Combined lining structure of underground gas storage

Abstract

The utility model discloses a combined lining structure of an underground gas storage. The combined lining structure comprises a plurality of linings and a plurality of buffer devices, wherein the number of the buffer devices is the same as that of the linings; the multiple linings are sequentially arranged on the inner wall of the underground gas storage cavern in the circumferential direction of the underground gas storage cavern, and buffering seams are reserved between the adjacent linings. Each buffering device is arranged at one buffering seam and comprises a bent buffering piece and two fixing pieces; the two ends of the buffering piece are connected with the two adjacent linings in a sealed mode through fixing pieces respectively. The buffering seams are arranged between the adjacent linings, and the buffering devices are used in a combined mode, so that during gas storage, gas pressure borne by the fragmented linings is transmitted to external surrounding rock, tension fracture damage of the linings is avoided, and the compression performance of the linings is remarkably improved; when the gas is released, the adjacent linings are mutually squeezed to form a stressed whole, instability damage is avoided, the service life of the underground gas storage can be remarkably prolonged, and the safety of the underground gas storage can be remarkably improved.

Description

Technical Field

[0001] The utility model discloses a combined lining structure of an underground gas storage, belonging to the technical field of energy storage systems. Background Art

[0002] Compressed air energy storage refers to compressing air into a gas storage reservoir for storage through electricity, and releasing high-pressure air to generate electricity when needed. As underground gas storage has the advantages of large gas storage capacity, high safety factor, and good economic benefits, most of the gas storage reservoirs in existing compressed air energy storage stations are underground gas storage.

[0003] According to the current economic requirements of energy storage technology, the internal pressure of the underground gas storage of compressed air energy storage stations has reached more than 10MPa. Considering the existing data and design experience, the conventional materials used as linings of underground gas storages with a diameter of more than 10m under an internal pressure of 10MPa have been torn and damaged. At the same time, under the action of storage and release cycle loads, the brittle lining concrete is prone to fatigue damage, which in turn leads to the destruction of the entire gas storage structure. Utility Model Content

[0004] The purpose of the present application is to provide a combined lining structure for an underground gas storage reservoir to solve the technical problem that the lining of the existing underground gas storage reservoir may be subjected to tension or fatigue damage during the alternation of compression and tension cyclic loads during the storage and release of energy.

[0005] The utility model provides a combined lining structure of an underground gas storage, comprising a plurality of linings and a plurality of buffer devices having the same number as the linings;

[0006] The plurality of linings are sequentially arranged on the inner wall of the cavern along the circumferential direction of the cavern of the underground gas storage reservoir, and buffer gaps are left between adjacent linings;

[0007] Each buffer device is arranged at one of the buffer seams, and each buffer device comprises a curved buffer member and two fixing members;

[0008] The two ends of the buffer are respectively sealed and connected to two adjacent linings through the fixing members.

[0009] Preferably, each of the fixing members comprises a screw and a compression nut;

[0010] The first surface of the buffer member is in contact with the corresponding lining;

[0011] One end of the screw rod passes through the buffer and extends into the lining;

[0012] The clamping nut is threadedly connected to the screw rod, and a surface of the clamping nut is connected to the second surface of the buffer.

[0013] Preferably, each of the fixing members further comprises a pressing sheet;

[0014] The pressing sheet is arranged between the pressing nut and the buffer member.

[0015] Preferably, the width of the pressing sheet is greater than the diameter of the pressing nut.

[0016] Preferably, the buffer component is made of elastic material.

[0017] Preferably, the elastic material is steel, copper or rubber.

[0018] Preferably, it also includes a plurality of water stopping devices;

[0019] The two ends of the water-stopping device are respectively connected to two adjacent linings, and the water-stopping device is located on a side of the buffer device close to the surrounding rock.

[0020] Preferably, it also includes a sealing layer;

[0021] The sealing layer is arranged on a side of the lining away from the surrounding rock.

[0022] Preferably, the number of linings arranged in the circumferential direction of the underground gas storage cavern is greater than 6.

[0023] Preferably, each of the buffer devices further comprises a flexible buffer plate;

[0024] The flexible buffer plate is arranged in the buffer gap.

[0025] Preferably, the lining is made of concrete.

[0026] Compared with the prior art, the combined lining structure of the underground gas storage of the utility model has the following beneficial effects:

[0027] The utility model provides a combined lining structure for an underground gas storage reservoir, wherein the buffer device plays the role of transmitting the gas pressure borne by the segmented lining to the external surrounding rock, and also plays the role of preventing gas leakage and adapting to deformation, thereby improving the internal pressure resistance performance of the underground gas storage reservoir; during the gas release process of the segmented lining, adjacent linings are squeezed against each other to form a force-bearing whole, while at the same time, the high compressive strength of the lining material and the high moment of inertia are brought into play, and combined with the water stopping at the buffer joint, the underground gas storage reservoir is effectively prevented from being damaged by pressure and unstable due to the action of external groundwater.

[0028] The utility model of underground gas storage combined lining structure combines lining, buffer device and deep surrounding rock to form a new type of gas storage lining structure, so that the lining-buffer device-deep surrounding rock can play their respective advantages in the process of energy storage and release, and carry the load in a coordinated manner, with clear physical and mechanical concepts. Since the stress conditions of each component are greatly improved, its fatigue damage resistance is significantly enhanced.

[0029] The utility model uses concrete lining in the combined lining structure of the underground gas storage reservoir. Since the concrete lining adopts conventional concrete materials and is combined with a buffer device composed of common building materials, the combined lining cost of the utility model is relatively low, the construction process requirements are relatively low, and the effect of reducing costs and increasing efficiency is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the combined lining structure of the underground gas storage of the utility model;

[0031] Figure 2 It is a schematic diagram of the structure of the buffer device when concrete lining is used in the embodiment of the utility model.

[0032] In the figure, 1 is a lining; 2 is a buffer device; 21 is a buffer member; 22 is a screw; 23 is a locking nut; 24 is a pressing plate; 3 is a cavern; 4 is a buffer joint; 5 is a water-stopping device; 6 is surrounding rock; 7 is a sealing layer; and 8 is a flexible buffer plate. DETAILED DESCRIPTION

[0033] In the following description, specific details such as specific system structures and technologies are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to avoid unnecessary details that hinder the description of the present invention.

[0034] The utility model provides a combined lining structure of an underground gas storage reservoir, such as Figure 1 and Figure 2 As shown, it includes a plurality of linings 1 and a plurality of buffer devices 2 having the same number as the linings 1;

[0035] Multiple linings 1 are sequentially arranged on the inner wall of the cavern 3 along the circumferential direction of the underground gas storage cavern, and a buffer gap 4 is left between adjacent linings 1; in this embodiment, each lining 1 extends along the axial direction of the cavern 3;

[0036] Each buffer device 2 is arranged at a buffer seam 4, and the structure of each buffer device 2 is as follows: Figure 2 As shown, it includes a curved buffer member 21 and two fixing members;

[0037] Both ends of the buffer member 21 are respectively sealed and connected to two adjacent linings 1 through fixing members.

[0038] The utility model of the combined lining structure of the underground gas storage reservoir sets the curved buffer 21 on the buffer joint 4, so that the buffer 21 forms an integral structure with the adjacent lining 1. During the gas pressurization process when storing energy, since the curved buffer 21 has high deformation and high ductility characteristics, the separated segmented lining 1 can transfer the internal pressure to the surrounding rock structure during the expansion of the underground gas storage reservoir without causing large deformation and damage itself; in the process of reducing the gas pressure during energy release, the segmented lining 1 gradually closes and compacts, and can bear its own weight and the pressure load from the external groundwater. The utility model of the combined lining structure of the underground gas storage reservoir can prevent the lining 1 from being subjected to tension or fatigue damage during the alternation of compression and tension cyclic loads during the storage and release of energy in the underground gas storage reservoir, thereby extending the life of the underground gas storage reservoir and significantly improving its safety.

[0039] In order to ensure the sealing of the underground gas storage and prevent gas leakage, the structure of each fixing member used in this embodiment is as follows: Figure 2 As shown, it includes a screw rod 22 and a compression nut 23;

[0040] The first surface of the buffer 21 is in contact with the corresponding lining 1;

[0041] One end of the screw rod 22 passes through the buffer member 21 and extends into the lining 1;

[0042] The clamping nut 23 is threadedly connected to the screw rod 22 , and a surface of the clamping nut 23 is in contact with the second surface of the buffer 21 .

[0043] In this embodiment, the buffer member 21 is fixed to the lining 1 by using a clamping nut 23 in cooperation with a screw rod 22, which can ensure both the stability of the fixation and the sealing performance to prevent leakage of the internal high-pressure gas.

[0044] In order to further enhance the sealing effect and the stability of the fixation, each fixing member of the present embodiment further includes a pressing sheet 24;

[0045] The pressing sheet 24 is disposed between the pressing nut 23 and the buffer member 21 .

[0046] Preferably, the width of the pressing sheet 24 is greater than the diameter of the clamping nut 23 , so that the buffer 21 and the lining 1 are more tightly connected by means of the pressing sheet 24 .

[0047] To further prevent gas leakage, the combined lining structure of this embodiment further includes a sealing layer 7;

[0048] The sealing layer 7 is arranged on the side of the lining 1 away from the surrounding rock 6 .

[0049] The sealing layer 7 may be a geomembrane or a polyurea coating.

[0050] The curved buffer member 21 in this embodiment is made of an elastic material. Since the elastic material has high ductility and high deformation characteristics, it will not be broken or damaged during the alternating process of energy storage and release cycle load.

[0051] Exemplarily, the elastic material is steel, copper or rubber.

[0052] In order to prevent external groundwater from flowing into the underground gas storage, the combined lining structure of this embodiment further includes a plurality of water stopping devices 5;

[0053] Both ends of the water-stopping device 5 are respectively connected to two adjacent linings 1 , and the water-stopping device 5 is located on a side of the buffer device 2 close to the surrounding rock 6 .

[0054] The water-stopping device 5 in this embodiment can be a copper sheet or a water-stopping strip, etc.

[0055] In order to avoid tensile damage to the lining 1 during the alternating process of energy storage and release cyclic loads, the number of linings 1 arranged in the circumferential direction of the underground gas storage cavern in this embodiment is greater than 6, preferably 8. This number makes the force on each lining 1 more uniform and extends its service life.

[0056] The material of the lining 1 of this embodiment is concrete.

[0057] In order to prevent the two linings 1 forming the buffer joint 4 from being worn during the closing and compacting process, in this embodiment, a flexible buffer plate 8 is arranged in the buffer joint 4. The material of the flexible buffer plate 8 can be a polyethylene closed-cell foam plastic plate.

[0058] The construction process of the combined lining structure of the underground gas storage in this embodiment is as follows:

[0059] Step 1: excavate the surrounding rock 6 to form a gas storage cavern.

[0060] Step 2: Construct the lining 1 in the cavern of the gas storage reservoir, so that multiple linings 1 are arranged in sequence along the circumferential direction of the cavern 3 of the underground gas storage reservoir, and buffer joints 4 are left between adjacent linings 1. The width of the buffer joints 4 is 12 mm to 20 mm, and the inside is filled with polyethylene closed-cell foam plastic boards. Among them, a water stop device 5 can be added at the buffer joint 4 according to the external groundwater distribution.

[0061] Step 3: After the construction of the lining 1 is completed, the buffer device 2 is installed on the high-pressure gas side of the adjacent lining 1 forming the buffer joint 4. The buffer device 2 is composed of a screw 22, a buffer 21, a pressing plate 24 and a clamping nut 23. After the screw 22 is fixed to the lining 1, the buffer 21 is installed, and the pressing plate 24 and the clamping nut 23 are used to press and fix the buffer 21 to the lining 1.

[0062] Step 4: After the above steps are completed, the sealing layer 7 is constructed on the gas side of the lining 1 to ensure that there is no leakage under the action of the gas storage pressure under normal operating conditions.

[0063] During the operation of the underground gas storage, under the action of air pressure, the buffer joints 4 between the linings 1 will open, and at the same time, the air pressure load will be transferred to the surrounding rock 6 in the deep part. Since the number of linings 1 arranged in the circumferential direction of the cavern 3 of the underground gas storage is greater than 6, the curvature of each lining 1 is small, and the tensile stress itself will not cause tensile damage to the lining 1. The high ductility of the buffer device 2 will ensure that the internal gas does not leak and reduce the excessive tension on the lining 1. When the gas is released, the internal air pressure is reduced to atmospheric pressure, and the external groundwater pressure squeezes the multiple linings 1, the buffer joints 4 will close, and the multiple linings 1 become a whole to resist the external groundwater pressure, and the water stop device 5 will prevent the external groundwater from flowing into the underground gas storage.

[0064] The utility model provides a combined lining structure for an underground gas storage reservoir, wherein the buffer device 2 serves to transmit the gas pressure borne by the segmented lining 1 to the external surrounding rock 6, and also serves to prevent gas leakage and adapt to deformation, thereby improving the internal pressure resistance performance of the underground gas storage reservoir. During the gas release process of the segmented lining 1, adjacent linings 1 are squeezed against each other to form a force-bearing whole, while taking advantage of the high compressive strength of the lining 1 material and the high moment of inertia it possesses, and combined with the water-stopping device at the buffer joint 4, the underground gas storage reservoir is effectively prevented from being damaged by pressure and unstable due to the action of external groundwater.

[0065] The utility model of the underground gas storage combined lining structure combines the lining 1, the buffer device 2 and the deep surrounding rock 6 to form a new type of gas storage lining structure, so that the lining 1-buffer device 2-deep surrounding rock 6 can play their respective advantages in the process of energy storage and release, and carry the load in a coordinated manner, with clear physical and mechanical concepts. Since the stress conditions of each component are greatly improved, its fatigue damage resistance is significantly enhanced.

[0066] In the combined lining structure of the underground gas storage reservoir of the utility model, concrete lining is used. Since the concrete lining adopts conventional concrete materials and is combined with the buffer device 2 composed of common building materials, the combined lining cost of the utility model is relatively low, the construction process requirements are relatively low, and the effect of reducing costs and increasing efficiency is achieved.

[0067] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A combined lining structure for an underground gas storage, characterized in that: It includes a plurality of linings and a plurality of buffer devices equal in number to the linings; The plurality of linings are sequentially arranged on the inner wall of the cavern along the circumferential direction of the cavern of the underground gas storage reservoir, and buffer gaps are left between adjacent linings; Each buffer device is arranged at one of the buffer seams, and each buffer device comprises a curved buffer member and two fixing members; The two ends of the buffer are respectively sealed and connected to two adjacent linings through the fixing members.

2. The combined lining structure of underground gas storage according to claim 1 is characterized in that: Each of the fixing members comprises a screw and a compression nut; The first surface of the buffer member is in contact with the corresponding lining; One end of the screw rod passes through the buffer and extends into the lining; The clamping nut is threadedly connected to the screw rod, and a surface of the clamping nut is connected to the second surface of the buffer.

3. The combined lining structure of underground gas storage according to claim 2 is characterized in that: Each of the fixing members further comprises a pressing sheet; The pressing sheet is arranged between the pressing nut and the buffer member.

4. The combined lining structure of underground gas storage according to claim 3 is characterized in that: The width of the pressing sheet is greater than the diameter of the clamping nut.

5. The combined lining structure of underground gas storage according to claim 1 is characterized in that: The material of the buffer component is elastic material.

6. The combined lining structure of the underground gas storage according to claim 5 is characterized in that: The elastic material is steel, copper or rubber.

7. The combined lining structure of underground gas storage according to claim 1 is characterized in that: Also included are multiple water-stopping devices; The two ends of the water-stopping device are respectively connected to two adjacent linings.

8. The combined lining structure of underground gas storage according to claim 1 is characterized in that: Also includes a sealing layer; The sealing layer is arranged on a side of the lining away from the surrounding rock.

9. The combined lining structure of underground gas storage according to claim 1, characterized in that: The number of the linings arranged in the circumferential direction of the underground gas storage cavern is greater than 6.

10. The combined lining structure of underground gas storage according to claim 1, characterized in that: Each of the buffer devices also includes a flexible buffer plate; The flexible buffer plate is arranged in the buffer gap.

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