Underground gas storage cavern and method of construction thereof

Abstract

The application belongs to the technical field of compressed air energy storage facilities, and particularly discloses an underground gas storage cavern and a construction method thereof. The underground gas storage cavern comprises a surrounding rock structure and a gas storage structure. The surrounding rock structure has a storage space, and the gas storage structure is located in the storage space and comprises, from outside to inside, an initial support, a lining layer, a sealing layer, a sliding layer and an inner lining layer arranged in sequence. A pressure reduction layer is arranged in the lining layer. The pressure reduction layer divides the lining layer into a first lining layer and a second lining layer. The pressure reduction layer is made of a deformable material. The traditional single lining layer is replaced by a double lining layer, and the structure with the pressure reduction layer arranged in the middle is used to relieve the dynamic load caused by the pressure fluctuation in the gas storage by the expansion and deformation of the pressure reduction layer, so as to reduce the risk of cracks in the lining layer, prolong the service life of the underground gas storage cavern, and have the advantages of pressure reduction and improved heat transfer. The design requirement for the geology is reduced, and the underground gas storage cavern is convenient to use and popularize.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of compressed air energy storage facilities, and particularly relates to an underground gas storage cavern and a construction method thereof. BACKGROUND

[0002] The basic principle of compressed air energy storage is that, when the power grid load is low, the excess power is used to drive a compressor to compress and store air in an underground gas storage or an above-ground high-pressure container; when the power grid load is high, the high-pressure air is released to drive a turbine to generate power, so as to realize the storage and release of electric energy and improve the stability of the energy system.

[0003] The underground gas storage is one of the most common underground gas storage devices, and has the advantages of good fire and explosion prevention performance, small influence on the surrounding environment, large gas storage capacity and the like. During the use of the compressed air energy storage power station, the gas storage and gas release cycles are continuously performed, and periodic load and large temperature change of the cavern are generated. However, the underground gas storage cavern is currently composed of surrounding rock, concrete lining and sealing layer, and these structures are extremely prone to cracks under the action of the generated periodic load and large temperature change of the cavern, which seriously affects the service life and safety of the gas storage cavern. SUMMARY

[0004] In view of the above problems, the present application aims to provide an underground gas storage cavern and a construction method thereof, so as to reduce the risk of cracks in the lining layer and improve the service life of the underground gas storage cavern.

[0005] The technical scheme of the present application is as follows: an underground gas storage cavern, comprising a surrounding rock structure and a gas storage structure, wherein the surrounding rock structure has a storage space, and the gas storage structure is located in the storage space and comprises, from outside to inside, an initial support, a lining layer, a sealing layer, a sliding layer and an inner lining layer arranged in sequence.

[0006] The lining layer is internally provided with a pressure reduction layer, which divides the lining layer into a first layer of lining and a second layer of lining, the first layer of lining is close to the initial support, and the second layer of lining is close to the sealing layer, and the pressure reduction layer is made of a deformable material. The inner lining layer is internally provided with a gas storage space, and the gas storage space is used for storing gas.

[0007] Further, the first layer of lining is formed by sequentially splicing a plurality of first lining blocks, and the second layer of lining is formed by sequentially splicing a plurality of second lining blocks.

[0008] Further, the pressure reduction layer comprises a circumferential buffer layer and a radial buffer layer.

[0009] The circumferential buffer layer is arranged between the first layer of lining and the second layer of lining, and the outer side of the circumferential buffer layer is in contact with the first lining block, and the inner side of the circumferential buffer layer is in contact with the second lining block.

[0010] The radial buffer layer comprises a plurality of outer side buffer blocks and a plurality of inner side buffer blocks.

[0011] Further, the first lining block is provided with a first inlay groove corresponding to the outer side buffer block, and the second lining block is provided with a second inlay groove corresponding to the inner side buffer block.

[0012] Further, the material of the radial buffer layer and the ring buffer layer is a composite phase change material made of paraffin, expanded graphite and graphene aerogel.

[0013] Further, the pressure reduction layer further comprises a plurality of outer sealing layers arranged one by one on the side of the outer side buffer block contacting the first lining block, and a plurality of inner sealing layers arranged one by one on the side of the inner side buffer block contacting the second lining block.

[0014] Further, the material of the outer sealing layer and the inner sealing layer is perfluoroether rubber.

[0015] Further, the contact between the first lining block and the ring buffer layer, the outer side buffer block and the outer sealing layer is glued, and the contact between the second lining block and the ring buffer layer, the inner side buffer block and the inner sealing layer is glued.

[0016] A construction method of an underground gas storage cavern, the underground gas storage cavern is constructed, specifically comprising:

[0017] Excavate the cavern, after the cavern is excavated and formed, clean the surrounding rock wall in the cavern, and then set the initial support.

[0018] Set the lining layer, after the first layer of lining is installed, clean the inner surface of the first layer of lining, set the pressure reduction layer, and then set the second layer of lining; after the second layer of lining is installed, clean the inner surface of the second layer of lining, and sequentially lay the sealing layer, the sliding layer and the inner lining layer.

[0019] Compared with the prior art, the beneficial effects of the present application are that:

[0020] 1. The present application replaces the traditional single lining layer with a double lining layer, and sets a pressure reduction layer structure in the middle, which utilizes the expansion and deformation of the pressure reduction layer to relieve the dynamic load caused by the pressure fluctuation in the gas storage, thereby reducing the risk of cracks in the lining layer and improving the service life of the underground gas storage cavern.

[0021] 2、The application sets a pressure reduction layer between the first lining layer and the second lining layer to weaken the pressure and deformation caused by the large temperature change in the inflation and deflation process, thereby improving the service life of the underground gas storage chamber.

[0022] 3、The outer sealing layer and the inner sealing layer arranged on the surface of the pressure reduction layer can effectively improve the overall sealing property of the structure, avoid water and gas seepage, and further improve the service life of the underground gas storage chamber.

[0023] 4、The underground gas storage chamber has the advantages of pressure reduction and improved heat transfer, reduces the design requirements for geology, and is convenient for popularization and use. BRIEF DESCRIPTION OF DRAWINGS

[0024] Fig. 1 is the overall structure schematic diagram of the application;

[0025] Fig. 2 is the partial structure schematic diagram of the lining layer of the application;

[0026] Fig. 3 is the partial structure schematic diagram of the pressure reduction layer of the application.

[0027] Wherein, 1-surrounding rock structure, 2-primary support, 3-lining layer, 31-first lining layer, 310-first lining block, 32-second lining layer, 320-second lining block, 4-pressure reduction layer, 41-circumferential buffer layer, 42-radial buffer layer, 421-outer buffer block, 422-inner buffer block, 43-outer sealing layer, 44-inner sealing layer, 5-sealing layer, 6-sliding layer, 7-inner lining layer, 8-gas storage space. DETAILED DESCRIPTION

[0028] The specific embodiments of the application will be described in detail below. Figs. 1 to 3 In the description of the application, it should be understood that the orientations or positional relationships indicated by the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0029] The terms "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more of the features; in the description of the application, unless otherwise specified, the meaning of "multiple" is two or more.

[0030] EMBODIMENT

[0031] As shown in Fig. 1 , a kind of underground gas storage cavern, including surrounding rock structure 1 and gas storage structure. Surrounding rock structure 1 has storage space, and gas storage structure is located in storage space, which includes primary support 2, lining layer 3, sealing layer 5, sliding layer 6 and inner lining layer 7 in turn from outside to inside.

[0032] As shown in Fig. 1 , Fig. 2 , lining layer 3 is provided with pressure relief layer 4 inside, and pressure relief layer 4 divides lining layer 3 into first layer lining 31 and second layer lining 32, first layer lining 31 is close to primary support 2, and second layer lining 32 is close to sealing layer 5, and pressure relief layer 4 adopts deformable material. Inner lining layer 7 is provided with gas storage space 8, and gas storage space 8 is used to store gas.

[0033] Pressure relief layer 4 has the functions of absorbing pressure and deformation, and high heat transfer efficiency; therefore, when underground gas storage cavern is inflated and deflated, the pressure and deformation caused by dynamic load generated in gas storage space 8 are transmitted to pressure relief layer 4 through second layer lining, so that pressure relief layer 4 deforms to release the stress of second layer lining 32, avoid the generation of cracks, and the high temperature generated in gas storage space 8 is more efficiently transmitted to surrounding rock structure 1 through pressure relief layer 4, so that the temperature of the whole underground gas storage structure tends to be the same, the pressure and deformation caused by temperature change are weakened, thereby improving the service life of underground gas storage cavern. Sealing layer 5 ensures that the gas in gas storage space 8 does not overflow. Sliding layer 6 ensures that the gas pressure in gas storage space 8 can be more smoothly transmitted to second layer lining 32.

[0034] Wherein, the materials of primary support 2 and lining layer 3 of the embodiment are all concrete, the material of sealing layer 5 is perfluoroether rubber, the material of sliding layer 6 is asphalt, and the material of inner lining layer 7 is steel plate.

[0035] Preferably, first layer lining 31 is formed by a plurality of first lining blocks 310 spliced in turn, and second layer lining 32 is formed by a plurality of second lining blocks 320 spliced in turn.

[0036] Preferably, as shown in Fig. 2 , Fig. 3 , pressure relief layer 4 includes annular buffer layer 41 and radial buffer layer 42. Annular buffer layer 41 and radial buffer layer 42 have the functions of absorbing pressure and deformation, and high heat transfer efficiency.

[0037] The circumferential buffer layer 41 is arranged between the first lining 31 and the second lining 32, and is in contact with the first lining block 310 on the outer side and in contact with the second lining block 320 on the inner side. The radial buffer layer 42 includes a plurality of outer buffer blocks 421 and a plurality of inner buffer blocks 422. The plurality of outer buffer blocks 421 are arranged on the outer side of the circumferential buffer layer 41, in contact with the first lining block 310 and corresponding to the connection between two adjacent first lining blocks 310; the plurality of inner buffer blocks 422 are arranged on the inner side of the circumferential buffer layer 41, in contact with the second lining block 320 and corresponding to the connection between two adjacent second lining blocks 320.

[0038] Preferably, the first lining block 310 is pre-provided with a first inlaid groove corresponding to the outer buffer block 421, and the second lining block 320 is pre-provided with a second inlaid groove corresponding to the inner buffer block 422.

[0039] Preferably, the material of the circumferential buffer layer 41 and the radial buffer layer 42 is a composite phase change material made of paraffin, expanded graphite and graphene aerogel. The graphene aerogel is obtained by chemical reduction or thermal reduction from graphene oxide dispersion. The expanded graphite is obtained by sequentially performing intercalation treatment and high-temperature expansion on natural graphite sheets to form loose and porous expanded graphite.

[0040] The preparation method of the composite phase change material is as follows: the paraffin is heated to a molten state, the expanded graphite powder is added to the molten paraffin, and the paraffin is fully adsorbed into the porous structure of the expanded graphite by stirring, and then cooled to room temperature to obtain a paraffin and expanded graphite composite. Then, the graphene aerogel is immersed or the molten paraffin / expanded graphite mixture is infiltrated into the porous structure of the graphene aerogel by a vacuum-assisted infiltration method, and then cooled to room temperature to solidify the paraffin. The composite material is cut or pressed into the required shape according to the design requirements.

[0041] Preferably, as shown in Fig. 2 The decompression layer 4 further includes a plurality of outer sealing layers 43 and a plurality of inner sealing layers 44. The plurality of outer sealing layers 43 are arranged one by one on the side of the outer buffer block 421 in contact with the first lining block 310; the plurality of inner sealing layers 44 are arranged one by one on the side of the inner buffer block 422 in contact with the second lining block 320. The outer sealing layer 43 and the inner sealing layer 44 are used to seal the cracks generated during the assembly and construction of the first lining block 310 and the second lining block 320, thereby improving the sealing performance of the structure.

[0042] Preferably, the material of the outer sealing layer 43 and the inner sealing layer 44 is perfluoroether rubber.

[0043] Preferably, the first lining block 310 is glued at the contact with the annular buffer layer 41, the outer buffer block 421 and the outer sealing layer 43; and the second lining block 320 is glued at the contact with the annular buffer layer 41, the inner buffer block 422 and the inner sealing layer 44.

[0044] A construction method of a cavern of an underground gas storage, which specifically comprises the following steps:

[0045] S1, after the cavern is excavated and formed, a cleaning device is used to thoroughly remove loose rocks, soil, sundries and the like on the surrounding rock wall of the surrounding rock structure 1; during the cleaning process, the surrounding rock wall surface of the surrounding rock structure 1 is ensured to be smooth and clean without any protrusions or recesses, and the surface is free of dust, oil stains and other pollutants; after the cleaning is completed, advanced shotcrete equipment is used to uniformly spray concrete on the surrounding rock wall according to the designed spraying thickness, spraying angle and spraying sequence, and the primary support 2 is arranged.

[0046] S2, in a factory, a mold for the first lining block 310 and the second lining block 320 is accurately made according to the designed size and shape of the first lining block 310 and the second lining block 320; the mold should be manufactured by using high-precision processing equipment and technology; the first lining block 310 and the second lining block 320 are cast in the mold, and a plug-in vibrator is used for vibration during the casting process; after the casting is completed, the first lining block 310 and the second lining block 320 are cured, and the concrete strength is detected regularly; when the concrete reaches the expected strength, the first lining block 310 and the second lining block 320 are demolded, and a comprehensive quality inspection is performed to ensure that the quality of the first lining block 310 and the second lining block 320 completely meets the design and construction requirements, and then the qualified lining is properly packaged and transported to the construction site for standby use.

[0047] S3, the first lining block 310 is used for assembly to build the first layer lining 31; after the first layer lining 31 is installed and the inner surface is cleaned, the inner surface of the first layer lining 31 is uniformly coated with an adhesive, and the adhesive should cover the entire inner surface, and the adhesive should be uniformly coated without leakage or thick coating during the coating process; after the adhesive reaches the appropriate bonding strength, the outer sealing layer 43 is laid at the preset position and compacted; then the annular buffer layer 41 and the outer buffer block 421 are closely laid on the inner surface of the first layer lining along the circumference of the cavern; before laying, the materials should be inspected to ensure that the materials are not damaged and have no wrinkles; during the laying process, the buffer layer should be completely attached to the lining surface without air pockets or wrinkles.

[0048] Then the adhesive is applied on the surface of the circumferential buffer layer 41 and the inner side buffer block 422, the inner sealing layer 44 is installed on the surface of the inner side buffer block 422, and then the second layer of lining 32 is constructed through the second lining block 320, and the installation is ensured to be closely attached to the pressure relief layer 4. It should be noted that the adhesive should be applied on the entire inner surface, and the adhesive should be evenly applied without leakage and thick coating during the application process; after the adhesive reaches the appropriate bonding strength, the outer sealing layer 43 is laid in the predetermined position and is compacted.

[0049] S4, after the installation of the second layer of lining 32 is completed and cleaned, the sealing layer 5 is laid first, the rubber coiled material is laid according to the design requirements of the laying direction and the laying sequence, starting from one end of the chamber and gradually laying to the other end, the hot melt connection is used for connection at the connecting position, and after the laying is completed, the air tightness of the entire sealing layer 5 is detected; then the pre-prepared inner lining layer 7 is placed in the chamber, and a uniform gap is reserved between the inner lining layer 7 and the sealing layer 5 to install the sliding layer 6; during the installation process, it is ensured that there is no impurity between the inner lining layer 7, the sliding layer 6 and the sealing layer 5, and they are closely attached.

[0050] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application, and it should be understood that the above description is only a specific embodiment of the present application, and does not limit the present application, and any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application is included in the protection scope of the present application.

Claims

1. An underground gas storage cavern, characterized in that, The utility model relates to a kind of underground gas storage caverns, including: Surrounding rock structure (1) with storage space; Gas storage structure is located in storage space, which includes sequentially arranged primary support (2), lining layer (3), sealing layer (5), sliding layer (6) and inner lining layer (7) from outside to inside; The lining layer (3) is provided with a pressure relief layer (4) inside, and the pressure relief layer (4) divides the lining layer (3) into a first layer lining (31) and a second layer lining (32), the first layer lining (31) is close to the primary support (2), and the second layer lining (32) is close to the sealing layer (5), and the pressure relief layer (4) is made of deformable material; The inner lining layer (7) is provided with a gas storage space (8) inside, and the gas storage space (8) is used for gas storage; The first layer lining (31) is formed by sequentially splicing a plurality of first lining blocks (310), and the second layer lining (32) is formed by sequentially splicing a plurality of second lining blocks (320); The pressure relief layer (4) includes: a circumferential buffer layer (41) arranged between the first layer lining (31) and the second layer lining (32), which is in contact with the first lining block (310) on the outside and in contact with the second lining block (320) on the inside;A radial buffer layer (42) includes: a plurality of outside buffer blocks (421), each arranged on the outside of the circumferential buffer layer (41), in contact with the first lining block (310) and corresponding to the connection between adjacent two first lining blocks (310);A plurality of inside buffer blocks (422) are arranged on the inside of the circumferential buffer layer (41), in contact with the second lining block (320) and corresponding to the connection between adjacent two second lining blocks (320); The first lining block (310) is provided with a first inlay groove corresponding to the outside buffer block (421), and the second lining block (320) is provided with a second inlay groove corresponding to the inside buffer block (422); The material of the circumferential buffer layer (41) and the radial buffer layer (42) is a composite phase change material made of paraffin, expanded graphite and graphene aerogel; The pressure relief layer (4) further includes: a plurality of outer sealing layers (43) corresponding to the outside buffer block (421) on the side in contact with the first lining block (310);A plurality of inner sealing layers (44) are arranged on the side in contact with the second lining block (320) corresponding to the inside buffer block (422).

2. An underground gas storage cavern as claimed in claim 1, wherein, The material of the outer sealing layer (43) and the inner sealing layer (44) is perfluoroether rubber.

3. An underground gas storage cavern as defined in claim 1, wherein The contact between the first lining block (310) and the circumferential buffer layer (41), the outside buffer block (421) and the outer sealing layer (43) is glued; The contact between the second lining block (320) and the circumferential buffer layer (41), the inside buffer block (422) and the inner sealing layer (44) is glued.

4. A method of constructing a cavern for a gas storage reservoir, characterized by, The underground gas storage caverns of any one of claims 1-3 are constructed, specifically including: Excavate the cavern, after the cavern is formed, clean the surrounding rock wall in the cavern, and then set the primary support (2); The lining layer (3) is arranged, the inner surface of the first layer lining (31) is cleaned after the first layer lining (31) is installed, the pressure reducing layer (4) is arranged, and the second layer lining (32) is arranged; the inner surface of the second layer lining (32) is cleaned after the second layer lining (32) is installed, and the sealing layer (5), the sliding layer (6) and the inner lining layer (7) are sequentially laid.

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