Composite structure for compensating axial deformation of artificial lining cavern

Abstract

The invention relates to an artificial lining cavern axial deformation compensation composite structure which comprises a surrounding rock body, a concrete lining and a steel lining sealing layer, and the surrounding rock body, the concrete lining and the steel lining sealing layer are sequentially arranged in an artificial lining cavern. The steel lining sealing layer comprises an annular steel lining and at least one corrugated steel lining, the corrugated steel lining is provided with a corrugated section and straight connecting sections, the corrugated section comprises a plurality of semicircular corrugations, the semicircular corrugations are connected end to end and are arranged in a wavy structure in the axial direction of the corrugated section, and the straight connecting sections are located on the two sides of the corrugated section in the axial direction. The straight connecting section is connected with the corrugated section and the annular steel lining. The composite structure can compensate for axial deformation caused by temperature reciprocating change in the compressed air energy storage operation process, the risk of axial buckling or tension damage of the steel lining is reduced, and therefore the long-term leakproofness and safety of the gas storage are guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of compressed air energy storage, and in particular to a composite structure for compensating for axial deformation of an artificial lining cavern. Background Art

[0002] Artificial lined caverns are one of the main types of compressed air storage, with wide selection of sites, large scale, and environmental friendliness. In order to ensure the stability and airtightness of the cavern under high internal pressure, a composite structure needs to be constructed. The composite structure is generally composed of a sealing layer, a lining, and surrounding rock. At present, the sealing layer mostly uses a thin steel lining. During the operation of compressed air energy storage, the temperature changes cyclically, and the composite structure (especially the steel lining) will have thermal expansion and contraction effects due to temperature changes. The hoop stress of the steel lining is mainly caused by the high internal pressure, and the thermal stress generated during thermal expansion is beneficial to the hoop stress. However, in the axial direction of the steel lining, the stress generated by the air pressure can be ignored. The limited thermal expansion and contraction of the steel lining may cause warping and tension damage of the steel lining. Therefore, it is necessary to take certain temperature deformation compensation measures for the axial direction of the steel lining. However, the composite structure at this stage has not taken effective measures for this. Summary of the invention

[0003] An embodiment of the present application provides a composite structure for compensating for axial deformation of an artificial lined cavern, which can compensate for the axial deformation caused by reciprocating temperature changes during the operation of compressed gas energy storage, reduce the risk of axial buckling or tension damage of the steel lining, and thus ensure the long-term airtightness and safety of the gas storage.

[0004] The composite structure for axial deformation compensation of an artificial lined cavern provided in an embodiment of the present application comprises a surrounding rock mass, a concrete lining and a steel lining sealing layer, wherein the surrounding rock mass, the concrete lining and the steel lining sealing layer are sequentially arranged in the artificial lined cavern; the steel lining sealing layer comprises an annular steel lining and at least one corrugated steel lining, the corrugated steel lining comprises a corrugated section and a straight connecting section, the corrugated section comprises a plurality of semicircular corrugations, the plurality of semicircular corrugations are connected end to end and are arranged in a wavy structure along the axial direction of the corrugated section, the straight connecting section is located on both sides of the corrugated section along the axial direction, and the straight connecting section connects the corrugated section and the annular steel lining.

[0005] In addition, the composite structure provided in the embodiment of the present application may also have the following additional technical features:

[0006] In an optional solution, if the thermal expansion and contraction deformation of the steel lining sealing layer caused by temperature is defined as ΔL, then ΔL=αΔTL1, where α is the thermal expansion coefficient, ΔT is the temperature change value, and L1 is the total length of the artificial lining cavern;

[0007] The compression deformation of the corrugated steel lining is L c The elongation deformation of the corrugated steel lining is Lt , then L c =dN / 2, Where d is the diameter of the semicircular corrugation, and N is the number of semicircular corrugations;

[0008] Then L c and L t Satisfies the inequality:

[0009]

[0010] In an optional scheme, the straight connecting section is flush with the wall surface of the annular steel lining, and the semicircular corrugations of the corrugated section on the side close to the straight connecting section are flush with the wall surface of the annular steel lining; the corrugated section also includes a transition section, which is a quarter circle and connects the corrugated section and the straight connecting section.

[0011] In an optional solution, the radius of the annular steel lining is 4 to 6 m, the thickness is 10 to 20 mm, and the material is high-strength steel; the number of the semicircular corrugations is 5 to 10.

[0012] In an optional scheme, the composite structure also includes a cushion layer and a supporting structure, wherein the supporting structure is arranged between the surrounding rock mass and the concrete lining, the cushion layer is capable of deformation, and the cushion layer is tightly arranged between the steel lining sealing layer and the concrete lining, and the thickness of the cushion layer gradually becomes thinner in the direction from the corrugated steel lining to the annular steel lining, and the gradually thinning transition distance is not less than 1m.

[0013] In an optional solution, the thickness of the cushion layer is at least 0.01 m greater than the height of the corrugated section, and the material of the cushion layer is clay or rubber.

[0014] The beneficial effects of the embodiments of the present application are:

[0015] The composite structure in the embodiment of the present application can absorb part of the lateral deformation through the corrugated steel lining, effectively reduce the thermal stress caused by temperature changes in the axial direction of the gas storage reservoir, and alleviate the tension or warping damage caused by thermal barriers and shrinkage in the axial direction, thereby ensuring the long-term airtightness and safety of the gas storage reservoir. In addition, the corrugated steel lining can also be arranged in areas with local weak surrounding rocks, so that it can resist part of the lateral deformation while compensating for the axial temperature.

[0016] It should be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the arrangement of the composite structure provided for this application in an artificial lined cavern;

[0018] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure of the artificial lined cavern at the corrugated steel lining;

[0019] Figure 3 A schematic structural diagram of a corrugated steel lining provided in the present application in a specific embodiment.

[0020] Figure numerals: surrounding rock mass 1, concrete lining 2, annular steel lining 3, corrugated steel lining 4, corrugated section 41, straight connecting section 42, semicircular corrugation 43, transition section 44, cushion layer 5, supporting structure 6, artificial lined cavern 7.

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application. DETAILED DESCRIPTION

[0022] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0023] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0024] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0025] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0026] It should be noted that the directional words such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described at the angles shown in the accompanying drawings and should not be understood as limiting the embodiments of the present application. In addition, in the context, it should also be understood that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element.

[0027] like Figure 1-3 As shown, the embodiment of the present application provides a composite structure for axial deformation compensation of an artificial lined cavern, the composite structure includes a surrounding rock mass 1, a concrete lining 2 and a steel lining sealing layer, the surrounding rock mass 1, the concrete lining 2 and the steel lining sealing layer are sequentially arranged in the artificial lined cavern 7; the steel lining sealing layer includes an annular steel lining 3 and at least one corrugated steel lining 4, the structural section where the corrugated steel lining 4 is located is also called a compensation section. Generally speaking, the radius of the annular steel lining 3 is 4 to 6m, the thickness is 10 to 20mm, and the material is high-strength steel. The corrugated steel lining 4 is annular in shape and wavy in shape in the axial direction. Specifically, the corrugated steel lining 4 has a corrugated section 41 and a straight connecting section 42. The corrugated section 41 includes a plurality of semicircular corrugations 43. The plurality of semicircular corrugations 43 are connected end to end and are arranged in a wavy structure along the axial direction of the corrugated section 41. The straight connecting section 42 is located on both sides of the corrugated section 41 along the axial direction. The straight connecting section 42 connects the corrugated section 41 and the annular steel lining 3, that is, the top and bottom of the corrugated section 41 are semicircles, each semicircle is a corrugation number, and the horizontal sections at both ends of the corrugated steel lining 4 are straight connecting sections 42.

[0028] In this embodiment, the composite structure can absorb part of the lateral deformation through the corrugated steel lining 4, effectively reduce the thermal stress caused by temperature change in the axial direction of the gas storage, and alleviate the tension or warping damage caused by thermal barrier and shrinkage in the axial direction, thereby ensuring the long-term airtightness and safety of the gas storage. In addition, the corrugated steel lining 4 can also be arranged in areas with local weak surrounding rocks, so that it can resist part of the lateral deformation while compensating for the axial temperature.

[0029] In a specific embodiment, the size and number of the semicircular corrugations 43 in the corrugated steel lining 4 are related to the amplitude of the temperature change in the cavern and the thermal expansion coefficient of the steel lining. The compression of the corrugated steel lining 4 needs to be greater than or equal to the thermal expansion deformation caused by the high temperature of the total steel lining of the cavern. Similarly, the elongation of the corrugated steel lining 4 needs to be greater than or equal to the cold contraction deformation caused by the low temperature of the total steel lining of the cavern.

[0030] Specifically, if the thermal expansion and contraction deformation of the steel lining sealing layer caused by temperature is defined as ΔL, then ΔL=αΔTL1, where α is the thermal expansion coefficient, ΔT is the temperature change value, and L1 is the total length of the artificial lining cavern 7;

[0031] The compression deformation of the corrugated steel lining 4 is L c , the elongation deformation of the corrugated steel lining 4 is L t , then L c =dN / 2, Wherein, d is the diameter of the semicircular corrugation 43, and N is the number of the semicircular corrugations 43;

[0032] Then L c and L t Satisfies the inequality:

[0033]

[0034] The diameter value obtained in the above inequality takes the larger value, which is the minimum corrugation circle diameter that meets the deformation compensation requirements. The above inequality is the design basis of the corrugated section 41. In addition, in order to avoid excessive axial deformation of a single compensation node, the number of corrugations of a compensation node is odd, generally controlled at about 5, and should not exceed 10. The corrugation size is also constrained by the manufacturing process and other structural dimensions. The size is appropriate, which will not be elaborated in this article. In addition, in order to achieve the effect of uniform compensation, multiple compensation nodes can be evenly arranged on the axis of the cavern.

[0035] like Figure 2 As shown, in a specific embodiment, the straight connecting section 42 is flush with the wall surface of the annular steel liner 3, and the straight connecting section 42 can be welded with the annular steel liner 3 to form a steel liner sealing layer. The semicircular corrugation 43 of the corrugated section 41 on the side close to the straight connecting section 42 is flush with the wall surface of the annular steel liner 3; the corrugated section 41 also includes a transition section 44, which is a quarter circle and connects the corrugated section 41 and the straight connecting section 42.

[0036] like Figure 2 As shown, in a specific embodiment, the composite structure also includes a cushion layer 5 and a supporting structure 6, the supporting structure 6 is arranged between the surrounding rock mass 1 and the concrete lining 2, the cushion layer 5 can be deformed, the cushion layer 5 is tightly arranged between the steel lining sealing layer and the concrete lining 2, and the thickness of the cushion layer 5 gradually becomes thinner in the direction from the corrugated steel lining 4 to the annular steel lining 3.

[0037] Specifically, a cushion layer 5 is backfilled behind the compensation joint. The cushion layer 5 can be made of clay or rubber, which fits tightly with the steel lining and lining and can undergo large deformation. The thickness of the cushion layer 5 is at least 0.01m greater than the corrugation height (equal to the diameter d), and the thickness gradually becomes thinner in the connection area with the conventional steel lining. The transition distance is at least 1m. The back cushion layer 5 allows the compensation joint to deform and is not constrained by concrete. The back of the remaining annular steel lining 3 sections is used to backfill the concrete lining 2. The support system is constructed during the excavation of the cavern. In the later backfilling of the concrete lining 2, the steel lining sealing layer, cushion layer 5, concrete lining 2, support structure 6 and surrounding rock mass 1 form a cavern composite structure.

[0038] Embodiment 1:

[0039] There is an artificial lined cavern for compressed air energy storage, which is arranged in a tunnel style. The designed cavern section diameter is 10m, the net space of the cavern is 200,000m3, and the total length of the cavern is about 2,600m. The cavern is arranged in a long strip tunnel. Each gas storage cavern is 520m long, with 1 horizontally and 4 vertically arranged side by side. The spacing meets the stability requirements. The cavern composite structure is now designed. According to the surrounding rock parameters, burial depth, cave diameter and operating pressure, 07mnmovr (600MPa grade) steel lining with a thickness of 20mm is selected.

[0040] The thermal expansion coefficient α of the steel lining is 0.012mm / m·℃. It is known that the temperature changes most significantly during the first charging and discharging. The highest temperature during inflation can be 80℃ higher than the normal temperature. According to this calculation, the thermal expansion length of each cavern can reach 0.4992m; when deflated, the temperature can drop to below zero, which is about 30℃ lower than the normal temperature, and each cavern shrinks by 0.1872m.

[0041] Each longitudinal cavern is equipped with a compensation section, 5 corrugations in the middle, a semicircle and a straight plate transition on each side, and the straight plate section is welded to the conventional circular steel lining. Two compensation sections are evenly arranged in the transverse caverns, and the number of corrugations in each compensation section is 3. According to the larger value of the inequality, the corrugation circle diameter is designed to be 0.2m.

[0042]

[0043] The rubber cushion layer is filled behind the corrugation, and the thickest part is designed to be 0.22m. It gradually thins from 0.22m to 0m at 1m at both ends of the compensation joint and the conventional steel lining. The excavation section of the cavern is 5.8m, the initial sprayed concrete is 0.02m, and a 3m long anchor support is designed. Plain concrete is backfilled between the cavern wall and the steel lining to form a lining. The thickest part of the concrete lining is 0.76m, and the thinnest part is 0.54m. Finally, a sealed composite structure of the gas storage cavern is formed. In order to facilitate construction, the compensation joint is generally set in the middle of the cavern, not at the plug, fork, or blind end.

[0044] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A composite structure for compensating axial deformation of an artificial lining cavern, characterized in that: It includes a surrounding rock mass, a concrete lining and a steel lining sealing layer, which are arranged in sequence in an artificial lined cavern; the steel lining sealing layer includes an annular steel lining and at least one corrugated steel lining, the corrugated steel lining has a corrugated section and a straight connecting section, the corrugated section includes a plurality of semicircular corrugations, the plurality of semicircular corrugations are connected end to end and are arranged in a wavy structure along the axial direction of the corrugated section, the straight connecting section is located on both sides of the corrugated section along the axial direction, and the straight connecting section connects the corrugated section and the annular steel lining.

2. The composite structure for compensating axial deformation of an artificial liner cavern according to claim 1 is characterized in that: The thermal expansion and contraction deformation of the steel lining sealing layer caused by temperature is defined as ΔL, then ΔL=αΔTL1, where α is the thermal expansion coefficient, ΔT is the temperature change value, and L1 is the total length of the artificial lining cavern; The compression deformation of the corrugated steel lining is L c The elongation deformation of the corrugated steel lining is L t , then L c =dN / 2, Where d is the diameter of the semicircular corrugation, and N is the number of semicircular corrugations; Then L c and L t Satisfies the inequality:

3. The composite structure for compensating axial deformation of an artificial liner cavern according to claim 1 or 2, characterized in that: The straight connecting section is flush with the wall surface of the annular steel liner, and the semicircular corrugations of the corrugated section on the side close to the straight connecting section are flush with the wall surface of the annular steel liner; the corrugated section also includes a transition section, which is a quarter circle and connects the corrugated section and the straight connecting section.

4. The composite structure for compensating axial deformation of an artificial liner cavern according to claim 3 is characterized in that: The radius of the annular steel lining is 4 to 6 m, the thickness is 10 to 20 mm, and the material is high-strength steel; the number of the semicircular corrugations is 5 to 10.

5. The composite structure for compensating axial deformation of an artificial liner cavern according to claim 1, 2 or 4, characterized in that: It also includes a cushion layer and a supporting structure, wherein the supporting structure is arranged between the surrounding rock mass and the concrete lining, the cushion layer can be deformed, and the cushion layer is tightly arranged between the steel lining sealing layer and the concrete lining, and the thickness of the cushion layer gradually becomes thinner in the direction from the corrugated steel lining to the annular steel lining, and the gradually thinning transition distance is not less than 1m.

6. The composite structure for compensating axial deformation of an artificial liner cavern according to claim 5, characterized in that: The thickness of the cushion layer is at least 0.01 m greater than the height of the corrugated section, and the material of the cushion layer is clay or rubber.

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