Construction method of integral flexible sealed compressed gas energy storage underground cavern

Abstract

The invention discloses a construction method for an integral flexible sealed compressed air energy storage underground cavern. During the lining construction process, an annular groove is pre-buried in the second lining. The anchoring scheme adopts a mechanical anchoring method to anchor the integral flexible sealing layer to the inner wall of the underground cavern to achieve sealing of the entire underground cavern. The invention has the advantages of convenient construction and reliable anchoring. The splicing scheme adopts a nested overlap method of hemispherical rubber and rubber rings prefabricated in the factory. At each nested overlap, the outer ring is sleeved with the inner ring for overlap. The nested overlap is achieved by a comprehensive construction method combining mechanical anchoring, rubber adhesive bonding, and sealing strip bonding to achieve overlap and construction of the flexible sealing layer. The invention has the advantages of strong feasibility and good sealing effect, can ensure the fixing effect of the flexible sealing layer on the inner wall of the underground cavern, and ensure the overall sealing of the flexible sealing layer, thereby effectively solving the problems of air leakage and falling off of the flexible sealing layer.

Description

Technical Field

[0001] The present invention belongs to the field of underground energy storage, and in particular relates to a construction method of an integral flexible sealed compressed air energy storage underground cavern. Background Art

[0002] As a storage container for high-pressure air, underground caverns play an important role in the operation of compressed gas energy storage power stations, and the key issue in their construction is the sealing of the caverns.

[0003] Flexible sealing technology is a promising sealing technology due to its low cost, good airtightness, and strong geological adaptability. However, there is currently no mature method for constructing flexible sealed caverns. Application No. 201410174203.2, entitled "Construction Method for Compressed Gas Energy Storage Cavern," published on September 3, 2014, discloses a method for constructing an adhesive flexible sealing layer. This method uses hot-melt bonding to splice and adhere polymer materials to the inner wall of the cavern to achieve sealing. However, this method results in a high air leakage rate due to the large number of joints. Furthermore, due to the close contact between the sealing layer and the lining, when the cavern is below the groundwater level, the sealing layer can fall off the inner wall of the lining due to the accumulation of water head pressure. The invention, application number 202110665113.3 and titled "Integral Rubber Bladder Sealed Compressed Gas Energy Storage Lined Cavern," published on November 18, 2022, uses a vulcanizer to connect the segmented sealing layers into a bladder-shaped whole within the compressed gas energy storage cavern, and then suspends the rubber bladder from the inner wall of the lining using slings and buckles. Because the integral bladder-type sealing layer has few splicing ends and the sealing layer and lining are not tightly attached, this method can effectively solve the problems encountered during the construction of adhesive flexible sealing layers, such as high air leakage rates and the shedding of the sealing layer due to accumulated head pressure. However, during the construction process, this method requires the development of single-sided vulcanization splicing equipment suitable for flexible sealing layers in large-diameter underground caverns, and the thickness of the sealing layer cannot be too thick. When the sealing layer is thick, the sling and buckle method is insufficient to secure the rubber bladder weighing several hundred kilograms per linear meter to the inner wall of the cavern. Therefore, this method has certain limitations during the construction process. Summary of the Invention

[0004] In view of the shortcomings of the existing flexible sealed cavern construction method, the present invention provides a construction method for an integral flexible sealed compressed air energy storage underground cavern. The anchoring scheme adopts a mechanical anchoring method, and the splicing scheme adopts a nested overlap method of factory-prefabricated hemispherical rubber and rubber rings. The nested overlap is achieved by a comprehensive construction method that combines mechanical anchoring, rubber adhesive bonding, and sealing strip bonding to achieve the overlap and construction of the flexible sealing layer. The construction is convenient and the anchoring is firm. It can ensure the fixing effect of the flexible sealing layer on the inner wall of the underground cavern and the overall sealing of the flexible sealing layer, thereby effectively solving the problems of air leakage and falling off of the flexible sealing layer.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a construction method of an integral flexible sealed compressed air energy storage underground cavern, comprising the following steps:

[0006] 1) Lining construction of compressed air energy storage underground cavern: spray concrete on the inner side of the bare hole of the underground cavern as the primary lining, set a waterproof board on the inner side of the primary lining, and then cast concrete on the inner side of the waterproof board as the secondary lining. During the construction of the secondary lining, a longitudinal drainage ditch is set at the bottom of the underground cavern. At the same time, a number of annular grooves are pre-buried in the secondary lining at a certain interval along the longitudinal direction of the underground cavern, so that the inner surface of each annular groove is flush with the inner surface of the secondary lining.

[0007] 2) After the secondary lining concrete curing is completed and reaches the strength requirement, clean the inner surface of the secondary lining;

[0008] 3) Use prefabricated perforated steel plates to cover the longitudinal drainage ditch, making the top surface of the perforated steel plates flush with the inner surface of the secondary lining;

[0009] 4) Fix a layer of wire mesh on the inner surface of the secondary lining and the annular channel by nailing, and then lay a layer of geotextile on the inner surface of the wire mesh;

[0010] 5) Prepare two hemispherical rubbers and several rubber rings prefabricated in the factory, with several anchor holes prefabricated at the longitudinal ends of each hemispherical rubber and each rubber ring; nest and overlap one hemispherical rubber, several rubber rings and the end of another hemispherical rubber in sequence along the longitudinal direction of the underground cavern, with the end with the larger inner diameter at each nested overlap as the outer ring and the end with the smaller outer diameter as the inner ring; adopt the outer ring sleeve inner ring overlap method at each nested overlap, and the inner surface of the outer ring is coated with rubber adhesive; after nesting and overlapping, cover the inner surface of each nested overlap with a circle of anchor pressure plates with several bolt holes pre-opened, so that the several bolt holes are aligned with the adjacent outer ring and inner ring The anchor holes on the geotextile correspond to each other one by one, and then the anchor pressure plate is pressed to make the adjacent inner rings and outer rings fit tightly and bonded, and the anchor bolts are respectively inserted into the several anchor holes at each nested overlap, so that each anchor bolt passes through the geotextile layer and the wire mesh and is fixedly connected to the annular groove, and the nuts of each anchor bolt are tightened to make the adjacent outer rings and inner rings fit tightly under the action of the anchor pressure plate and the rubber adhesive, and a circle of sealing strip is pasted on the end face of the outer ring at each nested overlap, so that the two hemispherical rubbers and several rubber rings are connected into a sealed capsule, which is an integral flexible sealing layer, and the construction of the integral flexible sealed compressed air energy storage underground cavern is completed.

[0011] The construction method of the integral flexible sealed compressed air energy storage underground cavern of the present invention is as follows: during the lining construction process, an annular groove is pre-buried in the second lining; the anchoring scheme adopts mechanical anchoring to anchor the integral flexible sealing layer to the inner wall of the underground cavern to achieve sealing of the entire underground cavern, which has the advantages of convenient construction and reliable anchoring; the splicing scheme adopts the nested overlap method of factory-prefabricated hemispherical rubber and rubber rings, and the outer ring is overlapped with the inner ring at each nested overlap, and the nested overlap is achieved by a comprehensive construction method combining mechanical anchoring, rubber adhesive bonding, and sealing strip pasting to achieve overlap and construction of the flexible sealing layer, which has the advantages of strong feasibility and good sealing effect, can ensure the fixing effect of the flexible sealing layer on the inner wall of the underground cavern, and ensure the overall sealing of the flexible sealing layer, thereby effectively solving the problems of air leakage and falling off of the flexible sealing layer.

[0012] Preferably, the longitudinal slope of the longitudinal drainage ditch is 1 to 3% to ensure drainage effect in the cave.

[0013] Preferably, each hemispherical rubber and each rubber ring has a longitudinal length of 2 to 4 meters, and the inner diameter of the outer ring at each nested overlap is 5 to 10 mm larger than the outer diameter of the inner ring. The hemispherical rubber and rubber rings have no longitudinal seams, and only the circumferential seam is considered during on-site assembly. The radial dimensions of the hemispherical rubber and rubber rings can be manufactured with one ring larger than the other.

[0014] Preferably, the annular groove is a steel annular groove, and a plurality of T-slots are provided on the annular groove, each of the T-slots includes a communicating narrow groove and a wide groove, the narrow groove is close to the wire mesh, and each of the anchor bolts includes an integrally arranged first T-end, a connecting rod, and a second T-end, the width of the second T-end is smaller than the width of the narrow groove, and the length of the second T-end is between the width of the narrow groove and the width of the wide groove. When installing each of the anchor bolts, first make the width direction of the second T-end of each of the anchor bolts parallel to the width direction of the narrow groove of a T-slot, then pass the second T-end of each of the anchor bolts through the geotextile layer, the wire mesh and the narrow groove of the T-slot and insert it into the wide groove of the T-slot, then rotate each of the anchor bolts as a whole 90 degrees so that the second T-end of each of the anchor bolts hooks the annular groove, and at this time, the width direction of the second T-end of each of the anchor bolts is perpendicular to the width direction of the narrow groove of the T-slot. The use of the above-mentioned anchor bolts for mechanical anchoring has low construction requirements and is easy to operate. The anchor bolts are not easy to loosen and have a good anchoring effect.

[0015] Compared with the prior art, the present invention has the following advantages: the construction method of the integral flexible sealed compressed air energy storage underground cavern of the present invention, pre-buries annular grooves in the second lining during the lining construction process, and the anchoring scheme adopts mechanical anchoring to anchor the integral flexible sealing layer to the inner wall of the underground cavern to achieve sealing of the entire underground cavern, which has the advantages of convenient construction and reliable anchoring; the splicing scheme adopts the method of nested overlap of factory-prefabricated hemispherical rubber and rubber rings, and overlaps the inner ring at each nested overlap, and the nested overlap is achieved by a comprehensive construction method combining mechanical anchoring, rubber adhesive bonding, and sealing strip bonding to achieve overlap and construction of the flexible sealing layer, which has the advantages of strong feasibility and good sealing effect, can ensure the fixing effect of the flexible sealing layer on the inner wall of the underground cavern, and ensure the overall sealing of the flexible sealing layer, thereby effectively solving the problems of air leakage and falling off of the flexible sealing layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the cross section of the overall structure of the integrated flexible sealed compressed air energy storage underground cavern at the annular groove in the embodiment;

[0017] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0018] Figure 3 is a schematic cross-sectional view of a single nested overlap in an embodiment;

[0019] The specific reference numerals in the figures are as follows:

[0020] 1-primary lining, 2-waterproof board, 3-secondary lining, 4-annular channel, 41-narrow groove, 42-wide groove, 5-nail, 6-wire mesh, 7-anchor bolt, 71-first T-end, 72-connecting rod, 73-second T-end, 8-geotextile layer, 9-flexible sealing layer, 91-outer ring, 92-inner ring, 93-anchor holes, 10-perforated steel plate, 11-longitudinal drainage ditch, 12-rubber adhesive, 13-sealing strip. DETAILED DESCRIPTION

[0021] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0022] The construction method of the integral flexible sealed compressed air energy storage underground cavern of the embodiment includes the following steps:

[0023] 1) Lining construction of compressed gas energy storage underground cavern: Figures 1 to 3As shown, a primary lining 1 is constructed by spraying concrete on the inner side of the bare hole of the underground cavern, a waterproof board 2 is installed on the inner side of the primary lining 1, and then a secondary lining 3 is constructed by cast concrete on the inner side of the waterproof board 2. During the construction of the secondary lining 3, a longitudinal drainage ditch 11 is provided at the bottom of the underground cavern. The longitudinal slope of the longitudinal drainage ditch 11 is 2%. At the same time, a plurality of annular grooves 4 are pre-embedded in the secondary lining 3 at regular intervals along the longitudinal direction of the underground cavern, so that the inner surface of each annular groove 4 is flush with the inner surface of the secondary lining 3.

[0024] 2) After the concrete curing of the secondary lining 3 is completed and the strength requirements are met, the inner surface of the secondary lining 3 is cleaned;

[0025] 3) Use prefabricated perforated steel plates 10 to cover the longitudinal drainage ditch 11, so that the top surface of the perforated steel plates 10 is flush with the inner surface of the secondary lining 3;

[0026] 4) Fix a layer of steel mesh 6 on the inner surface of the secondary lining 3 and the annular channel 4 by nailing 5 to make them flat, and then lay a layer of geotextile 8 on the inner surface of the steel mesh 6;

[0027] 5) Prepare two hemispherical rubbers and several rubber rings prefabricated in the factory, the longitudinal length of each hemispherical rubber and each rubber ring is 3m, and the longitudinal ends of each hemispherical rubber and each rubber ring are prefabricated with several anchor holes 93; nest and overlap one hemispherical rubber, several rubber rings and the end of another hemispherical rubber in sequence along the longitudinal direction of the underground cavern, with the end with the larger inner diameter at each nested overlap as the outer ring 91 and the end with the smaller outer diameter as the inner ring 92. In this embodiment, the inner diameter of the outer ring 91 at each nested overlap is 10mm larger than the outer diameter of the inner ring 92. At each nested overlap, the outer ring 91 is overlapped with the inner ring 92, and the inner surface of the outer ring 91 is coated with rubber adhesive 12. After nesting and overlapping, a circle of anchor pressure plates with several bolt holes pre-opened are pressed on the inner surface of each nested overlap to make Several bolt holes correspond one-to-one to the anchor holes 93 on the adjacent outer ring 91 and inner ring 92, and then the anchoring pressure plate is pressed to make the adjacent inner ring 92 fit tightly and bonded to the outer ring 91, and the anchoring bolts 7 are respectively inserted into the several anchoring holes 93 at each nested overlap, so that each anchoring bolt 7 passes through the geotextile layer 8 and the wire mesh 6 and is fixedly connected to the annular groove 4, and the nuts of each anchoring bolt 7 are tightened so that the adjacent outer ring 91 and the inner ring 92 fit tightly under the action of the anchoring pressure plate and the rubber adhesive 12 to ensure air tightness, and a circle of sealing strip 13 is pasted on the end face of the outer ring 91 at each nested overlap to further improve the air tightness, thereby connecting the two hemispherical rubbers and several rubber rings into a sealed capsule, which is an integral flexible sealing layer 9, and the construction of the integral flexible sealed compressed air energy storage underground cavern is completed.

[0028] In this embodiment, specifically, the annular groove 4 is a steel annular groove 4, the longitudinal length of each annular groove 4 is slightly larger than the maximum diameter of each anchor bolt 7, and a plurality of T-slots are provided on the annular groove 4, each T-slot includes a narrow groove 41 and a wide groove 42 that are connected, the narrow groove 41 is close to the wire mesh 6, and each anchor bolt 7 includes a first T-shaped end 71, a connecting rod 72 and a second T-shaped end 73 that are integrally provided, the width of the second T-shaped end 73 is smaller than the width of the narrow groove 41, and the length of the second T-shaped end 73 is between the width of the narrow groove 41 and the width of the wide groove 42, and each anchor bolt is installed. 7, first make the width direction of the second T-end 73 of each anchor bolt 7 parallel to the width direction of the narrow groove 41 of a T-slot, then insert the second T-end 73 of each anchor bolt 7 through the geotextile layer 8, the wire mesh 6 and the narrow groove 41 of the T-slot into the wide groove 42 of the T-slot, and then apply force to the first T-end 71 to rotate each anchor bolt 7 as a whole 90 degrees, so that the second T-end 73 of each anchor bolt 7 hooks the annular groove 4. At this time, the width direction of the second T-end 73 of each anchor bolt 7 is perpendicular to the width direction of the narrow groove 41 of the T-slot.

Claims

1. The construction method of an integral flexible sealed compressed air energy storage underground cavern is characterized in that: The following steps are involved: 1) Lining construction of compressed air energy storage underground cavern: spray concrete on the inner side of the bare hole of the underground cavern as the primary lining, set a waterproof board on the inner side of the primary lining, and then cast concrete on the inner side of the waterproof board as the secondary lining. During the construction of the secondary lining, a longitudinal drainage ditch is set at the bottom of the underground cavern. At the same time, a number of annular grooves are pre-buried in the secondary lining at a certain interval along the longitudinal direction of the underground cavern, so that the inner surface of each annular groove is flush with the inner surface of the secondary lining. 2) After the secondary lining concrete curing is completed and reaches the strength requirement, clean the inner surface of the secondary lining; 3) Use prefabricated perforated steel plates to cover the longitudinal drainage ditch, making the top surface of the perforated steel plates flush with the inner surface of the secondary lining; 4) Fix a layer of wire mesh on the inner surface of the secondary lining and the annular channel by nailing, and then lay a layer of geotextile on the inner surface of the wire mesh; 5) Prepare two hemispherical rubbers and several rubber rings prefabricated in the factory, with several anchor holes prefabricated at the longitudinal ends of each hemispherical rubber and each rubber ring; nest and overlap one hemispherical rubber, several rubber rings and the end of another hemispherical rubber in sequence along the longitudinal direction of the underground cavern, with the end with the larger inner diameter at each nested overlap as the outer ring and the end with the smaller outer diameter as the inner ring; adopt the outer ring sleeve inner ring overlap method at each nested overlap, and the inner surface of the outer ring is coated with rubber adhesive; after nesting and overlapping, cover the inner surface of each nested overlap with a circle of anchor pressure plates with several bolt holes pre-opened, so that the several bolt holes are aligned with the adjacent outer ring and inner ring The anchor holes on the geotextile correspond to each other one by one, and then the anchor pressure plate is pressed to make the adjacent inner rings and outer rings fit tightly and bonded, and the anchor bolts are respectively inserted into the several anchor holes at each nested overlap, so that each anchor bolt passes through the geotextile layer and the wire mesh and is fixedly connected to the annular groove, and the nuts of each anchor bolt are tightened to make the adjacent outer rings and inner rings fit tightly under the action of the anchor pressure plate and the rubber adhesive, and a circle of sealing strip is pasted on the end face of the outer ring at each nested overlap, so that the two hemispherical rubbers and several rubber rings are connected into a sealed capsule, which is an integral flexible sealing layer, and the construction of the integral flexible sealed compressed air energy storage underground cavern is completed.

2. The construction method of the integral flexible sealed compressed air energy storage underground cavern according to claim 1 is characterized in that: The longitudinal slope of the longitudinal drainage ditch is 1-3%.

3. The construction method of the integral flexible sealed compressed air energy storage underground cavern according to claim 1 is characterized in that: The longitudinal length of each hemispherical rubber and each rubber ring is 2 to 4 meters, and the inner diameter of the outer ring at each nested overlap is 5 to 10 mm larger than the outer diameter of the inner ring.

4. The construction method of the integral flexible sealed compressed air energy storage underground cavern according to claim 1 is characterized in that: The annular groove is a steel annular groove, and a plurality of T-slots are opened on the annular groove, each of the T-slots includes a communicating narrow groove and a wide groove, the narrow groove is close to the wire mesh, and each of the anchor bolts includes a first T-end, a connecting rod and a second T-end which are integrally arranged, the width of the second T-end is smaller than the width of the narrow groove, and the length of the second T-end is between the width of the narrow groove and the width of the wide groove. When installing each of the anchor bolts, first make the width direction of the second T-end of each of the anchor bolts parallel to the width direction of the narrow groove of a T-slot, then pass the second T-end of each of the anchor bolts through the geotextile layer, the wire mesh and the narrow groove of the T-slot and insert it into the wide groove of the T-slot, then rotate each of the anchor bolts as a whole 90 degrees so that the second T-end of each of the anchor bolts hooks the annular groove, and at this time, the width direction of the second T-end of each of the anchor bolts is perpendicular to the width direction of the narrow groove of the T-slot.

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