to provide an innovative, systematic approach that deeply integrates multi-source aquifer gas storage with compressed air energy storage technology, constructing a complete chain from underground energy storage to clean power generation, thereby comprehensively improving the overall energy efficiency, economic viability, and environmental benefits of the system. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a multi-source gas storage and fuel supply system and method for deep aquifers. This system has a reasonable structure, diverse functions, and low carbon emissions. It can significantly improve power generation and efficiency, and enhance economic benefits. It solves the problem that existing multi-source gas storage and compressed air energy storage technologies in aquifers do not work in synergy, enabling peak shaving and valley filling of renewable energy and cross-seasonal storage. The method is simple to implement and has low implementation costs. By synergistically controlling multi-source gas extraction, mixed supply, and CAES power generation, it can significantly improve power generation and efficiency while substantially reducing carbon emissions.

[0006] To achieve the above objectives, the present invention provides a multi-source gas storage and fuel supply system for deep aquifers, including a power grid, a composite gas storage unit, a renewable energy power plant, a CAES power station, and a control terminal; The composite gas storage unit includes an underground gas storage facility, an injection-production well network, a hydrogen storage facility, a carbon dioxide storage facility, and a mixing device. The injection-production well network includes hydrogen injection wells, carbon dioxide injection wells, hydrogen production wells, and methane production wells. These wells are spaced apart within the area of ​​the underground gas storage facility. The lower ends of the hydrogen injection and production wells extend into the top space of the underground gas storage facility, while the lower ends of the carbon dioxide injection wells extend into the bottom space. The methane production wells... The lower end of the well extends into the middle section of the underground gas storage facility; the hydrogen storage facility, carbon dioxide storage facility, and mixing device are installed on the ground; the exhaust port of the hydrogen storage facility is connected to the upper end of the hydrogen injection well via a hydrogen exhaust pump, the exhaust port of the carbon dioxide storage facility is connected to the upper end of the carbon dioxide injection well via a carbon dioxide pump, the first inlet of the mixing device is connected to the upper end of the hydrogen production well via a hydrogen inlet pump, and its second inlet is connected to the upper end of the methane production well via a methane inlet pump; the first outlet of the mixing device is connected to a first passage. The renewable energy power plant is installed on the ground and is connected to a hydrogen exhaust pump, a carbon dioxide pump, a hydrogen intake pump, and a methane intake pump, respectively. The CAES power plant includes an underground gas storage space, a second injection-production well network, a compressor, an engine, a combustion chamber, a turbine, and a generator. The second injection-production well network includes compressed air injection wells and compressed air production wells. The compressed air injection wells and compressed air production wells are alternately located in the area where the underground gas storage space is situated, and their lower ends extend into the middle section of the underground gas storage space. The compressor, engine, combustion chamber, turbine, and generator are installed on the ground. The outlet end of the compressor is connected to the upper end of the compressed air injection well. The engine is coaxially connected to the compressor and connected to the renewable energy power plant. The first inlet end of the combustion chamber is connected to the upper end of the compressed air production well via an air exhaust pump, and its second inlet end is connected to the second outlet of the mixing device via a second passage. The inlet of the turbine is connected to the outlet end of the combustion chamber. The generator is coaxially connected to the turbine. The control terminal is connected to the renewable energy power plant, the composite gas storage unit, the CAES power station, and the power grid, respectively.

[0007] As a preferred embodiment, a solenoid valve is connected in series at the upper end of the compressed air extraction well, and the solenoid valve is connected to a control terminal.

[0008] As a preferred embodiment, the underground gas storage facility is located in an aquifer; the underground gas storage space is an underground salt cavern, a pit, or an abandoned mine shaft.

[0009] As a preferred option, it also includes a water electrolysis hydrogen production device, which is connected to both the renewable energy power plant and the control terminal.

[0010] As a preferred option, the renewable energy power plant is a wind and solar power plant.

[0011] In this invention, hydrogen injection wells, carbon dioxide injection wells, hydrogen production wells, and methane production wells are respectively constructed in the area where the underground gas storage facility is located. The hydrogen injection wells are connected to the surface hydrogen storage facility, the carbon dioxide injection wells are connected to the surface carbon dioxide storage facility, and the hydrogen and methane production wells are simultaneously connected to a mixing device. This allows for the convenient injection of hydrogen from the hydrogen storage facility into the underground gas storage facility using the hydrogen injection wells. The hydrogen and methane production wells can be used to simultaneously collect hydrogen and methane and supply them to the mixing device. Furthermore, the mixing device can be used to mix hydrogen and methane according to a preset ratio, thereby forming a methane-hydrogen blend to provide green energy for efficient combustion power generation. Simultaneously, it facilitates the injection of carbon dioxide into the underground gas storage facility using carbon dioxide injection wells. This not only allows the carbon dioxide to serve as a base layer at the bottom of the underground gas storage facility, ensuring that hydrogen and methane do not leak out through the bottom, but also effectively balances the pressure within the underground gas storage facility during hydrogen and methane extraction. Connecting the two outlets of the mixing unit to the first and second passages respectively allows for the delivery of two different mixing ratios of methane-hydrogen blends to the user side and the combustion power generation side, respectively. Connecting the hydrogen exhaust pump, carbon dioxide pump, hydrogen intake pump, and methane intake pump to a renewable energy power plant facilitates the use of green energy to provide power for the gas injection and extraction operations of the underground gas storage facility. In a CAES power plant, compressed air injection wells and compressed air extraction wells located in the underground gas storage area are connected to the above-ground compressor and combustion chamber, respectively. This allows for easy access to electricity from a renewable energy power plant to power the compressor's engine during the gas storage phase. The compressor then compresses and delivers outside air into the underground storage space, raising its pressure to a predetermined range. Simultaneously, during the power generation phase, when a methane-hydrogen blend is supplied to the combustion chamber via a second channel, an air exhaust pump automatically pumps compressed air into the combustion chamber. This allows the oxygen in the compressed air to enhance combustion efficiency during the combustion of the methane-hydrogen blend, resulting in higher temperatures and pressures. These higher temperatures and pressures then efficiently drive the turbine to power the generator for extended periods of efficient power generation. A control terminal is connected to the renewable energy power plant, the integrated gas storage unit, the CAES power plant, and the power grid. This control terminal enables coordinated operation between the renewable energy power plant and the CAES power plant, facilitating more efficient power supplementation to the grid through mutual cooperation. At the same time, it can also facilitate intelligent and precise adjustment of gas extraction and power generation based on the operating status of renewable energy power plants and CAES power plants, so as to ensure power generation efficiency and duration and maximize benefits.

[0012] The system has a reasonable structure, diverse functions, and low carbon emissions. It can significantly improve power generation and efficiency, and enhance economic benefits. It can solve the problem that existing aquifer multi-source gas storage and compressed air energy storage technologies have not yet worked in synergy, and can achieve peak shaving and valley filling of renewable energy and cross-seasonal storage.

[0013] This invention also provides a method for multi-source gas storage and fuel supply in deep aquifers, employing a multi-source gas storage and fuel supply system for deep aquifers, comprising the following steps: Step 1: When wind and solar power are abundant, electricity is generated through a renewable energy power plant to supply power to the carbon dioxide pump, hydrogen intake pump, methane intake pump, and engine. The carbon dioxide pump is started and injected into the bottom space of the underground gas storage through the carbon dioxide injection well. At the same time, the hydrogen and methane intake pumps are started and extracted through the hydrogen and methane production wells, respectively, and supplied to the mixing device. By controlling the injection and extraction rates, the amount of carbon dioxide injected at any given time is lower than the sum of the amount of hydrogen and methane extracted. By utilizing the reduced pressure environment, the methane in the reservoir is desorbed from the adsorbed state into free gas. At the same time, the engine (8) is started and driven to compress air, and the compressed air is delivered to the underground gas storage space through the compressed air injection well for storage, so that the pressure of the underground gas storage space rises to the set pressure range; Step 2: Using a mixing device, hydrogen and methane are mixed in proportion to form a hydrogen-methane mixture. The hydrogen-methane mixture with a hydrogen content of 5%-30% is output through the first passage, and the hydrogen-methane mixture with a hydrogen content of 0%-100% is output to the combustion chamber through the second passage. Step 3: When the output of the renewable energy power plant is insufficient, the control solenoid valve is opened and the control air exhaust pump is started. The air exhaust pump is used to input compressed air into the combustion chamber through the compressed air extraction well, so that the compressed air and the methane-hydrogen mixture are mixed and burned in the combustion chamber. At the same time, the high temperature and high pressure generated by the combustion drive the turbine to expand and do work, and synchronously drive the generator to generate electricity. The generated electricity is fed into the grid through the control terminal.

[0014] To achieve coordinated control and maximize benefits, in step two, the control terminal monitors the operating status of the renewable energy power plant and the CAES power station in real time. When the output fluctuation of the renewable energy power plant exceeds a set threshold, the power of the hydrogen and methane inlet pumps is increased to improve the extraction rate of hydrogen and methane. At the same time, the mixing device is controlled to increase the hydrogen volume ratio of the methane-hydrogen blend in the second outlet to improve combustion power generation efficiency and power generation duration. When the output of the renewable energy power plant is stable, the power of the hydrogen and methane inlet pumps is reduced to decrease the extraction rate of hydrogen and methane. At the same time, the mixing device is controlled to reduce the hydrogen volume ratio of the methane-hydrogen blend in the second outlet to reduce combustion power generation efficiency and power generation duration, thereby balancing the fluctuations of the renewable energy power plant.

[0015] In order to maximize the utilization of resources, in step two, when the renewable energy power plant has excess electricity, the control terminal supplies part of the electricity to the water electrolysis hydrogen production unit for hydrogen production, and at the same time, the hydrogen is transported to the hydrogen storage tank through the pipeline.

[0016] As a preferred option, in step two, the first passage is delivered to the user side via a long delivery pipeline.

[0017] As a preferred embodiment, in step one, when the hydrogen content in the underground gas storage is lower than the set lower threshold, the renewable energy power plant generates electricity and supplies power to the hydrogen exhaust pump. At the same time, the hydrogen exhaust pump is controlled to start working and input hydrogen into the underground gas storage through the hydrogen injection well until the hydrogen content reaches the set upper threshold and then stops.

[0018] This invention provides a method for multi-source gas storage and fuel supply in deep aquifers coupled with compressed air energy storage. When renewable energy is abundant, it prioritizes the use of renewable energy for power generation, with surplus electricity used as a power source for injection and extraction operations in underground gas storage facilities, ensuring the reliable operation of these facilities. Simultaneously, surplus electricity can also power an engine, driving a compressor to compress outside air and deliver it to the underground gas storage space. When renewable energy output is insufficient, compressed air and a hydrogen-blended methane mixture can be simultaneously mixed and combusted in the combustion chamber, efficiently driving a generator for power generation. This effectively balances the fluctuating operating conditions of renewable energy. This invention uses a methane-hydrogen blend formed by mixing methane and hydrogen in shale reservoirs as fuel. By dynamically supplying different proportions of fuel gas through a control terminal, it achieves a synergistic increase in production and efficiency of renewable energy power plants, CAES power plants, and blending devices. It realizes the effective coupling of deep aquifer multi-source gas storage and compressed air energy storage (CAES) power generation systems, enabling coordinated gas extraction, blending supply, and supplementary combustion efficiency of the energy storage system. This achieves true "wind, solar, storage, and hydrogen" integration, solving the problem that existing aquifer multi-source gas storage and compressed air energy storage technologies have not yet worked synergistically. This results in improved power generation and efficiency, reduced carbon emissions, and the realization of peak shaving and valley filling, as well as cross-seasonal energy storage.

[0019] Compared with the prior art, the present invention has the following advantages: 1. Achieving true integration of wind, solar, storage and hydrogen: seamlessly linking the three links of renewable energy hydrogen production, large-scale underground hydrogen storage and energy storage power generation, forming a complete zero-carbon energy ecosystem.

[0020] 2. Significantly enhances the flexibility and performance of CAES power plants: By supplying high-hydrogen / pure hydrogen fuel, CAES power plants possess rapid start-up and ramp-up capabilities similar to gas turbines, becoming an excellent flexible regulation resource for the power grid.

[0021] 3. Significantly reduced carbon emissions: Replacing fossil fuels with green hydrogen can significantly reduce or even eliminate carbon emissions during the power generation process of CAES power plants, contributing to the decarbonization of the power system.

[0022] 4. Increased economic benefits: Based on real-time electricity prices, the gas supplier can flexibly choose to sell gas to the pipeline network or use it for power generation and sales, maximizing revenue. Simultaneously, it provides a stable and low-cost clean fuel source for CAES power plants.

[0023] 5. Enhanced energy security: Utilizing underground aquifers to achieve large-scale, seasonal storage of hydrogen and methane provides a new technological path for national energy strategic reserves.

[0024] This method is simple to implement and has low implementation costs. By coordinating the extraction of multiple gas sources, mixed supply and CAES power generation, it can significantly improve power generation and efficiency, and greatly reduce carbon emissions. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the system portion of the present invention; Figure 2 This is a schematic diagram of the CAES power station structure in this invention; Figure 3 This is a schematic diagram of carbon dioxide injection and methane and hydrogen extraction in the method of the present invention; Figure 4 This is a schematic diagram of the CAES power plant generating electricity in the method of this invention; Figure 5 This is a schematic diagram of power grid dispatching in the method of the present invention.

[0026] In the diagram: 1. Power grid, 2. Control terminal, 3. Renewable energy power plant, 4. Hydrogen storage, 5. Carbon dioxide storage, 6. Mixing device, 7. First passage, 8. Electric motor, 9. Compressor, 10. Second passage, 11. Generator, 12. Turbine, 13. Combustion chamber, 14. Underground gas storage, 15. Carbon dioxide injection well, 16. Hydrogen injection well, 17. Hydrogen production well, 18. Methane production well, 19. Compressed air injection well, 20. Underground space, 21. Compressed air production well. Detailed Implementation

[0027] The invention will now be further described with reference to the accompanying drawings.

[0028] like Figures 1 to 5 As shown, the present invention provides a multi-source gas storage and fuel supply system for deep aquifers, including a power grid 1, a composite gas storage unit, a renewable energy power plant 3, a CAES power station and a control terminal 2; The composite gas storage unit includes an underground gas storage tank 14, an injection-production well network, a hydrogen storage tank 4, a carbon dioxide storage tank 5, and a mixing device 6. The injection-production well network includes a hydrogen injection well 16, a carbon dioxide injection well 15, a hydrogen production well 17, and a methane production well 18. The hydrogen injection well 16, carbon dioxide injection well 15, hydrogen production well 17, and methane production well 18 are spaced apart in the area where the underground gas storage tank 4 is located. The lower ends of the hydrogen injection well 16 and the hydrogen production well 17 extend into the top space inside the underground gas storage tank 4, and the lower end of the carbon dioxide injection well 15 extends into the bottom space inside the underground gas storage tank 4. The lower end of the methane production well 18 extends into the middle section of the underground gas storage 4; the hydrogen storage 4, the carbon dioxide storage 5, and the mixing device 6 are installed on the ground; the exhaust port of the hydrogen storage 4 is connected to the upper end of the hydrogen injection well 16 via a hydrogen exhaust pump, the exhaust port of the carbon dioxide storage 5 is connected to the upper end of the carbon dioxide injection well 15 via a carbon dioxide pump, the first inlet of the mixing device 6 is connected to the upper end of the hydrogen production well 17 via a hydrogen inlet pump, and its second inlet is connected to the upper end of the methane production well 18 via a methane inlet pump; the first outlet of the mixing device 6 is connected to a first passage 7. The renewable energy power plant 3 is installed on the ground and is connected to a hydrogen exhaust pump, a carbon dioxide pump, a hydrogen intake pump and a methane intake pump, respectively, for supplying electricity based on renewable energy. The CAES power plant includes an underground gas storage space 20, a second injection-production well network, a compressor 9, an engine 8, a combustion chamber 13, a turbine 12, and a generator 11. The second injection-production well network includes a compressed air injection well 19 and a compressed air production well 21. The compressed air injection well 19 and the compressed air production well 21 are alternately located in the area where the underground gas storage space 20 is situated, and their lower ends extend into the middle section of the underground gas storage space 20. The compressor 9, engine 8, combustion chamber 13, turbine 12, and generator 11 are installed on the ground. The outlet end of the compressor 9 is connected to the upper end of the compressed air injection well 19. The engine 8 is coaxially connected to the compressor 9 and connected to the renewable energy power plant 3. The first inlet end of the combustion chamber 13 is connected to the upper end of the compressed air production well 21 via an air exhaust pump, and its second inlet end is connected to the second outlet of the mixing device 6 via a second passage 10. The inlet of the turbine 12 is connected to the outlet end of the combustion chamber 13. The generator 11 is coaxially connected to the turbine 12. The control terminal 2 is connected to the renewable energy power plant 3, the composite gas storage unit, the CAES power station and the power grid 1 respectively.

[0029] As an alternative, combustion chamber 13 can accommodate a wide range of fuels from pure methane to pure hydrogen and is equipped with a nitrogen oxide (NOx) reduction system, such as lean premixed combustion technology or selective catalytic reduction (SCR) system, to control the high-temperature nitrogen oxides that may be generated during hydrogen combustion.

[0030] As a preferred embodiment, a solenoid valve is connected in series at the upper end of the compressed air extraction well 21, and the solenoid valve is connected to the control terminal 2.

[0031] As a preferred embodiment, the underground gas storage facility 14 is located in an aquifer.

[0032] As a preferred embodiment, the underground gas storage space 20 is an underground salt cavern, a pit, or an abandoned mine.

[0033] As a preferred embodiment, it also includes a water electrolysis hydrogen production device, which is connected to the renewable energy power plant 3 and the control terminal 2 respectively.

[0034] As a preferred option, the renewable energy power plant 3 is a wind and solar power plant.

[0035] In this invention, hydrogen injection wells, carbon dioxide injection wells, hydrogen production wells, and methane production wells are respectively constructed in the area where the underground gas storage facility is located. The hydrogen injection wells are connected to the surface hydrogen storage facility, the carbon dioxide injection wells are connected to the surface carbon dioxide storage facility, and the hydrogen and methane production wells are simultaneously connected to a mixing device. This allows for the convenient injection of hydrogen from the hydrogen storage facility into the underground gas storage facility using the hydrogen injection wells. The hydrogen and methane production wells can be used to simultaneously collect hydrogen and methane and supply them to the mixing device. Furthermore, the mixing device can be used to mix hydrogen and methane according to a preset ratio, thereby forming a methane-hydrogen blend to provide green energy for efficient combustion power generation. Simultaneously, it facilitates the injection of carbon dioxide into the underground gas storage facility using carbon dioxide injection wells. This not only allows the carbon dioxide to serve as a base layer at the bottom of the underground gas storage facility, ensuring that hydrogen and methane do not leak out through the bottom, but also effectively balances the pressure within the underground gas storage facility during hydrogen and methane extraction. Connecting the two outlets of the mixing unit to the first and second passages respectively allows for the delivery of two different mixing ratios of methane-hydrogen blends to the user side and the combustion power generation side, respectively. Connecting the hydrogen exhaust pump, carbon dioxide pump, hydrogen intake pump, and methane intake pump to a renewable energy power plant facilitates the use of green energy to provide power for the gas injection and extraction operations of the underground gas storage facility. In a CAES power plant, compressed air injection wells and compressed air extraction wells located in the underground gas storage area are connected to the above-ground compressor and combustion chamber, respectively. This allows for easy access to electricity from a renewable energy power plant to power the compressor's engine during the gas storage phase. The compressor then compresses and delivers outside air into the underground storage space, raising its pressure to a predetermined range. Simultaneously, during the power generation phase, when a methane-hydrogen blend is supplied to the combustion chamber via a second channel, an air exhaust pump automatically pumps compressed air into the combustion chamber. This allows the oxygen in the compressed air to enhance combustion efficiency during the combustion of the methane-hydrogen blend, resulting in higher temperatures and pressures. These higher temperatures and pressures then efficiently drive the turbine to power the generator for extended periods of efficient power generation. A control terminal is connected to the renewable energy power plant, the integrated gas storage unit, the CAES power plant, and the power grid. This control terminal enables coordinated operation between the renewable energy power plant and the CAES power plant, facilitating more efficient power supplementation to the grid through mutual cooperation. At the same time, it can also facilitate intelligent and precise adjustment of gas extraction and power generation based on the operating status of renewable energy power plants and CAES power plants, so as to ensure power generation efficiency and duration and maximize benefits.

[0036] The system has a reasonable structure, diverse functions, and low carbon emissions. It can significantly improve power generation and efficiency, and enhance economic benefits. It can solve the problem that existing aquifer multi-source gas storage and compressed air energy storage technologies have not yet worked in synergy, and can achieve peak shaving and valley filling of renewable energy and cross-seasonal storage.

[0037] This invention also provides a method for multi-source gas storage and fuel supply in deep aquifers, employing a multi-source gas storage and fuel supply system for deep aquifers, comprising the following steps: Step 1: Gas storage facility operation and pressure maintenance: such as Figure 3 As shown, when wind and solar power are abundant, the renewable energy power plant 3 generates electricity and supplies power to the carbon dioxide pump, hydrogen intake pump, methane intake pump, and engine 8. The carbon dioxide pump is started and injected into the bottom space of the underground gas storage 14 through the carbon dioxide injection well 15. At the same time, the hydrogen intake pump and methane intake pump are started and extracted through the hydrogen extraction well 17 and methane extraction well 18, respectively, and supplied to the mixing device 6. Preferably, hydrogen and methane are extracted simultaneously while carbon dioxide is injected, so that the carbon dioxide can be used to balance the pressure in the underground gas storage. By controlling the injection and production rates, the amount of carbon dioxide injected at any given time is lower than the sum of the amount of hydrogen produced and the amount of methane produced. Preferably, the sum of the difference between the amount of carbon dioxide injected and the set value is equal to the sum of the amount of hydrogen produced and the amount of methane produced. By utilizing the reduced pressure environment, the methane in the reservoir is desorbed from the adsorbed state into free gas. At the same time, the engine 8 is started and driven to compress air by the compressor 9, and the compressed air is delivered to the underground gas storage space 20 through the compressed air injection well 19 for storage, so that the pressure of the underground gas storage space 20 rises to the set pressure range. Step Two: Customized Fuel Gas Mixing: such as Figure 4 As shown, the mixing device 6 mixes hydrogen and methane in proportion to form a methane-hydrogen blend. The methane-hydrogen blend with a hydrogen content of 5%-30% is output through the first passage 7, and the methane-hydrogen blend with a hydrogen content of 0%-100% is output through the second passage 10 to the combustion chamber 13. In this way, the proportion of hydrogen can be dynamically adjusted according to the power generation demand to meet the power generation demand under different operating conditions. Step 3: CAES system coupled power generation: such as Figure 4As shown, when the output of the renewable energy power plant 3 is insufficient, the control solenoid valve is opened and the control air exhaust pump is started. The air exhaust pump is used to input compressed air through the compressed air extraction well 21 into the combustion chamber 13, so that the compressed air and the methane-hydrogen mixture are mixed and burned in the combustion chamber 13. At the same time, the high temperature and high pressure generated by the combustion drive the turbine 12 to expand and do work, and synchronously drive the generator 11 to generate electricity. The generated electricity is connected to the power grid 1 through the control terminal 2.

[0038] To achieve coordinated control and maximize benefits, such as Figure 5 As shown, in step two, control terminal 2 monitors the operating status of renewable energy power plant 3 and CAES power plant in real time. When the output fluctuation of renewable energy power plant 3 exceeds the set amplitude threshold, the power of hydrogen inlet pump and methane inlet pump is increased to improve the extraction rate of hydrogen and methane. At the same time, the mixing device 6 is controlled to increase the hydrogen volume ratio of the methane-hydrogen mixture in the second outlet to improve combustion power generation efficiency and power generation duration. In addition, when grid 1 needs to quickly adjust peak loads or respond to frequency fluctuations exceeding the predetermined fluctuation amplitude threshold, the power of hydrogen inlet pump and methane inlet pump is increased to improve the extraction rate of hydrogen and methane. At the same time, the mixing device 6 is controlled to increase the hydrogen volume ratio of the methane-hydrogen mixture in the second outlet to improve combustion power generation efficiency and power generation duration. Because hydrogen has a fast combustion speed and a high flame propagation rate, the turbines in the CAES power plant can achieve faster power increases and a wider load regulation range.

[0039] When the output of renewable energy power plant 3 is stable, the power of the hydrogen and methane inlet pumps is reduced to decrease the extraction rate of hydrogen and methane. Simultaneously, the mixing device 6 is controlled to reduce the hydrogen volume ratio of the methane-hydrogen blend in the second outlet, thereby reducing combustion power generation efficiency and power generation duration, thus balancing the fluctuations in renewable energy power plant 3. Furthermore, when the CAES power plant is generating electricity at base load or for extended periods, the hydrogen volume ratio in the methane-hydrogen blend can be controlled between 0% and 30% to balance power generation efficiency, economy, and equipment compatibility.

[0040] In order to maximize the utilization of resources, in step two, when the renewable energy power plant 3 has excess electricity, the control terminal 2 supplies part of the electricity to the water electrolysis hydrogen production device for hydrogen production, and at the same time, the hydrogen is transported to the hydrogen storage tank 4 through the pipeline.

[0041] As a preferred embodiment, in step two, the first passage 7 is delivered to the user side via a long delivery pipeline.

[0042] As a preferred embodiment, in step one, when the hydrogen content in the underground gas storage 14 is lower than the set lower threshold, the renewable energy power plant 3 generates electricity and supplies power to the hydrogen exhaust pump. At the same time, the hydrogen exhaust pump is controlled to start working and input hydrogen into the underground gas storage 14 through the hydrogen injection well 16 until the hydrogen content reaches the set upper threshold and then stops.

[0043] This invention provides a method for multi-source gas storage and fuel supply in deep aquifers coupled with compressed air energy storage. When renewable energy is abundant, it prioritizes the use of renewable energy for power generation, with surplus electricity used as a power source for injection and extraction operations in underground gas storage facilities, ensuring the reliable operation of these facilities. Simultaneously, surplus electricity can also power an engine, driving a compressor to compress outside air and deliver it to the underground gas storage space. When renewable energy output is insufficient, compressed air and a hydrogen-blended methane mixture can be simultaneously mixed and combusted in the combustion chamber, efficiently driving a generator for power generation. This effectively balances the fluctuating operating conditions of renewable energy. This invention uses a methane-hydrogen blend formed by mixing methane and hydrogen in shale reservoirs as fuel. By dynamically supplying different proportions of fuel gas through a control terminal, it achieves a synergistic increase in production and efficiency of renewable energy power plants, CAES power plants, and blending devices. It realizes the effective coupling of deep aquifer multi-source gas storage and compressed air energy storage (CAES) power generation systems, enabling coordinated gas extraction, blending supply, and supplementary combustion efficiency of the energy storage system. This achieves true "wind, solar, storage, and hydrogen" integration, solving the problem that existing aquifer multi-source gas storage and compressed air energy storage technologies have not yet worked synergistically. This results in improved power generation and efficiency, reduced carbon emissions, and the realization of peak shaving and valley filling, as well as cross-seasonal energy storage.

[0044] Compared with the prior art, the present invention has the following advantages: 1. Achieving true integration of wind, solar, storage and hydrogen: seamlessly linking the three links of renewable energy hydrogen production, large-scale underground hydrogen storage and energy storage power generation, forming a complete zero-carbon energy ecosystem.

[0045] 2. Significantly enhances the flexibility and performance of CAES power plants: By supplying high-hydrogen / pure hydrogen fuel, CAES power plants possess rapid start-up and ramp-up capabilities similar to gas turbines, becoming an excellent flexible regulation resource for the power grid.

[0046] 3. Significantly reduced carbon emissions: Replacing fossil fuels with green hydrogen can significantly reduce or even eliminate carbon emissions during the power generation process of CAES power plants, contributing to the decarbonization of the power system.

[0047] 4. Increased economic benefits: Based on real-time electricity prices, the gas supplier can flexibly choose to sell gas to the pipeline network or use it for power generation and sales, maximizing revenue. Simultaneously, it provides a stable and low-cost clean fuel source for CAES power plants.

[0048] 5. Enhanced energy security: Utilizing underground aquifers to achieve large-scale, seasonal storage of hydrogen and methane provides a new technological path for national energy strategic reserves.

[0049] This method is simple to implement and has low implementation costs. By coordinating the extraction of multiple gas sources, mixed supply and CAES power generation, it can significantly improve power generation and efficiency, and greatly reduce carbon emissions.

Claims

1. A multi-source gas storage and fuel supply system for deep aquifers, comprising a power grid (1) and a composite gas storage unit, characterized in that, It also includes renewable energy power plants (3), CAES power plants and control terminals (2); The composite gas storage unit includes an underground gas storage tank (14), an injection-production well network, a hydrogen storage tank (4), a carbon dioxide storage tank (5), and a mixing device (6); the injection-production well network includes a hydrogen injection well (16), a carbon dioxide injection well (15), a hydrogen production well (17), and a methane production well (18); the hydrogen injection well (16), carbon dioxide injection well (15), hydrogen production well (17), and methane production well (18) are spaced apart in the area where the underground gas storage tank (4) is located, and the lower ends of the hydrogen injection well (16) and the hydrogen production well (17) extend into the top space inside the underground gas storage tank (4), and the lower end of the carbon dioxide injection well (15) extends into the bottom space inside the underground gas storage tank (4). In the space, the lower end of the methane production well (18) extends into the middle section of the underground gas storage tank (4); the hydrogen storage tank (4), the carbon dioxide storage tank (5), and the mixing device (6) are installed on the ground; the exhaust port of the hydrogen storage tank (4) is connected to the upper end of the hydrogen injection well (16) through a hydrogen exhaust pump, the exhaust port of the carbon dioxide storage tank (5) is connected to the upper end of the carbon dioxide injection well (15) through a carbon dioxide pump, the first air inlet of the mixing device (6) is connected to the upper end of the hydrogen production well (17) through a hydrogen air inlet pump, and its second air inlet is connected to the upper end of the methane production well (18) through a methane air inlet pump; the first air outlet of the mixing device (6) is connected to a first passage (7). The renewable energy power plant (3) is installed on the ground and is connected to a hydrogen exhaust pump, a carbon dioxide pump, a hydrogen intake pump and a methane intake pump respectively. The CAES power plant includes an underground gas storage space (20), a second injection-production well network, a compressor (9), an engine (8), a combustion chamber (13), a turbine (12), and a generator (11); the second injection-production well network includes a compressed air injection well (19) and a compressed air production well (21); the compressed air injection well (19) and the compressed air production well (21) are alternately located in the area where the underground gas storage space (20) is located, and their lower ends extend into the middle section of the underground gas storage space (20); the compressor (9), engine (8), combustion chamber (13), turbine (12), and generator (11) The generator (11) is installed on the ground; the outlet end of the compressor (9) is connected to the upper end of the compressed air injection well (19); the engine (8) is coaxially connected to the compressor (9) and connected to the renewable energy power plant (3); the first inlet end of the combustion chamber (13) is connected to the upper end of the compressed air extraction well (21) through an air exhaust pump, and its second inlet end is connected to the second outlet of the mixing device (6) through a second passage (10); the air inlet of the turbine (12) is connected to the outlet end of the combustion chamber (13); the generator (11) is coaxially connected to the turbine (12); The control terminal (2) is connected to the renewable energy power plant (3), the composite gas storage unit, the CAES power station and the power grid (1).

2. The deep aquifer multi-source gas storage and fuel supply system according to claim 1, characterized in that, A solenoid valve is connected in series at the upper end of the compressed air extraction well (21), and the solenoid valve is connected to the control terminal (2).

3. The deep aquifer multi-source gas storage and fuel supply system according to claim 1, characterized in that, The underground gas storage facility (14) is located in an aquifer; the underground gas storage space (20) is an underground salt cavern, a pit, or an abandoned mine.

4. A deep aquifer multi-source gas storage and fuel supply system according to claim 2, characterized in that, It also includes a water electrolysis hydrogen production device, which is connected to the renewable energy power plant (3) and the control terminal (2) respectively.

5. A deep aquifer multi-source gas storage and fuel supply system according to claim 3, characterized in that, The renewable energy power plant (3) is a wind and solar power plant.

6. A method for multi-source gas storage and fuel supply in deep aquifers, employing a multi-source gas storage and fuel supply system for deep aquifers as described in any one of claims 1 to 4, characterized in that, Includes the following steps: Step 1: When there is abundant wind and solar power, power generation is carried out through the renewable energy power plant (3), and electricity is supplied to the carbon dioxide gas pump, hydrogen gas pump, methane gas pump and engine (8). The carbon dioxide gas pump is started and carbon dioxide is injected into the bottom space of the underground gas storage (14) through the carbon dioxide injection well (15). At the same time, the hydrogen gas pump and methane gas pump are started and hydrogen and methane are extracted through the hydrogen extraction well (17) and methane extraction well (18) respectively, and supplied to the mixing device (6). By controlling the injection and extraction rates, the amount of carbon dioxide injected at the same time is lower than the sum of the amount of hydrogen extracted and the amount of methane extracted. By utilizing the reduced pressure environment, the methane in the reservoir is desorbed from the adsorbed state into free gas. At the same time, the engine (8) is started and driven to compress air by the compressor (9), and the compressed air is delivered to the underground gas storage space (20) through the compressed air injection well (19) for storage, so that the pressure of the underground gas storage space (20) rises to the set pressure range; Step 2: Using the mixing device (6), hydrogen and methane are mixed in proportion to form a methane-hydrogen mixture. The methane-hydrogen mixture with a hydrogen gas fraction of 5%-30% is output through the first passage (7), and the methane-hydrogen mixture with a hydrogen gas fraction of 0%-100% is output to the combustion chamber (13) through the second passage (10). Step 3: When the output of the renewable energy power plant (3) is insufficient, the control solenoid valve is opened and the control air exhaust pump is started. The compressed air is input into the combustion chamber (13) through the compressed air extraction well (21) by the air exhaust pump, so that the compressed air and the hydrogen-mixed methane mixture are mixed and burned in the combustion chamber (13). At the same time, the high temperature and high pressure generated by the combustion drive the turbine (12) to expand and do work, and synchronously drive the generator (11) to generate electricity. The generated electricity is connected to the power grid (1) through the control terminal (2).

7. A method for multi-source gas storage and fuel supply in deep aquifers according to claim 6, characterized in that, In step two, the control terminal (2) monitors the operating status of the renewable energy power plant (3) and the CAES power station in real time. When the output fluctuation of the renewable energy power plant (3) is greater than the set amplitude threshold, the power of the hydrogen inlet pump and the methane inlet pump is increased to improve the extraction rate of hydrogen and methane. At the same time, the mixing device (6) is controlled to increase the hydrogen volume ratio of the methane-hydrogen mixture in the second outlet to improve the combustion power generation efficiency and power generation time. When the output of the renewable energy power plant (3) is stable, the power of the hydrogen inlet pump and the methane inlet pump is reduced to reduce the extraction rate of hydrogen and methane. At the same time, the mixing device (6) is controlled to reduce the hydrogen volume ratio of the methane-hydrogen mixture in the second outlet to reduce the combustion power generation efficiency and power generation time, thereby achieving a balance of the fluctuation of the renewable energy power plant (3).

8. A method for multi-source gas storage and fuel supply in deep aquifers according to claim 7, characterized in that, In step two, when the renewable energy power plant (3) has excess power, the control terminal (2) supplies part of the power to the water electrolysis hydrogen production device for hydrogen production, and at the same time, the hydrogen is transported to the hydrogen storage tank (4) through the pipeline.

9. A method for multi-source gas storage and fuel supply in deep aquifers according to claim 6, characterized in that, In step two, the first passage (7) is delivered to the user side through a long delivery pipeline.

10. A method for multi-source gas storage and fuel supply in deep aquifers according to claim 6, characterized in that, In step one, when the hydrogen content in the underground gas storage (14) is lower than the set lower limit threshold, the renewable energy power plant (3) generates electricity and supplies power to the hydrogen exhaust pump. At the same time, the hydrogen exhaust pump is controlled to start working and hydrogen is input into the underground gas storage (14) through the hydrogen injection well (16) until the hydrogen content reaches the set upper limit threshold.

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