An underground artificial gas storage chamber and its construction method

Abstract

This invention discloses an underground artificial cavern gas storage facility and its construction method, relating to the field of artificial underground cavern technology. The underground artificial cavern gas storage facility is constructed within an underground surrounding rock layer. A concrete lining layer is provided within the surrounding rock layer, and a filling layer made of a pressure-induced flow material is provided inside the concrete lining layer. A sealing layer is provided within the filling layer, and the sealed area surrounded by the sealing layer is the gas storage area. This invention solves the technical problem of instability within the underground artificial cavern gas storage facility caused by cracking of the concrete layer in existing underground gas storage structures.

Description

Technical Field

[0001] This invention relates to the field of artificial underground chamber technology, and in particular to an underground artificial chamber gas storage facility and its construction method. Background Technology

[0002] Compressed air energy storage systems are a type of electrical energy storage technology. During periods of low grid load or power surplus, electricity drives a compressor to compress air to a high-pressure state, which is then stored in an air storage device. During periods of high grid load or power shortage, the high-pressure air in the storage device is released, causing it to expand in an expander and drive a generator to produce electricity. Once the compressed air energy storage system is operational, the storage device undergoes a daily cycle of charging and discharging to achieve peak shaving and valley filling.

[0003] To increase the discharge capacity of compressed air energy storage systems, both the storage volume and pressure rating of the storage device need to be increased. Currently, the storage volume of large-scale compressed air energy storage systems can reach 500,000 to 1,000,000 cubic meters, and the storage pressure can reach 10 to 30 MPa. One type of storage device used in compressed air energy storage systems is the underground artificial chamber gas storage facility, which is typically in the form of an underground adit, tunnel, or shaft. Due to the high storage pressure rating of underground artificial chambers used in compressed air energy storage systems, these systems are located in areas rich in underground surrounding rock layers. Currently, to distribute the stress of the surrounding rock, reduce its deformation, and ensure the long-term stability and safety of the chamber, an additional layer of concrete structure is added within the surrounding rock layer.

[0004] In the process of developing this invention, the inventors discovered at least the following problems in the prior art: Underground artificial chamber gas storage facilities used in compressed air energy storage systems operate under cyclic pressure loads. Concrete has poor tensile strength; even reinforced concrete is difficult to prevent cracking under alternating pressure loads during operation. Furthermore, the methods for inspecting and repairing concrete cracking in operating underground artificial chamber gas storage facilities are not yet mature. Currently, the design life of large-scale compressed air energy storage power plants under construction exceeds 30 years. Excessive concrete cracking within the gas storage facility will lead to unstable operation and even premature failure of the underground artificial chamber gas storage facility. Summary of the Invention

[0005] The purpose of this invention is to provide an underground artificial chamber gas storage facility to solve the technical problem of instability inside the underground artificial chamber gas storage facility caused by concrete cracking in existing underground gas storage structures.

[0006] To achieve this objective, on the one hand, an underground artificial chamber gas storage facility is provided, constructed inside an underground surrounding rock layer. The underground surrounding rock layer is provided with a concrete lining layer, and the concrete lining layer is provided with a filling layer made of a material with pressure-induced fluidity. The filling layer is provided with a sealing layer, and the sealed area surrounded by the sealing layer is the gas storage area. When cracks appear in the concrete lining layer, the filling layer deforms under pressure to fill the cracks in the concrete lining layer.

[0007] Furthermore, the filling layer uses a coating material with pressure-induced flowability, and the coating material of the filling layer is applied to the inner wall of the concrete lining layer and completely covers the inner wall of the concrete lining layer.

[0008] Furthermore, the coating material of the filling layer adopts a damping-constraint composite structure, which includes a damping layer and a constraint layer.

[0009] Furthermore, the damping layer is made of solvent-free polyurethane material, and the constraint layer is made of epoxy resin material.

[0010] Furthermore, the solvent-free polyurethane material forming the damping layer comprises two components: the first component is an isocyanate prepolymer, and the second component is a mixture of polyether polyol, bond extender, and filler.

[0011] Furthermore, the epoxy resin material forming the constraint layer comprises two components: the first component is an amine curing agent, and the second component is a mixture of epoxy resin and filler.

[0012] Furthermore, the sealing layer is a steel plate layer formed of steel material.

[0013] Furthermore, the sealing layer is made of an elastomeric coating material, and the coating material of the sealing layer is applied to the inner wall of the filling layer and completely covers the inner wall of the filling layer.

[0014] Furthermore, the inner wall of the sealed area formed by splicing steel plates is completely coated with a sealing material, and the sealed area surrounded by the sealing material is the gas storage area.

[0015] On the other hand, a construction method for the sealing structure of an underground gas storage facility is also provided, including the following steps:

[0016] A filling layer is applied to the inner wall of the concrete lining layer. During the construction of the filling layer, a damping layer is first applied to the inner wall of the concrete lining layer, and then a restraint layer is applied to the damping layer.

[0017] Furthermore, it also includes the following steps: applying a steel plate layer on the constraint layer and applying a sealing coating of elastomeric coating material to the interior of the steel plate layer.

[0018] Furthermore, the thickness of the damping layer coated on the inner wall of the concrete lining layer is between 0.8mm and 1.5mm, and the ratio of the thickness of the restraint layer to the thickness of the steel plate layer is 2:1.

[0019] The above-mentioned technical solution of the present invention has the following advantages or beneficial effects: In the underground artificial chamber gas storage facility of the present invention, the concrete lining layer is provided with a filling layer made of a material with pressure-induced fluidity. When cracks appear in the concrete lining layer, the filling layer can deform under pressure to fill the cracks in the concrete lining layer, thereby avoiding or mitigating the impact of concrete lining layer cracking on the underground artificial chamber gas storage facility. Even if a large number of irregular cracks appear in the concrete layer after long-term use of the underground artificial chamber gas storage facility, it will not affect the stability of the underground gas storage facility.

[0020] Meanwhile, the filling layer employs a damping-constraint composite structure, comprising a damping layer and a constraint layer. The damping layer uses solvent-free polyurethane, while the constraint layer uses epoxy resin. The solvent-free polyurethane damping layer has a low elastic modulus, allowing it to easily deform under pressure and return to its original shape after pressure removal, thus adapting to various cracks within the concrete layer. Furthermore, the solvent-free polyurethane damping layer absorbs vibrations within the gas storage tank during inflation, preventing cracking of the outer concrete layer of the filling layer. The epoxy resin used in the constraint layer possesses high stiffness and strength, with a high elastic modulus, effectively suppressing shear deformation of the damping layer. Epoxy resin also exhibits strong interfacial adhesion, resulting in high bonding strength between it and the solvent-free polyurethane damping layer, ensuring the damping-constraint composite structure maintains its integrity and preventing delamination failure of the filling layer. The filling layer adopts a damping constraint composite structure. Through the synergistic effect of the viscoelastic energy dissipation of solvent-free polyurethane and the rigid constraint of epoxy resin, it can quickly fill the cracked concrete when inflated and quickly recover when deflated, so as to minimize the impact of cracking of the concrete layer of the underground artificial cave gas storage structure. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the cross-sectional layer structure of the underground artificial cavern gas storage facility provided in an embodiment of the present invention.

[0022] In the diagram: 1-Underground surrounding rock layer; 2-Concrete lining layer; 3-Filling layer; 4-Sealing layer; 5-Gas storage area. Detailed Implementation

[0023] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0024] The underground artificial chamber gas storage facility in this embodiment is constructed within an underground surrounding rock layer 1. A concrete lining layer 2 is provided within the underground surrounding rock layer 1. The concrete lining layer 2, through its own strength and rigidity, can effectively constrain the deformation of the surrounding rock, disperse the surrounding rock pressure, prevent the gas storage cavity from being damaged due to structural instability, and ensure the integrity of the cavity shape. However, the concrete lining layer 2 has poor tensile strength. When the gas storage facility is in operation, tensile loads generated by internal and external pressure differences, temperature stress, etc., can easily cause cracks in the concrete lining layer 2, affecting the load-bearing capacity of the gas storage facility.

[0025] like Figure 1 As shown, in this embodiment of the underground artificial chamber gas storage facility, the concrete lining layer 2 is equipped with a filling layer 3 made of a pressure-induced flow material. When cracks appear in the concrete lining layer 2, the filling layer 3 can deform under pressure to fill the cracks, thus avoiding or mitigating the impact of the cracks in the concrete lining layer 2 on the underground artificial chamber gas storage facility. A sealing layer 4 is provided within the filling layer 3, and the sealed area surrounded by the sealing layer 4 is the gas storage area 5. For underground artificial chamber gas storage facilities, sealing performance is a crucial indicator of normal operation. In this embodiment, a sealing layer 4 is added inside the filling layer 3 to ensure the airtightness of the gas storage facility.

[0026] Furthermore, the filling layer 3 employs a coating material with pressure-induced flowability. This coating material is applied to the inner wall of the concrete lining layer 2 and completely covers it. The coating material refers to a material that forms a thin film on the surface of a substrate to impart specific functions to the substrate. When a coating material is used for the filling layer 3, the integrity of the filling layer 3 is ensured through the coating application process, guaranteeing that the filling layer 3 is fully coated on the inner wall of the concrete lining layer 2. In addition, the coating material has the advantages of wide applicability to various substrates and customizable functionality.

[0027] Furthermore, in this embodiment, the coating material of the filling layer 3 of the inner wall of the concrete lining layer 2 in the underground artificial gas storage chamber adopts a damping-constraint composite structure, which includes a damping layer and a constraint layer. More specifically, the damping layer is made of solvent-free polyurethane material, and the constraint layer is made of epoxy resin material. Preferably, the damping layer is made of a scraping-applied solvent-free polyurethane material, and the constraint layer is made of a scraping-applied epoxy resin material.

[0028] Solvent-free polyurethane materials have the advantages of no solvent evaporation, no bubbling, and no shrinkage. Underground gas storage tunnels made with this material are environmentally friendly and pollution-free, and are suitable for compressed air energy storage systems that help achieve carbon neutrality.

[0029] The solvent-free polyurethane damping layer has a low elastic modulus, making it easily deformable under pressure and able to return to its original shape after pressure is removed, thus adapting to various cracks within the concrete layer. Furthermore, the solvent-free polyurethane damping layer can absorb vibrations inside the gas storage tank during inflation, thereby preventing cracking of the concrete layer outside the filling layer. The epoxy resin material used in the restraint layer has high stiffness and strength, and its high elastic modulus effectively suppresses shear deformation of the damping layer. Epoxy resin also has strong interfacial adhesion, resulting in high bonding strength between it and the solvent-free polyurethane damping layer, ensuring the integrity of the damping-restraint composite structure and preventing delamination failure of the filling layer. The filling layer employs a damping-restraint composite structure, where the viscoelastic energy dissipation of the solvent-free polyurethane and the rigid restraint of the epoxy resin work synergistically. During inflation, it can quickly fill cracked concrete, and during deflation, it can quickly recover, minimizing the structural impact of concrete layer cracking in the underground artificial gas storage tank.

[0030] Furthermore, the solvent-free polyurethane material forming the damping layer comprises two components: the first component is an isocyanate prepolymer (such as aromatic or aliphatic isocyanates, such as MDI, TDI, etc.), and the second component is a mixture of polyether polyol, bond extender, and filler. Optionally, the mass ratio of the first component to the second component in the damping layer is 7:3. Through experiments and experience, the damping layer of the above formulation can be used in the gas storage tank of a large-scale compressed air energy storage system with large temperature and pressure changes during the charging and discharging process. It can maintain high energy efficiency over a wide temperature and pressure range, and has no solvent evaporation, no bubbling, and no shrinkage, making it very suitable for compressed air energy storage systems aimed at carbon neutrality.

[0031] Furthermore, the epoxy resin material forming the constraint layer comprises two components: a first component is an amine curing agent, and a second component is a mixture of epoxy resin and filler. Optionally, the mass ratio of the first component to the second component in forming the constraint layer is 1:13 or 9:130. Through experiments and experience, the low-amine, high-filler formulation allows the epoxy resin constraint layer to maintain high stiffness while enhancing the vibration reduction efficiency of the damping layer, and also reduces process costs.

[0032] In this embodiment, when the underground artificial gas storage chamber adopts the aforementioned filling layer 3 structure, the steps for constructing the filling layer 3 on the inner wall of the concrete lining layer 2 include: First, a damping layer is constructed on the inner wall of the concrete lining layer 2, and then a restraint layer is constructed on the damping layer. Further, the thickness of the damping layer initially applied to the inner wall of the concrete lining layer 2 is between 0.8mm and 1.5mm. Then, a restraint layer is constructed on the damping layer, the thickness of which is related to the sealing layer 4.

[0033] In this embodiment, the underground artificial chamber gas storage facility has a filling layer 3 made of a pressure-induced flowable material within the concrete lining layer 2. When cracks appear in the concrete lining layer 2, the filling layer 3 on the side closest to the concrete lining layer 2 can deform and fill the crack under pressure. However, the filling layer 3 on the side away from the concrete lining layer 2 is prone to stress concentration. Stress concentration inside the gas storage facility is detrimental to its airtightness and stable operation. In this embodiment, the above problem is solved by setting a sealing layer 4 that matches the filling layer 3.

[0034] Optionally, the sealing layer 4 can be made of steel. For smaller-diameter adits or shaft-type underground gas storage chambers, the sealing layer 4 can be made of steel pipe. For large-scale gas storage facilities, the maximum diameter of existing steel pipes is insufficient to meet the needs of the storage facility. For larger-diameter adits or basement-type underground gas storage chambers, the innermost sealing layer 4 is composed of multiple steel plates spliced ​​together. The sealing layer 4 made of steel has good sealing performance and high-pressure resistance.

[0035] Optionally, in this embodiment of the underground artificial chamber gas storage facility, the sealing layer 4 is made of an elastomeric coating material, and the coating material of the sealing layer 4 is applied to the inner wall of the filling layer 3 and completely covers the inner wall of the filling layer 3. In this embodiment of the gas storage facility, the sealing layer 4 can also be made of a coating material. To cooperate with the filling layer 3 in this embodiment, the sealing layer 4 is made of an elastomeric coating material. Elastomeric coating materials have the characteristics of high elasticity, flexibility, and weather resistance, and can be directly applied to the side of the filling layer 3 away from the concrete lining layer 2. Compared with the steel plate sealing layer 4, the advantage of using a coated sealing material is lower construction cost.

[0036] Optionally, when the sealing layer 4 is an elastomer coating material, it can be a polyurea material. Further, the polyurea material forming the sealing layer 4 comprises two components: component A can be an isocyanate prepolymer (such as aromatic or aliphatic isocyanates, such as MDI, TDI, etc.). Component B can be an amino compound, such as terminal amino polyethers, amine chain extenders, etc. After components A and B are mixed at room temperature, they are cured through a rapid amino-isocyanate addition reaction to form a three-dimensional network structure elastomer. Due to the fast curing speed of the above-mentioned polyurea coating material, compared with the steel plate sealing layer 4, the polyurea coating has the advantage of faster construction speed, further reducing the construction cost of the gas storage facility.

[0037] Because underground artificial chamber gas storage facilities are built underground, large-scale replacement and maintenance are difficult once completed, and routine inspections are usually the only option. Existing compressed air energy storage power stations have a design life exceeding 30 years. Theoretically, the design life of the underground artificial chamber gas storage facility used in compressed air energy storage power stations should be consistent with the design life of the power station; otherwise, it will increase the user's subsequent operating costs.

[0038] Furthermore, in this embodiment, the underground artificial gas storage chamber's sealing layer 4 comprises steel plates and a coating material. That is, the inner wall of the sealed area formed by the splicing of steel plates is completely coated with a sealing material, and the sealed area surrounded by the sealing coating material is the gas storage area. The sealing coating material can be the aforementioned polyurea material.

[0039] In summary, the structure of an underground artificial gas storage chamber is as follows: a concrete lining layer 2 is provided within the underground surrounding rock layer 1; a filling layer 3 is located inside the concrete lining layer 2; and the filling layer 3 adopts a damping constraint composite structure. Inside the filling layer 3 is a sealing layer 4, which is constructed of spliced ​​steel plates, with the inner walls of the steel plates uniformly coated with a sealing coating material.

[0040] The construction of the aforementioned underground artificial chamber gas storage facility includes the following steps: first, a damping layer is constructed on the inner wall of the concrete lining layer 2; then, a restraint layer is constructed on the damping layer; after the filling layer 3 is completed, a steel plate layer is laid; and a sealing coating of elastomeric material is applied to the inside of the steel plate layer. Optionally, the thickness of the damping layer coated on the inner wall of the concrete lining layer 2 is between 0.8mm and 1.5mm, and the ratio of the thickness of the restraint layer to the thickness of the steel plate layer is 2:1. Through simulation testing, the design life of the aforementioned underground artificial chamber gas storage facility exceeds 30 years.

[0041] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0043] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An underground artificial cavern gas storage is constructed in the interior of a surrounding rock layer, a concrete lining layer is arranged in the interior of the surrounding rock layer, a filling layer is arranged in the interior of the concrete lining layer, a sealing layer is arranged in the interior of the filling layer, and a closed area surrounded by the sealing layer is a gas storage area; characterized in that, The filling layer is made of a material with pressure-induced fluidity, and when cracks appear in the concrete lining layer, the filling layer deforms under pressure to fill the cracks in the concrete lining layer; The filling layer is made of a coating material with pressure-induced fluidity, and the coating material of the filling layer is coated on the inner wall of the concrete lining layer and covers the inner wall of the concrete lining layer; The coating material of the filling layer adopts a damping constraint composite structure, which includes a damping layer and a constraint layer; The damping layer is made of a solvent-free polyurethane material, and the constraint layer is made of an epoxy resin material; The solvent-free polyurethane material forming the damping layer includes two components, the first component is an isocyanate prepolymer, and the second component is a mixture of polyether polyol, chain extender and filler, the mass ratio of the first component forming the damping layer to the second component forming the damping layer is 7:3; The epoxy resin material forming the constraint layer includes two components, the first component is an amine curing agent, and the second component is a mixture of epoxy resin and filler, the mass ratio of the first component forming the constraint layer to the second component forming the constraint layer is 1:13 or 9:130; The sealing layer is made of an elastomer coating material, and the coating material of the sealing layer is coated on the inner wall of the filling layer and covers the inner wall of the filling layer; the polyurea material forming the sealing layer includes two components, component A is an isocyanate prepolymer, and component B is an amino compound.

2. The underground artificial cavern gas storage of claim 1, wherein, The sealing layer is made of a steel plate layer formed by a steel material.

3. The underground artificial cavern gas storage of claim 1, wherein, The inner wall of the sealed area formed by splicing the steel plate is completely coated with a coating material with sealing property, and the sealed area surrounded by the coating material with sealing property is a gas storage area.

4. A method of constructing an underground artificial cavern gas storage according to claim 1, characterized in that, The method comprises the following steps: The filling layer is applied to the inner wall of the concrete lining layer, and when the filling layer is constructed, the damping layer is first constructed on the inner wall of the concrete lining layer, and then the constraint layer is constructed on the damping layer.

5. The method of constructing an underground artificial cavern gas storage according to claim 4, wherein The method further comprises the following steps: A steel plate layer is applied to the constraint layer, and an elastomer coating material is coated on the inside of the steel plate layer to form a sealing coating.

6. The method of constructing an underground artificial cavern gas storage according to claim 5, wherein The thickness of the damping layer coated on the inner wall of the concrete lining layer is between 0.8mm and 1.5mm, and the thickness ratio of the constraint layer to the steel plate layer is 2:1.

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