Lining structure for underground salt cavern hydrogen storage

Abstract

The invention discloses a lining structure for underground salt cavern hydrogen storage, which comprises an inner layer, a load transfer layer and an outer layer, and the inner layer is made of a hydrogen embrittlement resistant material; the load transfer layer comprises an inner film layer, an outer film layer, a plurality of pressure sensors, a plurality of supporting bodies and a rigidity adjusting assembly, and the rigidity adjusting assembly is used for controlling the rigidity of the supporting bodies according to the liquid pressure detected by the pressure sensors; the outer film layer is sleeved with the outer layer, and the outer layer is used for transferring the borne load to surrounding rock. The inner layer is made of the hydrogen embrittlement-resistant material, the hydrogen embrittlement influence of hydrogen on the lining structure is reduced from the source, the durability of the contact part of the structure and the hydrogen is improved, the material performance degradation caused by hydrogen embrittlement is reduced, the risk that a storage tank and a pipeline are broken is further reduced, and meanwhile, through adjustment of the rigidity of the supporting body, it is guaranteed that the storage tank and the pipeline cannot be damaged even if damage occurs. And the inner layer cannot be damaged due to the fact that the pressure cannot be transmitted, so that the whole lining structure can better adapt to underground complex and changeable environments.

Description

Technical Field

[0001] The present invention relates to the technical field of underground salt cavern hydrogen storage, and particularly relates to a lining structure for underground salt cavern hydrogen storage. Background Art

[0002] In the process of actively promoting the transformation to clean energy globally, hydrogen energy, as a highly potential clean energy carrier, is attracting increasing widespread attention. However, hydrogen energy faces many severe challenges in the storage and transportation links, among which the problem of hydrogen embrittlement of materials is particularly prominent.

[0003] Hydrogen embrittlement refers to the phenomenon that hydrogen atoms or hydrogen molecules penetrate into the interior of metal materials, resulting in the deterioration of the mechanical properties of the materials, a significant increase in brittleness, and ultimately the cracking or fracture of the materials. This problem frequently occurs in common metal materials such as high-strength steel, titanium alloy, aluminum alloy, and certain nickel-based alloys. Due to the wide application of these metal materials in various engineering structures, the existence of hydrogen embrittlement poses a serious threat to the safety of engineering structures.

[0004] In the crucial field of underground salt cavern hydrogen storage systems, the problem is even more intractable. Underground salt cavern hydrogen storage has become a highly potential hydrogen energy storage method due to its cost-effectiveness and large-scale storage capacity. However, in this system, high-pressure hydrogen will accelerate the embrittlement process of high-strength steel materials under long-term action. This not only greatly increases the risk of rupture of storage tanks and pipelines but also may lead to hydrogen leakage, thereby triggering serious safety accidents and environmental pollution problems.

[0005] Regarding the problem of hydrogen embrittlement of materials, researchers have carried out a large amount of research work, which is currently mainly focused on the development of hydrogen embrittlement-resistant alloys or coatings. Although certain progress has been made, no high-strength steel material that can completely resist the influence of hydrogen embrittlement has been found so far. This technical bottleneck severely restricts the large-scale, safe, and stable application of underground salt cavern hydrogen storage systems, and there is an urgent need for new technical solutions to solve this difficult problem. Summary of the Invention

[0006] The purpose of the present invention is to overcome the above technical deficiencies, and propose a lining structure for underground salt cavern hydrogen storage, so as to solve the technical problems in the prior art such as the decline of the mechanical properties of high-strength steel materials in underground salt cavern hydrogen storage systems due to material hydrogen embrittlement, the increased risk of rupture of storage tanks and pipelines, and the hidden danger of hydrogen leakage.

[0007] To achieve the above technical purpose, the present invention adopts the following technical solutions:

[0008] The present invention provides a lining structure for underground salt cavern hydrogen storage, including:

[0009] An inner layer, which is made of hydrogen embrittlement-resistant material;

[0010] Load transfer layer, the load transfer layer includes an inner membrane layer, an outer membrane layer, a plurality of pressure sensors, a plurality of supports and a stiffness adjustment component. The inner membrane layer is sleeved outside the inner layer, the outer membrane layer is sleeved outside the inner membrane layer, and an accommodation space for encapsulating liquid is formed between the outer membrane layer and the inner membrane layer. A plurality of the pressure sensors are uniformly arranged between the inner membrane layer and the outer membrane layer and are used to detect the pressure of the liquid therein. A plurality of the supports are uniformly arranged between the inner membrane layer and the outer membrane layer. The stiffness adjustment component is used to control the stiffness of each support according to the pressure of the liquid detected by the pressure sensor; and,

[0011] Outer layer, the outer layer is sleeved outside the outer membrane layer and is used to transfer the applied load to the surrounding rock.

[0012] In some embodiments, the stiffness adjustment component is used to control the stiffness of each support according to the pressure of the liquid detected by the pressure sensor, specifically:

[0013] When the pressure value detected by any of the pressure sensors is lower than the preset pressure value, the stiffness adjustment component increases the stiffness of each support to the preset stiffness to transfer the pressure of the inner membrane layer to the outer membrane layer through the support.

[0014] In some embodiments, the support is a polycaprolactone block. One end of the polycaprolactone block is fixed to the inner membrane layer, and the other end of the polycaprolactone block is fixed to the outer membrane layer. A cooling channel is formed in the polycaprolactone block. In a certain set direction, the cooling channel of the latter polycaprolactone block is communicated with the cooling channel of the previous polycaprolactone block;

[0015] The stiffness adjustment component includes a freezer, a pump body, an inlet pipe, an outlet pipe and a refrigerator. The freezer stores a refrigerant. The inlet of the pump body is communicated with the freezer. One end of the inlet pipe is communicated with the outlet of the pump body, and the other end of the inlet pipe is communicated with the cooling channel of the first polycaprolactone block. One end of the outlet pipe is communicated with the cooling channel of the last polycaprolactone block, and the other end of the outlet pipe is communicated with the freezer. The refrigerator is used to refrigerate the refrigerant in the freezer.

[0016] In some embodiments, an inlet valve is arranged on the inlet pipe, and an outlet valve is arranged on the outlet pipe.

[0017] In some embodiments, a temperature sensor is arranged in the freezer, and the refrigerator is a semiconductor refrigerator or a compression refrigerator.

[0018] In some embodiments, in a certain set direction, the cooling channel of the latter polycaprolactone block is communicated with the cooling channel of the previous polycaprolactone block through a first connecting pipe.

[0019] In some embodiments, the lining structure for underground salt cavern hydrogen storage further includes an outer conduction mechanism. The outer conduction mechanism includes a number of conduction members, which are evenly arranged on the outer side wall of the outer layer and are used to transfer the load of the outer layer to the surrounding rock. The conduction member includes a first patch, a second patch, a sleeve, a piston and a shaft rod. The first patch is fixedly attached to the outer wall of the outer layer, the second patch is fixedly attached to the surrounding rock, the sleeve is fixed to the first patch, the piston is slidably arranged in the sleeve to form a variable-volume oil storage cavity in the sleeve, a through hole communicating with the oil storage cavity is formed on the sleeve, the through holes of every two adjacent conduction members are communicated, one end of the shaft rod is fixed to the piston, and the other end of the shaft rod is fixedly connected to the second patch.

[0020] In some embodiments, the through holes of every two adjacent conduction members are communicated through a second connecting pipe.

[0021] In some embodiments, the first patch is welded to the outer side wall of the outer layer.

[0022] In some embodiments, the second patch is fixed to the surrounding rock through a number of expansion bolts.

[0023] Compared with the prior art, the beneficial effects of the lining structure for underground salt cavern hydrogen storage provided by the present invention include:

[0024] (1)Enhanced hydrogen embrittlement resistance: The inner layer uses hydrogen embrittlement-resistant materials, which reduces the hydrogen embrittlement effect of hydrogen on the lining structure from the source, improves the durability of the part of the structure in contact with hydrogen, reduces the deterioration of material properties caused by hydrogen embrittlement, and thus reduces the risk of rupture of storage tanks and pipelines, greatly enhancing the safety of the underground salt cavern hydrogen storage system;

[0025] (2)Optimized load transfer mechanism: The pressure of the inner layer is transmitted to the inner membrane layer. The pressure received by the inner membrane layer can be smoothly transmitted to the outer membrane layer through the liquid contained between the inner membrane layer and the outer membrane layer, and then transmitted from the outer membrane layer to the outer layer, and the outer layer transmits the pressure to the surrounding rock. This pressure transfer mechanism can evenly transmit the pressure received by the inner layer to the surrounding rock, ensure that the load can be reasonably distributed and effectively transmitted, avoid local stress concentration, and improve the mechanical properties and stability of the structure;

[0026] (3) Improve the structural safety and reliability: The technical solution fully considers the possible damage of the inner membrane layer or the outer membrane layer in the design. By adjusting the stiffness of the support body, it ensures that even if damage occurs, the inner layer will not be damaged due to the inability to transmit pressure. Coupled with the protective effect of the outer layer, the entire lining structure can better adapt to the complex and changeable underground environment, effectively reducing the possibility of structural deformation and damage, reducing the hidden danger of hydrogen leakage, and significantly improving the reliability and service life of the underground salt cavern hydrogen storage system. Description of the Drawings

[0027] Figure 1 is a schematic structural diagram of a lining structure for underground salt cavern hydrogen storage provided by an embodiment of the present invention;

[0028] Figure 2 is Figure 1 a partial enlarged view of area A in

[0029] Figure 3 is Figure 1 a partial enlarged view of area B in

[0030] Figure 4 is Figure 1 a schematic structural diagram of the stiffness adjustment component in

[0031] Description of the reference numerals: 1 - inner layer, 2 - load transfer layer, 21 - inner membrane layer, 22 - outer membrane layer, 23 - pressure sensor, 24 - support body, 241 - cooling channel, 25 - stiffness adjustment component, 251 - freezer, 2511 - temperature sensor, 252 - pump body, 253 - inlet pipe, 2531 - inlet valve, 254 - outlet pipe, 2541 - outlet valve, 255 - refrigerator, 26 - first connecting pipe, 3 - outer layer, 4 - outer conduction mechanism, 41 - conduction member, 411 - first patch, 412 - second patch, 4121 - expansion bolt, 413 - sleeve, 4131 - through hole, 414 - piston, 415 - shaft rod, 42 - second connecting pipe, 5 - surrounding rock. Detailed Description of the Embodiment

[0032] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] In order to solve the technical problems in the prior art such as the decline of the mechanical properties of high-strength steel materials in the underground salt cavern hydrogen storage system due to hydrogen embrittlement of materials, the increased risk of rupture of storage tanks and pipelines, and the hidden danger of hydrogen leakage, the present invention provides a lining structure for underground salt cavern hydrogen storage, which can reduce the impact of material hydrogen embrittlement on the underground salt cavern hydrogen storage system and improve the stability of the underground salt cavern hydrogen storage system.

[0034] Please refer to Figures 1-4 , Figure 1 which is a schematic structural diagram of a lining structure for underground salt cavern hydrogen storage in an embodiment of the present invention. The lining structure for underground salt cavern hydrogen storage includes an inner layer 1, a load transfer layer 2, and an outer layer 3.

[0035] The inner layer 1 is made of a hydrogen embrittlement-resistant material. In this embodiment, the inner layer 1 is made of low-carbon steel or other hydrogen embrittlement-resistant metals as the inner layer to reduce the influence of high-pressure hydrogen on the material.

[0036] The load transfer layer 2 includes an inner membrane layer 21, an outer membrane layer 22, a plurality of pressure sensors 23, a plurality of support bodies 24, and a stiffness adjustment component 25. The inner membrane layer 21 is sleeved outside the inner layer 1, the outer membrane layer 22 is sleeved outside the inner membrane layer 21, and a receiving space for encapsulating liquid is formed between the outer membrane layer 22 and the inner membrane layer 21. A plurality of the pressure sensors 23 are uniformly arranged between the inner membrane layer 21 and the outer membrane layer 22 and are used to detect the pressure of the liquid therein. A plurality of the support bodies 24 are uniformly arranged between the inner membrane layer 21 and the outer membrane layer 22, and the stiffness adjustment component 25 is used to control the stiffness of each of the support bodies 24 according to the pressure of the liquid detected by the pressure sensors 23.

[0037] The outer layer 3 is sleeved outside the outer membrane layer 22 and is used to transfer the applied load to the surrounding rock.

[0038] The working process of the above solution is as follows: The inner layer 1 conducts hydrogen storage operation. Hydrogen comes into contact with the inner layer 1 made of hydrogen embrittlement-resistant material. Relying on its special material properties, the inner layer 1 can effectively resist the hydrogen embrittlement phenomenon that may be caused by hydrogen, preventing the degradation of material properties. At the same time, the pressure of hydrogen acts on the inner layer 1, and the pressure of the inner layer 1 is transmitted to the inner membrane layer 21. At normal temperature, the stiffness of the support body 24 is very low. The pressure on the inner membrane layer 21 from hydrogen and the like can be smoothly transmitted to the outer membrane layer 22 through the liquid contained between the inner membrane layer 21 and the outer membrane layer 22, and then transmitted from the outer membrane layer 22 to the outer layer 3, and the outer layer 3 transmits the pressure to the surrounding rock 5. This pressure transmission mechanism can evenly transmit the pressure received by the inner layer 1 to the surrounding rock 5, reducing the load on the inner layer 1; when the inner membrane layer 21 or the outer membrane layer 22 is damaged, resulting in leakage of the liquid contained between the two, the liquid pressure will decrease accordingly. The pressure sensors 23 evenly arranged between the inner membrane layer 21 and the outer membrane layer 22 will detect this pressure change and feedback the pressure value to the stiffness adjustment component 25. After receiving the pressure data feedback by the pressure sensors 23, the stiffness adjustment component 25 compares it with the preset pressure value. Once it is found that the pressure value detected by any pressure sensor 23 is lower than the preset pressure value, the stiffness adjustment component 25 will activate the adjustment mechanism. After the stiffness adjustment component 25 is activated, it will increase the stiffness of each support body 24 to the preset stiffness. At this time, the originally very low-stiffness support body 24 has significantly enhanced its ability to bear and transmit pressure. After the stiffness is increased, the support body 24 can more effectively transmit the pressure received by the inner membrane layer 21 to the outer membrane layer 22, realizing the transfer of the load from the inner membrane layer 21 to the outer membrane layer 22. Even when the inner membrane layer 21 or the outer membrane layer 22 is in a damaged state, it can ensure the effective transmission of pressure and avoid damage to the inner layer 1 due to the inability to transmit pressure.

[0039] The technical effects of the above solution include:

[0040] (1) Enhanced hydrogen embrittlement resistance: The inner layer 1 uses hydrogen embrittlement-resistant material, which reduces the hydrogen embrittlement effect of hydrogen on the lining structure from the source, improves the durability of the part of the structure in contact with hydrogen, reduces the degradation of material properties caused by hydrogen embrittlement, and further reduces the risk of rupture of storage tanks and pipelines, greatly enhancing the safety of the underground salt cavern hydrogen storage system;

[0041] (2) Optimized load transmission mechanism: The pressure of the inner layer 1 is transmitted to the inner membrane layer 21. The pressure received by the inner membrane layer 21 can be smoothly transmitted to the outer membrane layer 22 through the liquid contained between the inner membrane layer 21 and the outer membrane layer 22, and then transmitted from the outer membrane layer 22 to the outer layer 3, and the outer layer 3 transmits the pressure to the surrounding rock 5. This pressure transmission mechanism can evenly transmit the pressure received by the inner layer 1 to the surrounding rock 5, ensuring that the load can be reasonably distributed and effectively transmitted, avoiding local stress concentration, and improving the mechanical properties and stability of the structure;

[0042] (3) Improve the structural safety and reliability: This technical solution fully considers the possible damage of the inner membrane layer or the outer membrane layer in the design. By adjusting the stiffness of the support body, it ensures that even if damage occurs, the inner layer 1 will not be damaged due to the inability to transmit pressure. Coupled with the protective effect of the outer layer 3, the entire lining structure can better adapt to the complex and changeable underground environment, effectively reducing the possibility of structural deformation and damage, reducing the hidden danger of hydrogen leakage, and significantly improving the reliability and service life of the underground salt cavern hydrogen storage system.

[0043] In one embodiment, please refer to Figures 1-4 , the stiffness adjustment component 25 is used to control the stiffness of each support body 24 according to the pressure of the liquid detected by the pressure sensor 23. Specifically:

[0044] When the pressure value detected by any pressure sensor 23 is lower than the preset pressure value, the stiffness adjustment component 25 increases the stiffness of each support body 24 to the preset stiffness, so as to transmit the pressure of the inner membrane layer 21 to the outer membrane layer 22 through the support body 24.

[0045] In one embodiment, please refer to Figures 1-4 , the support body 24 is a polycaprolactone block. One end of the polycaprolactone block is fixed to the inner membrane layer 21, and the other end of the polycaprolactone block is fixed to the outer membrane layer 22. A cooling channel 241 is formed in the polycaprolactone block. In a certain set direction, the cooling channel 241 of the latter polycaprolactone block is communicated with the cooling channel 241 of the previous polycaprolactone block; the stiffness adjustment component 25 includes a freezer 251, a pump body 252, a liquid inlet pipe 253, a liquid outlet pipe 254 and a refrigerator 255. The freezer 251 stores a refrigerant. The inlet of the pump body 252 is communicated with the freezer 251. One end of the liquid inlet pipe 253 is communicated with the outlet of the pump body 252, and the other end of the liquid inlet pipe 253 is communicated with the cooling channel 241 of the first polycaprolactone block. One end of the liquid outlet pipe 254 is communicated with the cooling channel 241 of the last polycaprolactone block, and the other end of the liquid outlet pipe 254 is communicated with the freezer 251. The refrigerator 255 is used to cool the refrigerant in the freezer 251.

[0046] In this embodiment, polycaprolactone has the characteristic of changing its own properties with temperature. The chiller 255 cools the refrigerant in the freezer 251. Under the action of the pump body 252, the low-temperature refrigerant can flow in the liquid inlet pipe 253 and the cooling channel 241 to cool the polycaprolactone block. After the polycaprolactone block is cooled, its stiffness increases, thereby effectively adjusting the stiffness of the support 24. When the inner membrane layer 21 or the outer membrane layer 22 is damaged and the liquid pressure decreases, the stiffness of the support 24 can be increased in time to ensure that the pressure of the inner membrane layer 21 can be transmitted to the outer membrane layer 22 through the support 24, avoiding damage to the inner layer 1 due to the inability to transmit pressure, and improving the stability and reliability of the entire lining structure. At the same time, the cooling channels 241 communicate with each other within the polycaprolactone block, and the liquid inlet pipe 253, the liquid outlet pipe 254, the freezer 251, and the cooling channels 241 of the polycaprolactone block form a complete circulation system. The refrigerant enters the cooling channel 241 of the polycaprolactone block from the freezer 251 through the pump body 252 and the liquid inlet pipe 253. After cooling the polycaprolactone block, it flows back to the freezer 251 through the liquid outlet pipe 254 and can be recycled after being cooled by the chiller 255 again. This circulating cooling system can continuously and stably provide a low-temperature environment for the polycaprolactone block, ensuring the stability and continuity of the stiffness adjustment of the support 24.

[0047] In one embodiment, please refer to Figures 1-4 , a liquid inlet valve 2531 is provided on the liquid inlet pipe 253, and a liquid outlet valve 2541 is provided on the liquid outlet pipe 254. In this embodiment, the liquid inlet valve 2531 and the liquid outlet valve 2541 can flexibly control the circulation of the refrigerant in the system. When it is necessary to increase the stiffness of the support 24 (polycaprolactone block), the liquid inlet valve 2531 and the liquid outlet valve 2541 can be opened to enable the refrigerant in the freezer 251 to flow into the cooling channel 241 of the polycaprolactone block under the action of the pump body 252 and then flow back to the freezer 251 through the liquid outlet pipe 254, realizing the cooling of the support to increase the stiffness. When the stiffness adjustment is not required, these two valves can be closed to stop the circulation of the refrigerant and avoid unnecessary energy consumption and system operation losses.

[0048] In one embodiment, please refer to Figures 1-4, a temperature sensor 2511 is provided in the freezer compartment 251, and the refrigerator 255 is a semiconductor refrigerator or a compressor refrigerator. In this embodiment, the temperature sensor 2511 is provided in the freezer compartment 251, which can monitor the temperature of the refrigerant in the freezer in real time. Whether it is a semiconductor refrigerator or a compressor refrigerator, the refrigeration power can be adjusted according to the temperature data feedback by the temperature sensor. When the temperature is higher than the set value, the refrigerator increases the refrigeration intensity to lower the temperature of the refrigerant; when the temperature reaches or approaches the set value, the refrigerator appropriately reduces the refrigeration power to keep the temperature stable. In this way, the temperature of the refrigerant can be accurately controlled, and then the stiffness of the support (polycaprolactone block) can be adjusted more precisely, because the stiffness change of the polycaprolactone block is closely related to the temperature. The stable temperature of the refrigerant helps to achieve the stable adjustment of the stiffness of the support and improve the stability and reliability of the load transfer of the entire lining structure. The freezer compartment 251 is made of heat-insulating materials, and the refrigerant in the compartment can always be maintained at a low temperature whether it is in the stiffness adjustment stage or not. In this way, when the stiffness of the support needs to be adjusted, the low-temperature refrigerant can be immediately transported into the support without waiting for the refrigerant in the freezer compartment 251 to cool down, so as to quickly increase the stiffness of the support.

[0049] In one embodiment, please refer to Figures 1-4 , in a certain set direction, the cooling channel 241 of the latter polycaprolactone block is connected to the cooling channel 241 of the previous polycaprolactone block through the first connecting pipe 26.

[0050] In one embodiment, please refer to Figures 1-4, the lining structure for underground salt cavern hydrogen storage further includes an external conduction mechanism 4. The external conduction mechanism 4 includes a number of conduction members 41. The conduction members 41 are uniformly arranged on the outer side wall of the outer layer 3 and are used to transfer the load of the outer layer 3 to the surrounding rock 5. The conduction member 41 includes a first patch 411, a second patch 412, a sleeve 413, a piston 414 and a shaft rod 415. The first patch 411 is fixedly attached to the outer wall of the outer layer 3. The second patch 412 is fixedly attached to the surrounding rock 5. The sleeve 413 is fixed to the first patch 411. The piston 414 is slidably disposed in the sleeve 413 to form an oil storage cavity with variable volume in the sleeve 413. A through hole 4131 communicating with the oil storage cavity is formed in the sleeve 413. The through holes 4131 of every two adjacent conduction members 41 are communicated, so as to ensure that the oil pressures in the oil storage cavities of all the sleeves 413 are equal. In this way, the pressure borne by each shaft rod 415 can be ensured to be equal. One end of the shaft rod 415 is fixed to the piston 414, and the other end of the shaft rod 415 is fixedly connected to the second patch 412. During use, when the pressure on a certain shaft rod increases due to the change in the shape of the salt cavern, the pressure will be evenly conducted to other shaft rods, so that the pressure on each part of the outer side wall of the outer layer 3 is kept in a balanced state.

[0051] In this embodiment, the outer conduction mechanism 4 transfers the load borne by the outer layer 3 to the surrounding rock 5 through the conduction members 41 uniformly arranged on the outer sidewall. In the complex environment of an underground salt cavern, the outer layer 3 of the lining structure will bear various loads such as formation pressure. The presence of the conduction members 41 enables these loads to be smoothly conducted to the surrounding rock 5, reducing the pressure borne by the outer layer 3 alone, improving the bearing capacity and stability of the entire lining structure, and ensuring the safe operation of the underground salt cavern hydrogen storage system. The internal structure of the conduction member 41 is ingeniously designed. The piston 414 forms an oil storage cavity with variable volume within the sleeve 413, and the through holes 4131 of adjacent conduction members 41 are interconnected. This design makes the oil pressure in the oil storage cavities of each sleeve 413 always equal, thereby ensuring that each shaft rod 415 bears equal pressure. The uniform pressure distribution avoids damage to some shaft rods due to excessive stress, extends the service life of the outer conduction mechanism 4, and improves its working reliability. Moreover, when the shape of the salt cavern changes and the pressure on a certain shaft rod increases, the pressure can be quickly and evenly conducted to other shaft rods. This automatic pressure balance mechanism ensures that the forces on each part of the outer sidewall of the outer layer 3 always remain in a balanced state. Even when the shape of the salt cavern changes due to geological activities and other factors, the lining structure can still operate stably, reducing the risk of structural deformation and rupture caused by local pressure unevenness, and enhancing the ability of the underground salt cavern hydrogen storage lining structure to adapt to complex geological conditions. The outer conduction mechanism 4 tightly connects the outer layer 3 and the surrounding rock 5, making the entire underground salt cavern hydrogen storage lining structure form an organic whole. This integrity improves the ability of the structure to resist external interference, helps to enhance the long-term stability of the underground salt cavern hydrogen storage system, and provides a strong guarantee for the safe storage of hydrogen.

[0052] In one of the embodiments, please refer to Figures 1-4 , the through holes 4131 of every two adjacent conduction members 41 are connected through the second connecting pipe 42.

[0053] In one of the embodiments, please refer to Figures 1-4 , the first patch 411 is welded to the outer sidewall of the outer layer 3.

[0054] In one of the embodiments, please refer to Figures 1-4 , the second patch 412 is fixed to the surrounding rock 5 through a plurality of expansion bolts 4121, thereby improving the integration degree of the second patch 412 and the surrounding rock 5 to facilitate better transfer of the load to the surrounding rock.

[0055] In summary, the technical effects of the technical solution provided by the present invention include:

[0056] (1)Enhance the resistance to hydrogen embrittlement: The inner layer 1 is made of hydrogen embrittlement-resistant material, which reduces the hydrogen embrittlement effect of hydrogen on the lining structure at the source, improves the durability of the part of the structure in contact with hydrogen, reduces the deterioration of material properties caused by hydrogen embrittlement, and further reduces the risk of rupture of storage tanks and pipelines, greatly enhancing the safety of the underground salt cavern hydrogen storage system;

[0057] (2)Optimize the load transfer mechanism: The pressure of the inner layer 1 is transferred to the inner membrane layer 21. The pressure received by the inner membrane layer 21 can be smoothly transferred to the outer membrane layer 22 through the liquid contained between the inner membrane layer 21 and the outer membrane layer 22, and then transferred from the outer membrane layer 22 to the outer layer 3, and the outer layer 3 transfers the pressure to the surrounding rock 5. This pressure transfer mechanism can evenly transfer the pressure received by the inner layer 1 to the surrounding rock 5, ensuring that the load can be reasonably distributed and effectively transferred, avoiding local stress concentration, and improving the mechanical properties and stability of the structure;

[0058] (3)Improve the safety and reliability of the structure: This technical solution fully considers the possible damage of the inner membrane layer or the outer membrane layer in the design. By adjusting the stiffness of the support body, it is ensured that even if damage occurs, the inner layer 1 will not be damaged due to the inability to transfer pressure. Coupled with the protection of the outer layer 3, the entire lining structure can better adapt to the complex and changeable underground environment, effectively reducing the possibility of structural deformation and damage, reducing the hidden danger of hydrogen leakage, and significantly improving the reliability and service life of the underground salt cavern hydrogen storage system;

[0059] (4)The outer conduction mechanism 4 reliably transfers the load borne by the outer layer 3 to the surrounding rock 5 through the conduction parts 41 uniformly arranged on the outer sidewall. The piston 414 inside the conduction part 41 forms an oil storage cavity with variable volume in the sleeve 413, and the through holes 4131 of adjacent conduction parts 41 are interconnected. This design makes the oil pressure in the oil storage cavities of each sleeve 413 always equal, thereby ensuring that each shaft rod 415 bears equal pressure. The uniform pressure distribution avoids damage to some shaft rods due to excessive stress, extends the service life of the outer conduction mechanism 4, and improves its working reliability. Moreover, when the shape of the salt cavern changes and the pressure on a certain shaft rod increases, the pressure can be quickly and evenly conducted to other shaft rods. This automatic pressure balance mechanism ensures that the forces on all parts of the outer sidewall of the outer layer 3 always remain in a balanced state. Even when the shape of the salt cavern changes due to geological activities and other factors, the lining structure can still operate stably, reducing the risks of structural deformation and rupture caused by local pressure unevenness, and enhancing the ability of the underground salt cavern hydrogen storage lining structure to adapt to complex geological conditions.

[0060] The specific implementation manners of the present invention described above do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A lining structure for underground salt cavern hydrogen storage, characterized in that: include: An inner layer, wherein the inner layer is made of a hydrogen embrittlement resistant material; A load transfer layer, the load transfer layer includes an inner film layer, an outer film layer, a plurality of pressure sensors, a plurality of support bodies and a stiffness adjustment component, the inner film layer is sleeved outside the inner layer, the outer film layer is sleeved outside the inner film layer, a receiving space for encapsulating liquid is formed between the outer film layer and the inner film layer, a plurality of the pressure sensors are evenly arranged between the inner film layer and the outer film layer and are used to detect the pressure of the liquid therein, a plurality of the support bodies are evenly arranged between the inner film layer and the outer film layer, and the stiffness adjustment component is used to control the stiffness of each of the support bodies according to the pressure of the liquid detected by the pressure sensor; and, The outer layer is sleeved outside the outer membrane layer and is used to transfer the load to the surrounding rock.

2. The lining structure for underground salt cavern hydrogen storage according to claim 1, characterized in that: The stiffness adjustment component is used to control the stiffness of each of the supports according to the pressure of the liquid detected by the pressure sensor, specifically: When the pressure value detected by any of the pressure sensors is lower than a preset pressure value, the stiffness adjustment component increases the stiffness of each of the support bodies to a preset stiffness, so as to transmit the pressure of the inner membrane layer to the outer membrane layer through the support body.

3. The lining structure for underground salt cavern hydrogen storage according to claim 1, characterized in that: The support body is a polycaprolactone block, one end of the polycaprolactone block is fixed to the inner film layer, and the other end of the polycaprolactone block is fixed to the outer film layer. A cooling channel is formed in the polycaprolactone block, and in a certain set direction, the cooling channel of the latter polycaprolactone block is connected with the cooling channel of the former polycaprolactone block; The stiffness adjustment component includes a freezing chamber, a pump body, a liquid inlet pipe, a liquid outlet pipe and a refrigerator. Refrigerant is stored in the freezing chamber, the inlet of the pump body is connected to the freezing chamber, one end of the liquid inlet pipe is connected to the outlet of the pump body, the other end of the liquid inlet pipe is connected to the cooling channel of the first polycaprolactone block, one end of the liquid outlet pipe is connected to the cooling channel of the last polycaprolactone block, and the other end of the liquid outlet pipe is connected to the freezing chamber. The refrigerator is used to cool the refrigerant in the freezing chamber.

4. The lining structure for underground salt cavern hydrogen storage according to claim 3, characterized in that: The liquid inlet pipe is provided with a liquid inlet valve, and the liquid outlet pipe is provided with a liquid outlet valve.

5. The lining structure for underground salt cavern hydrogen storage according to claim 3, characterized in that: A temperature sensor is arranged in the freezing chamber, and the refrigerator is a semiconductor refrigerator or a compressor refrigerator.

6. The lining structure for underground salt cavern hydrogen storage according to claim 3, characterized in that: In a certain set direction, the cooling channel of the rear polycaprolactone block is connected with the cooling channel of the front polycaprolactone block through the first connecting pipe.

7. The lining structure for underground salt cavern hydrogen storage according to claim 1, characterized in that: It also includes an external conduction mechanism, which includes a plurality of conduction members, which are evenly arranged on the outer wall of the outer layer and are used to transfer the load of the outer layer to the surrounding rock. The conduction members include a first patch, a second patch, a sleeve, a piston and a shaft rod. The first patch is fixedly attached to the outer wall of the outer layer, the second patch is fixedly attached to the surrounding rock, the sleeve is fixed to the first patch, the piston is slidably arranged in the sleeve to form a variable-volume oil storage chamber in the sleeve, a through hole connected to the oil storage chamber is opened on the sleeve, and the through holes of every two adjacent conduction members are connected, one end of the shaft rod is fixed to the piston, and the other end of the shaft rod is fixedly connected to the second patch.

8. The lining structure for underground salt cavern hydrogen storage according to claim 7, characterized in that: The through holes of every two adjacent conductive members are connected through the second connecting pipe.

9. The lining structure for underground salt cavern hydrogen storage according to claim 7, characterized in that: The first patch is welded to the outer side wall of the outer layer.

10. The lining structure for underground salt cavern hydrogen storage according to claim 7, characterized in that: The second patch is fixed to the surrounding rock by a plurality of expansion bolts.

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