An underground energy storage sealed cavern and an underground energy storage sealed cavern system comprising the same

Abstract

The present application belongs to the technical field of energy storage, and particularly relates to an underground energy storage sealed cavern. The present application aims to solve the problem of large thickness size and poor air tightness of the sealing structure layer of the existing energy storage cavern. The present application first provides an underground energy storage sealed cavern, the energy storage sealed cavern body has a sealing structure layer, the sealing structure layer comprises a combined concrete sealing layer and an inner lining sealing layer from outside to inside, wherein the combined concrete sealing layer comprises at least one layer of casted ultra-high performance concrete layer, the at least one layer of casted ultra-high performance concrete layer is arranged at the innermost side of the combined concrete sealing layer, and the inner lining sealing layer is arranged in close contact with the inner surface of the layer of casted ultra-high performance concrete layer at the innermost side. Another purpose of the present application is to provide an underground energy storage sealed cavern system, which can provide a larger gas storage space under the premise of safety.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and more specifically, to an underground energy storage sealed chamber and an underground energy storage sealed chamber system including the same. Background Technology

[0002] Energy is the driving force behind human societal development. Throughout human history, with continuous advancements in productivity and the application of modern high technology, the demand for energy has become increasingly urgent. On the other hand, energy crises and energy depletion caused by over-exploitation threaten human society, while environmental pollution from the extensive use of unclean energy sources further exacerbates the deterioration of the Earth's environment. These issues have long attracted public attention, making the development of new, environmentally friendly energy sources an important part of human scientific practice, and energy storage methods a hot topic of discussion.

[0003] Air, hydrogen, and natural gas can be used as energy storage media. Compressed gas energy storage is a type of power storage that enables large-capacity and long-term electrical energy storage. It has advantages such as large capacity, long operating time, good economic performance, and multiple charge-discharge cycles. It is a practical way to help energy, transportation, petrochemical and other fields achieve deep decarbonization. However, the storage method of compressed gas is a technical challenge, and large-scale storage is even more difficult. At present, traditional compressed gas storage is mainly divided into above-ground storage and underground storage. Above-ground storage is mainly small-scale steel tank storage, which has limited volume and high cost, and has a high safety risk factor. Underground storage tanks are composed of a concrete inner lining and a steel plate sealing layer. However, the larger the diameter of the cylindrical storage tank, the greater the wall thickness required to withstand the pressure. The manufacturing and welding of steel plates are more difficult and costly. Moreover, the failure of the steel plate sealing layer can easily cause the storage tank to explode and be destroyed. Summary of the Invention

[0004] The present invention aims to overcome at least one of the defects of the prior art, and one of its objectives is to provide an underground energy storage sealed chamber to solve the problems of large thickness and poor airtightness of the sealing structure layer of existing energy storage chambers.

[0005] The technical solution adopted by this invention is to provide an underground energy storage sealed chamber. The energy storage sealed chamber body has a sealing structure layer, which includes a composite concrete sealing layer and an inner lining sealing layer from the outside to the inside. The composite concrete sealing layer includes at least one layer of cast ultra-high performance concrete, with at least one layer of cast ultra-high performance concrete located at the innermost side of the composite concrete sealing layer. The inner lining sealing layer is tightly attached to the inner surface of the innermost layer of cast ultra-high performance concrete. The composite concrete sealing layer includes at least one layer of cast ultra-high performance concrete, the thickness of which is 40-80 mm, the compressive strength of which is greater than 150 MPa, and the gas permeability of which is 1×10⁻⁶. -18 m 2 ~ 5×10 -19 m 2 The initial cracking strain of the cast ultra-high performance concrete layer is greater than 1000 microstrain.

[0006] In this scheme, ultra-high performance concrete is constructed using the principle of close packing. It is composed of cement, mineral admixtures, fine aggregates, additives, high-strength micro-steel fibers / or organic synthetic fibers, water, and other raw materials. After high-temperature activation, it exhibits superior properties compared to commonly used steel plate materials, including high compressive strength, high tensile strength, high durability, high toughness, high explosion resistance, high impact resistance, and low gas permeability. Furthermore, because the gas permeability of ultra-high performance concrete is much lower than that of ordinary concrete, the ultra-high performance concrete layer can also provide airtightness. Using a composite concrete sealing layer with ultra-high performance concrete in the sealing structure layer of the energy storage sealed chamber can solve the defects of insufficient airtightness and low structural strength in existing compressed gas energy storage. It can also save space occupied by the composite concrete sealing layer with less material, thereby providing high structural strength for the energy storage sealed chamber in conjunction with other concrete material layers in the composite concrete sealing layer, while also providing a larger compressed gas energy storage space. In addition, by setting an inner lining sealing layer on the inner wall of the composite concrete sealing layer, the gas in the energy storage sealed chamber can be provided with the first layer of airtight protection, thereby forming a multi-layer sealing effect in conjunction with the outer ultra-high performance concrete layer. At the same time, the inner lining sealing layer also has multiple effects such as preventing the loosening and delamination of the rock strata, solving the stability of the surrounding rock of the chamber, and preventing excessive groundwater from penetrating into the chamber, which can greatly improve the safety of gas storage.

[0007] Based on the parameter settings of the thickness, compressive strength, gas permeability, and initial cracking strain of the ultra-high performance concrete layer in this scheme, the ultra-high performance concrete layer can have good airtightness and structural strength, while also reducing the space occupied by the composite concrete sealing layer. Thus, under the same construction space conditions, it can provide a larger energy storage space for the underground energy storage sealing chamber.

[0008] Furthermore, a plurality of first fixing members are provided between the composite concrete sealing layer and the surrounding rock. Preferably, the first fixing members are anchor rods, and the two ends of the anchor rods are respectively inserted into the surrounding rock and the composite concrete sealing layer.

[0009] This solution improves the bond strength between the composite concrete sealing layer and the surrounding rock by using anchor bolts, greatly reducing the chance of the composite concrete sealing layer detaching and enhancing the structural strength of the sealing structure layer.

[0010] Furthermore, a plurality of second fasteners are provided between the inner lining sealing layer and the cast ultra-high performance concrete layer. Preferably, the second fasteners are herringbone anchors, which are sequentially embedded into the inner walls of the inner lining sealing layer and the composite concrete sealing layer to make the inner lining sealing layer fit against the inner wall of the composite concrete sealing layer.

[0011] This solution uses herringbone anchors to ensure the inner lining sealing layer is securely attached to the inner wall of the composite concrete sealing layer, thereby increasing the bond strength between the two and reducing the likelihood of the inner lining sealing layer falling off.

[0012] Further, the diameter of the anchor rod is 20-30 mm; and / or, the length of the anchor rod is 920-1520 mm; and / or, the length of the portion of the anchor rod embedded in the surrounding rock is 600-1200 mm; and / or, the spacing between multiple anchor rods is 1000-2000 mm.

[0013] Based on the diameter, length, length of the rock-embedded section, and spacing of the anchor bolts in this scheme, on the one hand, the anchor bolts have good connection strength when placed on the rock-embedded section, and on the other hand, the composite concrete sealing layer maintains good bonding force between the anchor bolts and the rock-embedded section, greatly reducing the probability of the composite concrete sealing layer falling off.

[0014] Furthermore, the composite concrete sealing layer also includes at least one layer of sprayed self-stressing concrete, wherein the at least one layer of sprayed self-stressing concrete and the at least one layer of cast ultra-high performance concrete are stacked from the outside to the inside.

[0015] This solution improves the structural strength of the composite concrete sealing layer by layering a sprayed self-stressing concrete layer and a cast ultra-high performance concrete layer, while reducing the amount of material and thickness of the sealing layer, thus providing a larger energy storage space. In addition, after the failure of the inner lining sealing layer or after an accidental overpressure in the energy storage sealing chamber, the strong airtightness of the composite concrete sealing layer can ensure that gas does not leak and the energy storage sealing chamber is not damaged.

[0016] Preferably, the thickness of each layer of the sprayed self-stressing concrete is 80~400mm, and / or the self-stress of each layer of the sprayed self-stressing concrete is not less than 1MPa, and / or the compressive strength of each layer of the sprayed self-stressing concrete is not less than 40MPa.

[0017] Based on the parameter settings of thickness, self-stress, and compressive strength in this scheme, the sprayed self-stressed concrete layer can have excellent structural strength, save material usage, reduce the thickness of the composite concrete sealing layer, ensure a high safety factor for the energy storage sealing chamber, and provide a larger gas storage space.

[0018] In some embodiments, the sprayed self-stressing concrete layer is a sprayed self-stressing ultra-high performance concrete layer. Preferably, the thickness of each layer of the sprayed self-stressing ultra-high performance concrete layer is 80~120mm.

[0019] This solution uses a sprayed self-stressed ultra-high performance concrete layer, which can reduce the amount of material used, thereby reducing the overall thickness of the composite concrete sealing layer. Furthermore, the high airtightness and high structural strength of ultra-high performance concrete enhance the sealing effect and safety performance of the energy storage sealing chamber sealing structure layer.

[0020] Furthermore, each layer of ultra-high performance concrete is provided with a second steel mesh layer inside.

[0021] By providing an additional support structure inside the cast ultra-high performance concrete layer through the second steel mesh layer, the structural strength of the cast ultra-high performance concrete layer is improved, which can enhance the overall performance of the composite concrete sealing layer and help to achieve the safety and reliability of the sealing structure layer of the energy storage sealing chamber.

[0022] Preferably, the volume of each layer of the second steel mesh is not less than 1.5% of the volume of the corresponding ultra-high performance concrete layer, and / or, each layer of the second steel mesh is formed by a plurality of second steel bars, the diameter of which is 4 to 10 mm, and / or, each layer of the second steel mesh has a plurality of second grids, the side length of which is 100 to 300 mm, and / or, the protective layer thickness of each layer of the second steel mesh is 25 to 40 mm.

[0023] Based on the settings for the volume, spacing, diameter of the second steel bar, and thickness of the protective layer in this scheme, the support strength of the second steel bar layer for the cast ultra-high performance concrete layer is improved.

[0024] Furthermore, each layer of the sprayed self-stressing concrete is provided with a first steel mesh layer inside.

[0025] This solution provides an additional support structure inside the sprayed self-stressing concrete layer through a first steel mesh, thereby enhancing the structural strength of the sprayed self-stressing concrete layer.

[0026] Preferably, the volume of the first steel mesh layer is not less than 1.5% of the volume of the corresponding sprayed self-stressing concrete layer, and / or, the first steel mesh layer is formed by a plurality of first steel bars, the diameter of the first steel bars being 8~12mm; and / or, the first steel mesh layer has a plurality of first grids, the side length of the first grids being 100~300mm; and / or, the protective layer thickness of the first steel mesh layer is 30~50mm.

[0027] Based on the settings for the volume, spacing, diameter of the first steel bar, and thickness of the protective layer in this scheme, the support strength of the first steel bar layer for the poured ultra-high performance concrete layer is improved.

[0028] Furthermore, the inner lining sealing layer is a high-density polyethylene layer.

[0029] This solution leverages the excellent airtightness of high-density polyethylene (HDPE) material to improve the sealing of the gas inside the energy storage sealed chamber. Furthermore, its extremely low water absorption prevents moisture from the surrounding rock from seeping into the chamber. Additionally, its high resistance to acid and alkali corrosion enhances the durability of the inner lining sealing layer, reducing maintenance and replacement costs.

[0030] Preferably, the thickness of the high-density polyethylene layer is 4~6mm, and / or the yield tensile strength of the high-density polyethylene layer is not less than 30MPa, and / or the ultimate tensile strength of the high-density polyethylene layer is not less than 50MPa, and / or the temperature resistance range of the high-density polyethylene layer is -50℃~90℃.

[0031] In this solution, the thickness, yield tensile strength, ultimate tensile strength, and temperature range of the high-density polyethylene layer are limited, which allows the inner lining to meet the storage requirements of more types of energy storage gases and provides better sealing and safety.

[0032] Furthermore, the shear strength between the high-density polyethylene layer and the inner wall of the composite concrete sealing layer through the herringbone anchor is not less than 20 MPa, the anchoring section bonding strength of the herringbone anchor is not less than 10 MPa, and the depth of the herringbone anchor into the composite concrete sealing layer is not less than 20 mm.

[0033] Furthermore, each of the energy storage sealed chambers is provided with a hollow cylindrical part and two hemispherical ends located at both ends of the hollow cylindrical part, and both the hollow cylindrical part and the hemispherical ends have the sealing structure layer.

[0034] Optionally, the inner diameter of the hollow cylindrical part is 8~15m, preferably 8m, and the length is 80~150m, preferably 80m.

[0035] Another object of the present invention is to provide an underground energy storage sealed chamber system, comprising at least two said energy storage sealed chambers, wherein the at least two said energy storage sealed chambers are arranged side by side along the radial direction of the cross section of the energy storage sealed chambers, and a connecting component for connecting the two is provided between the energy storage sealed chamber bodies of two adjacent said energy storage sealed chambers.

[0036] Optionally, the distance between adjacent energy storage sealed chambers is 50~80m.

[0037] Based on the spacing of this scheme, the gas storage space can be fully utilized while ensuring the safety of the energy storage sealed chamber.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The underground energy storage sealed chamber of the present invention has a much larger volume than the existing ground steel tank. By storing high-pressure gas in the underground energy storage sealed chamber, the storage volume is greatly increased, gas loss is reduced, and the application range is wide.

[0039] (2) The safety risk of the underground energy storage sealed chamber of the present invention is significantly reduced. When the underground energy storage sealed chamber is used to store flammable and explosive gases such as high-pressure hydrogen and natural gas, the performance of preventing gas leakage is improved, the safety risk index can be greatly reduced, and the consequences and impact of accidents are reduced.

[0040] (3) The construction difficulty of the underground energy storage sealed chamber of the present invention is reduced, materials are saved, and costs are reduced. By using ultra-high performance concrete to replace steel plates, the construction difficulty is reduced, and the thickness of the inner lining concrete layer can be reduced, saving materials and reducing energy consumption. Attached Figure Description

[0041] Figure 1 This is a structural diagram of the energy storage sealed chamber of the present invention.

[0042] Figure 2This is a cross-sectional view of an energy storage sealed chamber according to some embodiments of the present invention.

[0043] Figure 3 for Figure 2 A magnified view of part B in the middle.

[0044] Figure 4 This is a cross-sectional view of an energy storage sealed chamber according to other embodiments of the present invention.

[0045] Figure 5 This is a structural diagram of the inner lining sealing layer according to some embodiments of the present invention.

[0046] Figure 6 This is a structural diagram of the second fastener according to some embodiments of the present invention.

[0047] Figure 7 This is a structural diagram of the underground energy storage sealed chamber system of the present invention.

[0048] Figure 8 This is a cross-sectional view of the first steel mesh layer of the present invention.

[0049] Figure 9 This is a cross-sectional view of the second steel mesh layer of the present invention.

[0050] Reference numerals: 1. Surrounding rock; 2. Energy storage sealed chamber body; 21. Hollow cylindrical part; 22. Hemispherical end; 10. Composite concrete sealing layer; 100. Shotcrete self-stressing concrete layer; 110. First steel mesh layer; 111. First steel bar; 200. Cast ultra-high performance concrete layer; 210. Second steel mesh layer; 211. Second steel bar; 300. Inner lining sealing layer; 400. First fastener; 500. Second fastener; 510. Support part; 520. Herringbone embedded part; 600. Connecting component; 700. Shotcrete self-stressing ultra-high performance concrete layer. Detailed Implementation

[0051] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the invention. To better illustrate the following embodiments, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions; it is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0052] Example 1 like Figure 1-3As shown, this embodiment provides an underground energy storage sealed chamber, including an energy storage sealed chamber body 2 disposed within underground surrounding rock 1. The energy storage sealed chamber body 2 has a sealing structure layer, which includes a composite concrete sealing layer 10 and an inner lining sealing layer 300 from the outside to the inside. The composite concrete sealing layer 10 includes at least one layer of cast ultra-high performance concrete 200, which is located at the innermost side of the composite concrete sealing layer 10. The inner lining sealing layer 300 is tightly attached to the inner surface of the innermost cast ultra-high performance concrete layer 200. In specific implementations, to have a larger energy storage space and improve structural strength, the energy storage sealed chamber body 2 is a hollow cylinder. In some embodiments, the inner diameter of the hollow cylinder is 8-15m, preferably 8m, and the length is 80-150m, preferably 80m. In this embodiment, the composite concrete sealing layer 10 and the surrounding rock 1 are strengthened by setting multiple first fixing members 400. A preferred embodiment uses anchors. During construction, a portion of the anchor is first implanted into the surrounding rock 1, and then the composite concrete sealing layer 10 is applied to the surrounding rock 1. In a preferred embodiment, anchors with a diameter of 20-30 mm and a length of 920-1520 mm are implanted into the surface of the underground surrounding rock 1. The length of the anchors implanted into the surrounding rock 1 is 600-1200 mm, and the spacing between the anchors is 1000-2000 mm. This maximizes the bonding force between the composite concrete sealing layer 10 and the surrounding rock 1.

[0053] In specific implementation, the composite concrete sealing layer 10 is at least one layer of ultra-high performance concrete 200, which is combined with other concrete material layers in a layered manner. The ultra-high performance concrete is constructed using a close-packing principle, composed of cement, mineral admixtures, fine aggregates, additives, high-strength micro-fine steel fibers / or organic synthetic fibers, water, and other raw materials. After high-temperature activation, compared to commonly used steel plate materials, it possesses superior properties such as high compressive strength, high tensile strength, high durability, high toughness, high explosion resistance, high impact resistance, and low gas permeability. Furthermore, due to the lower gas permeability of ultra-high performance concrete compared to ordinary steel plates... The ultra-high performance concrete layer 200 is much smaller than that of conventional concrete, thus it can also provide sealing performance. Using the composite concrete sealing layer 10 with the ultra-high performance concrete layer 200 in the sealing structure layer of the energy storage sealed chamber can solve the defects of insufficient airtightness and low structural strength in existing compressed gas energy storage. It can also save space occupied by the composite concrete sealing layer 10 due to less material usage, thereby providing high structural strength for the energy storage sealed chamber in conjunction with other concrete material layers in the composite concrete sealing layer 10, while also providing a larger compressed gas energy storage space. In specific implementation, to ensure good airtightness and structural strength, the thickness of the ultra-high performance concrete layer 200 is 40~80mm, the compressive strength of the ultra-high performance concrete layer 200 is greater than 150MPa, and the gas permeability of the ultra-high performance concrete layer 200 is 1×10⁻⁶. -18 m 2 ~5×10-19m 2 And / or, the initial cracking strain of the ultra-high performance concrete layer 200 is greater than 1000 micro-strain. Based on this parameter condition, the ultra-high performance concrete layer 200 occupies less space in the sealing structure layer, but can provide greater structural strength. In this way, under the condition of a certain construction space, a larger gas storage space can be provided, and a higher safety factor and airtightness effect can be guaranteed.

[0054] In addition, the inner sealing layer 300 can provide the first layer of airtight protection for the gas in the energy storage sealed chamber, thereby forming a multi-layer sealing effect in conjunction with the outer ultra-high performance concrete layer. At the same time, the inner sealing layer 300 also has multiple effects such as preventing the surrounding rock 1 from loosening and falling off the layer, solving the stability of the surrounding rock 1 in the chamber, and preventing excessive groundwater from penetrating into the chamber, which can greatly improve the safety of gas storage.

[0055] like Figure 2-3As shown, the composite concrete sealing layer 10 also includes at least one layer of sprayed self-stressing concrete 100. The at least one layer of sprayed self-stressing concrete 100 and at least one layer of cast ultra-high performance concrete 200 are stacked from the outside in, with the inner sealing layer 300 tightly attached to the inner surface of the innermost layer of cast ultra-high performance concrete 200. In specific implementations, to reduce the overall structural thickness of the sealing layer and provide a larger gas storage space for the energy storage sealing chamber, the composite concrete sealing layer 10 is constructed by stacking a layer of sprayed self-stressing concrete 100 and a layer of cast ultra-high performance concrete 200 sequentially from the outside in. To ensure that the bonding strength between the sprayed self-stressing concrete layer 100 and the cast ultra-high performance concrete layer 200 is sufficient to meet the structural strength and airtightness requirements of the low-energy storage sealed chamber, the thickness of the sprayed self-stressing concrete layer 100 is 80~400mm. When using ordinary concrete layers for construction, the thickness of the sprayed self-stressing concrete layer 100 is required to reach 200~400mm to meet the structural strength requirements. In addition, the self-stress of the sprayed self-stressing concrete layer 100 is not less than 1MPa, and the compressive strength of the sprayed self-stressing concrete layer 100 is not less than 40MPa.

[0056] like Figure 4 As shown, to further reduce the thickness of the composite concrete sealing layer 10, in a more preferred embodiment, the sprayed self-stressing concrete layer 100 is specifically a sprayed self-stressing ultra-high performance concrete layer 700. In this case, the composite concrete sealing layer 10 consists of a sprayed self-stressing concrete layer 100 and a cast ultra-high performance concrete layer 200 stacked sequentially from the outside to the inside. Specifically, the thickness of the sprayed self-stressing ultra-high performance concrete layer 700 is 80~120mm. This significantly reduces the thickness of the composite concrete sealing layer 10. Simultaneously, based on the superposition of the inner and outer ultra-high performance concrete layers, the sealing effect and safety performance of the energy storage sealed chamber sealing structure layer can be synergistically improved.

[0057] like Figure 3 , Figure 8As shown, a first steel mesh layer 110 is provided inside the sprayed self-stressing concrete layer 100. In specific implementation, in order to have better structural strength, the volume of the first steel mesh layer 110 is not less than 1.5% of the volume of the sprayed self-stressing concrete layer 100. In implementation, the first steel reinforcement mesh layer 110 includes multiple first steel bars 111. A portion of the first steel bars 111 are arranged circumferentially along the cross-section of the sprayed self-stressing concrete layer 100, and another portion of the first steel bars 111 are arranged along the side height direction of the sprayed self-stressing concrete layer 100. The first steel bars 111 in the two directions are laid to form the first steel reinforcement mesh layer 110 and a dense first grid is formed on the first steel reinforcement mesh layer 110. In a preferred embodiment, the side length of the first grid is 100~300mm, which is equivalent to a spacing of 100~300mm between adjacent first steel bars 111. In addition, in specific implementation, the diameter of the first steel bars 111 is 8~12mm, and the protective layer thickness of the first steel reinforcement mesh layer 110 is 30~50mm. In this way, the structural strength of the sprayed self-stressing concrete layer 100 is high, and the thickness and amount of construction materials are reduced.

[0058] like Figure 3 , Figure 9 As shown, a second steel mesh layer 210 is provided inside the ultra-high performance concrete layer 200. In specific implementation, in order to ensure a certain structural strength, the volume of the second steel mesh layer 210 is not less than 1.5% of the volume of the ultra-high performance concrete layer 200. In practice, the second steel mesh layer 210 includes multiple second steel bars 211. A portion of the second steel bars 211 are arranged circumferentially along the cross-section of the ultra-high performance concrete layer 200, and another portion of the second steel bars 211 are arranged along the side height direction of the ultra-high performance concrete layer 200. The second steel bars 211 in the two directions are laid to form the second steel mesh layer 210, and a dense first grid 212 is formed on the second steel mesh layer 210. In a preferred embodiment, the side length of the second grid is 100~300mm, which is equivalent to a spacing of 100~300mm between adjacent second steel bars 211. In addition, in specific implementation, the diameter of the second steel bars 211 is 4~10mm, and the protective layer thickness of the second steel mesh layer 210 is 25~40mm. In practical use, the second steel mesh layer 210 provides an additional support structure inside the ultra-high performance concrete layer 200, enabling the ultra-high performance concrete layer 200 to maintain high structural strength under relatively small thickness conditions, which meets the safety performance requirements of underground energy storage sealed chambers.

[0059] like Figure 3 As shown, multiple second fasteners 500 are also provided between the inner sealing layer 300 and the poured ultra-high performance concrete layer 200. In specific implementation, combined with... Figure 5-6As shown, the second fastener 500 is a herringbone anchor, which has a connected support portion 510 and a herringbone embedded portion 520. The support portion 510 is closely supported on the inner surface of the inner lining sealing layer 300, and the herringbone embedded portion 520 is sequentially embedded into the inner wall of the inner lining sealing layer 300 and the cast ultra-high performance concrete layer 200 so that the inner lining sealing layer 300 fits against the inner wall of the cast ultra-high performance concrete layer 200.

[0060] In a preferred embodiment, the inner sealing layer 300 is a high-density polyethylene (HDPE) layer. When applied, HDPE material exhibits excellent airtightness, improving the sealing performance of the gas within the energy storage sealed chamber. Simultaneously, its minimal water absorption prevents moisture from the surrounding rock 1 from seeping into the energy storage sealed chamber. Furthermore, its high resistance to acid and alkali corrosion enhances the durability of the inner sealing layer 300, reducing maintenance and replacement costs. Specifically, the HDPE layer has a thickness of 4-6 mm, a yield tensile strength of not less than 30 MPa, an ultimate tensile strength of not less than 50 MPa, and a temperature resistance range of -50℃ to 90℃. Based on these parameter settings, the inner sealing layer 300, together with the aforementioned composite concrete sealing layer 10 formed by the combination of cast ultra-high performance concrete layer 200 and sprayed self-stressed concrete layer 100, achieves a good synergistic effect. This results in superior performance in both airtightness and structural strength, while occupying less space, thus providing a larger gas storage space for the underground energy storage sealed chamber.

[0061] In addition, in order to improve the bonding strength of the high-density polyethylene layer when it is bonded to the inner wall of the ultra-high performance concrete layer 200, in specific implementation, the shear strength between the high-density polyethylene layer and the inner wall of the composite concrete sealing layer 10 through the herringbone anchor is not less than 20 MPa, the bonding strength of the anchoring section of the herringbone anchor is not less than 10 MPa, and the depth of the herringbone anchor into the composite concrete sealing layer 10 is not less than 20 mm.

[0062] like Figure 1 As shown, the energy storage sealed chamber body 2 includes a hollow cylindrical portion 21, with hemispherical ends 22 at both ends. Both the hollow cylindrical portion 21 and the hemispherical ends 22 have the aforementioned sealing structure layer. During operation, the hemispherical ends 22 improve the pressure uniformity inside the gas storage tank and reduce pressure unevenness at end face corners or planes. Furthermore, in specific implementation, a first flange is installed and fixed between the hemispherical ends 22 and the adjacent underground energy storage sealed chamber, improving the sealing effect and pressure uniformity of the underground energy storage sealed chamber.

[0063] Example 2 like Figure 7As shown, this embodiment provides an underground energy storage sealed chamber system, including at least two underground energy storage sealed chambers as described in Embodiment 1. The at least two underground energy storage sealed chambers are arranged side-by-side radially along the cross-section of the energy storage sealed chamber. A connecting component 600 is provided between adjacent underground energy storage sealed chambers to ensure reliable connection between them. To improve airtightness, in a preferred embodiment, a second flange is provided at each connection position of the connecting component 600, and a sealing ring is added to the second flange. In specific implementation, to fully utilize the gas storage space while ensuring the safety of the underground energy storage sealed chamber, the distance between adjacent underground energy storage sealed chambers is 50~80m.

[0064] Example 3 This embodiment is a specific application example of Embodiment 1, providing an underground energy storage sealed chamber, as referenced. Figure 1-6 As shown, the underground energy storage sealed chamber is a cylinder with an inner diameter of 8m and a length of 80m, which is set in the underground surrounding rock 1. The underground energy storage sealed chamber is surrounded by a composite concrete sealing layer 10 and an inner lining sealing layer 300. The inner lining sealing layer 300 is set on the inner wall of the composite concrete sealing layer 10 and is anchored by a herringbone key.

[0065] The end face of the underground energy storage sealed chamber is hemispherical, and a first flange can be installed on the end face. Two adjacent energy storage sealed chambers are connected by the first flange, and a sealing ring is installed between the first flanges. The connection is sealed by bolts. The distance between the two rows of energy storage sealed chambers is 50m, which makes full use of the gas storage space while ensuring the safety of the chamber.

[0066] Anchor bolts with a diameter of 20 mm and a length of 920 mm are implanted on the surface of the underground surrounding rock 1. The length of the anchor bolts implanted in the rock layer is 600 mm, and the spacing between the anchor bolts is 1000 mm, which improves the bonding force between the composite concrete sealing layer 10 and the surrounding rock 1.

[0067] The composite concrete sealing layer 10 includes a sprayed self-stressing concrete layer 100 and a cast ultra-high performance concrete layer 200 arranged sequentially from the outside to the inside. The inner sealing layer 300 is arranged on the inner surface of the cast ultra-high performance concrete layer 200. A first steel mesh layer 110 is arranged inside the sprayed self-stressing concrete layer 100, and a second steel mesh layer 210 is arranged inside the cast ultra-high performance concrete layer 200. The steel volume of the first steel mesh layer 110 and the second steel mesh layer 210 is not less than 1.5% of the volume of the corresponding concrete layer. The first layer of shotcrete self-stressing concrete 100 has a self-stress of not less than 1 MPa, a compressive strength of not less than 40 MPa, and a thickness of 200 mm. The first mesh layer 110 has a first mesh side length of 100 mm and a first reinforcing bar 111 diameter of 8 mm. The first reinforcing bar layer 110 is fixed to the anchor rod, and the protective layer thickness of the first reinforcing bar mesh layer 110 is 30 mm. The second layer of cast-in-place ultra-high performance concrete 200 has a compressive strength greater than 150 MPa and a gas permeability of 1×10⁻⁶. -18 m2, initial cracking strain greater than 1000 microstrain, thickness of 40mm, second mesh of the second steel mesh layer 210 with side length of 100~300mm, diameter of the second steel bar 211 of 4mm, the second steel mesh layer 210 fixed on the anchor rod, and protective layer thickness of the second steel mesh layer 210 of 25mm; the pouring of ultra-high performance concrete layer 200 can not only significantly reduce the thickness of composite concrete sealing layer 10, but also ensure that gas does not leak and the sealing chamber is not damaged after the failure of inner lining sealing layer 300 or after accidental overpressure of the sealing chamber.

[0068] The sealing layer 300 inside the underground high-pressure energy storage sealed chamber serves two purposes: first, to prevent the loosening and delamination of the rock strata and to solve the stability problem of the surrounding rock 1; second, to solve the problem of gas leakage in the cracks of the surrounding rock 1, while preventing excessive groundwater from penetrating into the chamber.

[0069] The underground high-pressure energy storage sealed chamber has a pressure resistance of 10~15MPa and a temperature resistance of -30℃~80℃. The inner lining sealing layer 300 is 4mm thick high-density polyethylene with a temperature resistance range of -50℃~90℃, a yield tensile strength of not less than 30MPa, an ultimate tensile strength of not less than 50MPa, and a shear resistance of not less than 20MPa when combined with the inner wall structure through herringbone anchors. The anchorage section bonding strength is not less than 10MPa, and the key anchorage depth is not less than 20mm, which improves the sealing performance of the inner lining and prevents gas leakage.

[0070] Comparative Example 1 The underground energy storage sealed chamber scheme using conventional concrete is the same as Example 3, except that "a 300mm thick C40 concrete sprayed and a 200mm thick C40 steel fiber concrete poured are used as the concrete lining layer, and a 20mm thick steel plate is used as the sealing layer".

[0071] Test case The main features of Example 3 and the comparative example are compared in Table 1: As can be seen from the data in Table 1, the energy storage sealed chamber structure of Example 3 is lighter than that of the energy storage sealed chamber structure made of conventional concrete in Comparative Example 1. The inner lining concrete thickness is smaller, the excavation diameter is smaller, the excavation volume is smaller, and steel plates are not required as a sealing layer.

[0072] Example 3 uses ultra-high performance concrete and high-density polyethylene to replace steel plates to manufacture the storage tank of the present invention, which can reduce the construction difficulty and manufacturing cost of the sealing layer, while reducing the thickness of the inner concrete lining layer, saving materials, and improving the fatigue resistance and creep resistance of the inner concrete lining layer. At the same time, since the gas permeability of ultra-high performance concrete is much lower than that of ordinary concrete, the ultra-high performance concrete layer can also provide sealing performance.

[0073] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the technical solution of the present invention, and are not intended to limit the specific implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. An underground energy storage sealed chamber, comprising an energy storage sealed chamber body disposed within underground surrounding rock, characterized in that, The energy storage sealed chamber body has a sealing structure layer, which includes a composite concrete sealing layer and an inner lining sealing layer from the outside to the inside. The composite concrete sealing layer includes at least one layer of cast ultra-high performance concrete, with the cast ultra-high performance concrete layer located at the innermost side of the composite concrete sealing layer. The inner lining sealing layer is tightly attached to the inner surface of the innermost cast ultra-high performance concrete layer. The thickness of each cast ultra-high performance concrete layer is 40-80 mm, the compressive strength of each cast ultra-high performance concrete layer is greater than 150 MPa, and the gas permeability of each cast ultra-high performance concrete layer is 1×10⁻⁶. -18 m 2 ~ 5×10 -19 m 2 The initial cracking strain of each layer of ultra-high performance concrete is greater than 1000 microstrain. The composite concrete sealing layer also includes at least one layer of sprayed self-stressing concrete, and the at least one layer of sprayed self-stressing concrete and the at least one layer of cast ultra-high performance concrete are stacked from the outside to the inside. The sprayed self-stressing concrete layer is a sprayed self-stressing ultra-high performance concrete layer. The thickness of each layer of the sprayed self-stressing ultra-high performance concrete layer is 80~120mm, the self-stress is not less than 1Mpa, and the compressive strength is not less than 40Mpa.

2. The underground energy storage sealed chamber according to claim 1, characterized in that, A plurality of first fasteners are provided between the composite concrete sealing layer and the surrounding rock, and the first fasteners fix the composite concrete sealing layer to the surface of the surrounding rock.

3. The underground energy storage sealed chamber according to claim 2, characterized in that, The first fixing component is an anchor rod, and the two ends of the anchor rod are respectively inserted into the surrounding rock and the composite concrete sealing layer so that the surfaces of the two are tightly connected.

4. The underground energy storage sealed chamber according to claim 3, characterized in that, The diameter of the anchor rod is 20-30 mm, and / or the length of the anchor rod is 920-1520 mm, and / or the length of the portion of the anchor rod embedded in the surrounding rock is 600-1200 mm, and / or the spacing between multiple anchor rods is 1000-2000 mm.

5. The underground energy storage sealed chamber according to claim 1, characterized in that, Multiple second fasteners are also provided between the inner lining sealing layer and the cast ultra-high performance concrete layer.

6. The underground energy storage sealed chamber according to claim 5, characterized in that, The second fastener is a herringbone anchor, which is sequentially embedded into the inner wall of the inner lining sealing layer and the composite concrete sealing layer so that the inner lining sealing layer is tightly attached to the inner wall of the composite concrete sealing layer.

7. The underground energy storage sealed chamber according to any one of claims 1-6, characterized in that, Each layer of the sprayed self-stressing concrete is provided with a first steel mesh layer inside.

8. The underground energy storage sealed chamber according to claim 7, characterized in that, The volume of the first steel mesh layer is not less than 1.5% of the volume of the corresponding sprayed self-stressing concrete layer, and / or, the first steel mesh layer is formed by a plurality of first steel bars, the diameter of the first steel bars being 8~12mm; and / or, the first steel mesh layer has a plurality of first grids, the side length of the first grids being 100~300mm, and / or, the protective layer thickness of the first steel mesh layer is 30~50mm.

9. The underground energy storage sealed chamber according to any one of claims 1-6, characterized in that, Each layer of ultra-high performance concrete is equipped with a second steel mesh layer.

10. The underground energy storage sealed chamber according to claim 9, characterized in that, The volume of the second steel mesh layer is not less than 1.5% of the volume of the corresponding ultra-high performance concrete layer, and / or, the second steel mesh layer is formed by setting a number of second steel bars, the diameter of the second steel bars is 4~10mm, and / or, the second steel mesh layer has a number of second grids, the side length of the second grids is 100~300mm, and / or, the protective layer thickness of each layer of the second steel mesh layer is 25~40mm.

11. The underground energy storage sealed chamber according to any one of claims 1-6, characterized in that, The inner lining sealing layer is a high-density polyethylene layer.

12. The underground energy storage sealed chamber according to claim 11, characterized in that, The thickness of the high-density polyethylene layer is 4~6mm, and / or the yield tensile strength of the high-density polyethylene layer is not less than 30MPa, and / or the ultimate tensile strength of the high-density polyethylene layer is not less than 50MPa, and / or the temperature resistance range of the high-density polyethylene layer is -50℃~90℃.

13. The underground energy storage sealed chamber according to any one of claims 1-6, characterized in that, The energy storage sealed chamber body is provided with a hollow cylindrical part and two hemispherical ends located at both ends of the hollow cylindrical part. The hollow cylindrical part and the hemispherical ends are both provided with the sealing structure layer.

14. An underground energy storage sealed chamber system, characterized in that, It includes at least two energy storage sealed chambers as described in any one of claims 1-6, wherein the at least two energy storage sealed chambers are arranged side by side along the radial direction of the cross section of the energy storage sealed chamber, and a connecting component for connecting the two energy storage sealed chambers is provided between the energy storage sealed chamber bodies of two adjacent energy storage sealed chambers.

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