Compressed air energy storage underground cavern supporting structure, construction method and concrete proportioning method
By adopting a lining support structure design of fiber cloth layer and flexible concrete layer in the compressed air energy storage cavern, the problem of easy cracking of commercial concrete was solved, and the sealing and pressure resistance of the cavern were improved.
Patent Information
- Application Number
- CN202610503751.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-16
- Publication Date
- 2026-05-19
AI Technical Summary
Existing commercial concrete lining support structures are prone to cracking in compressed air energy storage caverns, leading to damage to the sealing layer and affecting the cavern's airtightness.
The lining support structure is designed with a fiber cloth layer and a flexible concrete layer. The flexible concrete layer is composed of P42.5 cement, water, gravel, sand, bentonite and water-reducing agent. The fiber cloth layer is fixed to the flexible concrete layer by a fiber impregnation adhesive layer, forming a structure of sealing layer, fiber cloth layer, flexible concrete layer and surrounding rock.
It improves the sealing performance of compressed air energy storage chambers, reduces or prevents the generation of cracks, ensures that the sealing layer does not suffer from cracking and damage, and enhances the pressure resistance of the structure.
Smart Images
Figure CN122061844A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of compressed air energy storage, and in particular to a support structure, construction method, and concrete mix proportioning method for an underground cavern for compressed air energy storage. Background Technology
[0002] Compressed air energy storage (CASS) boasts advantages such as large storage capacity, long storage cycle, high system efficiency, and long operational life, making it one of the most promising large-scale energy storage technologies. Specifically, CASS is analogous to installing a giant "air power bank" on the power grid. During periods of low electricity demand, it converts electrical energy into compressed air for storage, and releases this pressure during peak demand for power generation, thus becoming a stabilizer for the power grid and a crucial component of renewable energy. Structurally, the three elements constituting the underground rock-lined cavern of CASS energy storage are the sealing layer, lining, and surrounding rock. The sealing layer, typically made of steel or rubber, primarily seals the high-pressure gas. The lining, or concrete lining support structure, mainly transfers loads and protects the sealing layer. The surrounding rock bears most of the internal pressure load and is the primary load-bearer. The gas tightness of the air-storing cavern structure is a critical performance indicator for achieving effective CASS energy storage.
[0003] In existing lining support structures, commercial concrete is typically poured into the lining support structure and placed between the sealing layer and the surrounding rock, thus forming a "sealing layer-lining-surrounding rock" structure. Commercial concrete, also known as ready-mixed concrete or ready-mixed concrete, refers to concrete mixtures that are centrally mixed at a batching plant, sold as commodities, and transported to the construction site. Conventional commercial concrete has a high modulus of elasticity, weak deformation capacity, and low tensile strength. Therefore, when conventional commercial concrete is applied to compressed air storage caverns, the corresponding lining support structure is highly susceptible to cracking and the formation of cracks under high internal air pressure. This causes the sealing layer to sink into the cracks, leading to sinkholes and damage to the sealing layer, severely affecting the cavern's sealing performance. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a support structure, construction method and concrete mix proportioning method for compressed air energy storage underground caverns that can effectively improve the sealing performance of caverns.
[0005] The technical solution adopted by the present invention to solve its technical problem is: a compressed air energy storage underground cavern support structure, comprising a sealing layer, a lining support structure and surrounding rock arranged in sequence, wherein the lining support structure comprises a fiber cloth layer and a flexible concrete layer, wherein the fiber cloth layer is disposed between the sealing layer and the flexible concrete layer, and the flexible concrete layer is disposed between the fiber cloth layer and the surrounding rock.
[0006] Furthermore, the fiber cloth layer includes any one of carbon fiber cloth layer, basalt fiber cloth layer, or glass fiber cloth layer.
[0007] Furthermore, the lining support structure includes an initial support layer, which is disposed between the flexible concrete layer and the surrounding rock.
[0008] Furthermore, the flexible concrete layer comprises P42.5 cement, water, gravel, sand, bentonite, water-reducing agent, and fiber, with the mass ratio of each component being 1 : 0.56 : 0.45 : 1.36 : 0.25 : 0.03 : 0.002.
[0009] Furthermore, the fiber includes any one of polypropylene fiber, glass fiber, or carbon fiber.
[0010] Furthermore, a fiber-impregnated adhesive layer is provided on the flexible concrete layer, and the fiber cloth layer is provided on the flexible concrete layer through the fiber-impregnated adhesive layer.
[0011] The construction method for the support structure of an underground cavern for compressed air energy storage includes the following steps: a. Excavate the surrounding rock to obtain the cavern, and then uniformly install the initial support layer on the inner wall of the cavern; b. The flexible concrete layer is evenly placed on the surface of the initial support layer. When the flexible concrete layer solidifies, the surface of the flexible concrete layer is ground and the surface laitance and loose layer are removed to expose the new surface and clean the surface. c. The fiber impregnated adhesive layer is evenly applied to the surface of the flexible concrete layer, and then the fiber cloth layer is applied to the fiber impregnated adhesive layer, so that the fiber cloth layer and the flexible concrete layer are fixed together. d. The sealing layer is applied to the surface of the fiber cloth layer. Furthermore, Furthermore, in step c, the material of the fiber impregnation layer is SHB-A503 carbon fiber impregnation adhesive.
[0012] Furthermore, in step c, when the fiber cloth layer is placed on the fiber impregnated adhesive layer, a scraper is used to scrape and press the surface of the fiber cloth layer from the middle to both sides until the adhesive seeps out, so that the internal air bubbles are scraped out.
[0013] The method for mix design of flexible concrete for underground caverns used for compressed air energy storage includes the following steps: a. Determining the water-cement ratio of flexible concrete: ; In the formula: W / B is the water-cement ratio of flexible concrete. The coefficients are 0.53 and 0.2 respectively. The strength specified for concrete, expressed in MPa; The mortar strength of the cementitious material after 28 days is expressed in MPa. When no measured value is available, , The coefficient is 0.6, where The compressive strength of cement mortar after 28 days. , This is the redundancy factor for the cement strength grade. Take 1.16, The cement strength grade (MPa) is taken as 42.5 MPa. b. Determining the water content of flexible concrete: When an additive is added, m = m' (1-β); Where: m is the water consumption per cubic meter of concrete, in kilograms per cubic meter; m' is the water consumption per cubic meter of concrete without admixtures, in kilograms per cubic meter, with a value of 220 kilograms per cubic meter; The water reduction rate of the admixture is taken as 20%. When using fine sand, the water consumption per cubic meter of concrete should be increased by 5 kg to 10 kg based on the previous method. c. Determining the dosage of cementitious materials in flexible concrete: C = m / (W / B) In the formula: C is the amount of cementitious material used, m is the water used per cubic meter of concrete; W / B is the water-cement ratio of flexible concrete; d. Determination of the dosage of admixtures for flexible concrete:
[0014] In the formula: G is the dosage of flexible concrete admixture, and C is the dosage of cementitious material. The dosage of the admixture is specified, wherein the water reduction rate of the admixture is at least 20%. e. Complete the mix design of flexible concrete and produce flexible concrete.
[0015] The beneficial effects of this invention are: The lining support structure is designed to include a fiber cloth layer and a flexible concrete layer. Firstly, because flexible concrete has a low modulus of elasticity and tensile strength similar to existing commercial concrete, the modulus of elasticity of the lining support structure can be lowered. Under internal pressure, it can release some radial displacement, reducing tensile stress and minimizing or preventing the formation of new cracks. This addresses the problem of large and unpredictable crack depth and width in existing commercial concrete under high internal pressure. Secondly, by bonding a fiber cloth layer to the surface of the flexible concrete layer, the strong resistance to deformation of the fiber cloth ensures that even if cracks appear in the flexible concrete layer, the sealing layer will not collapse. Through the organic synergy of the flexible concrete layer and the fiber cloth layer, effective control of cracks in the lining support structure is achieved under high internal pressure conditions, thus ensuring the airtightness of the cavern.
[0016] This invention is applicable to the support structure of underground caverns for compressed air energy storage. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of one embodiment of the compressed air energy storage underground cavern support structure of the present invention.
[0018] The layers in the diagram are labeled as follows: 1. Sealing layer; 2. Fiber cloth layer; 3. Flexible concrete layer; 4. Initial support layer; 5. Surrounding rock. Detailed Implementation
[0019] The invention will be further described below with reference to the accompanying drawings.
[0020] like Figure 1This illustration shows an embodiment of the support structure for an underground cavern with compressed air energy storage. After the surrounding rock 5 is excavated, a cavern is formed. First, an initial support layer 4 is uniformly installed on the inner wall of the cavern. This initial support layer 4 can be formed by sprayed concrete, steel arches, and anchor bolts, creating a temporary support system to ensure safety and stability. Subsequently, a flexible concrete layer 3 is installed on the initial support layer 4, serving as a secondary lining to support the cavern. When the flexible concrete layer 3 solidifies, its surface is ground to remove surface laitance and loose layers, exposing a new surface, which is then cleaned. Then, a fiber cloth layer 2 is installed on the inner wall of the flexible concrete layer 3. In this embodiment, the fiber cloth layer 2 is carbon fiber cloth. The carbon fiber cloth is adhered to the inner wall of the flexible concrete layer 3 using SHB-A503 carbon fiber impregnated adhesive. SHB-A503 carbon fiber impregnating adhesive is a two-component modified epoxy structural adhesive (A:B) primarily used for bonding carbon fiber sheets and other materials. It is widely used in reinforcement projects for concrete, masonry, and wood structures. In practical application, SHB-A503 carbon fiber impregnating adhesive should be mixed according to an A:B ratio of 2:1. It is crucial to prepare only small batches at a time, mixing only the amount needed for immediate use, and stirring thoroughly until the color is uniform and no air bubbles are generated. Apply the thoroughly mixed SHB-A503 carbon fiber impregnating adhesive evenly to the surface of the flexible concrete layer 3, using a roller, to the substrate surface of the area to be bonded. Then, the carbon fiber cloth is cut to a suitable size and pasted onto the surface of the flexible concrete layer 3. A roller is used to repeatedly roll along the fiber direction of the carbon fiber cloth to remove air bubbles and ensure that the SHB-A503 carbon fiber impregnating adhesive fully penetrates the cloth. A scraper is then used to scrape and press the surface of the carbon fiber cloth from the center outwards until the SHB-A503 adhesive seeps out, removing air bubbles and ensuring complete wetting. After the carbon fiber cloth is pasted, another layer of SHB-A503 carbon fiber impregnating adhesive is applied to ensure full coverage of the cloth surface. After the carbon fiber cloth is pasted, the construction of both the flexible concrete layer 3 and the carbon fiber cloth in the lining support structure is complete. Finally, a sealing layer 1 is applied to the inner wall of the carbon fiber cloth to ensure the airtightness of the tunnel. The sealing layer 1 can be a steel plate or rubber. Thus, as... Figure 1 As shown, the surrounding rock 5 forms a structure from the inside out consisting of a sealing layer 1, a fiber cloth layer 2, a flexible concrete layer 3, and an initial support layer 4. In actual construction, the flexible concrete used in the flexible concrete layer 3 comprises P42.5 cement (515 kg / m³). 3 ), water (290kg / m 3 ), gravel (230kg / m 3 ), sand (700 kg / m³) 3), bentonite (130kg / m 3 ), water-reducing agent (15kg / m³) 3 ) and fiber (0.91kg / m 3 The mass ratio of each component is 1 : 0.56 : 0.45 : 1.36 : 0.25 : 0.03 : 0.002. The fibers in the flexible concrete layer 3 include any one of polypropylene fiber, glass fiber, or carbon fiber. The prepared flexible concrete has an elastic modulus of 4 GPa, a compressive strength of approximately 30 MPa, and a tensile strength of 1.6 MPa.
[0021] When proportioning the various components of flexible concrete, the following steps can be followed: a. Determining the water-cement ratio of flexible concrete: ; In the formula: W / B is the water-cement ratio of flexible concrete. The coefficients are 0.53 and 0.2 respectively. The strength specified for concrete, expressed in MPa; The mortar strength of the cementitious material after 28 days is expressed in MPa. When no measured value is available, , The coefficient is 0.6, where The compressive strength of cement mortar after 28 days. , This is the redundancy factor for the cement strength grade. Take 1.16, The cement strength grade (MPa) is taken as 42.5 MPa. b. Determining the water content of flexible concrete: When an additive is added, m = m' (1-β); Where: m is the water consumption per cubic meter of concrete, in kilograms per cubic meter; m' is the water consumption per cubic meter of concrete without admixtures, in kilograms per cubic meter, with a value of 220 kilograms per cubic meter; The water reduction rate of the admixture is taken as 20%. When using fine sand, the water consumption per cubic meter of concrete should be increased by 5 kg to 10 kg based on the previous method. c. Determining the dosage of cementitious materials in flexible concrete: C = m / (W / B) In the formula: C is the amount of cementitious material used, m is the water used per cubic meter of concrete; W / B is the water-cement ratio of flexible concrete; d. Determination of the dosage of admixtures for flexible concrete: ; In the formula: G is the dosage of flexible concrete admixture, and C is the dosage of cementitious material. The dosage of the admixture is specified, wherein the water reduction rate of the admixture is at least 20%. e. The main function of bentonite is to reduce the elastic modulus of concrete and improve its density and stability. The bentonite content should not be too high, as excessive bentonite content leads to lower concrete strength and consequently reduces its mechanical properties. Generally, the bentonite content can account for 1 / 4 of the total weight of the cementitious materials (including bentonite and cement). The sand ratio is related to the water-cement ratio (W / B) and the maximum aggregate size. For underwater concrete with a water-cement ratio of 0.4, when using pebbles with a maximum size of 40mm, the recommended sand ratio range is 24% to 30%; when using concrete with only one type of coarse aggregate, the sand ratio should be increased. Prepare the mix according to the calculated proportions and test the performance of the resulting flexible concrete. Based on the test results of strength and elastic modulus, adjust the water-cement ratio and bentonite content accordingly. Based on the benchmark mix proportion, the water-cement ratio, bentonite content, and water content can be increased or decreased slightly to design multiple mix proportions, which are then adjusted and corrected. Subsequently, test blocks are made from multiple mix proportions, cured to the standard strength of 28 days, and tested to select the flexible concrete mix proportion that meets the requirements and produce the required flexible concrete.
Claims
1. A compressed air storage underground cavern support structure, comprising a sealing layer (1), a lining support structure, and surrounding rock (5) arranged sequentially, characterized in that: The lining support structure includes a fiber cloth layer (2) and a flexible concrete layer (3). The fiber cloth layer (2) is disposed between the sealing layer (1) and the flexible concrete layer (3), and the flexible concrete layer (3) is disposed between the fiber cloth layer (2) and the surrounding rock (5).
2. The compressed gas storage underground cavern support structure as described in claim 1, characterized in that: The fiber cloth layer (2) includes any one of carbon fiber cloth layer, basalt fiber cloth layer or glass fiber cloth layer.
3. The compressed gas storage underground cavern support structure as described in claim 1 or 2, characterized in that: The lining support structure includes an initial support layer (4), which is disposed between the flexible concrete layer (3) and the surrounding rock (5).
4. The compressed gas storage underground cavern support structure as described in claim 1 or 2, characterized in that: The flexible concrete layer (3) consists of P42.5 cement, water, gravel, sand, bentonite, water-reducing agent and fiber, with the mass ratio of each component being 1:0.56:0.45:1.36:0.25:0.03:0.
002.
5. The compressed air energy storage underground cavern support structure as described in claim 4, characterized in that: The fiber includes any one of polypropylene fiber, glass fiber, or carbon fiber.
6. The compressed gas storage underground cavern support structure as described in claim 1 or 2, characterized in that: A fiber impregnated adhesive layer is provided on the flexible concrete layer (3), and the fiber cloth layer (2) is provided on the flexible concrete layer (3) through the fiber impregnated adhesive layer.
7. A construction method for the support structure of an underground compressed air storage cavern, comprising the support structure for an underground compressed air storage cavern as described in any one of claims 1 to 6, characterized in that, Includes the following steps: a. Excavate the surrounding rock (5) to obtain a tunnel, and then uniformly install an initial support layer (4) on the inner wall of the tunnel. b. The flexible concrete layer (3) is evenly placed on the surface of the initial support layer (4). When the flexible concrete layer (3) solidifies, the surface of the flexible concrete layer (3) is ground and the surface laitance and loose layer are removed to expose the new surface and clean the surface. c. The fiber impregnated adhesive layer is evenly placed on the surface of the flexible concrete layer (3), and then the fiber cloth layer (2) is placed on the fiber impregnated adhesive layer and the fiber cloth layer (2) and the flexible concrete layer (3) are fixed together. d. Place the sealing layer (1) on the surface of the fiber cloth layer (2).
8. The construction method for the support structure of the compressed air energy storage underground cavern as described in claim 7, characterized in that: In step c, the material of the fiber impregnation layer is SHB-A503 carbon fiber impregnation adhesive.
9. The construction method for the support structure of the compressed air storage underground cavern as described in claim 7, characterized in that: In step c, when the fiber cloth layer (2) is placed on the fiber impregnated adhesive layer, a scraper is used to scrape and press the surface of the fiber cloth layer (2) from the middle to both sides until the adhesive seeps out, so that the internal air bubbles are scraped out.
10. A flexible concrete mix design method for underground caverns used for compressed air energy storage, characterized in that, Includes the following steps: a. Determining the water-cement ratio of flexible concrete: ； In the formula: W / B is the water-cement ratio of flexible concrete. The coefficients are 0.53 and 0.2 respectively. The strength specified for concrete, expressed in MPa; The mortar strength of the cementitious material after 28 days is expressed in MPa. When no measured value is available, , The coefficient is 0.6, where The compressive strength of cement mortar after 28 days. , This is the redundancy factor for the cement strength grade. Take 1.16, The cement strength grade (MPa) is taken as 42.5 MPa. b. Determining the water content of flexible concrete: When an additive is added, m = m' (1-β); Where: m is the water consumption per cubic meter of concrete, in kilograms per cubic meter; m' is the water consumption per cubic meter of concrete without admixtures, in kilograms per cubic meter, with a value of 220 kilograms per cubic meter; The water reduction rate of the admixture is taken as 20%. When using fine sand, the water consumption per cubic meter of concrete should be increased by 5 kg to 10 kg based on the previous method. c. Determining the dosage of cementitious materials in flexible concrete: C = m / (W / B) In the formula: C is the amount of cementitious material used, m is the water used per cubic meter of concrete; W / B is the water-cement ratio of flexible concrete; d. Determination of the dosage of admixtures for flexible concrete: ； In the formula: G is the dosage of flexible concrete admixture, and C is the dosage of cementitious material. The dosage of the admixture is specified, wherein the water reduction rate of the admixture is at least 20%. e. Complete the mix design of flexible concrete and produce flexible concrete.