Air energy storage integrated system and method for coupling hydrogen energy and carbon dioxide capture

Abstract

The invention relates to the technical field of energy storage, in particular to an air energy storage integrated system and method for coupling hydrogen energy and carbon dioxide trapping. The system comprises an air energy storage subsystem, the air energy storage subsystem comprises an energy storage module and an energy release module which are connected, the energy storage module can generate compressed air in the energy storage stage, and the energy release module uses the compressed air to do work in the energy release stage so as to transmit power to a power grid; the methanation subsystem is connected with the air energy storage subsystem and can be used for preparing methane by utilizing the reaction of carbon dioxide and hydrogen; the methane combustion power generation subsystem is respectively connected with the methanation subsystem and the air energy storage subsystem and can utilize methane to combust in compressed air to do work so as to transmit power to a power grid; and the reaction heat recovery subsystem is connected between the methanation subsystem and the energy release module and can recover reaction waste heat of the methanation subsystem. According to the integrated system, methanation reaction heat can be effectively utilized, the efficiency of the air energy storage system and the comprehensive performance of the whole integrated system are improved, and meanwhile the problems of energy consumption and cyclic utilization are solved.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to an integrated air energy storage system and method for coupling hydrogen energy and carbon dioxide capture. Background Art

[0002] The intermittent, volatile and unstable nature of renewable energy generation such as wind power and photovoltaic power makes large-scale long-term energy storage technology a key technology for the development of future power systems. Air energy storage technology represented by compressed air and liquid air energy storage has outstanding advantages such as clean, low-carbon, safe and long life, and is one of the most promising and competitive long-term energy storage technologies.

[0003] Compared with a single air energy storage system, a coupled system is more conducive to improving system efficiency, energy storage scale / duration, and the effective use of cold energy and clean air resources. However, the current air energy storage coupling system still has problems such as low system efficiency, insufficient reaction heat utilization, and failure to utilize multiple substances as resources. Moreover, the existing coupling system still cannot achieve both the effective utilization of multiple resources and the effective enhancement of the power generation efficiency of the air energy storage system. For example, existing coupling schemes have proposed storing carbon dioxide, air, and methane underground. The storage conditions depend on the special geographical environment. When the system production scale needs to be expanded, the storage device cannot be reliably transferred. Moreover, the reaction heat cannot be recovered, and it is difficult to effectively enhance the system efficiency of air energy storage. Summary of the invention

[0004] The present invention provides an integrated air energy storage system and method for coupling hydrogen energy and carbon dioxide capture, so as to solve the defect in the prior art that it is impossible to achieve both effective utilization of multiple resources and effective enhancement of the working efficiency of the air energy storage system.

[0005] The present invention provides an air energy storage integrated system for coupling hydrogen energy and carbon dioxide capture, comprising: an air energy storage subsystem, suitable for connecting to a power grid, the air energy storage subsystem comprising a connected energy storage module and an energy release module, the energy storage module can generate compressed air in the energy storage stage, the energy release module uses compressed air expansion to do work in the energy release stage to transmit electricity to the power grid; a methanation subsystem, connected to the air energy storage subsystem, the methanation subsystem can use carbon dioxide and hydrogen to react to prepare methane; a methane combustion and power generation subsystem, respectively connected to the methanation subsystem and the air energy storage subsystem, and suitable for connecting to the power grid, the methane combustion and power generation subsystem can use methane to burn in compressed air to do work to transmit electricity to the power grid; a reaction heat recovery subsystem, connected between the methanation subsystem and the energy release module, the reaction heat recovery subsystem can recover the reaction waste heat of the methanation subsystem.

[0006] According to an integrated air energy storage system for coupling hydrogen energy and carbon dioxide capture described in the present invention, the energy storage module includes an air compressor, a compressor-stage aftercooler and a compressed air storage tank, the air compressor, the compressor-stage aftercooler and the compressed air storage tank are connected in sequence, and the air compressor is connected to an air source; the energy release module includes a heat exchanger and an expander, the compressed air storage tank is connected to the expander through the heat absorption side of the heat exchanger, and the expander is connected to the power grid through a generator; the heat release side of the heat exchanger is connected to the methanation subsystem through at least one group of the reaction heat recovery subsystem.

[0007] According to an integrated air energy storage system coupling hydrogen energy and carbon dioxide capture described in the present invention, the methanation subsystem includes a methanation device, a methane cooler, a separator and a methane cache tank, and the methanation device, the methane cooler, the separator and the methane cache tank are connected in sequence; the methanation device is respectively connected to the hydrogen preparation subsystem and the carbon dioxide capture subsystem; the methanation device is connected to the energy release module through at least one group of the reaction heat recovery subsystem.

[0008] According to an integrated air energy storage system for coupling hydrogen energy and carbon dioxide capture described in the present invention, the reaction heat recovery subsystem includes at least one of an over-temperature heat recovery module and an outlet heat recovery module; the heat recovery output port of the methanation device is connected to the energy release module through the over-temperature heat recovery module; the heat absorption side of the methane cooler is connected to the energy release module through the outlet heat recovery module, and the methanation device is connected to the separator through the heat release side of the methane cooler.

[0009] According to an integrated air energy storage system for coupling hydrogen energy and carbon dioxide capture described in the present invention, the reaction heat recovery subsystem also includes a waste heat recovery pipeline, which is connected to the heat release side of the heat exchanger; the super-temperature heat recovery module includes a first branch, the heat recovery output port of the methanation device is connected to the waste heat recovery pipeline through the first branch, and the heat recovery input port of the methanation device is connected to the compressed air storage tank through a first compressed air pipeline, and the first compressed air pipeline is used to introduce compressed air into the methanation device to send the compressed air after heat absorption into the heat release side of the heat exchanger through the super-temperature heat recovery module; the outlet heat recovery module includes a second branch, the heat absorption side outlet of the methane cooler is connected to the waste heat recovery pipeline through the second branch, and the heat absorption side inlet of the methane cooler is connected to the compressed air storage tank through a second compressed air pipeline, and the second compressed air pipeline is used to introduce compressed air into the methane cooler to send the compressed air after heat absorption into the heat release side of the heat exchanger through the outlet heat recovery module.

[0010] According to an integrated air energy storage system coupling hydrogen energy and carbon dioxide capture described in the present invention, the input end of the methanation device is connected to a mixing cache tank; the hydrogen preparation subsystem includes an electrolyzer and a hydrogen storage tank, the input end of the electrolyzer is connected to a water source, the output end of the electrolyzer is connected to the hydrogen storage tank, and the hydrogen storage tank is connected to the mixing cache tank; the carbon dioxide capture subsystem includes a carbon dioxide capture device and a carbon dioxide storage tank, the input end of the carbon dioxide capture device is connected to a carbon dioxide source, the output end of the carbon dioxide capture device is connected to the carbon dioxide storage tank, and the carbon dioxide storage tank is connected to the mixing cache tank; the separation output end of the separator is connected to the input end of the electrolyzer; and the emission end of the methane combustion power generation subsystem is connected to the input end of the carbon dioxide capture device.

[0011] According to an integrated air energy storage system coupled with hydrogen energy and carbon dioxide capture described in the present invention, the methane combustion power generation subsystem includes a combustion chamber and a gas turbine, a first input end of the combustion chamber is connected to a methane cache tank, and a second input end of the combustion chamber is connected to the compressed air storage tank via a third compressed air pipeline; an output end of the combustion chamber is connected to the gas turbine, and the gas turbine is connected to the power grid via a generator.

[0012] According to an integrated air energy storage system for coupling hydrogen energy and carbon dioxide capture described in the present invention, the air energy storage subsystem also includes a hot water tank and a cold water tank, the output end of the hot water tank is connected to the input end of the cold water tank through the heat release side of the heat exchanger, and the output end of the cold water tank is connected to the input end of the hot water tank through the heat absorption side of the compressor stage aftercooler.

[0013] According to an integrated air energy storage system coupled with hydrogen energy and carbon dioxide capture described in the present invention, the reaction heat recovery subsystem also includes a solid phase heat accumulator, and the solid phase heat accumulator includes an energy storage input end, an energy release output end, a waste heat recovery input end and a discharge end; the energy storage input end of the solid phase heat accumulator is connected to the energy storage module; the energy release output end of the solid phase heat accumulator is connected to the energy release module; and the waste heat recovery input end of the solid phase heat accumulator is connected to all the reaction heat recovery subsystems.

[0014] The present invention also provides an integrated air energy storage method for coupling hydrogen energy and carbon dioxide capture, which is performed using the above-mentioned integrated air energy storage system for coupling hydrogen energy and carbon dioxide capture; the integrated air energy storage method for coupling hydrogen energy and carbon dioxide capture includes the following steps.

[0015] The air energy storage and power transmission steps include an energy storage stage and an energy release stage. The energy storage stage uses the energy storage module of the air energy storage subsystem to prepare and store compressed air. The energy release stage uses the energy release module of the air energy storage subsystem to heat the compressed air and expand it to generate electricity.

[0016] The methanation step uses the methanation subsystem to react hydrogen and carbon dioxide to produce methane.

[0017] The methane combustion power generation step utilizes methane to burn in compressed air to produce work through a methane combustion power generation subsystem, so as to transmit electricity to the power grid.

[0018] The reaction heat recovery step recovers the heat generated by the methanation subsystem and introduces the heat into the energy release module to heat the compressed air in the energy release stage.

[0019] The air energy storage integrated system coupled with hydrogen energy and carbon dioxide capture provided by the present invention (the present invention may be referred to as "integrated system" or "system") comprises an air energy storage subsystem, a methanation subsystem, a methane combustion power generation subsystem and a reaction heat recovery subsystem; the air energy storage subsystem is suitable for connecting to a power grid, the air energy storage subsystem comprises a connected energy storage module and an energy release module, the energy storage module can generate compressed air in the energy storage stage, and the energy release module uses compressed air expansion to do work in the energy release stage to transmit electricity to the power grid; the methanation subsystem is connected to the air energy storage subsystem, and the methanation subsystem can use carbon dioxide and hydrogen to react to prepare methane; the methane combustion power generation subsystem is respectively connected to the methanation subsystem and the air energy storage subsystem, and is suitable for connecting to a power grid, the methane combustion power generation subsystem can use methane combustion in compressed air to do work to transmit electricity to the power grid; the reaction heat recovery subsystem is connected between the methanation subsystem and the energy release module, and the reaction heat recovery subsystem can recover the reaction waste heat of the methanation subsystem. The integrated system can effectively recycle the heat of the methanation reaction in the energy release module of the air energy storage system, significantly increase the temperature of the compressed air before it expands to do work, improve the power generation efficiency of the air energy storage system and the comprehensive performance of the entire integrated system, and at the same time solve the problems of large-scale consumption of resources such as hydrogen and carbon dioxide, and the recycling of carbon dioxide.

[0020] Furthermore, in this integrated system, since hydrogen, carbon dioxide and methane can be consumed in a timely manner and carbon dioxide can be recycled, it can also effectively solve the defect in related technologies that the storage conditions of energy depend on the special geographical environment, and the storage device cannot be reliably transferred when the system production scale needs to be expanded, which easily leads to energy waste or unreasonable discharge, which is not conducive to low-carbon and environmental protection. It can maximize the utilization of resources, and the actual discharge is air, which is more conducive to environmental protection and has higher environmental protection significance.

[0021] The present invention also provides an integrated method for air energy storage coupled with hydrogen energy and carbon dioxide capture (the present invention may be referred to as "integrated method" or "method"), which is performed using the above-mentioned air energy storage integrated system coupled with hydrogen energy and carbon dioxide capture. The integrated method for air energy storage coupled with hydrogen energy and carbon dioxide capture includes an air energy storage and power transmission step, a methanation step, a methane combustion power generation step, and a reaction heat recovery step. The integrated method is performed by the above-mentioned integrated system, so that the integrated method has all the advantages of the above-mentioned integrated system, and the details are not repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 This is one of the structural schematic diagrams of the air energy storage integrated system for coupling hydrogen energy and carbon dioxide capture provided by the present invention.

[0024] Figure 2 This is the second structural schematic diagram of the air energy storage integrated system for coupling hydrogen energy and carbon dioxide capture provided by the present invention.

[0025] Reference numerals: 1. Air compressor; 2. Compressor stage aftercooler; 3. Compressed air storage tank; 4. First valve body; 5. Heat exchanger; 6. Expander; 7. Hot water tank; 8. Cold water tank; 9. Electrolyzer; 10. Oxygen storage tank; 11. Hydrogen storage tank; 12. Carbon dioxide capture device; 13. Carbon dioxide storage tank; 14. Mixing buffer tank; 15. Methanation device; 16. Methane cooler; 17. Separator; 18. Methane buffer tank; 19. Combustion chamber; 20. Gas turbine; 21. Second valve body; 22. Third valve body; 23. Fourth valve body; 24. Fifth valve body; 25. Sixth valve body; 26. Seventh valve body; 27. Eighth valve body; 28. Solid phase heat accumulator; 29. ​​Ninth valve body; 30. Emission control valve; 31. Tenth valve body. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Combine the following Figure 1 and Figure 2 The air energy storage integrated system and method for coupling hydrogen energy and carbon dioxide capture of the present invention are described. The air energy storage integrated system for coupling hydrogen energy and carbon dioxide capture of the present invention can be referred to as an "integrated system" or "system". The air energy storage integrated method for coupling hydrogen energy and carbon dioxide capture of the present invention can be referred to as an "integrated method" or "method".

[0028] like Figure 1 and Figure 2 As shown, the integrated system described in the embodiment of the present invention includes an air energy storage subsystem, a methanation subsystem and a methane combustion power generation subsystem.

[0029] In some embodiments, both the air energy storage subsystem and the methane combustion power generation subsystem are suitable for connection to the power grid, so that compressed air expansion power generation and methane combustion power generation can be carried out simultaneously; or, according to the power consumption situation, compressed air expansion is used to generate power during peak power consumption periods, and the air energy storage subsystem is driven to prepare and store compressed air during low power consumption periods, and the methane combustion power generation subsystem is driven to generate power as needed at any time period to meet the power demand of the external power grid.

[0030] In some specific embodiments, the air energy storage subsystem is provided with an energy storage stage and an energy release stage. The air energy storage subsystem comprises a connected energy storage module and an energy release module. The energy storage module can generate compressed air in the energy storage stage. The energy release module uses compressed air expansion to do work in the energy release stage to transmit electricity to the power grid. The methanation subsystem can produce methane by reacting carbon dioxide with hydrogen. The methane combustion and power generation subsystem is respectively connected to the methanation subsystem and the air energy storage subsystem, and the methane combustion and power generation subsystem can introduce the methane generated by the methanation subsystem and the compressed air generated by the air energy storage subsystem in the energy storage module into the methane combustion and power generation subsystem for combustion, thereby utilizing methane to burn in compressed air to do work to transmit electricity to the power grid.

[0031] In some embodiments, the integrated system also includes a reaction heat recovery subsystem. Since the methanation reaction is a highly exothermic reaction and the reaction outputs high-temperature gas, the integrated system connects the methanation subsystem to the air energy storage subsystem, so that the compressed air generated by the air energy storage subsystem can be introduced into the methanation subsystem to absorb the heat generated during the reaction and after the reaction. Correspondingly, the reaction heat recovery subsystem is connected between the methanation subsystem and the energy release module. The reaction heat recovery subsystem can recover the reaction waste heat of the methanation subsystem, thereby realizing heat supplement for the air energy storage subsystem, improving power generation efficiency and power generation, and meeting the power demand at any time period.

[0032] It can be seen that the integrated system can effectively recycle the heat of the methanation reaction in the energy release module of the air energy storage system, greatly increase the temperature of the compressed air before expansion to do work, improve the power generation efficiency of the air energy storage system and the comprehensive performance of the entire integrated system, and at the same time solve the problems of large-scale consumption of resources such as hydrogen energy and carbon dioxide, and the recycling of carbon dioxide.

[0033] Furthermore, in this integrated system, since hydrogen, carbon dioxide and methane can be consumed in a timely manner and carbon dioxide can be recycled, it can also effectively solve the defect in related technologies that the storage conditions of energy depend on the special geographical environment, and the storage device cannot be reliably transferred when the system production scale needs to be expanded, which easily leads to energy waste or unreasonable discharge, which is not conducive to low-carbon and environmental protection. It can maximize the utilization of resources, and the actual discharge is air, which is more conducive to environmental protection and has higher environmental protection significance.

[0034] In some embodiments, the energy storage module includes an air compressor 1, a compressor-stage aftercooler 2, and a compressed air storage tank 3. The air compressor 1, the compressor-stage aftercooler 2, and the compressed air storage tank 3 are connected in sequence. The air compressor 1 is connected to an air source. In the energy storage stage, off-peak electricity such as wind power and photovoltaic power is used as power input to drive clean air into the air compressor 1 to be compressed into a high-temperature and high-pressure state, and then cooled into compressed air in the compressor-stage aftercooler 2, and the compressed air is stored in the compressed air storage tank 3.

[0035] In some embodiments, the energy release module includes a heat exchanger 5 and an expander 6. The compressed air storage tank 3 is connected to the expander 6 via the heat absorption side of the heat exchanger 5. The expander 6 is connected to the power grid via a generator. In the energy release stage, the compressed air is passed from the compressed air storage tank 3 into the heat exchanger 5 to be heated, and then enters the expander 6 to perform work through expansion, driving the generator to generate electricity, thereby transmitting electricity to the power grid.

[0036] In some embodiments, the heat release side of the heat exchanger 5 is connected to the methanation subsystem through at least one set of reaction heat recovery subsystems, so that the high-temperature waste heat in and / or after the methanation reaction can be recovered and utilized in the energy release module, further increasing the gas temperature at the inlet of the expander 6, accelerating the gas heating efficiency, thereby improving the working efficiency of the expander 6, and further improving the power generation efficiency. The specific structural setting and connection relationship of the reaction heat recovery subsystem will be described in detail later, and will not be described in detail here.

[0037] In some specific embodiments, Figure 1 and Figure 2As shown, at least one set of heat recovery loops is preferably connected between the energy storage module and the energy release module. Specifically, the air energy storage subsystem includes a hot water tank 7 and a cold water tank 8. The output end of the hot water tank 7 is connected to the input end of the cold water tank 8 through the heat release side of the heat exchanger 5, and the output end of the cold water tank 8 is connected to the input end of the hot water tank 7 through the heat absorption side of the compressor stage aftercooler 2. This structural arrangement uses water as a heat exchange medium. In the energy storage stage, the heat recovery loop uses the low-temperature heat exchange medium in the cold water tank 8 to flow through the heat absorption side of the compressor stage aftercooler 2, absorbs the heat in the compressed air under high temperature and high pressure state flowing through the heat release side of the compressor stage aftercooler 2, and the heated heat exchange medium is stored in the hot water tank 7; in the energy release stage, the high-temperature heat exchange medium in the hot water tank 7 flows through the first heat release side of the heat exchanger 5, releases heat and returns to the cold water tank 8 after cooling, so as to carry out the next heat recovery process. Therefore, the air energy storage subsystem can use the heat recovery circuit to recycle the heat generated by the energy storage module in the process of preparing compressed air and reuse it in the energy release module, thereby increasing the temperature rise and heating efficiency of the gas temperature at the input end of the expander 6, thereby improving the expansion work efficiency, and then improving the power generation efficiency, and the overall performance of the entire integrated system is significantly improved.

[0038] It should be noted that the above-mentioned heat exchange medium can be water, or other heat storage medium with flow properties, such as heat transfer oil.

[0039] The operation process of the air energy storage subsystem described in the embodiment of the present invention is as follows. Figure 1 As shown, in the energy storage stage, off-peak electricity such as wind power and photovoltaic power is used as power input to drive the purified air to be compressed to a high temperature and high pressure state through the air compressor 1 group. The compressed air enters the compressor stage after cooler 2 to recover the compression heat, and the air cooled by the heat exchange medium is stored in the compressed air storage tank 3. In the energy release stage, the first valve body 4 is opened. The first valve body 4 is installed on the pipeline connecting the energy storage module and the energy release module (that is, the pipeline between the compressed air storage tank 3 and the heat exchanger 5). After being heated by the heat exchanger 5, the compressed air in the compressed air storage tank 3 enters the expander 6 to expand and do work, thereby driving the generator to generate electricity. In addition, part of the compressed air in the energy release stage is used for expansion and power generation, and part is used to recover the heat of methanation reaction; further, part of the heat in the energy release stage comes from the compression heat recovered in the energy storage module, and part comes from the heat generated by the methanation reaction, thereby forming a heat supplement for the air energy storage subsystem in the energy release stage, thereby improving the power generation efficiency.

[0040] In some embodiments, Figure 1 and Figure 2As shown, the methanation subsystem includes a methanation device 15, a methane cooler 16, a separator 17 and a methane buffer tank 18. The methanation device 15, the methane cooler 16, the separator 17 and the methane buffer tank 18 are connected in sequence. The methanation device 15 is respectively connected to the hydrogen preparation subsystem and the carbon dioxide capture subsystem. The hydrogen preparation subsystem can generate hydrogen. The carbon dioxide capture subsystem can capture carbon dioxide. The methanation device 15 can prepare methane by mixing and reacting hydrogen and carbon dioxide respectively. The methanation device 15 is connected to the energy release module through at least one set of reaction heat recovery subsystems. The reaction heat recovery subsystem can recover the heat generated during the methanation reaction and the heat generated after the reaction and transport them to the energy release module to supplement the heat in the energy release stage of the air energy storage subsystem.

[0041] In some specific embodiments, the input end of the methanation device 15 is connected to the mixing buffer tank 14. The mixing buffer tank 14 is respectively connected to the hydrogen preparation subsystem and the carbon dioxide capture subsystem, and hydrogen and carbon dioxide can be premixed in the mixing buffer tank 14, thereby ensuring that the mixed gas entering the methanation device 15 reacts more thoroughly and quickly due to full mixing, thereby improving the reaction efficiency and output efficiency.

[0042] In some specific embodiments, the hydrogen preparation subsystem includes an electrolyzer 9 and a hydrogen storage tank 11. The input end of the electrolyzer 9 is connected to a water source. The electrolyzer 9 can ionize water to prepare hydrogen and oxygen. The output end of the electrolyzer 9 is connected to the hydrogen storage tank 11, and the prepared hydrogen can be stored in the hydrogen storage tank 11. The output end of the electrolyzer 9 is also connected to an oxygen storage tank 10. The prepared oxygen can be stored in the oxygen storage tank 10. It is understandable that the prepared oxygen can also be directly discharged, and storing oxygen can improve the resource utilization rate of intermediate products. The hydrogen storage tank 11 is connected to the mixing cache tank 14, and hydrogen can be passed into the mixing cache tank 14 to avoid long-term storage that increases the danger of the system, and can reduce the possibility of long-term storage, so that the hydrogen can be consumed in time.

[0043] It should be noted that the hydrogen described in the embodiments of the present invention can be prepared by the above-mentioned hydrogen preparation subsystem, or can be hydrogen directly introduced from an external hydrogen source.

[0044] It should be noted that the water described in the embodiment of the present invention can be obtained from a water source outside the system; it can also be a by-product of a related subsystem co-produced within the system. For example, the separation output end of the separator 17 is preferably connected to the input end of the electrolyzer 9, and the separator 17 of the methanation subsystem separates water from the product of the methanation reaction, and the water can flow back into the electrolyzer 9 to participate in the electrolysis to produce hydrogen.

[0045] In some specific embodiments, the carbon dioxide capture subsystem includes a carbon dioxide capture device 12 and a carbon dioxide storage tank 13. The input end of the carbon dioxide capture device 12 is connected to a carbon dioxide source. The output end of the carbon dioxide capture device 12 is connected to the carbon dioxide storage tank 13. The carbon dioxide storage tank 13 can store the carbon dioxide captured by the carbon dioxide capture device 12. The carbon dioxide storage tank 13 is connected to a mixing buffer tank 14, and hydrogen can be passed into the mixing buffer tank 14 to reduce the possibility of long-term storage and enable carbon dioxide to be consumed in a timely manner.

[0046] It should be noted that the carbon dioxide described in the embodiment of the present invention can be captured from a carbon dioxide source outside the system by the carbon dioxide capture device 12 of the carbon dioxide capture subsystem and stored. The carbon dioxide source is preferably a tail gas enriched with carbon dioxide such as tail gas from a chemical plant and tail gas from biomass combustion. Carbon dioxide can also be obtained from the emissions of the co-generation subsystem in the system. For example, the emission end of the methane combustion power generation subsystem is connected to the input end of the carbon dioxide capture device 12, so that the carbon dioxide generated by the methane combustion flows back to the carbon dioxide capture device 12, and re-participates in the methanation reaction to form energy recovery.

[0047] In some embodiments, Figure 1 As shown, in order to reliably recover the reaction heat of the methanation subsystem and effectively improve the working efficiency of the air energy storage subsystem, the reaction heat recovery subsystem includes at least one of an over-temperature heat recovery module and an outlet heat recovery module.

[0048] For the overheating heat recovery module, in the embodiment of the present invention, Figure 1 As shown, the heat recovery output port of the methanation device 15 is connected to the energy release module through an over-temperature heat recovery module. The over-temperature heat recovery module can recover the heat generated by the methanation device 15 due to over-temperature during the methanation reaction, and utilize it to supplement the heat of the energy release module of the air energy storage subsystem. On the one hand, it can improve the working efficiency of the energy release module, and on the other hand, it can prevent the methanation device 15 from over-temperature and cause danger, thereby ensuring safe production.

[0049] Preferably, the reaction heat recovery subsystem also includes a waste heat recovery pipeline. The waste heat recovery pipeline is connected to the heat release side of the heat exchanger 5. The super-temperature heat recovery module includes a first branch. The heat recovery output port of the methanation device 15 is connected to the waste heat recovery pipeline through the first branch. The heat recovery input port of the methanation device 15 is connected to the compressed air storage tank 3 through the first compressed air pipeline. The first compressed air pipeline is used to introduce compressed air into the methanation device 15, so as to send the compressed air after absorbing heat into the heat release side of the heat exchanger 5 through the super-temperature heat recovery module.

[0050] For the outlet heat recovery module, in the embodiment of the present invention, if Figure 1As shown, the heat absorbing side of the methane cooler 16 is connected to the energy release module through the outlet heat recovery module, and the methanation device 15 is connected to the separator 17 through the heat releasing side of the methane cooler 16. The methane cooler 16 recovers the heat in the high-temperature gas output from the output end of the methanation device 15 and uses it to supplement the heat of the energy release module of the air energy storage subsystem. On the one hand, it can improve the working efficiency of the energy release module, and on the other hand, it can reliably reduce the temperature of the high-temperature gas generated after the methanation reaction to protect the safety of the separator 17, improve the working efficiency of the separator 17, and ensure safe production.

[0051] Preferably, the outlet heat recovery module includes a second branch. The heat absorption side outlet of the methane cooler 16 is connected to the waste heat recovery pipeline through the second branch. The heat absorption side inlet of the methane cooler 16 is connected to the compressed air storage tank 3 through the second compressed air pipeline. The second compressed air pipeline is used to introduce compressed air into the methane cooler 16, so as to send the compressed air after heat absorption to the heat release side of the heat exchanger 5 through the outlet heat recovery module.

[0052] It should be noted that the waste heat recovery pipelines connecting the above-mentioned over-temperature heat recovery module and the outlet heat recovery module can be two pipelines or the same pipeline. In addition, for the sake of system safety and structural selectivity, the waste heat recovery pipeline is connected to the second heat release side of the heat exchanger 5 so as to be isolated from the first heat release side of the heat exchanger 5 connected to the above-mentioned heat recovery loop. On the one hand, this setting can avoid medium mixing and improve system safety; on the other hand, it can be selected to increase or decrease pipelines according to system needs, so that the integrated system can flexibly adjust the number of pipelines on the heat release side according to the needs of the heat exchanger 5.

[0053] The methanogenation subsystem described in the embodiment of the present invention is as follows: Figure 1 As shown, oxygen and hydrogen are produced by electrolyzing water in an electrolyzer 9, oxygen is stored in an oxygen storage tank 10, and hydrogen is stored in a hydrogen storage tank 11. A portion of the carbon dioxide-rich gas comes from carbon dioxide-enriched gases such as thermal power generation flue gas, chemical plant tail gas, and biomass combustion gas, and the other portion comes from tail gas generated by a methane combustion power generation subsystem. The carbon dioxide captured by the carbon dioxide capture device 12 is stored in a carbon dioxide storage tank 13. The methanation subsystem passes both carbon dioxide and hydrogen into a mixing buffer tank 14 for thorough mixing, and the mixed product enters a methanation device 15 for a methanation reaction. The reaction product of the methanation reaction is cooled by a methane cooler 16 and then enters a separator 17 for dehydration. The reactants after dehydration are stored in a methane buffer tank 18.

[0054] In the embodiment of the present invention, since the methanation reaction is a highly exothermic reaction and the output end of the methanation device 15 outputs high-temperature gas, it is preferred that the integrated system of the embodiment of the present invention recovers the reaction heat in at least the following two ways, such as: Figure 1 shown.

[0055] (a) A portion of the compressed air carries away the heat generated when the methanation reactor is overheated.

[0056] In the embodiment of the present invention, the output end of the compressed air storage tank 3 is connected to a compressed air output pipeline, and a second valve body 21 is installed on the compressed air output pipeline. A reaction space is provided in the methanation device 15, and a reaction heat heat exchange pipeline is provided to pass through the reaction space. The compressed air output pipeline is connected to the compressed air output pipeline and the input end of the reaction heat heat exchange pipeline through the first compressed air pipeline, and the output end of the reaction heat heat exchange pipeline is connected to the waste heat recovery pipeline through the first branch. A third valve body 22 is installed on the first compressed air pipeline, a fourth valve body 23 is installed on the first branch, and a seventh valve body 26 is installed on the waste heat recovery pipeline. When the reaction temperature of the methanation device 15 is higher than the set value, the second valve body 21, the third valve body 22, the fourth valve body 23 and the seventh valve body 26 are opened, and the compressed air is passed into the reaction heat heat exchange pipeline of the methanation device 15 to absorb the reaction heat. The heated compressed air can return to the heat exchanger 5 to replenish heat for the energy release module, thereby effectively controlling the methanation device 15 to be within a safe temperature range, and utilizing the compressed air to effectively recover the reaction heat, thereby improving the system working efficiency.

[0057] (ii) Using a portion of the compressed air to recover the heat of the high-temperature gas output by the methanation device 15.

[0058] In the embodiment of the present invention, the second compressed air pipeline is connected between the compressed air output pipeline and the methane cooler 16. The second compressed air pipeline is equipped with a fifth valve body 24, and the second branch is equipped with a sixth valve body 25. During the operation of the methanation subsystem, the second valve body 21, the fifth valve body 24, the sixth valve body 25 and the seventh valve body 26 are opened to pass the compressed air into the heat absorption side of the methane cooler 16 to absorb heat, so as to cool down the methanation reaction product flowing through the heat release side of the methane cooler 16. Similarly, the heated compressed air can return to the heat exchanger 5 to supplement the heat for the energy release module.

[0059] In the embodiment of the present invention, in order to decouple the reaction heat storage of the methanation subsystem from the energy release stage of the compressed air energy storage subsystem and avoid the situation where the reaction state and reaction stage of the compressed air energy storage subsystem and the methanation subsystem are difficult to match, it is preferred that the embodiment of the present invention further proposes the following on the basis of the above two waste heat recovery methods: Figure 2 The integrated system shown.

[0060] like Figure 2As shown, the reaction heat recovery subsystem of the embodiment of the present invention also includes a solid-phase heat accumulator 28. The solid-phase heat accumulator 28 includes an energy storage input end, an energy release output end, a waste heat recovery input end and a discharge end. The energy storage input end of the solid-phase heat accumulator 28 is connected to the energy storage module, and the energy release output end of the solid-phase heat accumulator 28 is connected to the energy release module, so that the heat energy contained in the compressed air generated by the air energy storage subsystem during operation can be stored in the solid-phase heat accumulator 28. The waste heat recovery input end of the solid-phase heat accumulator 28 is connected to all reaction heat recovery subsystems, so that the reaction heat generated by the methanation subsystem during operation can be recovered and stored in the solid-phase heat accumulator 28. The discharge end of the solid-phase heat accumulator 28 can discharge excess compressed air as needed, release heat and pressure, and achieve temperature and pressure regulation.

[0061] After adding the solid phase heat storage device 28, the integrated system described in the embodiment of the present invention is as follows: Figure 2 The operation mode of the integrated system is as follows.

[0062] In the air energy storage subsystem, the solid phase heat accumulator 28 is installed on the pipeline connecting the energy storage module and the energy release module, the first valve body 4 is installed on the pipeline connecting the compressed air storage tank 3 and the input end of the solid phase heat accumulator 28, and the tenth valve body 31 is installed on the pipeline connecting the output end of the solid phase heat accumulator 28 and the heat exchanger 5. Figure 1 The integrated systems are basically the same, and the similarities are not repeated here. The difference is that the compressed air is cooled to room temperature in the compressor stage aftercooler 2 and then stored in the compressed air storage tank 3. In the energy release stage of the air energy storage subsystem, the compressed air output from the compressed air storage tank 3 flows through the solid phase heat accumulator 28 for preheating before entering the heat exchanger 5. That is, the compressed air of the air energy storage subsystem can be heated in stages during the energy release stage, and is preheated by the solid phase heat accumulator 28 before heat exchange and temperature rise.

[0063] In the methanation subsystem, the first branch and the second branch are connected to the waste heat recovery input end of the solid phase heat accumulator 28 through the waste heat recovery pipeline. The discharge end of the solid phase heat accumulator 28 is connected to a discharge pipeline, and a discharge control valve 30 is installed on the discharge pipeline. The heat absorption side of the solid phase heat accumulator 28 is connected to the energy storage module and the energy release module, and the heat release side of the solid phase heat accumulator 28 is connected to the waste heat recovery pipeline and the discharge pipeline. The operation mode of the methanation subsystem, the overheating heat recovery module and the outlet heat recovery module of the reaction heat recovery subsystem are the same as Figure 1 The integrated systems are basically the same, and the similarities are not repeated here. The differences are: For the over-temperature heat recovery module, when the reaction temperature of the methanation device 15 is higher than the set value, the first valve body 4, the second valve body 21, the third valve body 22, the fourth valve body 23 and the emission control valve 30 are opened, and the compressed air is passed into the reaction heat heat exchange pipeline of the methanation device 15 to absorb the reaction heat. For the outlet heat recovery module, the first valve body 4, the second valve body 21, the fifth valve body 24, the sixth valve body 25 and the emission control valve 30 are opened, and the compressed air is passed into the heat absorption side of the methane cooler 16 to absorb the heat released by the reaction products after the reaction. The heated compressed air can flow through the heat release side of the solid phase heat accumulator 28 to release heat. The cooled compressed air can be directly discharged through the emission pipeline.

[0064] like Figure 2 As shown, the integrated system of the embodiment of the present invention uses compressed air to store the heat generated by the overheating of the methanation device 15 and the heat of the high-temperature gas output by the methanation device 15 in the solid phase heat accumulator 28. On the one hand, the compressed air energy storage subsystem and the methanation subsystem can achieve operational decoupling, that is, the methanation reaction and the energy release stage do not have to be carried out at the same time, so that the operation of the energy release module is not restricted by the methanation reaction, which is conducive to improving the overall efficiency of the system and the flexibility of system operation; on the other hand, the temperature of the methanation reaction is relatively high (the reaction temperature range is usually 270 degrees Celsius to 400 degrees Celsius), and there are fewer liquid phase heat storage materials applicable in this temperature range, and the phase change heat storage material faces the risk of leakage. The use of solid phase heat storage materials to achieve thermal energy storage is more environmentally friendly and safe. In addition, the integrated system can adjust the temperature of the methanation device 15 and achieve efficient heat recovery by adjusting the flow rate of compressed air, and is easy to operate.

[0065] It should be noted that the heat storage medium used in the solid phase heat accumulator 28 described in the embodiment of the present invention is preferably a mixture of one or more materials selected from the group consisting of concrete, rock, gravel, steel, and magnetite.

[0066] It should be noted that in the above Figure 1 and Figure 2 In the integrated system shown, the over-temperature heat recovery module and the outlet heat recovery module can exist separately and be turned on independently, or they can exist at the same time and be turned on synchronously.

[0067] In some embodiments, Figure 1 and Figure 2As shown, the methane combustion power generation subsystem includes a combustion chamber 19 and a gas turbine 20. The first input end of the combustion chamber 19 is connected to the methane buffer tank 18 so that the methane generated in the methanation subsystem can be introduced into the combustion chamber 19 for combustion. The second input end of the combustion chamber 19 is connected to the compressed air storage tank 3 through the third compressed air pipeline. The third compressed air pipeline can introduce the compressed air prepared in the air energy storage subsystem into the combustion chamber 19 to assist combustion and improve the methane combustion efficiency. The output end of the combustion chamber 19 is connected to the gas turbine 20, and the gas turbine 20 is connected to the power grid through the generator.

[0068] In some specific embodiments, Figure 1 and Figure 2 As shown, the third compressed air pipeline is preferably connected to the compressed air output pipeline. An eighth valve body 27 is installed on the third compressed air pipeline. The exhaust port of the gas turbine 20 is connected to the carbon dioxide capture device 12.

[0069] The operation of the methane combustion power generation subsystem described in the embodiment of the present invention is as follows. During the operation of the methane combustion power generation subsystem, the second valve body 21 and the eighth valve body 27 are opened, and the methane in the methane storage tank and a part of the compressed air in the compressed air storage tank 3 are passed into the combustion chamber 19 to realize methane combustion. The fuel gas generated by the combustion of methane enters the gas turbine 20 to drive the generator to generate electricity. The exhaust gas generated by the gas turbine 20 is returned to the carbon dioxide capture device 12 for recycling.

[0070] The embodiment of the present invention also provides an integrated method for air energy storage that couples hydrogen energy and carbon dioxide capture. The integrated method can be performed using the above-mentioned integrated system. The integrated method provided by the present invention is described in detail below. The integrated method described below and the integrated system described above can be referenced to each other.

[0071] like Figure 1 As shown, the integrated method includes an air energy storage and power transmission step, a methanation step, a methane combustion power generation step, and a reaction heat recovery step.

[0072] The air energy storage and power transmission step includes an energy storage stage and an energy release stage. In the energy storage stage, the energy storage module of the air energy storage subsystem is used to prepare and store compressed air. In the energy release stage, the energy release module of the air energy storage subsystem is used to heat the compressed air and then expand it to generate power. In the methanation step, the methanation subsystem uses hydrogen and carbon dioxide to react to prepare methane. In the methane combustion power generation step, the methane combustion power generation subsystem uses methane to burn in compressed air to perform work to transmit power to the power grid. The reaction heat recovery step recovers the heat generated by the methanation subsystem and introduces the heat into the energy release module to heat the compressed air in the energy release stage. By setting the steps corresponding to the above-mentioned integrated system and associating the steps, the integrated method has all the advantages of the above-mentioned integrated system, and the details will not be repeated here.

[0073] Each step of the integration method of this embodiment is executed by each subsystem of the above-mentioned integration system. The operation process and operation principle of the above-mentioned integration system in the process of executing the integration method are described in detail in the integration system, and will not be repeated here.

[0074] In some embodiments, Figure 2 As shown, the reaction heat recovery step of the integrated method further includes a reaction heat pre-storage sub-step. In the reaction heat pre-storage sub-step, all the reaction heat generated in the methanation step is pre-stored in the solid phase heat accumulator 28 by using the solid phase heat accumulator 28, and is used to preheat the compressed air in the energy release stage of the air energy storage and power transmission step, forming a pre-stage preheating process of the heat exchanger 5.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated air energy storage system coupling hydrogen energy and carbon dioxide capture, characterized in that: include: An air energy storage subsystem, suitable for connecting to a power grid, the air energy storage subsystem comprising a connected energy storage module and an energy release module, the energy storage module can generate compressed air in the energy storage stage, and the energy release module uses the compressed air to expand and perform work in the energy release stage to transmit electricity to the power grid; A methanogenic subsystem connected to the air energy storage subsystem, wherein the methanogenic subsystem can produce methane by reacting carbon dioxide with hydrogen; A methane combustion power generation subsystem, connected to the methanation subsystem and the air energy storage subsystem respectively, and suitable for connecting to the power grid, wherein the methane combustion power generation subsystem can utilize methane to burn in compressed air to perform work, so as to transmit electricity to the power grid; A reaction heat recovery subsystem is connected between the methanation subsystem and the energy release module, and the reaction heat recovery subsystem can recover the reaction waste heat of the methanation subsystem.

2. The air energy storage integrated system for coupling hydrogen energy and carbon dioxide capture according to claim 1 is characterized in that: The energy storage module comprises an air compressor, a compressor-stage aftercooler and a compressed air storage tank, wherein the air compressor, the compressor-stage aftercooler and the compressed air storage tank are connected in sequence, and the air compressor is connected to an air source; The energy release module includes a heat exchanger and an expander, the compressed air storage tank is connected to the expander via the heat absorption side of the heat exchanger, and the expander is connected to the power grid via a generator; The heat release side of the heat exchanger is connected to the methanation subsystem via at least one set of the reaction heat recovery subsystem.

3. The air energy storage integrated system for coupling hydrogen energy and carbon dioxide capture according to claim 2 is characterized in that: The methanation subsystem comprises a methanation device, a methane cooler, a separator and a methane cache tank, wherein the methanation device, the methane cooler, the separator and the methane cache tank are connected in sequence; The methanation device is respectively connected to the hydrogen preparation subsystem and the carbon dioxide capture subsystem; The methanation device is connected to the energy release module via at least one set of the reaction heat recovery subsystem.

4. The air energy storage integrated system for coupling hydrogen energy and carbon dioxide capture according to claim 3 is characterized in that: The reaction heat recovery subsystem includes at least one of an over-temperature heat recovery module and an outlet heat recovery module; The heat recovery output port of the methanation device is connected to the energy release module through the over-temperature heat recovery module; The heat absorption side of the methane cooler is connected to the energy release module through the outlet heat recovery module, and the methanation device is connected to the separator through the heat release side of the methane cooler.

5. The air energy storage integrated system for coupling hydrogen energy and carbon dioxide capture according to claim 4 is characterized in that: The reaction heat recovery subsystem further comprises a waste heat recovery pipeline, and the waste heat recovery pipeline is connected to the heat release side of the heat exchanger; The super-temperature heat recovery module includes a first branch, the heat recovery output port of the methanation device is connected to the waste heat recovery pipeline through the first branch, and the heat recovery input port of the methanation device is connected to the compressed air storage tank through a first compressed air pipeline, and the first compressed air pipeline is used to introduce compressed air into the methanation device, so as to send the compressed air after absorbing heat to the heat release side of the heat exchanger through the super-temperature heat recovery module; The outlet heat recovery module includes a second branch, and the heat absorption side outlet of the methane cooler is connected to the waste heat recovery pipeline through the second branch. The heat absorption side inlet of the methane cooler is connected to the compressed air storage tank through a second compressed air pipeline. The second compressed air pipeline is used to introduce compressed air into the methane cooler to send the compressed air after absorbing heat into the heat release side of the heat exchanger through the outlet heat recovery module.

6. The air energy storage integrated system for coupling hydrogen energy and carbon dioxide capture according to claim 3 is characterized in that: The input end of the methanation device is connected to a mixing cache tank; The hydrogen preparation subsystem comprises an electrolyzer and a hydrogen storage tank, the input end of the electrolyzer is connected to a water source, the output end of the electrolyzer is connected to the hydrogen storage tank, and the hydrogen storage tank is connected to the mixing cache tank; The carbon dioxide capture subsystem comprises a carbon dioxide capture device and a carbon dioxide storage tank, the input end of the carbon dioxide capture device is connected to a carbon dioxide source, the output end of the carbon dioxide capture device is connected to the carbon dioxide storage tank, and the carbon dioxide storage tank is connected to the mixing cache tank; The separation output end of the separator is connected to the input end of the electrolytic cell; The discharge end of the methane combustion power generation subsystem is connected to the input end of the carbon dioxide capture device.

7. The air energy storage integrated system coupled with hydrogen energy and carbon dioxide capture according to claim 3 is characterized in that: The methane combustion power generation subsystem includes a combustion chamber and a gas turbine. The first input end of the combustion chamber is connected to the methane cache tank, and the second input end of the combustion chamber is connected to the compressed air storage tank through a third compressed air pipeline; the output end of the combustion chamber is connected to the gas turbine, and the gas turbine is connected to the power grid through a generator.

8. The air energy storage integrated system coupled with hydrogen energy and carbon dioxide capture according to claim 2, characterized in that: The air energy storage subsystem also includes a hot water tank and a cold water tank. The output end of the hot water tank is connected to the input end of the cold water tank through the heat release side of the heat exchanger, and the output end of the cold water tank is connected to the input end of the hot water tank through the heat absorption side of the compressor stage aftercooler.

9. The air energy storage integrated system for coupling hydrogen energy and carbon dioxide capture according to any one of claims 1 to 8, characterized in that: The reaction heat recovery subsystem also includes a solid phase heat accumulator, which includes an energy storage input end, an energy release output end, a waste heat recovery input end, and a discharge end; The energy storage input end of the solid phase heat accumulator is connected to the energy storage module; The energy release output end of the solid phase heat accumulator is connected to the energy release module; The waste heat recovery input end of the solid phase heat accumulator is connected to all the reaction heat recovery subsystems.

10. An integrated method for air energy storage coupled with hydrogen energy and carbon dioxide capture, performed using the integrated system for air energy storage coupled with hydrogen energy and carbon dioxide capture as claimed in any one of claims 1 to 9; the integrated method for air energy storage coupled with hydrogen energy and carbon dioxide capture comprises: The air energy storage and power transmission step includes an energy storage stage and an energy release stage. The energy storage stage uses the energy storage module of the air energy storage subsystem to prepare and store compressed air. The energy release stage uses the energy release module of the air energy storage subsystem to heat the compressed air and then expand it to perform work to generate electricity. A methanation step, in which methane is produced by reacting hydrogen and carbon dioxide through a methanation subsystem; A methane combustion power generation step, in which methane is burned in compressed air to produce work through a methane combustion power generation subsystem, so as to transmit electricity to the power grid; The reaction heat recovery step recovers the heat generated by the methanation subsystem and introduces the heat into the energy release module to heat the compressed air in the energy release stage.

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