Construction method of integral type flexible sealing compressed air energy storage underground cavern

Abstract

According to the construction method of the integral type flexible sealing compressed air energy storage underground cavern, the annular groove channel is pre-buried in the second lining in the lining construction process, a mechanical anchoring mode is adopted in the anchoring scheme, the integral type flexible sealing layer is anchored to the inner wall of the underground cavern so as to seal the whole underground cavern, and the construction method has the advantages of being convenient to construct, low in construction cost and the like. The anchoring is firm; according to the splicing scheme, the mode that hemispherical rubber and rubber rings prefabricated in a factory are in nested lap joint is adopted, lap joint is conducted at each nested lap joint position through an outer ring and an inner ring, and lap joint and construction of the flexible sealing layer are achieved at the nested lap joint positions in the comprehensive construction mode that the three modes of mechanical anchoring, rubber adhesive bonding and sealing strip bonding are combined. The flexible sealing layer has the advantages of being high in feasibility and good in sealing effect, the fixing effect of the flexible sealing layer on the inner wall of the underground cavern can be guaranteed, the overall sealing performance of the flexible sealing layer is guaranteed, and therefore the problems of air leakage and falling of the flexible sealing layer are effectively solved.

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] Due to the intermittent and volatile characteristics of renewable energy, large-scale direct grid connection will bring a huge impact to the power grid. Therefore, corresponding energy storage technology is needed. Compressed air energy storage (i.e. compressed gas energy storage) is one of the few large-scale energy storage technologies. Unlike pumped storage technology, it does not have special geographical and hydrological conditions. It has urgent and huge development potential in areas rich in renewable energy in my country. Among them, underground caverns, as storage containers for high-pressure air, 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 very promising sealing technology due to its advantages of low cost, good air tightness and strong geological adaptability. However, there is no mature method for the construction of flexible sealing caverns. The invention with application number 201410174203.2 and titled "Construction Method of Compressed Gas Energy Storage Cavern" published on September 3, 2014 discloses a construction method of an adhesive flexible sealing layer. This method uses hot-melt bonding to splice and paste polymer materials on the inner wall of the cavern to achieve the sealing of the cavern. This method has a large number of splicing joints and a large air leakage rate. In addition, since the sealing layer and the lining are closely attached, when the cavern is below the groundwater level, the sealing layer will fall off from the inner wall of the lining due to the accumulation of water head pressure. The invention with application number 202110665113.3 and title "Integral rubber bladder sealed compressed air energy storage liner cavern" published on November 18, 2022, uses a vulcanizer to vulcanize and connect the segmented sealing layer into a bladder-shaped whole in the compressed air energy storage cavern, and hangs the rubber bladder on the inner wall of the lining by means of slings and buckles. Since the integral bladder-type sealing layer has few splicing ends and the sealing layer and the lining are not closely attached, this method can well solve the problems of high air leakage rate and falling off of the sealing layer due to accumulation of head pressure encountered during the construction of the adhesive flexible sealing layer. However, during the construction process, this method requires the development of single-sided vulcanization splicing equipment suitable for flexible sealing layers of large-diameter underground caverns, and the thickness of the sealing layer cannot be too thick. When the thickness of the sealing layer is thick, the sling plus the buckle method is not enough to fix the rubber bladder weighing hundreds of kilograms per linear meter on 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 methods, 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 factory-prefabricated hemispherical rubber and rubber ring nested overlap method. The nested overlap is achieved by a comprehensive construction method that combines mechanical anchoring, rubber adhesive bonding, and sealing strip bonding. The flexible sealing layer is overlapped and constructed at the nested overlap. The construction is convenient and the anchoring is firm. The fixing effect of the flexible sealing layer on the inner wall of the underground cavern can be ensured, and the overall sealing of the flexible sealing layer can be ensured, 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 concrete curing of the secondary lining 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, so that the top surface of the perforated steel plates is 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, and each hemispherical rubber and each rubber ring are prefabricated with several anchor holes at the longitudinal ends respectively; nest and overlap one hemispherical rubber, several rubber rings and the ends 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, and adopt the overlap method of outer ring sleeve inner ring at each nested overlap, and the inner surface of the outer ring is coated with rubber adhesive, and after nesting and overlapping, a circle of anchoring pressure plate with several bolt holes pre-opened is pressed on the inner surface of each nested overlap, so that the several bolt holes are connected with the adjacent outer ring and inner ring. The anchor holes on the geotextile correspond to each other one by one, and then the anchoring pressure plate is pressed to make the adjacent inner rings fit tightly and bonded with the outer rings, and the anchoring bolts are respectively inserted into the several anchoring holes at each nested overlap, so that each anchoring bolt passes through the geotextile layer and the wire mesh and is fixedly connected to the annular groove, and the nuts of each anchoring bolt are tightened to make the adjacent outer rings fit tightly with the inner rings under the action of the anchoring pressure plate and the rubber adhesive, and a circle of sealing strip is pasted and covered on the end face of the outer ring at each nested overlap, so as to connect the two hemispherical rubbers and several rubber rings 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, and 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, which has the advantages of convenient construction and reliable anchoring; the splicing scheme adopts a factory-prefabricated hemispherical rubber and rubber ring nested overlap method, and at each nested overlap, an outer ring is sleeved with an inner ring for overlap, and the nested overlap is achieved by a comprehensive construction method that combines mechanical anchoring, rubber adhesive bonding, and sealing strip bonding. The flexible sealing layer is overlapped and constructed, 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 1-3% to ensure the drainage effect in the cave.

[0013] Preferably, 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. The hemispherical rubber and rubber ring have no longitudinal seams, and only the annular seams are considered during the on-site splicing construction. The radial dimensions of the hemispherical rubber and rubber ring can be made in the manner of "one ring is larger and the other is smaller".

[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 insert 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 into the wide groove of the T-slot, and 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 the anchoring effect is good.

[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, during the lining construction process, an annular groove is pre-buried in the second lining, and 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, which has the advantages of convenient construction and reliable anchoring; the splicing scheme adopts a factory-prefabricated hemispherical rubber and rubber ring nested overlap method, and at each nested overlap, the outer ring is sleeved with the inner ring for overlap, and the nested overlap is achieved by a comprehensive construction method that combines mechanical anchoring, rubber adhesive bonding, and sealing strip bonding. The flexible sealing layer is overlapped and constructed, 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 air leakage and falling off problems of the flexible sealing layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a cross-sectional schematic diagram 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 figure 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 is further described in detail below with reference to the accompanying drawings.

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

[0023] 1) Lining construction of compressed gas energy storage underground cavern: Figure 1 to Figure 3 As 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 arranged on the inner side of the primary lining 1, and then a secondary lining 3 is constructed by casting concrete on the inner side of the waterproof board 2. During the construction of the secondary lining 3, a longitudinal drainage ditch 11 is arranged at the bottom of the underground cavern, and the longitudinal slope of the longitudinal drainage ditch 11 is 2%. At the same time, a plurality of annular grooves 4 are pre-buried in the secondary lining 3 at a certain interval 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 wire 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 wire mesh 6;

[0027] 5) Prepare two hemispherical rubbers and several rubber rings prefabricated in the factory, each of which has a longitudinal length of 3m, and each of which has a longitudinal end 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 a larger inner diameter at each nested overlap being the outer ring 91 and the end with a smaller outer diameter being 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, an outer ring 91 is overlapped with an inner ring 92, and the inner surface of the outer ring 91 is coated with a rubber adhesive 12. After nesting and overlapping, a circle of anchoring pressure plates with several bolt holes pre-opened are pressed on the inner surface of each nested overlap to make it Several bolt holes correspond one by one to the anchor holes 93 on the adjacent outer ring 91 and inner ring 92, and then the anchoring plate is pressed to make the adjacent inner ring 92 fit tightly and bond with 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 to make the adjacent outer ring 91 and the inner ring 92 fit tightly under the action of the anchoring plate and the rubber adhesive 12 to ensure air tightness, and a circle of sealing strip 13 is pasted and covered 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 the present 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, a plurality of T-slots are provided on the annular groove 4, each T-slot includes a communicating narrow groove 41 and a wide groove 42, the narrow groove 41 is close to the wire mesh 6, each anchor bolt 7 includes a first T-shaped end 71, a connecting rod 72 and a second T-shaped end 73 which are integrally arranged, the width of the second T-shaped end 73 is smaller than the width of the narrow groove 41, 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 90 degrees as a whole, so that the second T-end 73 of each anchor bolt 7 hooks the annular groove 4, and 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 concrete curing of the secondary lining 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, so that the top surface of the perforated steel plates is 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, and each hemispherical rubber and each rubber ring are prefabricated with several anchor holes at the longitudinal ends respectively; nest and overlap one hemispherical rubber, several rubber rings and the ends 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, and adopt the overlap method of outer ring sleeve inner ring at each nested overlap, and the inner surface of the outer ring is coated with rubber adhesive, and after nesting and overlapping, a circle of anchoring pressure plate with several bolt holes pre-opened is pressed on the inner surface of each nested overlap, so that the several bolt holes are connected with the adjacent outer ring and inner ring. The anchor holes on the geotextile correspond to each other one by one, and then the anchoring pressure plate is pressed to make the adjacent inner rings fit tightly and bonded with the outer rings, and the anchoring bolts are respectively inserted into the several anchoring holes at each nested overlap, so that each anchoring bolt passes through the geotextile layer and the wire mesh and is fixedly connected to the annular groove, and the nuts of each anchoring bolt are tightened to make the adjacent outer rings fit tightly with the inner rings under the action of the anchoring pressure plate and the rubber adhesive, and a circle of sealing strip is pasted and covered on the end face of the outer ring at each nested overlap, so as to connect the two hemispherical rubbers and several rubber rings 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 m, 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 provided on the annular groove. Each of the T-slots includes a communicating narrow groove and a wide groove, and the narrow groove is close to the wire mesh. Each of the anchor bolts includes a first T-end, a connecting rod, and a second T-end that 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, firstly 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, and then insert 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 into the wide groove of the T-slot, and 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. 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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