Compressed air energy storage hard rock gas storage chamber and construction method

Abstract

The invention relates to the technical field of underground gas storage, in particular to a compressed air energy storage hard rock gas storage chamber and a construction method. The gas storage chamber comprises a sealing layer and a lining layer which are sequentially arranged from inside to outside. The sealing layer comprises a sealing steel lining and stiffening ribs, the sealing steel lining is of a tubular structure formed by splicing a plurality of steel linings, the stiffening ribs are annularly and sequentially arranged on the outer wall of the tubular sealing steel lining along the axis, the cross section of each stiffening rib is of a stepped structure, and an elastic metal gasket is attached to the surface of each stiffening rib; the lining layer comprises a supporting framework and concrete, and the supporting framework is of a latticed structure and wound on the outer walls of the stiffening ribs. By optimizing the sealing layer structure, improving the concrete pouring process and perfecting the drainage system design, higher air tightness, structural stability and construction economy of the gas storage chamber are achieved, and meanwhile the influence on the environment is reduced.

Description

Technical Field

[0001] This invention relates to the field of underground gas storage technology, and in particular to a compressed air energy storage hard rock gas storage chamber and its construction method. Background Technology

[0002] Compressed air energy storage hard rock gas storage chambers are mainly used to store compressed air to support power system peak shaving and renewable energy consumption. This technology achieves efficient energy storage and release by constructing sealed chambers in underground hard rock, utilizing the natural barrier of the rock mass and artificial structures to withstand the high-pressure gas inside.

[0003] In existing technologies, hard rock gas storage chambers typically use organic flexible materials to form the sealing layer, which is mostly made of polymer-based composite materials. Firstly, organic flexible sealing materials are prone to aging and decomposition under long-term high pressure and temperature fluctuations, leading not only to a decline in sealing performance but also the release of harmful substances causing environmental pollution. Secondly, the sealing layer lacks an effective mechanical interlocking structure with the lining layer, relying solely on interfacial friction to resist loads. Under the influence of concrete shrinkage and temperature stress, relative sliding easily occurs, reducing the overall collaborative working capacity.

[0004] Furthermore, the existing stability and sealing design structure is too complex and does not match the actual extensive construction mode, resulting in high construction difficulty, uneven efficiency, and difficulty in accurately controlling the construction period. Finally, the chamber needs to withstand high temperature and high pressure alternating loads for a long time during its service life. During the construction of its lining structure, the pumped concrete is prone to forming air bubbles and cavities, which significantly reduces the structural bearing capacity and durability, threatening the long-term safe operation of the system. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a compressed air energy storage hard rock gas storage chamber and its construction method. By optimizing the sealing layer structure, improving the concrete pouring process, and perfecting the drainage system design, the gas storage chamber achieves higher airtightness, structural stability, and construction economy, while reducing its environmental impact.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions: A compressed air energy storage hard rock gas storage chamber includes a sealing layer and a lining layer arranged sequentially from the inside out. The sealing layer includes a sealing steel lining and stiffening ribs. The sealing steel lining is composed of multiple steel lining sheets spliced ​​into a tubular structure. The stiffening ribs are arranged in a ring on the outer wall of the tubular sealing steel lining and are spaced apart along the axis of the sealing steel lining. The lining layer includes a supporting frame and concrete. The supporting frame is a grid structure and is wrapped around the outer wall of the stiffening ribs. The concrete is poured on the stiffening ribs and the supporting frame to form the lining layer.

[0007] Optionally, multiple steel lining sheets are welded along the weld to form a tubular structure, the weld including a longitudinal steel lining seam and a transverse steel lining seam, the longitudinal steel lining seam being parallel to the axis of the sealing steel lining, and the transverse steel lining seam being perpendicular to the axis of the sealing steel lining.

[0008] Optionally, the longitudinal seams of adjacent steel liners are staggered along the axial direction of the sealing steel liner.

[0009] Optionally, the cross-section of the stiffening rib is rectangular.

[0010] Optionally, the cross-section of the stiffening rib is a stepped structure, and an elastic metal gasket is attached to the surface of the stiffening rib.

[0011] Optionally, the support frame includes circumferential reinforcing bars and axial reinforcing bars, wherein the axial reinforcing bars are arranged in a direction parallel to the axis of the sealing steel liner, and the circumferential reinforcing bars are arranged in a direction perpendicular to the axis of the sealing steel liner.

[0012] Optionally, the lining layer can be made of C25 concrete or gradient material. The inner concrete of the gradient material is infused with steel fibers, and the outer concrete is infused with polypropylene fibers. The fiber volume fraction decreases from the inside to the outside. The specific material used is determined by numerical calculation and verification based on the size of the gas storage chamber and the gas storage pressure.

[0013] Optionally, a drainage system is also provided outside the lining layer. The drainage system includes a main drainage blind pipe and branch drainage blind pipes arranged along the axial direction of the chamber, which, together with the annular drainage groove on the surface of the initial support of the surrounding rock, form a three-dimensional network drainage system.

[0014] Optionally, the outer layer of the tunnel is provided with initial support for the surrounding rock, which uses anchor bolts and cables and shotcrete.

[0015] This invention also provides a construction method for the compressed air energy storage hard rock gas storage chamber as described above, comprising: Prefabricated steel plates with circumferential stiffening ribs are transported into the chamber and then welded into an annular sealed steel lining. Excavate the chamber, install mortar anchors in the surrounding rock, hang steel mesh, and spray concrete for initial support; A U-shaped trench is excavated on the surface of the initial support of the surrounding rock and a ring-shaped drainage trench is laid. The main drainage blind pipe and branch drainage blind pipes are laid and connected to the ring-shaped drainage trench. The blind pipes are wrapped with geotextile. The main blind pipe is connected to the water collection well and a submersible pump is installed. Sliding tracks are installed inside the tunnel to transport and fix the annular sealed steel lining. The circumferential and axial reinforcing bars of the lining layer are tied and then spot-welded into a skeleton. Prepare concrete, pump it into the concrete using a long rubber hose or flexible pump pipe, leave the pump pipe inside the concrete after pumping, vibrate to compact it, and cure it to the design strength.

[0016] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages: 1. The gas storage chamber of this invention mainly comprises a sealing layer and a lining layer arranged sequentially from the inside out. The sealing layer consists of a sealing steel lining and stiffening ribs. The sealing steel lining is formed into a tubular shape by splicing multiple steel lining sheets, and the stiffening ribs are arranged in a ring on the outer wall of the sealing steel lining and spaced apart along the axis. The lining layer includes a supporting frame and concrete. The supporting frame has a grid structure and is wrapped around the outer wall of the stiffening ribs. The concrete is poured on the stiffening ribs and supporting frame to form a whole. This structure provides airtightness through the sealing steel lining, enhances the instability resistance of the sealing steel lining through the stiffening ribs, and bears the structural load. The two work together through a mechanical interlocking interface to improve the overall load-bearing stability and durability. This gas storage chamber solves the problems of easy aging and environmental pollution of traditional organic sealing materials, while avoiding the risk of local instability of thin-shell structures under the pressure of uncured concrete and external grouting pressure during the construction stage. The stiffening ribs and the sealing steel lining form a rib-shell collaborative stress-bearing system, improving the section moment of inertia and buckling resistance. The lining layer optimizes the load transfer path and reduces stress concentration through a grid-like support skeleton. The sealing layer uses metallic materials instead of organic materials, reducing environmental pollution risks and extending service life.

[0017] 2. The sealing layer employs multiple stiffened steel plates welded into a ring structure. When welding transverse seams, longitudinal seams are staggered. Simultaneously, prefabricated circumferential stiffening ribs are installed on the outer side of the steel lining. These stiffening ribs are rigidly connected to the main steel lining body, forming a rib-shell collaborative load-bearing system. This system effectively enhances the moment of inertia and buckling resistance of the steel lining section, preventing local instability or overall buckling when subjected to lateral pressure from uncured concrete (instantaneous loads during construction) and external grouting pressure (continuous loads during consolidation), thus ensuring structural safety during construction.

[0018] 3. The circumferential stiffening ribs adopt a flanged cross-section design. Their protruding structure from the outer wall of the steel lining creates a mechanical interlocking interface between the steel lining and the lining concrete during pouring. On one hand, the stiffening ribs increase the contact area between the steel lining and the concrete, enhancing interfacial friction. On the other hand, the flanged structure of the stiffening ribs can be embedded within the concrete, forming a tenon-and-mortise constraint, effectively limiting the relative sliding between the steel lining and the concrete. This ensures that the steel lining and the lining concrete work together, improving the overall structural load-bearing stability and durability, and eliminating the need for a sliding layer in existing designs.

[0019] 4. For the lining layer outside the sealing layer, firstly, the circumferential and axial reinforcing bars are tied in layers to form a reinforcing bar skeleton; then, the reinforcing bar skeleton is fixed by layer spot welding to ensure that the reinforcing bars are accurately positioned and firmly connected; finally, concrete is poured in layers to form the shape.

[0020] 5. When pumping concrete, use pump pipes made of elastic material, which are kept inside the lining structure. This can effectively inhibit the formation of concrete cracks, thereby improving air tightness.

[0021] 6. Lay out the tracks inside the tunnel to facilitate the transportation of construction materials in the later stage. The prefabricated sealed steel lining with stiffening ribs is transported to the proper position through the sliding tracks, and is fixed by steel frame for subsequent reinforcement network laying of the lining layer.

[0022] 7. The construction process is simple and convenient, reducing complex construction steps; at the same time, the structural stress path is clear, which can evenly transfer and disperse the internal pressure load, avoid stress concentration, and ensure that the overall structure is in a safe stress state for a long time, taking into account both practicality and stability.

[0023] Advantages of additional aspects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In addition, the dimensions or spacing between the components are exaggerated to show the position of each component, and the schematic diagrams are for illustrative purposes only.

[0025] Figure 1 This is a schematic cross-sectional view of the overall structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the sealing layer and supporting frame provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the sealing steel liner provided in an embodiment of the present invention; In the diagram: 1. Surrounding rock; 2. Lining layer; 21. Lining layer concrete; 22. Circumferential reinforcement; 23. Axial reinforcement; 3. Stiffening ribs; 4. Sealing steel lining; 41. Longitudinal joint of steel lining; 42. Transverse joint of steel lining; 5. Branch drainage blind pipe; Detailed Implementation It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0026] Example 1 like Figure 1 , Figure 2As shown, this embodiment proposes a compressed air energy storage hard rock gas storage chamber, including a sealing layer and a lining layer 2 arranged sequentially from the inside to the outside; the sealing layer includes a sealing steel lining 4 and stiffening ribs 3, the sealing steel lining 4 is a tubular structure spliced ​​from multiple steel lining sheets, and the stiffening ribs 3 are arranged in a ring on the outer wall of the tubular sealing steel lining 4, and multiple stiffening ribs are arranged at intervals along the axis of the sealing steel lining 4; the lining layer 2 includes a supporting frame and concrete, the supporting frame is a grid structure and is wrapped around the outer wall of the stiffening ribs 3, and the lining layer concrete 21 is poured on the stiffening ribs 3 and the supporting frame to form the lining layer 2.

[0027] The combined design of the sealing steel liner 4 and the stiffening rib 3 forms a rib-shell cooperative stress system, which improves the cross-sectional moment of inertia and buckling resistance of the sealing layer, effectively preventing the sealing layer from local instability or overall buckling when subjected to the lateral pressure of uncured concrete and external grouting pressure, thus ensuring safety during construction.

[0028] like Figure 3 As shown, multiple steel lining sheets are welded along a weld seam to form a tubular structure. The weld seam includes a longitudinal weld seam 41 and a transverse weld seam 42. The longitudinal weld seam 41 is parallel to the axis of the sealing steel lining 4, and the transverse weld seam 42 is perpendicular to the axis of the sealing steel lining 4. This weld seam design avoids weak points caused by weld seam concentration, improving the reliability of the sealing steel lining 4 under high-pressure environments. A shielded gas welding process is used to ensure weld quality and reduce the risk of gas leakage. The longitudinal weld seam bears circumferential stress, and the transverse weld seam bears axial stress; this arrangement optimizes the stress performance of the sealing steel lining 4.

[0029] Furthermore, along the axial direction of the sealing steel liner 4, the longitudinal seams 41 of adjacent steel liners are staggered, thereby reducing welding residual stress and the risk of fatigue cracking, and improving the durability of the sealing steel liner 4 under long-term alternating loads. The staggered longitudinal seams ensure uniform load distribution and enhance the overall structural integrity.

[0030] In one embodiment, the stiffening rib 3 has a rectangular cross-section. The rectangular cross-section stiffening rib 3 is easy to manufacture and install, providing uniform support through a rigid connection with the sealing steel lining 4. During concrete pouring, the rectangular stiffening rib 3 forms an effective mechanical interlocking interface, increasing the contact area to enhance interfacial friction and restricting relative sliding between the sealing layer and the lining layer 2. This simple geometry reduces processing costs while enhancing the stiffness of the rib-shell cooperative stress-bearing system.

[0031] In another embodiment, the stiffening rib 3 has a stepped cross-section, and an elastic metal gasket is attached to its surface. The stepped structure forms a multi-level interlocking interface, increasing the mechanical interlocking effect with the lining concrete 21. The elastic metal gasket absorbs the stress caused by the difference in thermal expansion coefficients between the steel lining and the lining concrete 21. This combined design solves the problem of interface delamination under long-term temperature and pressure variable loads, improving the stability of the joint stress. The stepped flange enhances the constraint strength, and the elastic metal gasket provides cushioning, reducing the generation of microcracks. The elastic metal gasket can be made of materials that combine elasticity and corrosion resistance, such as nickel-titanium alloy.

[0032] like Figure 2 As shown, the supporting frame includes circumferential reinforcing bars 22 and axial reinforcing bars 23. The axial reinforcing bars 23 are arranged parallel to the axis of the sealing steel lining 4, and the circumferential reinforcing bars 22 are arranged perpendicular to the axis of the sealing steel lining 4. The circumferential and axial reinforcing bars 23 form a mesh-like frame, which is connected into a whole by spot welding. This frame optimizes the stress path of the concrete. The circumferential reinforcing bars 22 bear the circumferential stress, and the axial reinforcing bars 23 bear the axial stress, uniformly transferring the internal pressure load to the outside of the lining layer 2, avoiding excessive local stress. Combined with the stiffening ribs 3, it enhances the interfacial bonding force and the overall structural integrity.

[0033] Furthermore, in the embodiment, C25 concrete is preferred for the lining layer concrete 21. If C25 concrete cannot meet the strength requirements when simulating the gas filling and releasing cycle of a specific gas storage, a gradient material is selected. The inner concrete of the gradient material is mixed with steel fibers, and the outer concrete is mixed with polypropylene fibers, with the fiber volume fraction decreasing from the inside to the outside. Both different concrete selection methods can enable the structure to meet the requirements of long-term bearing of 10MPa~20MPa temperature and pressure alternating loads under different surrounding rock grades, and to bear the design life of the gas storage for 40~50 years.

[0034] The gradient material design allows the lining concrete 21 to exhibit different properties according to the stress requirements at different locations. Steel fibers are incorporated into the inner concrete; these fibers have high tensile strength, enhancing the tensile capacity of the inner concrete and resisting the tensile stress generated by the high pressure transmitted by the sealed steel lining 4, thus reducing cracking of the inner concrete. Polypropylene fibers are incorporated into the outer concrete; these fibers have good toughness, enhancing the crack resistance and impact resistance of the outer concrete, resisting the stress generated by the surrounding rock 1 and the shrinkage stress caused by temperature changes, further reducing cracking of the outer concrete. The fiber volume fraction decreases from the inside to the outside, allowing the concrete performance to smoothly transition from high strength on the inside to high toughness on the outside, avoiding stress concentration caused by abrupt performance changes, further reducing concrete cracking, and improving the airtightness and durability of the lining layer 2.

[0035] A drainage system is also provided outside the lining layer 2. The drainage system includes a main drainage blind pipe and branch drainage blind pipes 5 arranged along the axial direction of the chamber, which, together with the annular drainage groove on the initial support surface of the surrounding rock 1, form a three-dimensional network drainage system.

[0036] The drainage system diverts groundwater and condensate, with the main drainage blind pipe collecting water flow axially. Branch drainage blind pipes 5 connect to the annular drainage channel to form a network. This three-dimensional drainage system rapidly diverts water, preventing water pressure buildup from damaging the structure and extending its service life.

[0037] The outer layer of the chamber is initially supported by surrounding rock 1, which employs anchor bolts and shotcrete. The anchor bolts and shotcrete work together to effectively reinforce the surrounding rock 1, preventing collapse or deformation after chamber excavation. The anchor bolts and cables penetrate deep into the surrounding rock 1, connecting the fragmented blocks into a unified structure through their tension, thus enhancing the stability of the surrounding rock 1. The shotcrete covers the surface of the surrounding rock 1, sealing surface cracks and preventing further damage from weathering or water erosion. Simultaneously, the shotcrete and anchor bolts combine to form a composite support structure, jointly bearing the pressure of the surrounding rock 1 and providing a stable working space for the subsequent construction of the sealing layer, lining layer 2, and drainage system.

[0038] Specifically: The sealing layer is the core sealing component, which is a ring structure welded together by multiple steel linings of the same specification with prefabricated stiffening ribs 3. The material is high manganese steel 07Mn-MoVR and Q460CF, with a wall thickness of 18-24mm.

[0039] Both high-manganese steel 07Mn-MoVR and Q460CF possess excellent strength, toughness, and fatigue resistance. 07Mn-MoVR maintains stable mechanical properties even at low temperatures, while Q460CF boasts a high yield strength (≥460MPa), meeting the structural load-bearing requirements under complex stress conditions. Besides high-manganese steel, other stainless steel materials suitable for the operating pressure range of underground gas storage chambers can also be selected. The steel lining wall thickness is designed to be 18–24 mm. This thickness range ensures the structural foundation rigidity while also considering material economy, avoiding increased structural weight and construction difficulty due to excessive wall thickness.

[0040] Stiffening ribs 3 are arranged according to relevant standards, serving to prevent structural instability, reserve space for the reinforcement of the lining layer 2, protect the steel lining from deformation during transportation, and limit the relative sliding between the steel lining and concrete. The ring structure design can transform concentrated internal pressure into uniform circumferential tension, avoiding local stress concentration that could lead to steel plate cracking. Stiffening ribs 3 can also provide radial restraint reaction force to suppress instability and deformation of the steel lining.

[0041] On the other hand, since the coefficients of thermal expansion of the steel lining and concrete differ, interfacial delamination or concrete cracking is prone to occur during temperature fluctuations. Therefore, in one embodiment, the flange cross-section is set as a stepped type, with each step being 5-8 mm high and 10-15 mm wide, forming a multi-level interlocking interface. Simultaneously, a 1-2 mm thick elastic metal gasket, such as a nickel-titanium alloy, is attached to the surface of the stiffening rib 3, combining elasticity and corrosion resistance. The elastic metal gasket can absorb the stress caused by the difference in thermal expansion between the steel lining and concrete, preventing interfacial delamination; the stepped flange can increase the interlocking contact area, improving interfacial friction and constraint strength. Through the combination of the stepped flange and the elastic metal gasket, the problem of interfacial stress concentration caused by the difference in thermal expansion coefficients between the steel lining and concrete under long-term alternating temperature and pressure loads is solved, improving the cooperative stress stability under long-term alternating loads.

[0042] In general, in actual engineering projects, C25 concrete can be used for lining layer 2 as in Example 2. This concrete can withstand alternating temperature and pressure loads of 10MPa~20MPa for a long time, meeting the design life of 40~50 years for gas storage facilities. Higher strength concrete is not required, significantly reducing material costs. Internally, circumferential reinforcing bars 22 and axial reinforcing bars 23 are arranged, tied and spot-welded to form a reinforcing steel skeleton, optimizing the concrete stress path and reducing the risk of cracking. This example uses C25 ordinary concrete; prestressed concrete can be preferred to improve crack resistance. The reinforcing steel network relies on stiffening ribs 3, forming a mesh structure through spot welding of axial and circumferential threaded steel bars. This allows the internal pressure load borne by the sealing layer to be evenly transferred to the outside through the reinforcing steel nodes, avoiding load concentration that could cause localized stress peaks.

[0043] Furthermore, since a single type of concrete cannot simultaneously meet the requirements of internal crack resistance and external impermeability, it is prone to gradient stress under alternating temperature conditions. Therefore, in one embodiment, the lining concrete 21 can use a gradient material, with steel fibers incorporated on the inner side (near the sealing layer) and polypropylene fibers incorporated on the outer side (near the surrounding rock 1), with the fiber volume fraction decreasing from the inside to the outside. The steel fibers improve the tensile strength on the inner side, while the polypropylene fibers enhance the toughness on the outer side. The gradient design matches the stress distribution, reduces overall cracking, and improves airtightness and durability.

[0044] The drainage system is a water hazard prevention component. It consists of a main drainage blind pipe, branch drainage blind pipes 5, and an annular drainage trough on the outer side of the initial support surface of the surrounding rock 1, forming a three-dimensional network system. It can guide groundwater and condensate to the water collection well at the bottom of the chamber. The outer side of the branch drainage blind pipes 5 is wrapped with geotextile to prevent silt blockage.

[0045] The drainage system should be constructed by excavating U-shaped trenches at the designed intervals on the outside of the lining layer 2, laying circumferential drainage channels, and laying main drainage blind pipes along the axial direction of the chamber. Branch blind pipes should be connected to the circumferential drainage channels. All pipes should be wrapped with geotextile to prevent silt blockage. The end of the main blind pipe should be connected to the water collection well at the bottom of the chamber, and a submersible pump should be installed in the water collection well.

[0046] As can be seen, this embodiment balances structural protection and efficiency improvement. The prefabricated stiffening ribs 3 on the outside of the steel lining can prevent large deformations or instability of the steel lining during transportation and construction, reducing rework. At the same time, some processes, such as the prefabrication of the steel lining and the initial support of the surrounding rock 1, can be carried out simultaneously in the factory and on-site in the tunnel, with reasonable connection and significantly improving the overall construction efficiency. Moreover, this embodiment abandons large-scale organic sealing materials and uses rigid materials such as steel plates, rebar, and C25 concrete, reducing the environmental pollution risk of organic materials and making it more environmentally friendly. In addition, the materials used are readily available and do not rely on expensive special materials, significantly reducing construction costs.

[0047] Example 2 This embodiment provides a construction method for a compressed air energy storage hard rock gas storage chamber as described in Embodiment 1. The structure is distributed along the outline of the underground rock chamber, and a sealing steel lining 4, a lining layer 2, a drainage system, and initial support of the surrounding rock 1 are sequentially arranged in the "from inside to outside" direction. The drainage system is fixed to the inner side of the surrounding rock 1.

[0048] The construction method includes the following steps: S1: Prefabricated steel plates with circumferential stiffening ribs 3 are transported into the chamber and then welded into annular sealed steel linings 4 using protective gas to control dimensional accuracy; S2: Install mortar anchors, hang steel mesh, and spray C25 concrete to provide initial support for the surrounding rock 1; S3: Excavate a U-shaped trench on the surface of the initial support of the surrounding rock 1 and lay an annular drainage trench. Lay the main drainage blind pipe and branch drainage blind pipe 5 and connect them to the annular drainage trench. Wrap the blind pipe with geotextile. Connect the main blind pipe to the water collection well and install a submersible pump. S4: Sliding tracks are installed inside the tunnel to transport and fix the annular steel lining. The axial and circumferential threaded steel bars of the lining layer are tied and then spot-welded into a skeleton. S5: Prepare C25 concrete, and pour it using a long rubber hose or elastic pump hose under high pressure. After pumping, the pump hose remains in the concrete. Vibrate to compact and cure to the design strength.

[0049] This method improves construction efficiency through prefabrication and on-site assembly, and staggered longitudinal seams during welding ensure sealing quality. Drainage system installation is carried out in advance to prevent water damage. Rail transport simplifies the installation of large components, and spot welding of the steel reinforcement cage ensures precise positioning. The placement of flexible pump pipes inhibits concrete crack formation. This method optimizes the construction process, reduces rework, and improves structural airtightness and stability.

[0050] Specifically: 1. Sealing layer construction: 1.1. Prefabrication: Select 07Mn-MoVR and Q460CF steel to make steel plates of the same specifications (wall thickness 18-24mm) with stiffening ribs 3. Cut them into shape according to the design drawings, strictly control the dimensional accuracy of the sealing steel lining 4 and stiffening ribs 3, and reserve assembly connection points.

[0051] 1.2. Transportation and Installation: Lay flat and firm tracks in the chamber according to construction requirements and transportation route. The spacing should match the transportation equipment. Slowly transport the precast steel rings to the designated position by sliding the tracks. Fix them at multiple points with temporary steel frames. Adjust the center of the steel rings to align with the center of the chamber and ensure that the spacing of each part is uniform.

[0052] 1.3. Welding and forming: The steel ring is welded into an annular sealing steel lining 4 using the protective gas welding method. When welding the transverse seam 42 of the steel lining, ensure that the longitudinal seams 41 of the steel lining of each pipe section are staggered to ensure the quality of the weld and the overall sealing performance.

[0053] 2. Construction of Lining Layer 2: 2.1. Reinforcement Layout: Based on the stiffening ribs 3 of the sealed steel lining 4, axial reinforcement 23 and circumferential reinforcement 22 are tied in layers with threaded steel bars, and then connected into an integrated support frame by spot welding process to ensure accurate reinforcement position and firm connection.

[0054] 2.2. Concrete pouring: Prepare C25 concrete and use high-pressure pumping equipment for pouring. The pump pipe should be a long rubber pipe or elastic material with compressive strength and flexibility. It does not need to be removed after pouring and should remain in the concrete to enhance tensile strength and inhibit cracking. During pouring, use an immersion vibrator to vibrate and control the insertion depth and time to ensure that the concrete is dense and free of honeycomb, pitting, and voids.

[0055] 2.3. Curing and shaping: After pouring, the concrete is cured according to the specifications. When the strength reaches the design value, the lining layer 2 is completed.

[0056] 3. Drainage system construction: 3.1. Initial Support Pretreatment: The initial support parameters, such as the spacing of anchor bolts and cables, should be determined based on the rock mass level of the chamber. Before construction, the rock mass level of the chamber should be surveyed. Only rock mass level III and above can be excavated. Initial support should be provided for the rock mass: mortar anchor bolts should be installed at the designed spacing, steel mesh should be hung, and C25 concrete should be sprayed to reinforce the rock mass and level its surface.

[0057] 3.2. Drainage component installation: On the initial support surface of the surrounding rock 1, U-shaped grooves matching the size of the annular drainage channel are precisely excavated at the designed intervals. The annular drainage channel is laid in the U-shaped groove and ensured to fit tightly. The main drainage blind pipe is laid along the axial direction of the chamber, and the branch drainage blind pipes 5 are laid at the intervals. The branch blind pipes are connected to the annular drainage channel to form a complete drainage network.

[0058] 3.3. Blockage Prevention and Water Collection: Wrap the outside of the main drainage blind pipe and the branch drainage blind pipe 5 with complete and undamaged geotextile; connect the end of the main drainage blind pipe to the pre-set water collection well at the bottom of the chamber, and install a submersible pump in the water collection well to ensure that the accumulated water is discharged in time.

[0059] In summary, the compressed air energy storage hard rock gas storage chamber and construction method provided by this invention have the following advantages: 1. By combining the sealed steel lining 4 with the circumferential stiffening rib 3, the risk of instability of the thin shell structure under the pressure of uncured concrete and external grouting pressure is effectively prevented, and the overall structural stability is significantly improved.

[0060] 2. The sealing layer is constructed using high-performance 07Mn-MoVR and Q460CF materials, combined with a strict welding process (protective gas welding and staggered design of horizontal and vertical seams) to minimize gas leakage and ensure the long-term reliable operation of the gas storage system.

[0061] 3. The innovative three-dimensional mesh drainage system design enables rapid drainage of groundwater and condensate around the chamber, effectively preventing water pressure accumulation from damaging the structure and extending its service life.

[0062] 4. The combination of prefabricated stiffening rib steel plates and sliding track transportation scheme simplifies the on-site construction process, improves construction efficiency, and shortens the construction period.

[0063] 5. The flexible pump pipe retention technology avoids the defects of air bubbles and cavities in traditional concrete pouring, improves the density of concrete, and enhances the overall performance of the structure.

[0064] 6. Compared with traditional organic flexible sealing materials, the metal sealing layer used in this invention not only reduces the risk of environmental pollution, but also has a higher cost performance and a longer service life, which is in line with the concept of green energy development.

[0065] 7. The design scheme is highly compatible with the on-site construction conditions, and is particularly suitable for Class III and above surrounding rock conditions, meeting the long-term service requirements of 40 to 50 years under 10-20MPa temperature and pressure alternating loads.

[0066] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A compressed air energy storage hard rock gas storage chamber, characterized in that, It includes a sealing layer and a lining layer arranged sequentially from the inside out; The sealing layer includes a sealing steel liner and stiffening ribs. The sealing steel liner is a tubular structure formed by splicing multiple steel liner sheets. The stiffening ribs are arranged in a ring on the outer wall of the tubular sealing steel liner and are arranged at intervals along the axis of the sealing steel liner. The lining layer includes a supporting frame and concrete. The supporting frame is a grid structure and is wrapped around the outer wall of the stiffening rib. The concrete is poured on the stiffening rib and the supporting frame to form the lining layer.

2. The compressed air energy storage hard rock gas storage chamber as described in claim 1, characterized in that, Multiple steel lining sheets are welded along a weld to form a tubular structure. The weld includes a longitudinal steel lining seam and a transverse steel lining seam. The longitudinal steel lining seam is parallel to the axis of the sealing steel lining, and the transverse steel lining seam is perpendicular to the axis of the sealing steel lining.

3. The compressed air energy storage hard rock gas storage chamber as described in claim 2, characterized in that, Along the axial direction of the sealing steel lining, the longitudinal seams of adjacent steel linings are arranged alternately.

4. The compressed air energy storage hard rock gas storage chamber as described in claim 1, characterized in that, The stiffening rib has a rectangular cross-section.

5. The compressed air energy storage hard rock gas storage chamber as described in claim 1, characterized in that, The stiffening rib has a stepped cross-section, and an elastic metal pad is attached to the surface of the stiffening rib.

6. The compressed air energy storage hard rock gas storage chamber as described in claim 1, characterized in that, The supporting frame includes circumferential reinforcing bars and axial reinforcing bars. The axial reinforcing bars are arranged in a direction parallel to the axis of the sealing steel liner, and the circumferential reinforcing bars are arranged in a direction perpendicular to the axis of the sealing steel liner.

7. The compressed air energy storage hard rock gas storage chamber as described in claim 1, characterized in that, The lining layer is numerically simulated based on C25 concrete. If it meets the engineering requirements, it is poured with C25 concrete. If it does not meet the engineering requirements, it is poured with a gradient material. The gradient material has steel fibers added to the inner concrete and polypropylene fibers added to the outer concrete, and the fiber volume fraction decreases from the inside to the outside.

8. The compressed air energy storage hard rock gas storage chamber as described in claim 1, characterized in that, A drainage system is also provided outside the lining layer. The drainage system includes a main drainage blind pipe and branch drainage blind pipes arranged along the axial direction of the chamber, which, together with the annular drainage groove on the surface of the initial support of the surrounding rock, form a three-dimensional network drainage system.

9. The compressed air energy storage hard rock gas storage chamber as described in claim 1, characterized in that, The outer layer of the tunnel is supported by the initial support of the surrounding rock, which uses anchor bolts and cables and shotcrete.

10. A construction method for a compressed air energy storage hard rock gas storage chamber as described in any one of claims 1-9, characterized in that, include: Prefabricated steel plates with circumferential stiffening ribs are transported into the chamber and then welded into an annular sealed steel lining. Excavate the chamber, install mortar anchors in the surrounding rock, hang steel mesh, and spray concrete for initial support; A U-shaped trench is excavated on the surface of the initial support of the surrounding rock and a ring-shaped drainage trench is laid. The main drainage blind pipe and the branch drainage blind pipe are laid and connected to the ring-shaped drainage trench. The blind pipe is wrapped with geotextile. The main blind pipe is connected to the water collection well and a submersible pump is installed. Sliding tracks are installed inside the tunnel to transport and fix the annular sealed steel lining. The circumferential and axial reinforcing bars of the lining layer are tied and then spot-welded into a skeleton. Prepare concrete, pump it into the concrete using a long rubber hose or flexible pump pipe, leave the pump pipe inside the concrete after pumping, vibrate to compact it, and cure it to the design strength.

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