An adaptive deformation sealing structure of artificial rock cavity gas storage

Abstract

The application provides a self-adapting deformation sealing structure of an artificial rock cavity gas storage, which comprises a sealing structure body, and a sealing structure layer of the sealing structure body comprises, from outside to inside, a stratum surrounding rock, a shotcrete layer, a concrete prefabricated lining layer, a transition layer and a flexible sealing layer; the concrete prefabricated lining layer is formed by mutually splicing a plurality of concrete prefabricated components, a wedge-shaped block is installed between two adjacent concrete prefabricated components, and the wedge-shaped block is anchored in an anchor rod drilling hole of the surrounding rock by an anchor rod; an inner surface of the concrete prefabricated lining layer is provided with the flexible sealing layer, and the flexible sealing layer is attached to an inner surface of the transition layer. The concrete structure layer and the flexible sealing layer of the application have strong deformation adaptation capability, the concrete prefabricated lining layer has low tensile stress, the flexible structure layer does not bear tensile stress, the flexible structure layer does not crack under normal operation pressure conditions of the gas storage, and the application has the advantages of being especially suitable for construction of a large-deformation high-pressure underground gas storage in a soft rock stratum.

Description

Technical Field

[0001] This invention belongs to the field of energy storage engineering, and in particular relates to an adaptive deformation sealing structure for an artificial rock cave gas storage facility. Background Technology

[0002] Compressed air energy storage technology is a novel energy storage technology that utilizes high-pressure compressed air to store electrical energy. It can effectively address the intermittency and volatility of clean energy sources such as solar and wind power, and contribute to the achievement of global "dual carbon" goals.

[0003] The bottleneck in the widespread application of large-scale compressed air energy storage technology is how to construct efficient and economical compressed air storage devices. Artificial rock cavern gas storage facilities offer the possibility of widespread application of compressed air energy storage technology due to their site selection flexibility. However, the construction of artificial rock cavern gas storage facilities needs to meet basic requirements such as engineering safety, sealing reliability, and economic rationality, with sealing reliability and economic rationality remaining the core considerations.

[0004] Since artificial rock cavern gas storage facilities are buried deep underground in hard rock strata, the safety of their chambers can be ensured through the implementation of certain engineering measures. The high-pressure gas sealing of artificial rock cavern gas storage facilities can be achieved through various measures. Different sealing methods result in significant differences in engineering costs.

[0005] Under current technological conditions, artificial rock cave gas storage facilities can use steel plates, rubber plates, fiberglass, or polymers to construct the sealing layer.

[0006] Chinese invention patent application publication number CN115110995A proposes a gas storage sealing structure based on steel plate sealing, belonging to the field of new energy technology. Specifically, it discloses that the underground storage chamber is located within the original geological strata. The sealing structure of the underground storage chamber comprises, from the outside in, a grouting layer, a lining layer, inner reinforcing bars, a buffer layer, and a steel sealing layer, all nested sequentially. The grouting layer, lining layer, inner reinforcing bars, buffer layer, and steel sealing layer are aligned. The construction method includes: excavating a accommodating space within the original geological strata; and forming the underground storage chamber sealing structure within the accommodating space.

[0007] Chinese invention patent applications CN110371568A and CN105905512A employ a multi-layer fiberglass reinforced plastic (FRP) sealing layer structure to ensure the airtightness of the gas storage facility.

[0008] Chinese invention patent application publication number CN115324647A proposes a sealing scheme for setting an epoxy resin sealing layer on the inner wall of a cave structure. The precast concrete lining layer, which is integrally cast, is divided into blocks by concrete joints. The relative mobility reserved at the joints is used to release the tensile stress in the concrete as much as possible, reducing the occurrence of tensile cracks in the concrete caused by temperature loads. The inner lining protrusions are connected to the inner lining layer as a whole, and the shape of the inner lining protrusions matches the concrete grooves, reducing stress concentration in the inner lining layer. The self-locking structure formed by the inner lining protrusions locking into the precast concrete lining layer ensures coordinated deformation of the two under alternating loads, preventing damage to the adhesion between them. The epoxy resin sealing layer uses a bisphenol A type epoxy resin matrix and is compounded with 5% by mass of alumina and 5% by mass of boron nitride nanosheets, improving the thermal conductivity and hydrogen sealing ability of the epoxy resin.

[0009] However, the above solutions are essentially rigid sealing solutions. As rigid sealing layer solutions, their biggest drawback is that the sealing structure layer bears most of the gas storage pressure. Furthermore, the complex environment of underground compressed air energy storage facilities, including internal temperature changes and cyclic loading and unloading, can cause a decline in the performance of the rigid sealing layer (steel plate, fiberglass, and epoxy resin), leading to voids between the sealing structure layers and ultimately resulting in sealing failure and a significant risk of gas leakage. In addition, steel-lined sealing and fiberglass sealing structure layer solutions also suffer from high costs and significant construction difficulties.

[0010] In the complex environment of gas storage filling and discharging cycles, in order to meet the long-term airtightness requirements of cavern gas storage, solve the shortcomings of existing sealing structures in long-term operation, and reduce construction difficulty and construction cost of sealing projects, this invention proposes a flexible sealing layer structure with adaptive deformation. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide an underground gas storage sealing structure system that combines a segmented prestressed concrete lining with an integral flexible sealing layer, addressing the issues of insufficient deformation adaptation of the existing gas storage sealing structure layer under cyclic pressure and high cost.

[0012] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows:

[0013] An adaptive deformation sealing structure for an artificial rock cave gas storage facility, the sealing structure includes a sealing structure body, the sealing structure layer of the sealing structure body including, from the outside to the inside, the surrounding rock, the shotcrete layer, the precast concrete lining layer and the flexible sealing layer, and multiple anchor bolt holes are opened on the inner surface of the surrounding rock.

[0014] The precast concrete lining layer is composed of multiple precast concrete components spliced ​​together. A wedge block is installed between two adjacent precast concrete components, and the wedge block is anchored in the anchor bolt hole of the surrounding rock by anchor bolts.

[0015] A transition layer is provided between the precast concrete lining layer and the flexible sealing layer. The outer surface of the transition layer is in contact with the inner surface of the precast concrete component, and the inner surface of the transition layer is in contact with the flexible sealing layer.

[0016] Therefore, this invention designs the precast concrete lining layer as precast concrete components, forming reserved joints between adjacent precast concrete components. Anchor rods are installed within the joint spaces between adjacent precast concrete components to prevent excessive tensile stress and wide cracks in the precast concrete components under high internal pressure. Furthermore, by casting a transition layer on the inner surface of the precast concrete components, the expansion of cracks in the precast concrete components to the inner surface of the transition layer under high internal pressure is limited. This provides a crack-free substrate for the flexible polymer sprayed sealing layer inside the gas storage facility, ensuring that the flexible polymer sprayed sealing layer does not crack or fail due to deformation caused by high internal pressure, thus ensuring the long-term effectiveness of the flexible sealing layer. This application features a clear force transmission path, well-defined structural stress, and a low overall failure risk of the sealing structure. Compared to steel linings and fiberglass sealing structures, the engineering cost can be significantly reduced.

[0017] Furthermore, a sliding layer is provided between the precast concrete lining layer and the shotcrete layer, and the sliding layer is in contact with the outer surface of the precast concrete component. The sliding layer effectively reduces the constraint friction between the precast concrete component and the shotcrete layer, further reducing the crack width of the precast concrete component.

[0018] Furthermore, a gap exists between the wedge block and the sliding layer. A certain amount of deformation adaptation space is reserved on the outer side of the wedge block to ensure that the wedge block can undergo corresponding deformation during operation, reduce the prestress loss of the precast concrete component, and at the same time ensure that the precast concrete component and the shotcrete layer always maintain contact and do not separate.

[0019] Furthermore, the precast concrete component is an arc-shaped reinforced concrete precast component, and the cross-section of the precast concrete lining layer is generally circular.

[0020] Furthermore, the entire sealing layer is a one-piece structure, and its cross-section is circular.

[0021] Furthermore, the flexible sealing layer is a flexible polymer spray-coated sealing layer. The flexible sealing layer employs a flexible polymer spraying process, and the flexible polymer is preferably a two-component polyurea. This significantly reduces the difficulty and time required for sealing layer construction.

[0022] Furthermore, the transition layer is a flexible polymer concrete or a flexible polymer mortar precast sheet.

[0023] Furthermore, the anchor bolt is a spring anchor bolt, and the spring section of the spring anchor bolt applies a preload to the wedge block. The spring anchor bolt uses a wedge block anchor head. After installation, the spring anchor bolt is pre-stretched, forming a preload in the spring section of the anchor bolt. The wedge block moves outward under the preload, thereby forming a certain prestress on the precast concrete components on both sides of the wedge block. This prestress can offset or partially offset the tensile stress formed by the gas pressure in the gas storage tank in the precast concrete components, thereby minimizing the risk of cracking and the crack width of the precast concrete components.

[0024] Furthermore, a steel channel is installed between adjacent transition layers, and the bottom of the steel channel is connected to a wedge-shaped block. The steel channel is preferably a U-shaped steel channel.

[0025] Furthermore, a corrugated steel sheet is provided between the steel trough and the flexible sealing layer, the corrugated steel sheet is attached to the flexible sealing layer, and the steel trough is filled with quartz sand.

[0026] Thus, the U-shaped steel channel transfers the enormous internal pressure from the flexible sealing layer through the flexible corrugated steel sheet to the high-strength precast concrete component. The pressure transmitted from the corrugated steel sheet is transferred to the bottom edge of the U-shaped steel channel by filling the space between the U-shaped steel channel and the corrugated steel sheet with dense silica sand. The flexible polymer sprayed sealing layer is directly sprayed onto the surface of the corrugated steel sheet, locally forming a flexible corrugated sealing layer to accommodate the large tensile deformation that may occur at the joint without cracking.

[0027] The adaptive deformation sealing structure of the artificial rock cave gas storage facility of the present invention has the following advantages:

[0028] The adaptive deformation sealing structure proposed in this invention has the advantages of strong deformation adaptability of the concrete structural layer and the flexible sealing layer, low stress of the flexible sealing layer, and no cracking under the normal operating pressure conditions of the gas storage facility. It is especially suitable for the construction of large deformation high-pressure underground gas storage facilities in soft rock strata. Attached Figure Description

[0029] Figure 1 This is a cross-sectional view of the sealing structure of the present invention;

[0030] Figure 2 This is a detailed drawing of the seam structure of the present invention.

[0031] The markings in the diagram are as follows: 1. Surrounding rock; 2. Shotcrete layer; 3. Sliding layer; 4. Precast concrete component; 5. Transition layer; 6. Flexible sealing layer; 8. Anchor bolt; 9. Quartz sand; 10. Corrugated steel sheet; 11. Steel channel; 12. Wedge block; 13. Void; 14. Anchor bolt hole; 20. Sealing structure body; 21. Precast concrete lining layer. Detailed Implementation

[0032] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0033] like Figure 1 As shown in the figure, an adaptive deformation sealing structure for an artificial rock cave gas storage facility in this embodiment includes a sealing structure body 20. The sealing structure layer of the sealing structure body 20 includes, from the outside to the inside, the surrounding rock 1, the shotcrete layer 2, the sliding layer 3, the precast concrete lining layer 21, the transition layer 5, and the flexible sealing layer 6.

[0034] like Figure 1 and Figure 2 As shown, the precast concrete lining layer 21 is composed of multiple precast concrete components 4 spliced ​​together. Each precast concrete component 4 is an arc-shaped reinforced concrete precast component, and the cross-section of the precast concrete lining layer 21 is generally annular. A trapezoidal wide joint is formed between adjacent precast concrete components 4, and a wedge-shaped block 12 is installed within the trapezoidal wide joint. The wedge-shaped block 12 is anchored to the anchor borehole 14 in the surrounding rock 1 using anchor rods 8. By designing the precast concrete lining layer 21 as precast concrete components 4, and creating a reserved trapezoidal wide joint between the precast concrete components 4, excessive tensile stress and wide cracks are avoided under high internal pressure. Specifically, spring anchor rods are installed within the trapezoidal wide joint between the precast concrete components 4, and the spring anchor rods use wedge-shaped block anchor heads. After installation, the spring anchor rods are pre-stretched, forming a pre-tightening force in the spring section of the anchor rod. The wedge block 12 moves outward under preload, thereby creating a certain prestress on the precast concrete components 4 on both sides of the wedge block 12. This prestress can offset or partially offset the tensile stress formed in the precast concrete components 4 by the gas pressure in the gas storage tank, thereby minimizing the risk of cracking and the crack width of the precast concrete components 4.

[0035] like Figure 1 and Figure 2 As shown, a sliding layer 3 is provided between the precast concrete lining layer 21 and the shotcrete layer 2. The sliding layer 3 is used to reduce the constraint friction between the precast concrete component 4 and the shotcrete layer 2, further reducing the crack width of the precast concrete component 4. The sliding layer 3 is in contact with the outer surface of the precast concrete component 4. Specifically, there is a gap 13 between the wedge block 12 and the sliding layer 3. The gap 13 provides redundancy for the later deformation of the wedge block 12. A certain deformation adaptation gap space is reserved on the outside of the wedge block 12 to ensure that the wedge block 12 can undergo corresponding following deformation during operation, reducing the prestress loss of the precast concrete component 4, and also ensuring that the precast concrete component 4 and the shotcrete layer 2 always remain in contact and do not separate.

[0036] like Figure 1 As shown, a transition layer 5 and a flexible sealing layer 6 are respectively provided on the inner surface of the precast concrete lining layer 21. The transition layer 5 is a precast sheet of flexible polymer concrete or flexible polymer mortar. The flexible sealing layer 6 is a flexible polymer sprayed sealing layer, preferably a two-component polyurea. By casting a second layer of low-elasticity, high-tensile-strength flexible concrete on the inner surface of the precast concrete component 4, the expansion of cracks in the precast concrete component 4 to the inner surface of the flexible concrete layer under high internal pressure is limited. This provides a crack-free substrate for the flexible polymer sprayed sealing layer in the gas storage facility, ensuring that the flexible polymer sprayed sealing layer does not crack or break due to deformation caused by high internal pressure, thereby ensuring the long-term effectiveness of the sealing layer.

[0037] like Figure 1 and Figure 2 As shown, the outer surface of the transition layer 5 is bonded to the inner surface of the precast concrete component 4, and the inner surface of the transition layer 5 is bonded to the flexible sealing layer 6. The entire sealing layer 6 is an integral structure with a circular cross-section. A steel channel 11 is installed between adjacent transition layers 5, and the bottom of the steel channel 11 is connected to a wedge block 12. A corrugated steel sheet 10 is provided between the steel channel 11 and the flexible sealing layer 6, and the corrugated steel sheet 10 is bonded to the flexible sealing layer 6. The steel channel 11 is filled with dense quartz sand 9. Preferably, the flexible polymer spray sealing layer is directly sprayed onto the surface of the corrugated steel sheet 10 to locally form a flexible corrugated sealing layer, so as to accommodate the large tensile deformation that may occur at the joint without cracking. Specifically, the steel channel 11 is installed in the wide joint between adjacent transition layers 5. The steel channel 11 is preferably a U-shaped steel channel, which can transfer the huge internal pressure transmitted by the sealing layer through the flexible corrugated steel sheet to the high-strength precast concrete component. The pressure transmitted from the corrugated steel sheet is transferred to the bottom edge of the U-shaped steel channel by filling the space between the U-shaped steel channel and the corrugated steel sheet with dense quartz sand.

[0038] This application addresses the issue that in existing technologies, the sealing structure layer bears most of the gas storage pressure, making cracking of the reinforced concrete structure layer inevitable, limiting the amount of reinforcement required, and resulting in high costs. Furthermore, the large crack width after the reinforced concrete cracks inevitably leads to thin-layer compression failure when using a sprayed flexible sealing thin-layer solution, affecting long-term sealing performance. Simultaneously, the complex environment of underground compressed air energy storage facilities, including internal temperature changes and cyclic loading / unloading, causes performance degradation of rigid sealing layers (steel plates, fiberglass, and epoxy resin). This application proposes a novel flexible sealing layer structure with adaptive deformation, which can prevent voids between sealing structure layers, thereby avoiding the risk of significant gas leakage due to sealing structure failure. The key challenge of this design is how to effectively solve the problem of flexible sealing layer structural damage caused by cracking of the reinforced concrete structure layer. By employing the low-elasticity modulus crack-resistant flexible composite material structure layer of this invention, the problem of thin-layer cracking and leakage caused by cracking of the reinforced concrete structure layer is solved. It has the advantages of strong deformation adaptability of both the concrete structure layer and the flexible sealing layer, low stress in the flexible sealing layer, and no cracking under normal operating pressure conditions of the gas storage facility, making it particularly suitable for the construction of high-pressure underground gas storage facilities with large deformations in soft rock strata.

[0039] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. An adaptive deformation sealing structure for an artificial rock cavern gas storage facility, comprising a sealing structure body (20), characterized in that, The sealing structure body (20) includes, from the outside to the inside, the surrounding rock (1), the shotcrete layer (2), the precast concrete lining layer (21), and the flexible sealing layer (6). Multiple anchor bolt holes (14) are opened on the inner surface of the surrounding rock (1). The precast concrete lining layer (21) is formed by splicing together multiple precast concrete components (4). A wedge block (12) is installed between two adjacent precast concrete components (4). The wedge block (12) is anchored in the anchor borehole (14) of the surrounding rock (1) by anchor rods (8). A transition layer (5) is provided between the precast concrete lining layer (21) and the flexible sealing layer (6). The outer surface of the transition layer (5) is in contact with the inner surface of the precast concrete component (4), and the inner surface of the transition layer (5) is in contact with the flexible sealing layer (6). A sliding layer (3) is provided between the precast concrete lining layer (21) and the shotcrete layer (2), and the sliding layer (3) is in contact with the outer surface of the precast concrete component (4); There is a gap (13) between the wedge block (12) and the sliding layer (3); The anchor (8) is a spring anchor, and the spring section of the spring anchor applies a preload force to the wedge block (12); A steel channel (11) is installed between adjacent transition layers (5), and the bottom of the steel channel (11) is connected to a wedge block (12); A corrugated steel sheet (10) is provided between the steel trough (11) and the flexible sealing layer (6), the corrugated steel sheet (10) is attached to the flexible sealing layer (6), and the steel trough (11) is filled with quartz sand (9).

2. The adaptive deformation sealing structure of the artificial rock cave gas storage facility according to claim 1, characterized in that, The precast concrete component (4) is an arc-shaped reinforced concrete precast component, and the cross-section of the precast concrete lining layer (21) is generally circular.

3. The adaptive deformation sealing structure of the artificial rock cave gas storage facility according to claim 1, characterized in that, The entire flexible sealing layer (6) is an integral structure, and its cross-section is circular.

4. The adaptive deformation sealing structure of the artificial rock cave gas storage facility according to claim 1, characterized in that, The flexible sealing layer (6) is a flexible polymer spray sealing layer.

5. The adaptive deformation sealing structure of the artificial rock cave gas storage facility according to claim 1, characterized in that, The transition layer (5) is a flexible polymer concrete or a flexible polymer mortar precast sheet.

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