Flexible sealing structure of underground cavern

Abstract

The invention discloses an underground cavern flexible sealing structure in the technical field of underground energy storage. The sealing structure comprises lining segments and sealing units, the sealing units are distributed in the lining segments and used for sealing the surrounding area of the lining segments, the lining segments are of a split structure, the multiple lining segments are arranged in the circumferential direction, and the adjacent lining segments are connected through telescopic structures; the sealing unit is divided into a first sealing piece and a second sealing piece, the first sealing piece is used for sealing the large face of the inner side of each independent lining segment, and the second sealing piece is used for sealing the inner side of the joint between the adjacent lining segments. The multiple lining segments are arranged in the circumferential direction in a split mode, and the adjacent lining segments are connected through the telescopic structures, so that when the internal pressure of gas stored in the underground cavern becomes large, the lining segments cannot be subjected to or are subjected to small tension, storage deformation is mainly contributed by the telescopic structures, concrete is prevented from being damaged by tension, and the service life of the lining segments is prolonged. And the safety and durability of the underground cavern are improved.

Description

Technical Field

[0001] The invention relates to the technical field of underground energy storage, and in particular to an underground cavern flexible sealing structure. Background Art

[0002] Reducing the use of fossil energy and increasing the use of renewable energy are important ways to achieve the "dual carbon" goal. Large-scale energy storage technologies, including pumped storage and compressed air energy storage, can solve the problems of intermittency and volatility of wind power and photovoltaic power. Pumped storage technology is mature, but it is strictly restricted by geographical conditions and ecological environmental protection, while compressed air energy storage is more flexible in site selection, has strong geological adaptability, and has little ecological disturbance. Especially in areas rich in renewable energy such as the "Three Norths" in my country, there is a large demand for application and broad prospects. Compressed air energy storage is a commonly used large-scale energy storage technology. Compressed air energy storage technology uses high-pressure air as a medium to realize the storage and release of energy in the power grid. Through the reasonable regulation of energy storage and release, intermittent energy such as wind power and photovoltaic power can be converted into stable and controllable high-quality energy. Among them, the underground cavern, as a storage container for high-pressure air, plays an important role in the operation of the compressed air energy storage power station, and the key issue of its construction is the sealing problem of the underground cavern and the tensile crack resistance of the cavern lining structure under high internal pressure environment.

[0003] The Chinese invention patent with the publication number of "CN104018717A" and the name of "A construction method for a compressed air energy storage cavern" discloses a construction method for a compressed air energy storage cavern using steel fiber reinforced concrete as lining and applying a polymer material as a sealing layer inside. Although the method applies a lining, the polymer material is a sealing structure formed by splicing each other, and the air leakage rate is relatively large. The Chinese invention patent with the publication number of "CN113513696A" and the name of "Compressed air energy storage lined cavern with integral rubber bladder seal" discloses a compressed air energy storage lined cavern with integral rubber bladder seal. The cavern support structure is a reinforced concrete lining, and a whole rubber bladder is used as a sealing layer, and the volume of the sealing layer is slightly larger than the volume of the cavern. This method avoids the risk of the sealing layer being torn during the gas storage process, but the reinforced concrete lining is still at risk of tensile damage under high internal pressure, and the lining will damage the flexible sealing material after being tensilely cracked. Therefore, the internal pressure that the above-mentioned lining structure can withstand is very low, the lining structure has poor crack resistance, and is not suitable for environments with poor surrounding rock conditions. In addition, the rated gas storage pressure of the cavern is low, and the scope of application is relatively limited. Summary of the invention

[0004] In order to solve the problem of crack resistance design of existing high internal air pressure cavern lining structures and overcome the situation where the concrete lining of existing underground caverns is damaged by tension when storing gas at high internal pressure, the present invention proposes a flexible sealing structure for underground caverns that is suitable for higher gas storage pressure, has better feasibility, and has lower risks and costs.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] The flexible sealing structure of an underground cavern comprises lining segments and sealing units. The sealing units are distributed inside the lining segments and are used to seal the enclosed area of ​​the lining segments. The lining segments are split structures and are arranged in multiple numbers along the circumferential direction, and adjacent lining segments are connected by a retractable structure. The sealing unit is divided into a first sealing member and a second sealing member. The first sealing member is used to seal the inner large surface of each individual lining segment, and the second sealing member is used to seal the inner side of the connection between adjacent lining segments.

[0007] In the present application, the lining segments are configured as a plurality of segments separated along the circumferential direction, and adjacent lining segments are connected by a retractable structure, so that when the internal pressure of the stored gas in the underground cavern increases, the lining segments will not be subjected to or will be subjected to very little tensile force, and the storage deformation is mainly contributed by the retractable structure, which largely avoids tensile damage to the concrete and greatly improves the safety and durability of the underground cavern; and the first seal and the second seal are used to respectively seal the inner large surface of the lining segment and between adjacent linings.

[0008] In some embodiments, the retractable structure includes a spring, and adjacent lining segments are connected by the spring, so that when the internal pressure of the underground cavern changes, the distance between adjacent lining segments changes.

[0009] In some embodiments, the telescopic structure is a telescopic joint, which includes a first cable and a second cable, which are connected by a spring and are respectively fixed between adjacent lining segments.

[0010] In some embodiments, a limiting portion is provided on the first card cable, and the limiting portion is used to control the movement stroke of the first card cable relative to the second card cable, thereby controlling the deformation amount of the spring.

[0011] In some embodiments, embedded bolts are provided at both ends of the lining segments for connecting the telescopic joints.

[0012] In some embodiments, the retractable structure includes rubber pads, and adjacent lining segments are connected by rubber pads, so that when the internal pressure of the underground cavern changes, the distance between adjacent lining segments changes.

[0013] In some embodiments, grooves are provided at both ends of the lining segments, and the segments also include bolts and elastic washers. The bolts connect adjacent lining segments through the grooves, and elastic washers are provided at the connection points of the bolt heads, so that when the internal pressure in the underground cavern changes, the rubber pads are deformed, the elastic washers are also deformed, and the distance between adjacent lining segments changes.

[0014] In some embodiments, the second sealing member is a sealing layer applied to the inner large surface of the lining segment.

[0015] In some embodiments, both ends of the first seal are respectively fixed on adjacent lining segments, and in a natural state, the first seal does not fit the retractable structure. When the internal pressure of the underground cavern increases, the first seal can fit the retractable structure.

[0016] In some embodiments, embedded pressure plates are arranged on the inner sides of both ends of the lining segment, and corresponding fixed pressure plates are arranged, and the first sealing member is fixed between the embedded pressure plate and the fixed pressure plate by fixing screws.

[0017] The beneficial effects of the present invention are:

[0018] The lining segments are configured as multiple segments separated along the circumferential direction, and adjacent lining segments are connected by a retractable structure, so that when the internal pressure of the stored gas in the underground cavern increases, the lining segments will not be subjected to or will be subjected to very little tensile force, and the storage deformation is mainly contributed by the retractable structure, which largely avoids tensile damage to the concrete and greatly improves the safety and durability of the underground cavern; and supplemented by the first seal and the second seal, the inner large surface of the lining segment and the adjacent linings are sealed respectively; compared with the existing high internal pressure underground caverns, the underground cavern flexible sealing structure provided by the present invention has a wider range of application, better feasibility, and lower risks and costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the overall structure of the underground cavern flexible sealing structure provided by the present invention;

[0020] Figure 2 for Figure 1 Schematic diagram of the state of the retractable structure in the natural state;

[0021] Figure 3 for Figure 1 A schematic diagram of a state in which the retractable structure is in a stretched state;

[0022] Figure 4 for Figure 1 A schematic diagram of a state in which the retractable structure is in a compressed state;

[0023] Figure 5 for Figure 1 Simplified schematic diagram of the structure of the middle lining segment end;

[0024] Figure 6 for Figure 1 Schematic diagram of the connection status of the fixed end of the second seal.

[0025] Markings in the figure are: 1-lining segment, 2-expandable joint, 3-sealing rubber, 4-first cable, 5-second cable, 6-spring, 7-fixing pressure plate, 8-embedded bolt, 9-embedded pressure plate, 10-fixing screw. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings.

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] Embodiment 1

[0029] like Figure 1-Figure 6 As shown, the present invention provides a flexible sealing structure for an underground cavern.

[0030] The underground cavern flexible sealing structure comprises a lining segment 1 and a sealing unit. The sealing unit is distributed inside the lining segment 1 and is used for sealing the enclosed area of ​​the lining segment 1.

[0031] The lining segments 1 are of split structure, and are arranged in multiple pieces along the circumferential direction, and adjacent lining segments 1 are connected by a telescopic structure.

[0032] The sealing unit is divided into a first sealing member and a second sealing member. The first sealing member is used to seal the inner large surface of each individual lining segment 1 , and the second sealing member is used to seal the inner side of the connection between adjacent lining segments 1 .

[0033] like Figure 1 As shown, in the present invention, the lining segments 1 are configured as a plurality of segments separated along the circumferential direction, and adjacent lining segments 1 are connected by a retractable structure, so that when the internal pressure of the stored gas in the underground cavern increases, the lining segments 1 will not be subjected to or will be subjected to very little tensile force, and the storage deformation is mainly contributed by the retractable structure, which largely avoids the tensile damage of the concrete and greatly improves the safety and durability of the underground cavern; assisted by the first seal and the second seal, the inner large surface of the lining segment 1 and the adjacent linings are sealed respectively; compared with the existing high internal pressure underground caverns, the underground cavern flexible sealing structure provided by the present invention has a wider range of application, better feasibility, and lower risks and costs.

[0034] In this embodiment, the telescopic structure includes a spring 6, and adjacent lining segments 1 are connected by the spring 6, so that when the internal pressure of the underground cave changes, the distance between adjacent lining segments 1 changes. The telescopic structure is realized by the spring 6, which is convenient to implement.

[0035] Specifically, the telescopic structure is a telescopic joint 2, and the telescopic joint 2 includes a first card cable 4 and a second card cable 5, and the first card cable 4 and the second card cable 5 are connected by a spring 6, and the first card cable 4 and the second card cable 5 are respectively fixed between adjacent lining segments 1. The spring 6 is connected through the telescopic joint 2, so that the spring 6 connection between the lining segments 1 is conveniently realized.

[0036] Combination Figure 2-Figure 4 As shown, before construction, the telescopic joint 2 is in a natural state; during the process of inflating the underground cavern, the internal pressure of the underground cavern increases, and the spring 6 in the telescopic joint 2 is in a stretched state; when the underground cavern is deflated, the internal pressure of the underground cavern decreases, and the spring 6 in the telescopic joint 2 is in a compressed state.

[0037] In this embodiment, a limiting portion is provided on the first card cable 4 , and the limiting portion is used to control the movement stroke of the first card cable 4 relative to the second card cable 5 , thereby controlling the deformation amount of the spring 6 .

[0038] Combination Figure 2-Figure 4 As shown, in the present application, the first cable 4 and the second cable 5 are mutually limited to control the deformation of the spring 6, that is, to control the change in the spacing between adjacent lining segments 1. As in the present embodiment, the first cable 4 is provided with a groove on the side, and the second cable 5 is provided with an inward protrusion correspondingly. When the first cable 4 and the second cable 5 cooperate, the protrusion is limited in the groove, and the upper and lower walls of the groove limit the movement of the protrusion, thereby realizing the control of the movement between the first cable 4 and the second cable 5, thereby controlling the deformation of the spring 6. Obviously, the setting of the limiting part has many forms, and the present invention does not specifically limit its specific form.

[0039] like Figure 4 As shown, in this embodiment, embedded bolts 8 are provided at both ends of the lining segment 1 for connecting the telescopic joint 2. The provision of the embedded bolts 8 facilitates the fixation of the first card cable 4 and the second card cable 5, and the connection strength can be ensured.

[0040] In this embodiment, the second seal is a sealing layer applied to the inner large surface of the lining segment 1. Based on the above-mentioned lining segment 1 of the present invention, when the internal pressure of the gas stored in the underground cavern changes, it will not be subjected to or will be subjected to very small tensile force, so there is no need to consider that the second seal will be broken by tension. Here, the second seal can be directly implemented as a sealing layer applied to the inner large surface of the lining segment 1, which is convenient to implement and has low cost.

[0041] Combination Figure 2-Figure 4 As shown, in this embodiment, both ends of the first seal are respectively fixed on the adjacent lining segments 1, and in the natural state, the first seal does not fit the retractable structure. When the pressure in the underground cavern increases, the first seal can fit the retractable structure. In this embodiment, the first seal is a sealing rubber 3.

[0042] Combination Figure 2-Figure 4 As shown, before construction, the telescopic joint 2 is in a natural state, in which the length of the first seal is relatively long, and there is a certain redundancy in the telescopic joint 2 relative to the adjacent lining segments 1, so that it is completely in contact with the lining segments 1 and the telescopic joint 2; during the process of inflating the underground cavern, the internal pressure of the underground cavern increases, the spring 6 in the telescopic joint 2 is in a stretched state, and the first seal can be tightly fitted to the lining segment 1 and the telescopic joint 2; when the underground cavern is deflated, the internal pressure of the underground cavern decreases, the spring 6 in the telescopic joint 2 is in a compressed state, the first seal and the telescopic joint 2 are separated, and the sealing can still meet the requirements.

[0043] It is worth noting that the lining segment 1 is relatively large in size. Those skilled in the art can Figure 1 It can be concluded without a doubt that the lining segment 1 is arc-shaped in structure. Figure 2-Figure 6 The shape of the lining segment 1 is only a simplified illustration.

[0044] like Figure 5 and Figure 6 As shown, in this embodiment, embedded pressure plates 9 are arranged on the inner sides of both ends of the lining segment 1, and corresponding fixed pressure plates 7 are provided, and the first sealing member is fixed between the embedded pressure plate 9 and the fixed pressure plate 7 by fixing screws 10.

[0045] The first sealing member is connected by the embedded pressure plate 9, the fixed pressure plate 7 and the fixing screws 10, so as to achieve a good sealing effect between adjacent lining segments 1 and facilitate implementation. Figure 6 As shown, the outer contour of the embedded pressure plate 9 and the inner contour of the fixed pressure plate 7 should be matched to ensure the fit of the first sealing member and to effectively protect the first sealing member, thereby ensuring the sealing of the cavern and optimizing the sealing effect.

[0046] As implemented above, the flexible sealing structure of the underground cavern is formed by connecting the segmented lining segments 1 at the construction site through the telescopic joint 2. When the lining segments 1 are manufactured, bolts 8 are pre-embedded at both ends, and the lining segments 1 are connected to the telescopic joint 2 through the pre-embedded bolts 8. A reserved pressure plate is set on the inner side of the lining segment 1 of the high internal pressure underground cavern to prepare for the subsequent sealing of the cavern. The manufacturing is flexible and convenient, and can effectively protect the concrete tensile damage caused by the repeated inflation and deflation of the lining structure.

[0047] The telescopic joint 2 is composed of a first card cable 4, a second card cable 5, and a spring 6. The components are prefabricated and are assembled with the lining segment 1 at the construction site through factory processing. The first card cable 4, the second card cable 5 and the lining segment 1 are all provided with embedded parts. The lining segment 1 is connected to the telescopic joint 2 by embedded bolts 8. The manufacturing and construction process is simple and convenient, easy to implement and promote, and has high economic benefits.

[0048] Embodiment 2

[0049] The difference between this embodiment and the first embodiment is that the retractable structure used to connect the lining segments 1 is different.

[0050] In this embodiment, the telescopic structure is configured to include rubber pads, and adjacent lining segments 1 are connected by rubber pads, so that when the internal pressure of the underground cavern changes, the distance between adjacent lining segments 1 changes.

[0051] Furthermore, grooves are provided at both ends of the lining segments 1, and bolts and elastic washers are also included. The bolts connect adjacent lining segments 1 through the grooves, and elastic washers are provided at the connection points of the bolt heads, so that when the internal pressure in the underground cavern changes, the rubber pad is deformed, the elastic washer is also deformed, and the distance between adjacent lining segments 1 changes.

[0052] 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 in the protection scope of the present invention.

Claims

1. An underground cavern flexible sealing structure, comprising a lining segment (1) and a sealing unit, wherein the sealing unit is distributed inside the lining segment (1) and is used to seal the enclosed area of ​​the lining segment (1), and is characterized in that: The lining segment (1) is a split structure, and is arranged in a plurality along the circumferential direction, and adjacent lining segments (1) are connected via a telescopic structure; The sealing unit is divided into a first sealing member and a second sealing member, the first sealing member is used to seal the inner large surface of each individual lining segment (1), and the second sealing member is used to seal the inner side of the connection between adjacent lining segments (1).

2. The underground cavern flexible sealing structure according to claim 1, characterized in that: The telescopic structure comprises a spring (6), and adjacent lining segments (1) are connected via the spring (6), so that when the internal pressure of the underground cave changes, the distance between adjacent lining segments (1) changes.

3. The underground cavern flexible sealing structure according to claim 2, characterized in that: The telescopic structure is a telescopic joint (2), and the telescopic joint (2) comprises a first card cable (4) and a second card cable (5), the first card cable (4) and the second card cable (5) are connected by a spring (6), and the first card cable (4) and the second card cable (5) are respectively fixed between adjacent lining segments (1).

4. The underground cavern flexible sealing structure according to claim 3, characterized in that: A limiting portion is provided on the first card cable (4), and the limiting portion is used to control the movement stroke of the first card cable (4) relative to the second card cable (5), thereby controlling the deformation amount of the spring (6).

5. The underground cavern flexible sealing structure according to claim 3, characterized in that: Embedded bolts (8) are provided at both ends of the lining segment (1) for connecting the telescopic joint (2).

6. The underground cavern flexible sealing structure according to claim 1, characterized in that: The telescopic structure comprises a rubber pad, and adjacent lining segments (1) are connected by the rubber pad, so that when the internal pressure of the underground cave changes, the distance between adjacent lining segments (1) changes.

7. The underground cavern flexible sealing structure according to claim 6, characterized in that: The lining segments (1) are provided with grooves at both ends and also include bolts and elastic washers. The bolts are connected to adjacent lining segments (1) via the grooves, and elastic washers are provided at the connection points of the bolt heads, so that when the internal pressure of the underground cavern changes, the rubber pads are deformed, the elastic washers are also deformed, and the distance between adjacent lining segments (1) changes.

8. The underground cavern flexible sealing structure according to claim 1, characterized in that: The second sealing member is a sealing layer applied on the inner large surface of the lining segment (1).

9. The underground cavern flexible sealing structure according to any one of claims 1 to 8, characterized in that: The two ends of the first sealing member are respectively fixed on adjacent lining segments (1), and in a natural state, the first sealing member does not fit the retractable structure; when the internal pressure of the underground cavern increases, the first sealing member can fit the retractable structure.

10. The underground cavern flexible sealing structure according to claim 9, characterized in that: Embedded pressure plates (9) are arranged inside the two ends of the lining segment (1), and corresponding fixed pressure plates (7) are arranged. The first sealing member is fixed between the embedded pressure plate (9) and the fixed pressure plate (7) by means of fixing screws (10).

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