Underground gas storage cavern lining structure

Abstract

The present application provides a kind of underground gas storage cave lining structure, to solve the problem of inconsistent deformation with secondary lining in the use of steel plate layer steel plate, steel plate is easily dropped, and the problems such as wrinkle deformation, relate to underground gas storage cave technical field.Underground gas storage cave lining structure, including secondary lining and steel plate lining, further comprising internal support system;Along the circumferential direction of the steel plate lining, the steel plate lining is provided with at least two spaced and convex arch slopes for expansion compensation, the inner side of the second groove and the outer side of the arch slope are provided with spacing to form deformation accommodation cavity, the deformation accommodation cavity is filled with elastic support body that is consistent with the outer side of the arch slope;The internal support system includes the inner surface of the arc segment that is pressed and combined with the outer side of the steel plate lining between the arch slope.The present application can better guarantee the service life and reliability of steel plate lining, and can further reduce the thickness of steel plate lining and reduce engineering investment.

Description

Technical Field

[0001] This invention relates to the field of underground gas storage tunnel technology, specifically an underground gas storage tunnel lining structure. Background Technology

[0002] Compressed air energy storage is a technology that converts electrical energy into the potential energy of high-pressure air to achieve energy storage. One of the key technical issues in constructing compressed air energy storage power stations is the safe and economical storage of high-pressure gas. Compared with using special geological structures such as salt caverns for gas storage, artificial underground gas storage caverns have significant advantages in terms of wide applicability and flexible layout, and thus have greater advantages in promotion. Artificial underground gas storage caverns adopt a circular cavern structure.

[0003] For artificial underground gas storage tunnels, the diverse and extreme rock and soil environments, including high pressure and complex geology, pose significant challenges. The surrounding rock deforms under pressure, easily developing cracks and leading to gas leakage. Therefore, sealing is crucial for underground gas storage tunnels, especially artificial ones. Currently, a common method is to install a sealing layer within the secondary lining of the tunnel. Sealing layer materials include steel plates or flexible materials such as plastics, rubber, and fibers. While flexible materials possess a certain degree of self-adaptive deformation capacity during the deformation of the surrounding rock, they are more susceptible to being pressed into cracks and torn under high pressure, making them less reliable than steel plates.

[0004] Patent application CN117145535A discloses a corrugated arch structure for an underground gas storage cavern, comprising: a steel plate lining, a rubber support, and a secondary lining. The corrugated arch is mounted on the steel plate lining, with an arc-shaped slope. A groove is formed on the outer side of the corrugated arch, and the rubber support is fitted into the groove formed on the outer side of the corrugated arch. The secondary lining is located on the outer side of the steel plate lining, with its inner surface in contact with the outer surfaces of the steel plate lining and the rubber support. The outer surface of the secondary lining is in contact with the surrounding rock of the tunnel. This structure allows the sealing layer, i.e., the steel plate lining, to have a certain degree of self-adaptive deformation capability through the corrugated arch, and can transfer the load of high-pressure air in the gas storage cavern to the surrounding rock through the secondary lining. This significantly reduces the thickness of the steel plate lining, saves steel consumption, and lowers project investment. In the aforementioned structure, due to the repeated storage and release of gas during the use of the underground gas storage tunnel, the elasticity of the rubber support gradually decreases over time. Meanwhile, as the steel lining thins, its stiffness decreases. During gas release from the storage tunnel, and the shrinkage and deformation of the surrounding rock, secondary lining, and sealing layer, there will be inconsistencies between the deformation of the steel plate layer and the deformation of the secondary lining. Furthermore, these problems will also arise when the surrounding rock conditions change. This inconsistency between the deformation of the steel plate layer and the secondary lining makes the sealing layer steel plate prone to deformation and detachment under gravity. Once detached, its deformation is difficult to control, easily resulting in wrinkles, deformation, and damage. These problems also make it difficult to further thin the sealing layer steel plate, hindering further reductions in project investment. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an underground gas storage tunnel lining structure to solve the problems of inconsistent deformation between the steel plate layer and the secondary lining, easy detachment of the steel plate, and wrinkling deformation during the use of the steel plate layer.

[0006] The technical solution adopted by the present invention to solve its technical problem is: an underground gas storage tunnel lining structure, including a secondary lining and a sealing steel plate lining that is attached to the inner surface of the secondary lining, and also including an internal support system that keeps the steel plate lining always attached to the inner surface of the secondary lining. Along the circumferential direction of the steel plate lining, the steel plate lining is provided with at least two spaced and outwardly convex arch slopes for expansion compensation. The inner side of the arch slope forms a first groove. The inner surface of the secondary lining is provided with at least two second grooves that correspond one-to-one with the arch slopes and are adapted to accommodate the arch slopes. A gap is provided between the inner side of the second groove and the outer side of the arch slope to form a deformation relief cavity. The deformation relief cavity is filled with an elastic support that fits against the outer side of the arch slope. The internal support system includes a pressure plate whose outer side is pressed against the inner surface of the arc-shaped segment between the arch slopes of the steel plate lining. The pressure plate is movably configured to move outward with the corresponding arc-shaped segment when the steel plate lining expands outward, and move inward with the corresponding arc-shaped segment when it contracts inward, thereby ensuring that the steel plate lining is always in contact with the inner surface of the secondary lining.

[0007] Furthermore, the arch slope has a circular arc structure.

[0008] Furthermore, the elastic support is a polytetrafluoroethylene (PTFE) sheet.

[0009] Furthermore, the inner support system includes an annular retaining ring with a notch, which is engaged within the steel plate liner to form the pressure plate.

[0010] Furthermore, the notch of the retaining ring is provided with a first spring that widens the notch to provide elastic force.

[0011] Furthermore, the internal support system also includes a central frame and at least two support springs spaced apart around the central frame. The central frame is disposed within the retaining ring, and the support springs are disposed along the radial direction of the retaining ring, with one end abutting against the inner surface of the retaining ring and the other end compressed and connected to the central frame to support and fix the central frame within the retaining ring.

[0012] Furthermore, the support springs are evenly distributed around the central frame.

[0013] Furthermore, the inner support system also includes adjusting screws along the radial direction of the retaining ring for adjusting the compression of the support spring. There are at least two adjusting screws, each corresponding to one of the support springs. One end of each adjusting screw is threaded to the center frame, and one end of each support spring is compressed and connected to the other end of its corresponding adjusting screw.

[0014] Furthermore, the secondary lining is formed by sequentially splicing and enclosing multiple pipe segments.

[0015] Furthermore, compressed rubber is installed in the joints between adjacent segments.

[0016] The beneficial effects of this invention are as follows: In the underground gas storage tunnel lining structure of this invention, a pressure plate is provided on the inner side of the arc-shaped section of the steel plate lining, which is pressed against its inner surface. The pressure plate can always be pressed against the corresponding arc-shaped section of the steel plate lining. The function of the pressure plate can increase the rigidity of the arc-shaped section, promote and inhibit the deformation of the arch slopes at both ends, so that the deformation of the steel plate lining tends to be consistent with the required outward expansion compensation or inward contraction. This ensures that the steel plate lining is always in contact with the inner surface of the secondary lining, which can control and constrain its deformation, allowing it to deform in the required manner. This can better ensure the service life and reliability of the steel plate lining, and can also further reduce the thickness of the steel plate lining and reduce project investment. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a structural design for the lining of an underground gas storage tunnel according to the present invention. Figure 2 This is a structural schematic diagram of the steel plate lining; Figure 3 It is the installation diagram of the arch slope; Figure 4 This is another structural schematic diagram of the underground gas storage tunnel lining structure of the present invention; Figure 5 This is a structural diagram of the support spring; The figure shows: secondary lining 1, steel plate lining 2, internal support system 3, compressed rubber 4, elastic support body 5, arch slope 21, arc segment 22, first groove 23, second groove 11, deformation relief cavity 12, pipe segment 13, pressure plate 31, support spring 32, snap ring 33, first spring 34, central frame 35, and adjusting screw 36. Detailed Implementation

[0018] like Figure 1As shown, the underground gas storage tunnel lining structure of the present invention includes a primary lining, a secondary lining 1, and a sealing steel plate lining 2 that is fitted onto the inner surface of the secondary lining 1. It also includes an internal support system 3 that ensures the steel plate lining 2 remains in contact with the inner surface of the secondary lining 1. The primary and secondary linings 1 are generally made of concrete. Along the circumferential direction of the steel plate lining 2, the steel plate lining 2 has at least two spaced-apart and outwardly convex arch slopes 21 for expansion compensation. A first groove 23 is formed on the inner side of each arch slope 21. At least two second grooves 11, corresponding one-to-one with and adapted to accommodate the arch slopes 21, are provided on the inner surface of the secondary lining 1. A gap is provided between the inner side of the second groove 11 and the outer side of the arch slope 21 to form a deformation relief cavity 12. The deformation relief cavity 12 is filled with an elastic support 5 that fits against the outer side of the arch slope 21. The internal support system 3 includes pressure plates 31 whose outer surfaces are pressed against the inner surface of the arc-shaped segments 22 between the arch slopes 21 of the steel plate lining 2. The pressure plates 31 are movably configured to move outward with the corresponding arc-shaped segments 22 when the steel plate lining 2 expands outward, and move inward with the corresponding arc-shaped segments 22 when it contracts inward, thereby ensuring that the steel plate lining 2 is always in contact with the inner surface of the secondary lining 1. The pressure plates 31 are generally spaced apart along the longitudinal direction of the steel plate lining 2.

[0019] The arch slope in this invention includes, but is not limited to, U-shaped, V-shaped or arc-shaped structures. In this embodiment of the invention, the arch slope adopts an arc-shaped structure.

[0020] In the gas storage tunnel lining structure of this invention, during gas storage, the gas pressure can be transmitted to the surrounding rock through the steel plate lining and secondary lining. Since the steel plate lining is fitted onto the inner surface of the secondary lining, it primarily serves a force-transmitting function and can be relatively thin. During the pressurization process, as the surrounding rock and secondary lining 1 expand and deform outwards, the steel plate lining 2 also undergoes corresponding outward expansion and deformation. This outward expansion deformation of the steel plate lining 2 can be compensated for by the deformation of the arch slope 21, ensuring smooth outward expansion of the steel plate lining 2. The elastic support 5 helps improve the stress distribution on the arch slope 21, making the stress more uniform.

[0021] The elastic support 5 can be made of materials with a certain elastic deformation capacity, such as rubber, polytetrafluoroethylene, or steel. In this invention, polytetrafluoroethylene is preferred. Polytetrafluoroethylene has the advantages of wear resistance and low frictional resistance, which facilitates relative sliding between it and the elastic support when the arch slope deforms, and is more conducive to improving the stress on the arch slope 21.

[0022] The underground gas storage tunnel lining structure of the present invention includes a pressure plate 31 on the inner side of the arc-shaped segment 22 of the steel plate lining 2, which is pressed against its inner surface. The pressure plate 31 is movably configured to move outward with the corresponding arc-shaped segment 22 when the steel plate lining 2 expands outward, and move inward with the corresponding arc-shaped segment 22 when it contracts inward. In this way, the pressure plate can always press against the corresponding arc-shaped segment of the steel plate lining. Thus, when the gas storage tunnel expands or contracts, the pressure plate increases the stiffness of the arc-shaped segment 22, which can promote and inhibit the deformation of the arch slopes 21 at both ends. This makes the deformation of the steel plate lining 2 more consistent with the required expansion compensation or contraction, thereby ensuring that the steel plate lining 2 always adheres to the inner surface of the secondary lining 1. This allows for control and constraint of its deformation, ensuring that it deforms in the required manner. Therefore, the lining structure of the present invention can better guarantee the service life and reliability of the steel plate lining.

[0023] Specifically, during the outward expansion process, the main inconsistency is that the outward deformation of the arch slope 21 is greater than the outward expansion compensation required by the steel plate lining 2. Due to the effect of the pressure plate, the stiffness of the arc segment 22 can be increased, making it difficult for the arch slope 21 at both ends of the arc segment 22 to undergo excessive outward deformation. This allows the deformation of the arch slope 21 to be consistent with the outward expansion compensation required by the steel plate lining 2. During the inward contraction process, the main inconsistency is that the inward contraction deformation of the arch slope 21 is less than the inward contraction deformation required by the steel plate lining 2. Also, due to the effect of the pressure plate, the stiffness of the arc segment 22 is strengthened, and the inward contraction force of the secondary lining 1 on the arc segment 22 can be better transmitted to the steel plate at the arch slope, causing it to contract back. This makes the inward contraction of the secondary lining 1 consistent with the inward contraction of the steel plate lining 2, ensuring that the steel plate lining 2 always adheres to the inner surface of the secondary lining 1.

[0024] It is understandable that when the steel plate lining expands or contracts, a certain amount of relative sliding needs to be generated between the pressure plate 31 and the arc segment 22 to ensure that the steel plate lining expands or contracts smoothly. Therefore, the pressure between the pressure plate 31 and the arc segment 22 should not be too great.

[0025] In this invention, the pressure plate 31 can be multiple pieces, each independent of the others. Each arc segment 22 can have its own pressure plate 31, or a certain number of arc segments 22 can share a single pressure plate. See also Figure 4The pressure plate can move radially along the gas storage tunnel via a support spring 32 located on its inner side. When the steel plate lining 2 expands outward, it moves outward with the corresponding arc segment 22; when it contracts inward, it moves inward with the corresponding arc segment 22, thus ensuring that the steel plate lining 2 always adheres to the inner surface of the secondary lining 1. Theoretically, when there are multiple pressure plates, a greater number of pressure plates is more effective in preventing the steel plate lining from falling off, but a greater number of pressure plates also occupies more space inside the gas storage tunnel. The outward convexity of the arch slope 21 in this invention is also based on the consideration of facilitating the installation of the pressure plate 31 and reducing the number of pressure plates. Furthermore, the deformation direction of the outward convex arch slope under air pressure is consistent with the outward expansion compensation deformation direction, which also helps to reduce the stress on the steel plate lining.

[0026] like Figure 4 As shown, in one embodiment of the present invention, an annular retaining spring 33 with a notch is fitted inside the steel plate liner 2, and the retaining spring 33 forms the pressure plate 31. That is, the pressure plate is a single piece, and it is annular, and the pressure plate is composed of a retaining spring with a notch. When the steel plate liner 2 expands outward, the retaining spring 33 expands outward accordingly due to being released; when it contracts inward, the retaining spring 33 contracts inward due to the squeezing action of the steel plate liner 2, so that it can always be pressed against the arc-shaped segment 22.

[0027] The retaining spring 33 can be bent from an elastic material, forming a single integral structure. During installation, compressing the spring reduces its notch, allowing it to engage within the steel plate liner 2. The elastic force of the retaining spring 33 is primarily provided by the elastic deformation of its own material. However, this structure presents an inconvenience in installation. To facilitate installation, such as... Figure 4 As shown, in this invention, a first spring 34 is provided within the notch of the retaining ring 33 to expand the notch and thus provide elastic force. That is, the elastic force of the retaining ring 33 is mainly provided by the first spring 34. Therefore, when installing the retaining ring, it is not necessary to compress the retaining ring 33 beforehand; the first spring 34 can be placed within the notch after installation. The retaining ring can be installed using an in-hole assembly method, making installation more convenient. In the above structure, the retaining ring can be assembled from structural steel.

[0028] like Figure 5As shown, in this embodiment of the invention, the inner support system 3 further includes a central frame 35 and at least two support springs 32 spaced apart around the central frame 35. The central frame 35 is disposed within the retaining ring 33, and the support springs 32 are disposed radially along the retaining ring 33. One end of each support spring 32 abuts against the inner surface of the retaining ring 33, and the other end is compressed and connected to the central frame 35 to support and fix the central frame 35 within the retaining ring 33. This structure provides an outward deformation force to the retaining ring 33 through the support springs 32. This force allows the retaining ring to better fit and press against the steel plate lining at the corresponding position of the support spring during the outward expansion and deformation process of the steel plate lining. This ensures that the retaining ring remains in close and pressed fit with the steel plate lining.

[0029] To better ensure the force balance of the central frame, the support springs 32 are optimally distributed around the central frame 35 and arranged symmetrically about the center.

[0030] The support spring 32 can be directly or indirectly connected to the center frame 35, and the connection can be made by welding or snap-fitting. In this embodiment of the invention, the inner support system 3 further includes adjusting screws 36 along the radial direction of the retaining spring 33 for adjusting the compression of the support spring 32. There are at least two adjusting screws 36, each corresponding to one of the support springs 32. One end of the adjusting screw 36 is threaded to the center frame 35, and one end of the support spring 32 is compressed and connected to the other end of its corresponding adjusting screw 36. That is, the support spring 32 is connected to the center frame 35 through the adjusting screws 36. The above structure allows adjustment of the compression of the corresponding support spring 32 by turning the adjusting screws 36 to adjust their extension length.

[0031] The secondary lining 1 can be an integral structure. In this invention, the secondary lining 1 is formed by sequentially splicing multiple pipe segments 13. This sequential splicing of multiple pipe segments 13 facilitates the deformation of the secondary lining 1, helps control cracking (cracking mainly occurs at the splicing points), and ensures the sealing performance of the steel plate lining. Compression rubber 4 is provided in the splicing joints between adjacent pipe segments 13 to support the steel plate lining 2 during the expansion of the secondary lining 1.

Claims

1. An underground gas storage tunnel lining structure, comprising a secondary lining (1) and a sealing steel plate lining (2) fitted onto the inner surface of the secondary lining (1), characterized in that: It also includes an internal support system (3) that keeps the steel plate lining (2) always in contact with the inner surface of the secondary lining (1); Along the circumferential direction of the steel plate lining (2), the steel plate lining (2) is provided with at least two spaced and outwardly protruding arch slopes (21) for expansion compensation. The inner side of the arch slope (21) forms a first groove (23). The inner surface of the secondary lining (1) is provided with at least two second grooves (11) that correspond one-to-one with the arch slope (21) and are adapted to accommodate the arch slope (21). The inner side of the second groove (11) and the outer side of the arch slope (21) are provided with a gap to form a deformation relief cavity (12). The deformation relief cavity (12) is filled with an elastic support (5) that fits against the outer side of the arch slope (21). The inner support system (3) includes a pressure plate (31) on the inner surface of the arc segment (22) between the arch slope (21) of the steel plate lining (2). The pressure plate (31) is movably configured to move outward with the corresponding arc segment (22) when the steel plate lining (2) expands outward, and move inward with the corresponding arc segment (22) when it contracts inward, so that the steel plate lining (2) is always attached to the inner surface of the secondary lining (1).

2. The underground gas storage tunnel lining structure as described in claim 1, characterized in that: The arch slope (21) is a circular arc structure.

3. The underground gas storage tunnel lining structure as described in claim 1, characterized in that: The elastic support (5) is a polytetrafluoroethylene plate.

4. The underground gas storage tunnel lining structure as described in claim 1, characterized in that: The inner support system (3) includes an annular notched retainer (33), which is engaged within the steel plate liner (2) to form the pressure plate (31).

5. The underground gas storage tunnel lining structure as described in claim 4, characterized in that: The notch of the snap ring (33) is provided with a first spring (34) that widens the notch to provide elastic force.

6. The underground gas storage tunnel lining structure as described in any one of claims 4 to 5, characterized in that: The inner support system (3) further includes a central frame (35) and at least two support springs (32) spaced around the central frame (35). The central frame (35) is disposed inside the snap ring (33). The support springs (32) are disposed along the radial direction of the snap ring (33), with one end abutting against the inner side of the snap ring (33) and the other end compressed and connected to the central frame (35) to support and fix the central frame (35) inside the snap ring (33).

7. The underground gas storage tunnel lining structure as described in claim 6, characterized in that: The support springs (32) are evenly distributed around the central frame (35).

8. The underground gas storage tunnel lining structure as described in claim 6, characterized in that: The inner support system (3) further includes an adjusting screw (36) along the radial direction of the snap ring (33) for adjusting the compression of the support spring (32). There are at least two adjusting screws (36) and they are arranged one-to-one with the support spring (32). One end of the adjusting screw (36) is threaded to the center frame (35) through its thread, and one end of the support spring (32) is compressed and connected to the other end of the corresponding adjusting screw (36).

9. The underground gas storage tunnel lining structure as described in claim 1, characterized in that: The secondary lining (1) is formed by splicing and enclosing multiple segments (13) in sequence.

10. The underground gas storage tunnel lining structure as described in claim 9, characterized in that: Compression rubber (4) is provided in the splice joint between adjacent segments (13).

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