A compressed air energy storage cavern sealing system and design method

Abstract

The present application relates to compressed air energy storage technology field, specifically to a kind of compressed air energy storage cavern sealing system, by setting up steel pipe in the maintenance passage, steel pipe is welded with gas storage cavern steel lining, end plate is embedded in the concrete of plugging body, sealing door is set on end plate, and steel pipe is welded and connected with end plate, not only effectively solve the difficult installation of sealing door in traditional curved interface, the problem of poor sealing performance, also significantly improve the structural safety and air tightness of plugging body.The setting of end plate can ensure that the sealing door body is firmly fixed, realize internal pressure uniform dispersion, effectively avoid the risk of crushing caused by stress concentration of concrete, which is beneficial to significantly reduce the probability of gas leakage.The design of the sealing system fully embodies the unity of structural safety and sealing reliability.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage technology, and in particular to a compressed air energy storage cavern sealing system and design method. Background Technology

[0002] Compressed air energy storage (CAES) technology is a large-scale energy storage solution that stores energy through compressed air and releases it to generate electricity when needed. Traditional CAES systems typically rely on underground salt caverns or abandoned mines as storage chambers, but these are geographically restrictive and require extremely high sealing. In recent years, artificial gas storage caverns have gradually become an important choice for compressed air energy storage power plants due to their advantages such as flexible site selection and layout. Artificial gas storage caverns are underground gas storage structures with a certain volume, artificially excavated. Common types of artificial caverns include tunnel-type and large tank-type, with internal pressures typically ranging from several megapascals to tens of megapascals. To meet maintenance needs, maintenance access channels must be provided between the gas storage cavern and the outside world for maintenance personnel and equipment to enter and exit. These access channels are sealed by maintenance doors (also known as sealing doors). In traditional designs, maintenance doors are often located inside the gas storage cavern. The enormous load exerted by the air pressure inside the cavern acts on the maintenance door, which transfers the load through the door frame to the cavern sealing layer and then through the lining layer to the surrounding rock. Because the rock mass at the door frame of the inspection door bears a significantly different load compared to other parts of the rock mass, it is prone to fracture at the location where the door frame is installed, resulting in excessive deformation and gas leakage. Furthermore, since the inspection passage needs to lead directly into the gas storage chamber, which is often a circular cross-section chamber, the junction between the inspection door and the gas storage chamber is often an irregular curved surface, easily creating installation gaps, increasing the risk of leakage from the inspection door, and making the installation of the inspection door difficult. Summary of the Invention

[0003] The purpose of this invention is to address the problems in existing sealing systems where inspection doors are installed on the curved surface inside the gas storage cavern, causing the load to be transferred to the surrounding rock via the door frame. This leads to significant deformation of the rock mass at the door frame, resulting in gas leakage. Furthermore, the inspection doors often form installation gaps on the curved surface inside the gas storage cavern, increasing the risk of leakage. This invention provides a compressed air energy storage cavern sealing system and its design method.

[0004] This invention provides a compressed air energy storage cavern sealing system, including an air storage cavern and a maintenance passage. The air storage cavern is lined with a steel lining, and the maintenance passage is connected to the air storage cavern and located within a sealing body. At least one end plate is provided within the maintenance passage for laterally sealing it. The end plate is a flat steel plate, and its edge extends radially into the sealing body. A sealing door is provided on the end plate. A steel pipe is installed along the maintenance passage and welded to the end plate. The steel pipe extends into the air storage cavern, and its outer contour is welded to the steel lining.

[0005] Preferably, the size of the maintenance passage on the side of the end plate away from the gas storage chamber is less than or equal to the size of the maintenance passage on the side of the same end plate close to the gas storage chamber.

[0006] Preferably, at least one side of the two sides of the end plate is provided with a plurality of anchor bars, which are used to connect with the structural steel bars in the sealing body.

[0007] Preferably, the sealing door is located on the side of the end plate near the gas storage chamber.

[0008] Preferably, the end plate has a groove on one side connected to the sealing door, the groove is adapted to the shape and size of the sealing door, the end plate is hinged to the sealing door, and a sealing ring or sealing gasket or other sealing material is provided between the sealing door and the groove.

[0009] Preferably, the number of end plates is provided in a plurality of manner, and the steel pipe includes a first steel pipe and a second steel pipe. The first steel pipe connects the gas storage chamber and the end plate, and the second steel pipe connects two adjacent end plates. The first steel pipe and the second steel pipe have the same size and are coaxially arranged.

[0010] Preferably, an air inlet is provided in the cavity between two adjacent end plates, and the air inlet is connected to the gas storage cavity through an air guide pipe. The air guide pipe is pre-embedded in the sealing body and is connected to a differential pressure reducing valve.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention provides a compressed air energy storage cavern sealing system. By installing a steel pipe within the maintenance passage and welding it to the steel lining of the storage cavern, an end plate is embedded within the concrete of the sealing body. A sealing door is installed on the end plate, and the steel pipe is welded to the end plate. This system effectively solves the problems of difficult installation and poor sealing performance of the sealing door at traditional curved surface junctions, and significantly improves the structural safety and airtightness of the sealing body. The end plate ensures the sealing door is firmly fixed, achieves uniform internal pressure distribution, effectively avoids the risk of crushing due to concrete stress concentration, and significantly reduces the overall probability of gas leakage. The design of this sealing system fully embodies the unity of structural safety and sealing reliability.

[0012] 2. This invention provides a design method for a compressed air energy storage cavern sealing system. By adopting a multi-stage sealing door with graded load-bearing capacity, a multi-stage pressure chamber with progressively decreasing pressure is formed from the high-pressure chamber near the storage cavern to the atmospheric pressure outlet far away from the storage cavern. This reduces the load-bearing requirements and design difficulty of a single door, and also significantly reduces the manufacturing cost of the sealing door and end plate. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of a compressed air energy storage cavern sealing system in one embodiment; Figure 2 This is a half-section structural schematic diagram of a compressed air energy storage cavern sealing system model in the embodiment; Figure 3 This is a schematic diagram of the internal structure of the sealing body.

[0014] Marked in the image: 1-Gas storage chamber; 11-Steel lining; 2-Maintenance passage; 21-First steel pipe; 22-Second steel pipe; 3-End plate; 31-Sealing door; 32-Anchor bar; 4-Gas duct; 5-Differential pressure reducing valve; 6-Sealing body. Detailed Implementation

[0015] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0016] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0017] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but that it can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0018] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0019] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0020] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0021] Example 1 like Figures 1-3 As shown, a compressed air energy storage cavern sealing system includes an air storage cavern 1 and a maintenance passage 2. The air storage cavern 1 is lined with a steel lining 11. The maintenance passage 2 is connected to the air storage cavern 1 and is located within a sealing body 6. At least one end plate 3 is provided within the maintenance passage 2 for laterally sealing it. The end plate 3 is a flat steel plate, with its edge extending radially into the sealing body 6. A sealing door 31 is provided on the end plate 3. A steel pipe is installed along the maintenance passage 2, welded to the end plate 3, extending into the air storage cavern 1. The outer contour of the steel pipe is welded to the steel lining 11. The end plate 3 acts as the door frame of the sealing door, enabling pressure diffusion and ensuring the stability of the sealing door 31. Correspondingly, the end plate 3 has a through hole for pedestrian passage at the location of the sealing door.

[0022] In this design, the end plate is a flat plate, serving as a partition to isolate high-pressure gas in the gas storage chamber and also as a load-bearing plate for the sealing door. Compared to the traditional design of using an arc-shaped steel plate that connects to the curved contour of the gas storage chamber for inspection doors, installing the sealing door on the flat end plate makes installation easier, ensures better sealing of the connection between the sealing door and the end plate, and allows for a larger load-bearing area for the sealing door on the end plate, thus reducing stress concentration at the door frame (i.e., the overlapping part of the sealing door on the end plate). By pre-embedding the end plate within the sealing body and then installing the sealing door on it, compared to placing the sealing door inside the gas storage chamber, the sealing door can evenly transmit pressure to the concrete of the sealing body through the end plate. The end plate experiences more uniform stress, effectively avoiding the risk of concrete cracking and ensuring the long-term stability of the structure.

[0023] Furthermore, this solution employs a steel circular tube structure as a sealing structure within the maintenance passage, which is then welded to the steel lining inside the gas storage cavity to form an integrated connection. This ensures both the airtightness of the connection points and the overall sealing performance of the maintenance passage. Compared to using a steel lining constructed by splicing and welding multiple steel plates on-site in the circumferential (circumferential direction) and axial (length direction), constructing the maintenance passage with steel pipes is more convenient and faster, and offers better pressure resistance.

[0024] In addition, this solution involves pre-embedding the end plate supporting the sealing door around the perimeter of the sealing body and welding the end plate to the end face of the steel pipe in the maintenance passage. Compared with the method of expanding and backfilling the side wall of the maintenance passage to fix the door, the connection strength of the welded end plate and steel pipe is greater, and the contact stiffness between the end plate and the sealing body is greater, resulting in better stress performance. The connection node of the end plate at the side wall of the maintenance passage has high shear strength and is not easily deformed, which is more conducive to ensuring the sealing performance at the connection node between the end plate 3 and the maintenance passage 2 and reducing the risk of gas leakage.

[0025] In this embodiment, the size of the maintenance passage 2 on the side of the end plate 3 away from the gas storage chamber 1 is less than or equal to the size of the maintenance passage 2 on the side of the end plate 3 closer to the gas storage chamber 1. This allows the shoulder of the sealing concrete to assist the end plate in resisting the chamber pressure, which helps reduce the concentrated stress at the door frame of the sealing door and reduces end plate deformation.

[0026] In one or more possible implementations, several end plates 3 are arranged at intervals in the maintenance passage 2, such as two or three. Each end plate 3 is respectively equipped with a sealing door. No sealing door 31 is set inside the gas storage chamber 1. The steel pipe includes a first steel pipe 21 and a second steel pipe 22. The first steel pipe 21 connects the gas storage chamber 1 and the end plate 3 closest to the gas storage chamber 1. The second steel pipe 22 is set between two adjacent end plates 3. The two ends of the second steel pipe 22 are welded to the end plates 2 at the corresponding ends.

[0027] An adjustable pressure gas chamber is provided between two adjacent end plates 3 to provide a reaction force to the sealing door 31 and end plate 3 on the side near the gas storage chamber 1. This balances or reduces the normal stress generated by the internal pressure of the gas storage chamber 1 on the front sealing door 31 and end plate 3, improving the pressure resistance of the end plate 3. This allows for a reduction in the structural thickness of the end plate 3 or sealing door 31, thus lowering economic costs. The first steel pipe 21 and the second steel pipe 22 can withstand the high pressure of the gas within the maintenance passage 2.

[0028] In optional implementations, such as Figure 3As shown, an air inlet is installed in the cavity between two adjacent end plates 3. The air inlet is connected to the gas storage cavity 1 through an air guide pipe 4, which is pre-embedded in the sealing body 6 and connected to a differential pressure reducing valve 5. The differential pressure reducing valve 5 allows for multi-stage pressure reduction settings, forming a multi-stage pressure chamber with progressively decreasing pressure between multiple chambers from the high-pressure chamber near the gas storage cavity to the atmospheric pressure outlet away from the gas storage cavity. For example, if the internal pressure of the sealed cavity is 15 MPa, the pressure of the chamber after the first sealing door 31 can be adjusted to 10 MPa, the pressure of the chamber after the second sealing door 31 can be 5 MPa, and the third door can be at atmospheric pressure. Since there is pressure on both sides of a single sealing door, a single sealing door 31 only needs to withstand the pressure difference, such as 5 MPa, which significantly reduces the design requirements and difficulty of a single sealing door 31.

[0029] Preferably, the first steel pipe 21 and the second steel pipe 22 are of the same size and coaxially arranged, with the same cross-section and thickness, that is, the diameter of the maintenance passage on both sides of the end plate 3 near the gas storage chamber 1 is the same; the diameter of the maintenance passage on the side of the outermost end plate 3 away from the gas storage chamber 1 is reduced, and the shoulder of the reduced diameter maintenance passage is used as the end plate to resist the gas pressure of the gas chamber, which helps to reduce the design requirements of the sealing door. The maintenance passage 2 in this section does not need to be equipped with steel pipes and can be used as a general passage, saving economic costs.

[0030] In optional implementations, such as Figure 3 As shown, at least one side of the end plate 3 is preferably provided with several anchor bars 32. These anchor bars 32 are connected to the structural steel bars inside the sealing body 6, facilitating the fixation of the end plate 3 during the pouring of the sealing body 6 and preventing displacement. Furthermore, the anchor bars 32 maintain the continuity of the internal steel bars of the sealing body 6, ensuring the compressive and shear strength at the end plate 3. The end plate 3 is made of a thick steel plate disc. At the installation location of the inspection door, the pressure diffusion of the sealing door 31 is achieved by setting the thick steel plate disc and the anchor bars 32, ensuring the stability of the sealing door 31.

[0031] As other possible implementation methods, the end plate can also be made of other planar shapes such as rectangles, triangles, and ellipses; the edges of the end plate can also be made of shapes such as lace, and are not limited to the examples mentioned above, as long as the four edges can be combined with the concrete of the sealing body.

[0032] In one or more embodiments, the sealing body 6 connects the gas storage chamber 1 and the auxiliary tunnel. The sealing body 6 includes a wedge-shaped block segment and a constant cross-section segment. The constant cross-section segment connects the gas storage chamber 1 and the wedge-shaped block segment. The wedge-shaped block segment has a variable cross-section structure, and its cross-sectional dimension is larger than that of the constant cross-section segment. Preferably, a sealing door 31 is provided at the connection position between the constant cross-section segment and the wedge-shaped block segment. The end plate 3 of the sealing door 31 can be consistent with the cross-sectional dimension of the constant cross-section sealing body. At least one sealing door 31 is provided inside the wedge-shaped block segment.

[0033] In an optional embodiment, the sealing door 31 is located on the side of the end plate 3 near the gas storage chamber 1, which is convenient to install and helps to resist gas pressure.

[0034] Furthermore, it is preferable to provide a groove on the side of the end plate 3 that connects to the sealing door 31. The groove is adapted to the shape and size of the sealing door 31. The end plate 3 and the sealing door 31 are hinged together. The sealing effect between the sealing door 31 and the groove can be enhanced by providing sealing materials such as sealing rings or sealing gaskets.

[0035] This solution constructs a highly efficient sealing system through the synergistic action of components such as finished round steel pipes, end plates 3, and sealing doors 31. This not only ensures that the connection nodes have both high strength and reliable sealing, but also completely blocks the gas leakage path, effectively solving the sealing problem of the underground gas storage cavern 1. It fully meets the stringent sealing requirements for the long-term stable operation of the gas storage cavern 1, and improves the overall performance and operating efficiency of the system.

[0036] This sealing system boasts excellent geological adaptability and is compatible with the complex operating conditions of tunnel-type and large-tank-type gas storage facilities. It integrates core advantages such as structural stability, superior structural sealing, wide applicability, and economy. Through modular collaborative design, it overcomes the technical challenges of sealing underground gas storage caverns, significantly improving the overall performance and operational efficiency of energy storage systems, and providing an innovative solution for the construction of underground space energy storage facilities.

[0037] Example 2 Based on Example 1, this example also provides a design method for the above-mentioned compressed air energy storage cavern sealing system, and the technical solution is as follows.

[0038] Using the above-mentioned compressed air energy storage cavern sealing system, assuming that it is designed within maintenance passage 2... n The sealing door 31 diffuses the pressure into the concrete of the sealing body 6 through the end plate 3. The maintenance passage 2 is sealed with steel pipes with the same cross-section and thickness. The pressure of the multiple air chambers formed by the multiple end plates 3 is set to decrease step by step from the side closer to the gas storage chamber to the side farther away from the gas storage chamber by adjusting the differential pressure reducing valve 5.

[0039] (1) The thickness of the sealing door is determined using the following expression: Equation (1); In the formula, δ This indicates the thickness of the sealed door 31. p c This indicates the pressure that the surface of the sealed door 31 bears. D i Indicates the height dimension of the sealed door 31, [ σ ] t This indicates the allowable stress of the steel used for sealing the door at the design temperature. This indicates the welding coefficient.

[0040] (2) Determine the thickness of the steel pipe in the maintenance passage using the following expression. t 1: Equation (2); Equation (3); Equation (4); in, t 1 indicates the wall thickness of the steel pipe. p Indicates internal pressure. r 1 indicates the radius of the steel pipe. σ R This indicates the resistance limit of steel pipe structural members. f 1 represents the design strength value of the steel pipe. Indicates the structural importance coefficient. ψ Indicates the design condition coefficient. This represents the structural coefficient for different tubular types. K 0 indicates the unit resistance coefficient of the surrounding rock of the concrete. δ 2 indicates the gap width. Es 2 represents the elastic modulus of steel in a plane strain problem. Es This indicates the elastic modulus of steel. This represents the Poisson's ratio of steel.

[0041] (3) Determine the end plate thickness and the dimensions of the outward expansion portion through the following steps: S1: First, set the initial dimensions of the end plate; S2: Calculate the end plate stress under internal pressure. : Equation (5); Determine the stress of the end plate If the stress is less than or equal to the allowable stress of the concrete, determine the selected end plate size; otherwise, readjust the end plate size until the end plate stress is less than or equal to the allowable stress of the concrete. Indicates stress, Indicates internal pressure. This indicates the area of ​​the quick-expansion section of the end plate; S3: Based on end plate stress The end plate thickness is calculated using the following formula. : Equation (6); in D Indicates the diameter of the end plate. r 2 indicates the end plate radius. f 2 indicates the design strength value of the end plate steel.

[0042] Examples illustrating the above design method: 1. Determine design parameters: A domestic compressed air energy storage peak-shaving power station project has a total installed capacity of 700MW / 1400MWh. The project adopts advanced compressed air energy storage technology, and the gas storage facility adopts a newly excavated underground artificial cavern with a design volume of 251,000 m³. 3 The design adopts a large tank type, with a maximum gas storage pressure of approximately 15 MPa.

[0043] 2. Sealing door design thickness The thickness of the sealing door is based on the spherical head of the pressure vessel. A two-stage sealing door system (more than two can be installed as needed) is used for stress bearing and sealing. Each sealing door bears half of the total pressure of the gas storage chamber. The height dimension of the sealing door is 2000 mm. mm The sealed door bears the pressure. p c The pressure is 15MPa / 2 = 7.5MPa. Substituting the existing data into equation (1) above, we obtain the design thickness of the sealing door: .

[0044] 3. Determine the thickness of the round steel pipe for the maintenance access. t 1: r Take 1000 mm Substituting the existing data into equation (4) above, we get: ; Substituting into equation (3) above, we get: ; The thickness of the circular steel pipe is calculated according to the above formula (2): .

[0045] 4. Determine the end plate thickness and calculate the outward expansion: Determine the end plate stress based on the above formula (5): ; Calculate the end plate thickness according to the above formula (6): .

[0046] The sealing system obtained by adopting the above design method has good stress and sealing effect, low risk of gas leakage, high safety, and a safer and more reliable structure.

[0047] Compared with existing technologies, the sealing system design in this solution achieves the following innovations: First, the embedded channel design of the sealing door effectively solves the problems of difficult installation and poor sealing performance at traditional curved surface junctions; second, by setting steel pipes in the maintenance channel, the structural safety and airtightness of the sealing body are significantly improved; third, the multi-level sealing door graded load-bearing scheme reduces the load-bearing requirements of a single door and significantly reduces design difficulty and manufacturing costs; fourth, the specially designed end plate structure achieves multiple functional advantages, namely, ensuring the door is stably fixed, achieving uniform distribution of internal pressure, and effectively avoiding the risk of crushing caused by concrete stress concentration, thereby significantly reducing the overall probability of gas leakage. The design of this sealing system fully embodies the unity of structural safety and sealing reliability.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A compressed air energy storage cavern sealing system, comprising an air storage cavern (1) and a maintenance passage (2), wherein the air storage cavern (1) is provided with a steel lining (11), the maintenance passage (2) is connected to the air storage cavern (1), and the maintenance passage (2) is disposed within a sealing body (6), characterized in that, The maintenance passage (2) is provided with at least one end plate (3) for laterally blocking the maintenance passage (2). The end plate (3) is a flat steel plate. The edge of the end plate (3) extends radially into the pre-embedded sealing body (6). A sealing door (31) is provided on the end plate (3). A steel pipe is installed along the maintenance passage (2), the steel pipe is welded to the end plate (3), the steel pipe extends into the gas storage chamber (1), and the outer contour of the steel pipe is welded to the steel lining (11); The number of end plates (3) is provided in several places. The steel pipe includes a first steel pipe (21) and a second steel pipe (22). The first steel pipe (21) connects the gas storage chamber (1) and the end plate (3) closest to the gas storage chamber (1). The second steel pipe (22) connects two adjacent end plates (3). The first steel pipe (21) and the second steel pipe (22) have the same size and are coaxially arranged.

2. The compressed air energy storage cavern sealing system according to claim 1, characterized in that, The size of the maintenance passage (2) located on the side of the end plate (3) away from the gas storage chamber (1) is less than or equal to the size of the maintenance passage (2) located on the other side of the same end plate (3).

3. The compressed air energy storage cavern sealing system according to claim 1, characterized in that, At least one side of the end plate (3) is provided with a plurality of anchor bars (32), which are used to connect with the structural steel bars in the sealing body (6).

4. The compressed air energy storage cavern sealing system according to claim 1, characterized in that, The sealing door (31) is located on the side of the end plate (3) near the gas storage chamber (1).

5. The compressed air energy storage cavern sealing system according to claim 1, characterized in that, The end plate (3) has a groove on one side connected to the sealing door (31). The groove is adapted to the shape and size of the sealing door (31). The end plate (3) is hinged to the sealing door (31). A sealing material is provided between the sealing door (31) and the groove.

6. The compressed air energy storage cavern sealing system according to claim 1, characterized in that, An air inlet is provided in the cavity between two adjacent end plates (3). The air inlet is connected to the gas storage cavity (1) through an air guide pipe (4). The air guide pipe (4) is pre-embedded in the sealing body (6). The air guide pipe (4) is connected to a differential pressure reducing valve (5).

7. A design method for a compressed air energy storage cavern sealing system, characterized in that, The compressed air energy storage cavern sealing system described in claim 6 is designed within the maintenance passage (2). n A level sealing door (31) is used, which diffuses pressure into the concrete of the sealing body (6) through end plates (3). The maintenance passage (2) is sealed with steel pipes of uniform cross-section and thickness. The pressure of the multiple air chambers formed by the multiple end plates (3) is set to decrease step by step from the side closer to the gas storage chamber to the side farther away from the gas storage chamber. The thickness of the sealing door is determined by the following expression: ； In the formula, δ Indicates the thickness of the sealing door (31), p c This indicates the pressure exerted on the surface of the sealed door (31). D i Indicates the height dimension of the sealed door (31), [ σ ] t This represents the allowable stress of steel at the design temperature. This indicates the welding coefficient.

8. The design method for a compressed air energy storage cavern sealing system according to claim 7, characterized in that, The thickness of the steel pipe is determined by the following expression. t 1: ； In the formula, , ; t 1 indicates the wall thickness of the steel pipe. p Indicates internal pressure. r Indicates the radius of the steel pipe. σ R This indicates the resistance limit of steel pipe structural members. f This indicates the design strength value of the steel. Indicates the structural importance coefficient. ψ Indicates the design condition coefficient. This represents the structural coefficient for different tubular types. K 0 indicates the unit resistance coefficient of the sealing concrete. δ 2 indicates the gap width. Es 2 represents the elastic modulus of steel in a plane strain problem. Es This indicates the elastic modulus of steel. This represents the Poisson's ratio of steel.

9. A design method for a compressed air energy storage cavern sealing system according to claim 7 or 8, characterized in that, Determine the end plate thickness and the dimensions of the outward expansion portion using the following steps: S1: First, set the initial dimensions of the end plate; S2: Calculate the end plate stress under internal pressure. Determine the stress of the end plate Determine if the end plate dimensions are less than or equal to the allowable stress of the concrete; if so, determine the end plate dimensions. S3: Based on end plate stress The end plate thickness is calculated using the following formula. t 2: ； In the formula, D Indicates the diameter of the end plate. r 2 indicates the end plate radius. f 2 indicates the design strength value of the end plate steel.

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