Composite lining structure of high-pressure underground gas storage hole

Abstract

The present application relates to a kind of high-pressure underground gas storage cave composite lining structure.The present application is applicable to the technical field of new energy energy storage.The technical problem to be solved by the present application is to provide a kind of high-pressure underground gas storage cave composite lining structure.The technical scheme employed by the present application is: a kind of high-pressure underground gas storage cave composite lining structure, characterized in that, the structure has successively from outside to inside: main lining layer;Pad layer, the pad layer material used can enhance rheological property after absorbing certain heat;Elastic sealing layer, can transmit the heat generated by high-pressure gas in gas storage cave to the pad layer;The pressure of high-pressure gas in gas storage cave can be transmitted to the pad layer, and then the pad layer material after rheological property is enhanced is pressed into the crack in the inner wall of the main lining layer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy storage, in particular to a high-pressure underground gas storage cavern composite lining structure. BACKGROUND

[0002] With the continuous recommendation of the double carbon strategy, China's energy pattern is gradually changing from traditional fossil energy to clean energy. A large number of new energy generators are connected to the grid. However, due to the close relationship between solar energy, wind energy and weather such as sunlight and wind speed, new energy power generation has strong volatility, and large-scale energy storage systems are needed to improve new energy consumption capacity.

[0003] Compressed air energy storage is a technology that converts electrical energy into the potential energy of high-pressure air to achieve energy storage. One of the key technical problems of building a compressed air energy storage power station is to safely and economically store high-pressure gas. Compared with using special geological structures such as salt caves to store gas, artificial underground caverns have the advantages of wide application range and flexible arrangement, and have greater promotion advantages. Most of the artificial underground caverns under construction use steel lining, which has good pressure-bearing capacity and sealing performance. However, its main disadvantages are: (1) complex construction process, requiring a large amount of steel plate transportation, assembly and welding in a closed cavern; (2) using a large amount of high-strength steel, which has high material cost; (3) the rigidity of steel is large, and the allowable elastic deformation is small, which makes it difficult to coordinate with the deformation of the surrounding rock, resulting in the inability to fully utilize the bearing potential of the surrounding rock.

[0004] Chinese patent publication No. CN 104018717A, published on September 3, 2014, has the title of a compressed air energy storage cavern construction method. The application discloses a construction method for a compressed air energy storage cavern. First, a reinforced concrete layer is cast on the inner wall of the artificially excavated cavern, and then a butyl rubber plate is bonded to the concrete lining by hot melt gasket. Compared with the traditional steel plate and concrete lining, this method can reduce the cost of the gas storage cavern lining. However, it has the following disadvantages: (1) complex construction process, the butyl rubber plate still needs to be installed one by one through hot melt gasket; (2) using cement nails to fix the hot melt gasket will cause the butyl rubber plate on the inner side to have different heights, and the butyl rubber plate at the edge of the hot melt gasket is prone to stress concentration and damage during the cyclic pressurization process; (3) the effect of external water pressure on the cavern is not considered, which can easily cause the butyl rubber plate inside to be detached under the action of external water. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a high-pressure underground gas storage cavern composite lining structure to solve the above problems.

[0006] The technical scheme adopted by the present application is: a high-pressure underground gas storage hole composite lining structure, characterized in that the structure has, from outside to inside, a main lining layer, a cushion layer, an elastic sealing layer, and the cushion layer material used in the cushion layer can enhance rheological property after absorbing a certain amount of heat, the elastic sealing layer can transfer the heat generated by the high-pressure gas in the gas storage hole to the cushion layer, and can transfer the pressure of the high-pressure gas in the gas storage hole to the cushion layer, and then press the cushion layer material with enhanced rheological property into the cracks in the inner wall of the main lining layer.

[0007] Through the above technical means, the gas storage hole can be effectively opened in Class II and above surrounding rock, and the problem of cracks in the lining layer caused by excessive internal gas pressure of the gas storage hole can be effectively solved.

[0008] In some embodiments, the elastic sealing layer uses sprayed rapid-setting rubber asphalt.

[0009] Through the above technical means, the sprayed rapid-setting rubber asphalt has the characteristics of high elasticity, self-sealing and self-healing, and simple construction. The coating film formed by the sprayed rapid-setting rubber asphalt can coat the lining layer. The high elasticity and high elongation of the sprayed rapid-setting rubber asphalt create the self-healing function of the coating film, which can effectively deal with the lining layer structure deformation problem caused by the internal gas pressure of the gas storage hole.

[0010] In some embodiments, the thickness of the elastic sealing layer is 1-2 cm.

[0011] In some embodiments, the cushion layer is poured with AC-10 fine-grained asphalt concrete.

[0012] Through the above technical means, the AC-10 fine-grained asphalt concrete has the characteristics of dense structure and small void ratio. When the main lining layer cracks due to high pressure in the gas storage hole, the temperature of the gas storage hole under high pressure rises, and the rheological property of the AC-10 fine-grained asphalt concrete is enhanced. The fine-grained state is conducive to filling the cracks.

[0013] In some embodiments, the thickness of the cushion layer is 10-20 cm.

[0014] In some embodiments, the main lining layer is embedded with inner and outer double-layer reinforcement, which includes surface reinforcement and bottom reinforcement. The surface reinforcement is close to the inner side of the sprayed concrete layer, the bottom reinforcement is close to the outer side of the cushion layer, and the surface reinforcement is fixedly connected with the part of the anchor rod that penetrates into the main lining layer.

[0015] Through the above technical means, the inner and outer double-layer reinforcement is used and the contact part is fixedly connected, which plays a role in bearing load and transferring load.

[0016] In some embodiments, the thickness of the main lining layer is 60-90 cm.

[0017] In some embodiments, the main lining layer is provided with a primary support lining outside, which circumscribes the inner wall of the surrounding rock, and the primary support lining is used for initial support after the gas storage hole is excavated.

[0018] Through the above technical means, the initial support can timely support and reinforce the surrounding rock, so that the initial support and the surrounding rock work together to improve the stability of the surrounding rock.

[0019] In some embodiments, the primary support lining comprises anchor rods and a sprayed concrete layer, the sprayed concrete layer is poured with steel fiber concrete, one end of the anchor rod penetrates into the surrounding rock, the other end penetrates through the sprayed concrete layer and penetrates into the main lining layer, and the anchor rod is arranged along the inner wall of the surrounding rock at intervals.

[0020] Through the above technical means, the initial support formed by the anchor rod and the sprayed concrete layer has a certain shear strength. The sprayed concrete can support the surrounding rock and fill and reinforce the surrounding rock. Through the joint use of the anchor rod and the sprayed concrete, the free development of the deformation of the surrounding rock is further limited, and the stress distribution of the surrounding rock is adjusted, so that the anchor rod, the sprayed concrete layer and the surrounding rock form a system that works together to prevent the rock mass from loosening and separating.

[0021] In some embodiments, the thickness of the sprayed concrete layer is 8-20 cm.

[0022] The beneficial effects of the present application are:

[0023] 1. The present application utilizes the characteristics of the cushion material that the rheological property is enhanced after absorbing a certain amount of heat, the heat generated by the high-pressure gas in the gas storage hole is transmitted to the cushion material through the elastic sealing layer, and the pressure of the high-pressure gas in the gas storage hole is also transmitted to the cushion material, and then the cushion material with enhanced rheological property is pressed into the cracks in the inner wall of the main lining layer, thereby enhancing the crack resistance and permeability resistance of the lining, and improving the integrity and sealing performance of the lining.

[0024] 2. The present application utilizes the characteristics of the elastic sealing layer material that has high elasticity and high elongation, ensures that the elastic sealing layer coating has good impermeability, the temperature resistance of the elastic sealing layer material ensures that the elastic sealing layer coating will not be damaged during the pressurization and temperature rise process of the gas storage hole, and the construction method is simple.

[0025] 3. The main body of the present application adopts a concrete structure, which significantly saves the amount of steel material and reduces the engineering cost.

[0026] 4. The present application cancels the steel lining structure while adopting the concrete structure, which significantly reduces the site welding and assembly work, greatly shortens the construction period, and has a fast construction speed.

[0027] 5. The present application uses the sprayed anchor support as the primary support lining, which is beneficial to the deformation coordination with the external surrounding rock, beneficial to the effective stability of the surrounding rock, and beneficial to the full utilization of the bearing potential of the surrounding rock. Attached Figure Description

[0028] Figure 1 This is a typical cross-sectional view of a composite lining structure for a high-pressure underground gas storage tunnel in one of the embodiments.

[0029] Figure 2 This is a schematic diagram of a partial crack in a composite lining structure of a high-pressure underground gas storage tunnel, as described in the embodiment.

[0030] Explanation of reference numerals in the attached drawings: 1. Initial support lining; 2. Main lining layer; 3. Subbase layer; 4. Elastic sealing layer; 5. Anchor bolt; 6. Shotcrete layer; 7. Top reinforcement; 8. Bottom reinforcement; 9. Crack. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below with reference to specific embodiments.

[0032] like Figure 1 As shown, the embodiment of the present invention is a composite lining structure for a high-pressure underground gas storage tunnel, which is suitable for opening gas storage tunnels in Class II and above surrounding rock. The structure has the following components from the outside to the inside: initial support lining 1, main lining layer 2, cushion layer 3, and elastic sealing layer 4.

[0033] In this embodiment, the initial support lining 1 is mainly used for the initial support after the gas storage tunnel is excavated; the main lining layer 2 is mainly used to bear the load and transfer the load to the surrounding rock outside; the cushion layer 3 material can enhance its rheological properties after absorbing a certain amount of heat; the elastic sealing layer 4 can transfer the heat generated by the high-pressure gas in the gas storage tunnel to the cushion layer 3, and can also transfer the pressure of the high-pressure gas in the gas storage tunnel to the cushion layer 3, thereby pressing the rheologically enhanced cushion layer 3 material into the cracks in the inner wall of the main lining layer 2.

[0034] Furthermore, the gas storage tunnel is excavated in Class II surrounding rock with an excavation diameter of 10m and a lining diameter of 8m. The initial support lining 1 is laid close to the excavated surrounding rock surface and includes anchor bolts 5 and a shotcrete layer 6. The anchor bolts 5 are spaced along the circumferential direction of the inner wall of the excavated surrounding rock, with a length of 6m and a radial penetration of 5.7m into the inner wall of the surrounding rock. The inner wall of the surrounding rock is covered with a shotcrete layer 6, which is made of steel fiber reinforced concrete with a radial thickness of 10cm. The anchor bolts 5 pass through the shotcrete layer 6 and protrude 20cm.

[0035] Furthermore, the inner wall of the shotcrete layer 6 is reinforced with a main lining layer 2. The main lining layer 2 is embedded with inner and outer double-layer reinforcement, and the inner and outer double-layer reinforcement is in a circumferential structure. The inner and outer double-layer reinforcement includes top reinforcement 7 and bottom reinforcement 8. The top reinforcement 7 is close to the inner side of the shotcrete layer 6, and the top reinforcement 7 is welded and fixed to the anchor rod 5 that extends into the main lining layer 2. The bottom reinforcement 8 is far away from the inner side of the shotcrete layer 6. The main lining layer 2 is constructed using a vertical formwork casting method, and concrete is poured circumferentially along the top reinforcement 7 and the bottom reinforcement 8, with a radial thickness of 80cm.

[0036] Furthermore, a cushion layer 3 is added to the inner wall of the main lining layer 2. The cushion layer 3 is made of AC-10 fine-grained asphalt concrete with a thickness of 10cm and the inner surface is smoothed.

[0037] Furthermore, the elastic sealing layer 4 is formed by spraying quick-setting rubber asphalt, which is sprayed multiple times on the inner surface of the padding layer 3 to form the elastic sealing layer 4 with a thickness of 2cm.

[0038] The implementation principle of a composite lining structure for a high-pressure underground gas storage tunnel according to an embodiment of the present invention is as follows:

[0039] like Figure 2 As shown, when subjected to high pressure from the gas inside the gas storage tunnel, the elastic sealing layer 4 has a strong elastic deformation capacity. After expanding under pressure, it will transfer all the internal gas pressure to the cushion layer 3 and the main lining layer 2. The elastic modulus of the cushion layer 3 is between that of the elastic sealing layer 4 and the main lining layer 2. The cushion layer 3 forms an elastic buffer zone and plays a transition role. After the main lining layer 2 bears the load, it transfers the load to the surrounding rock outside, and at the same time, cracks 9 will appear on its inner surface. At this time, the temperature of the gas storage tunnel is high under high pressure, and the rheological properties of the cushion layer 3 are enhanced. Under the action of internal pressure, it fills the cracks 9 generated in the main lining layer 2, plays a bonding role, and greatly enhances the airtightness and integrity of the lining.

[0040] According to calculations, the lining structure of this embodiment can withstand internal air pressure of 10 to 15 MPa and maintain airtightness.

[0041] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A composite lining structure for a high-pressure underground gas storage tunnel, characterized in that, The structure, from the outside in, has the following characteristics: Main lining layer (2); The cushion layer (3) is made of a material whose rheological properties are enhanced after absorbing a certain amount of heat. The elastic sealing layer (4) can transfer the heat generated by the high-pressure gas in the gas storage tunnel to the cushion layer (3); it can transfer the pressure of the high-pressure gas in the gas storage tunnel to the cushion layer (3), thereby pressing the rheologically enhanced cushion layer (3) material into the cracks in the inner wall of the main lining layer (2); The elastic sealing layer (4) is made of sprayed quick-setting rubber asphalt; the thickness of the elastic sealing layer (4) is 1~2cm; The subbase (3) is made of AC-10 fine-grained asphalt concrete; the thickness of the subbase (3) is 10~20cm. The main lining layer (2) is surrounded by a primary support lining (1), which is connected to the inner wall of the surrounding rock. The primary support lining (1) is used for initial support after the gas storage tunnel is excavated. The initial support lining includes anchor bolts (5) and a shotcrete layer (6).

2. The composite lining structure for a high-pressure underground gas storage tunnel according to claim 1, characterized in that, The main lining layer (2) is internally reinforced with inner and outer double layers of reinforcement, including top reinforcement (7) and bottom reinforcement (8). The top reinforcement (7) is close to the inner side of the shotcrete layer (6), and the bottom reinforcement (8) is close to the outer side of the cushion layer (3). The top reinforcement (7) is fixedly connected to the part of the anchor rod (5) that penetrates into the main lining layer (2).

3. The composite lining structure for a high-pressure underground gas storage tunnel according to claim 2, characterized in that, The thickness of the main lining layer (2) is 60~90cm.

4. The composite lining structure for a high-pressure underground gas storage tunnel according to claim 1, characterized in that, The shotcrete layer (6) is made of steel fiber concrete; one end of the anchor rod (5) extends into the surrounding rock, and the other end passes through the shotcrete layer (6) and extends into the main lining layer (2), and is arranged at intervals along the inner wall of the surrounding rock.

5. The composite lining structure for a high-pressure underground gas storage tunnel according to claim 4, characterized in that, The thickness of the sprayed concrete layer (6) is 8~20cm.

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