A compressed air energy storage chamber surrounding rock-structure interface air tightness testing device and method

Abstract

The application discloses a kind of compressed air energy storage chamber surrounding rock-structure interface air tightness testing device and method, it is characterized in that, including shell, concrete air plug, in the shell pouring concrete, and cavity is formed in concrete, and the cavity is cooperated with concrete air plug, and forms self-gas storage chamber below concrete air plug, on the concrete air plug installation gas injection pipeline, gas injection pipeline can inject gas into the self-gas storage chamber, high-pressure air compressor and high-pressure gas cylinder are connected at the end of gas injection pipeline, and gas valve and flowmeter are installed;Sealing plate is arranged in the surface of gas injection pipeline and self-gas storage chamber contact, sealing steel plate is arranged in the top of shell, and sealing steel plate is formed with closed area with concrete, concrete air plug top, the closed area is installed with air pressure sensor.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, specifically to a device and method for testing the airtightness of the surrounding rock-structure interface of a compressed air energy storage chamber. Background Technology

[0002] New energy sources such as wind and solar power are inherently unstable and require energy storage technology for regulation to achieve large-scale grid connection. Compressed air energy storage (CAS), as a large-scale mechanical energy storage technology, stores potential energy in compressed air and releases it when needed to drive turbines for power generation. This effectively regulates the instability of new energy power generation and increases the proportion of renewable energy. The main form of CAS is underground gas storage caverns. Specifically, current CAS technology still faces several challenges in engineering applications:

[0003] 1) The quality of the surrounding rock of the gas storage cave is uneven, with local fracture zones, resulting in poor sealing performance of the gas storage cave and serious leakage of the stored compressed air.

[0004] 2) The fit between the surrounding rock and the air plug is not good, and the compressive strength and elasticity of the sealing material are difficult to adapt to the deformation of the surrounding rock, resulting in poor long-term sealing effect;

[0005] 3) The existing air plug structure has poor design rationality, limited pressure resistance, and short service life;

[0006] 4) There is a lack of effective monitoring methods to monitor the sealing performance of gas storage caverns in real time;

[0007] 5) There is no suitable experimental equipment to simulate the working environment and conditions of the gas storage cavern, which makes it difficult to improve the sealing technology.

[0008] 6) During gas storage, changes in temperature and pressure can affect the stability of the surrounding rock, but the mechanism of this effect is still unclear.

[0009] 7) Groundwater can corrode gas storage caverns and gas pipelines, so it is necessary to strengthen waterproofing and anti-corrosion measures.

[0010] 8) The cave's interior space is enormous, and the gases are not fully mixed;

[0011] 7) The potential impact of trace gas leakage during storage on the environment and health lacks systematic research. Summary of the Invention

[0012] The purpose of this invention is to overcome the lack of research on the long-term airtightness of underground compressed air storage caverns in existing technologies, and to provide a device and method for testing the airtightness of the surrounding rock-structure interface of compressed air energy storage chambers, capable of simulating the underground gas storage environment. This device can establish different pressure working environments to simulate the confining pressure force and its consequences on deep rock caused by high-pressure gas. By applying different pressures and monitoring the sealing performance parameters of the gas plugs in real time, the influence of confining pressure and storage time on the gas plug sealing performance can be systematically studied. This provides important reference for the selection and optimization of gas plugs and interface sealing measures in underground compressed air storage facilities, thereby improving the safety and economy of compressed air energy storage technology.

[0013] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0014] In a first aspect, embodiments of the present invention provide a test device for the airtightness of the surrounding rock-structure interface of a compressed air storage chamber capable of simulating an underground gas storage environment. The device includes a shell and a concrete air plug. Concrete is poured inside the shell, forming a cavity within the concrete. This cavity mates with the concrete air plug, forming a gas storage chamber below the air plug. An injection pipeline is installed on the concrete air plug, capable of injecting gas into the gas storage chamber. A high-pressure air compressor and a high-pressure gas cylinder are connected to the end of the injection pipeline, and a valve, a pressure sensor, and a flow meter are installed thereon. An anti-misalignment steel plate is installed at the connection between the upper end of the air plug and the injection pipeline, and an anti-leakage steel plate is installed at the connection between the lower end of the air plug and the injection pipeline. The steel plate on the surface where the injection pipeline contacts the gas storage chamber is called the anti-leakage steel plate. A sealing steel plate is installed on the top of the shell, forming a closed area with the concrete and the top of the concrete air plug. A pressure sensor is installed in this closed area.

[0015] As a further technical solution, the shell is a steel cylinder, and the inner wall of the steel cylinder is made of the same material as the outer shell and has been densified to simulate the stiffness under deep stress environment.

[0016] As a further technical solution, the concrete air plug is shaped like two conical frustums joined together, with the area of ​​the upper conical frustum increasing from top to bottom and the area of ​​the lower conical frustum increasing from bottom to top. The area of ​​the upper and lower bases of the concrete air plug is the same as the area of ​​the air storage chamber.

[0017] As a further technical solution, the concrete air plug sidewall can be grooved to simulate different roughness.

[0018] As a further technical solution, a displacement sensor is also installed on the top of the concrete air plug to detect changes in the air plug displacement under different air pressures.

[0019] Secondly, the present invention also provides a test device for the airtightness of the surrounding rock-structure interface of a compressed air energy storage chamber, comprising a shell and an air plug. A first steel block and a second steel block are cast inside the shell, and cavities are formed inside the first steel block and the second steel block. The cavities cooperate with the air plug to form an air storage chamber below the air plug. An injection pipeline is installed on the air plug, which can inject gas into the air storage chamber. A high-pressure air compressor and a high-pressure gas cylinder are connected to the end of the injection pipeline, and an air valve and a flow meter are installed thereon. A sealing plate is provided on the surface of the injection pipeline in contact with the air storage chamber. A sealing steel plate is provided on the top of the shell. The sealing steel plate, the first steel block, and the top of the air plug form a closed area, and a pressure sensor is installed in the closed area.

[0020] As a further technical solution, the side of the air plug is made of epoxy resin and sand of different particle sizes to simulate rock cracks with different roughness, which further improves the interfacial adhesion and achieves a tight fit with the steel block.

[0021] As a further technical solution, the concrete air plug is shaped like two conical frustums joined together, with the area of ​​the upper conical frustum increasing from top to bottom and the area of ​​the lower conical frustum increasing from bottom to top. The area of ​​the upper and lower bases of the concrete air plug is the same as the area of ​​the air storage chamber.

[0022] As a further technical solution, a displacement sensor is also installed on the top of the concrete air plug to detect changes in the air plug displacement under different air pressures.

[0023] The test method for the above-mentioned air tightness test device for the surrounding rock-structure interface of the compressed gas energy storage chamber is as follows:

[0024] Step 1. Check that all connections of the test apparatus are secure; open the air valve, turn on the air compressor switch, and slowly fill the unfilled air storage chamber with compressed air through the air injection line; at the same time, observe the real-time reading changes of the pressure display screen, and record the pressure and time data of the pressure sensor and flow meter, as well as the air injection volume;

[0025] Step 2. When the pressure display reading reaches the preset value, immediately turn off the compressor switch, cut off the gas supply, stop the gas filling, and close the gas valve; conduct the test and observe the change in gas pressure in the gas storage chamber; the average leakage rate and leakage amount are obtained through the changes in the pressure sensor and flow meter;

[0026] Step 3. Calculate the leakage within the set time. Confirm that the pressure in the air storage chamber is stable at the preset value and that the leakage at the interface between the air plug and the concrete or steel block is less than the first set value within the set time. Continue to increase the atmospheric pressure to carry out the test. Start the air compressor loading system, open the air valve, and increase the pressure by the second set value for each stage until the maximum pressure value is reached. After each stage of pressure is maintained at a set time and the gas leakage is less than the first set value, increase the pressure to the next stage.

[0027] Step 4. During the set time of each pressure level, record the real-time reading of the pressure display screen, and at the same time record the real-time data of the displacement sensor, air pressure sensor, flow meter, and air pressure sensor.

[0028] Step 5. Plot the data change curves of each sensor based on the test records, and calculate the deformation and leakage rate of the air plug.

[0029] The beneficial effects of the above embodiments of the present invention are as follows:

[0030] This device offers a novel approach to testing the airlock sealing performance of underground compressed air storage facilities, enabling realistic simulation of the impact of the underground gas storage environment on the airlock. Previous testing methods could not establish working environments at different pressures, leading to discrepancies between test results and actual usage conditions. This device, however, applies different pressures through a loading system, progressively simulating the confining pressure of rock layers at different depths. It is simple, convenient, and quick to operate, and can systematically acquire the airlock's sealing parameters under varying pressures. The test results provide crucial references for airlock selection and design optimization, significantly improving the safety and economy of compressed air energy storage technology.

[0031] This device employs a gas injection loading system to apply different gas pressures in stages, overcoming the challenge of existing devices failing to fully simulate underground gas storage environments. This avoids significant discrepancies between test results and actual conditions, making the gas plug sealing performance test more closely resemble real-world usage. Unlike direct hydraulic loading, this device allows for flexible adjustment of different pressure levels through a high-pressure gas injection loading system, obtaining the gas plug's sealing parameters at each pressure level. Operation is simple and convenient; by altering the pressure distribution of the loading system, the most unfavorable operating conditions for gas plug testing can be achieved. Compared to field testing, this device offers a more systematic, accurate, and controllable testing method, forming a scientifically sound approach to testing gas plug sealing performance.

[0032] The device employs a modular design, facilitating easy assembly of components, ensuring a high safety factor, and enabling it to withstand pressures exceeding the design load. It simulates various extreme operating conditions of the air plug during use. By varying the pressure level and distribution of the high-pressure injection loading system, the sealing performance of the air plug under different pressure and deformation conditions can be analyzed, determining the key control parameters for air plug design. This device can evaluate the sealing reliability of air plugs at different pressure levels, providing important reference for air plug selection and design optimization in underground gas storage facilities, and improving the air plug sealing performance evaluation system in the field of compressed air energy storage technology.

[0033] Based on the sealing performance parameters of the air plugs obtained by this device under various operating conditions, the sealing reliability level of the air plugs can be classified according to their actual size and operating environment, and corresponding preventive measures can be formulated, such as optimized air plug design and improved manufacturing process requirements. Through testing with this device, the influence of pressure and time on air plug sealing performance can be quantitatively obtained, providing a basis for evaluating the sealing performance of air plug interfaces and a reference for the selection and engineering application of air plugs in underground gas storage facilities. This enables proactive prevention of air plug sealing failures, ensuring the safe and reliable operation of underground compressed air energy storage projects. Attached Figure Description

[0034] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation thereof.

[0035] Figure 1 This is a cross-sectional view of the experimental design schematic diagram for Example 1.

[0036] Figure 2 This is a top view of the experimental design.

[0037] Figure 3 This is a cross-sectional view of the experimental design schematic diagram for Example 2.

[0038] The components include: 1. Shell; 2. Concrete air plug at the rock interface; 3. Pressure sensor and flow meter; 4. Valve; 5. Air storage chamber; 6. Air plug; 7. Upper steel plate; 8. Lower steel plate; 9. Pouring concrete; 10. Air injection pipeline; 11. Enclosed area; 12. Pressure sensor; 13. Area for binding the reinforcing cage; 14. Second steel block; 15. First steel block; 16. Displacement sensor; 17. Interface between the upper and lower steel blocks. Detailed Implementation

[0039] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0040] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0041] As introduced in the background section, the structure and airtightness of the storage chamber affect the storage loss of compressed air, but the quantitative relationship between the two is not yet clear. To address the above issues, this embodiment proposes a device for studying the airtightness of compressed air energy storage chambers, filling the gap in compressed air energy storage airtightness testing and helping to improve the airtightness level of underground compressed air energy storage.

[0042] This embodiment discloses a compressed air energy storage chamber sealing performance research device, comprising an adjustable-volume air storage chamber, a pressure loading system, a pressure detection system, and a data acquisition system. The air storage chamber simulates an underground chamber structure and stores compressed air inside. The loading system is used to fill the air storage chamber with air to a set pressure. The detection system monitors pressure changes within the chamber. The data acquisition system records pressure decay over time to evaluate the airtightness of the air storage chamber. This device can obtain compressed air sealing performance data under a chamber structure, establish a quantitative correlation model between structural parameters and airtightness, and optimize the design of underground compressed air storage facilities.

[0043] Example 1:

[0044] like Figure 1 , Figure 2 As shown, the experimental device disclosed in this embodiment includes a housing 1 and an air plug 6. A cavity is formed inside the housing 1, which is filled with concrete, and a cavity is formed within the concrete. This cavity mates with the air plug 6, forming a gas storage chamber 5 below the air plug 6. An injection pipe 10 is installed on the air plug 6, which can inject gas into the gas storage chamber 5. A high-pressure air compressor and a high-pressure gas cylinder are connected to the end of the injection pipe 10, and an air valve 4 and a flow meter 3 are installed thereon. A sealing plate 8 is provided on the surface of the injection pipe 10 that contacts the gas storage chamber 5, and a sealing steel plate is provided on the top of the housing 1. The sealing steel plate, the concrete, and the top of the air plug form a closed area, and a pressure sensor is installed in the closed area. Based on this device, the sealing performance parameters of the air plug under various working conditions can be obtained. The sealing reliability level of the air plug can be classified according to the actual size of the air plug and the usage environment, and corresponding preventive measures can be formulated, such as optimizing the design of the air plug and improving the manufacturing process requirements. The testing using this device allows for the quantitative determination of the influence of pressure and time on the sealing performance of airlocks, providing a basis for evaluating the sealing performance of airlock interfaces and a reference for the selection and engineering application of airlocks in underground gas storage facilities. This enables proactive prevention of airlock sealing failures, ensuring the safe and reliable operation of underground compressed air energy storage projects.

[0045] Specifically, in this embodiment, the outer shell is a steel cylinder 1 with a diameter of 0.4 meters and a height of 1.0 meter. The inner wall of the steel cylinder is made of the same material as the outer shell and has been densified to simulate the stiffness under deep stress environment.

[0046] In this embodiment, the concrete air plug 6 is cast separately and contains an injection pipeline 10 and an upper steel plate 7 to prevent misalignment and slippage of the pipeline. The injection pipeline 10 passes through the upper steel plate 7. The injection pipeline 10 is made of steel pipe and extends upward from the center of the air storage chamber 5. The upper end of the injection pipeline 10 is connected to a high-pressure air compressor and a high-pressure gas cylinder. It is also equipped with an air valve 4, a pressure sensor 12, and a flow meter 3 to monitor the air pressure inside the air storage chamber 5. The lower end of the injection pipeline 10 is the injection end, which leads into the air storage chamber 5. The entire injection pipeline 10 is fixedly connected to the air storage chamber 5 by multiple circular steel plates with a diameter slightly smaller than that of the air storage chamber. The purpose of the upper steel plate 7 is to prevent the injection pipeline 10 from misalignment and slippage under air pressure. The purpose of the lower steel plate 8 is to prevent high-pressure gas from leaking from the interface between the injection pipeline 10 and the inside of the concrete plug 6, ensuring that the simulated surrounding rock and air plug interface 2 is the only leakage channel.

[0047] Furthermore, the air plug 6 is shaped like two conical frustums joined together, with the area of ​​the upper frustum increasing from top to bottom, and the area of ​​the lower frustum increasing from bottom to top. The overall height of the air plug 6 is 0.8 meters, the diameter of each end face is 0.1 meters, and the area of ​​the upper and lower bases is the same as that of the air storage chamber 5. The top surface of the air plug 6 is 0.05 meters from the top of the steel cylinder. The concrete strength grade of the air plug is C50.

[0048] Furthermore, grooves can be engraved on the sidewalls of the air plug 6 to simulate different roughnesses. The surface roughness calculation method involves converting the surface to a plane based on the groove depth and width, and then calculating using a 3D laser scanner or the sand-filling method. In the sand-filling method, fine sand is evenly spread on the rough surface, and the roughness Ra is obtained by dividing the sand volume by the surface area of ​​the rock sidewall.

[0049] Furthermore, the gas storage chamber 5 is shaped as a cylinder with a diameter of 0.1 meters and a height of 0.05 meters, with its bottom surface 0.15 meters away from the bottom of the steel cylinder 1.

[0050] Furthermore, during construction, a reinforcing cage is lowered into area 13 at the bottom of the cylinder. Wooden formwork is then placed on top of the reinforcing cage. An air plug 6 is fixed to the designed position above the wooden formwork using an overhead crane. Concrete is then poured into areas 13 and 14 sequentially, and after 7 days of curing, testing can begin.

[0051] A steel plate is used to enclose area 11, and a pressure sensor 12 is installed to collect leaked gas and read the gas pressure in the enclosed area 11. A displacement sensor 16 is installed on the upper part of the air plug 6 to analyze the displacement changes of the air plug under different gas pressures.

[0052] This device employs a gas injection loading system to apply different gas pressures in stages, overcoming the challenge of existing devices failing to fully simulate underground gas storage environments. This avoids significant discrepancies between test results and actual conditions, making the gas plug sealing performance test more closely resemble real-world usage. Unlike direct hydraulic loading, this device allows for flexible adjustment of different pressure levels through a high-pressure gas injection loading system, obtaining the gas plug's sealing parameters at each pressure level. Operation is simple and convenient; by altering the pressure distribution of the loading system, the most unfavorable operating conditions for gas plug testing can be achieved. Compared to field testing, this device offers a more systematic, accurate, and controllable testing method, forming a scientifically sound approach to testing gas plug sealing performance.

[0053] Example 2:

[0054] like Figure 3 As shown, this embodiment also provides a test device for the air tightness of the surrounding rock-structure interface of a compressed air storage chamber. The difference between the test device for the air tightness of the surrounding rock-structure interface of a compressed air storage chamber disclosed in this embodiment and that in embodiment 1 is that a second steel block 14 and a first steel block 15 are used to simulate hard rock, replacing the concrete pouring process in embodiment 1. Epoxy resin glue and sand of different particle sizes are used on the side of the air plug 6 to simulate rock cracks of different roughness, further improving the interface adhesion and achieving a tight fit with the second steel block 14 and the first steel block 15.

[0055] During construction, the custom-made first steel block 14 below the gas plug's turning angle is first placed in the housing 1. Then, the gas plug 6 is fixed to its designed position above the gas storage chamber using an overhead crane. Epoxy resin is applied around the gas plug 6, and sand is sprayed on top. Epoxy resin is then applied to the top surface of the second steel block 14 in the housing 1, the bottom surface of the remaining first steel block 15 to be installed, and the inner surface that contacts the gas plug 6. Next, the remaining first steel block 15 is hoisted into the housing 1, completing the installation.

[0056] Example 3

[0057] This embodiment proposes a testing method based on the air tightness testing device for the surrounding rock-structure interface of the compressed gas storage chamber disclosed in Embodiment 1 or Embodiment 2:

[0058] 1. Check that all connections of the test apparatus are secure. Open air valve 4, turn on the air compressor switch, and slowly inject compressed air into the unfilled air storage chamber 5 through the air injection line 10. At the same time, observe the real-time reading changes on the pressure display screen, and record the pressure and time data of the pressure sensor and flow meter 3, as well as the air injection volume.

[0059] 2. When the pressure display reading reaches the preset value of 0.5 MPa, immediately turn off the compressor switch, cut off the gas supply, stop the gas filling, and close the gas valve 4. Conduct the test and observe the pressure change in the gas storage chamber 5. The average leakage rate and leakage volume are obtained through the pressure sensor and flow meter 3.

[0060] 3. Calculate the 24-hour air leakage. After confirming that the pressure in the air storage chamber 5 is stable at 0.5 MPa and the air leakage at the interface between the concrete air plug 6 and the surrounding rock or steel block is less than 1% after 24 hours, continue to increase the atmospheric pressure to carry out the test. Start the air compressor loading system, open the air valve 4, and increase the pressure by 0.5 MPa at each stage until the maximum pressure of 10 MPa is reached. Maintain the gas leakage at each stage for 24 hours until it is less than 1% before increasing to the next stage.

[0061] 4. During the 24-hour period of each pressure level, record the real-time reading of the pressure display screen, and simultaneously record the real-time data of displacement sensor 16, air pressure sensor, flow meter 3, and air pressure sensor 12.

[0062] 5. Plot the data change curves of each sensor based on the test records, and calculate the deformation and leakage rate of the air plug.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. All modifications and variations that do not conform to the spirit and principles of the invention are permitted.

[0064] Any modifications, equivalent substitutions, improvements, etc., made within this scope shall be included within the protection scope of this invention.

Claims

1. A device for testing the airtightness of the surrounding rock-structure interface of a compressed air energy storage chamber, characterized in that, The device includes a shell and a concrete air plug. Concrete is poured inside the shell, forming a cavity that mates with the concrete air plug, creating an air storage chamber below the air plug. An injection pipe is installed on the concrete air plug, allowing gas to be injected into the air storage chamber. A high-pressure air compressor and a high-pressure gas cylinder are connected to the end of the injection pipe, and a valve, a pressure sensor, and a flow meter are installed thereon. An anti-misalignment steel plate is installed at the connection between the upper end of the air plug and the injection pipe, and an anti-leakage steel plate is installed at the connection between the lower end of the air plug and the injection pipe. A sealing steel plate is installed on the top of the shell, forming a closed area with the concrete and the top of the concrete air plug. A pressure sensor is installed in this closed area.

2. The airtightness testing device for the surrounding rock-structure interface of a compressed air energy storage chamber as described in claim 1, characterized in that, The shell is a steel cylinder, and the inner wall of the steel barrel is made of the same material as the shell and has been densified.

3. The airtightness testing device for the surrounding rock-structure interface of a compressed air energy storage chamber as described in claim 1, characterized in that, The concrete air plug is shaped like two conical frustums joined together. The area of ​​the upper conical frustum increases from top to bottom, and the area of ​​the lower conical frustum increases from bottom to top. The area of ​​the upper and lower bases of the concrete air plug is the same as the area of ​​the air storage chamber.

4. The airtightness testing device for the surrounding rock-structure interface of a compressed air energy storage chamber as described in claim 1, characterized in that, The concrete air plug has grooves cut into its sidewalls to simulate different roughness levels.

5. The airtightness testing device for the surrounding rock-structure interface of a compressed air energy storage chamber as described in claim 1, characterized in that, A displacement sensor is also installed on the top of the concrete air plug to detect changes in air plug displacement under different air pressures.

6. A device for testing the airtightness of the surrounding rock-structure interface of a compressed air energy storage chamber, characterized in that, The device includes a housing and an air plug. A first steel block and a second steel block are cast inside the housing, and cavities are formed within the first and second steel blocks. These cavities cooperate with the air plug to form an air storage chamber below the air plug. An injection pipe is installed on the air plug, which can inject gas into the air storage chamber. A high-pressure air compressor and a high-pressure gas cylinder are connected to the end of the injection pipe, and an air valve and a flow meter are installed thereon. A sealing plate is provided on the surface of the injection pipe that contacts the air storage chamber. A sealing steel plate is provided on the top of the housing. The sealing steel plate, the first steel block, and the top of the air plug form a closed area, and a pressure sensor is installed in the closed area.

7. The airtightness testing device for the surrounding rock-structure interface of a compressed air energy storage chamber as described in claim 6, characterized in that, The sides of the air plug are made of epoxy resin and sand of different particle sizes to simulate rock cracks with different roughness.

8. The airtightness testing device for the surrounding rock-structure interface of a compressed air energy storage chamber as described in claim 6, characterized in that, The gas plug is shaped like two conical frustums joined together. The area of ​​the upper conical frustum increases from top to bottom, and the area of ​​the lower conical frustum increases from bottom to top. The area of ​​the upper and lower bases of the gas plug is the same as the area of ​​the gas storage chamber.

9. The airtightness testing device for the surrounding rock-structure interface of a compressed air energy storage chamber as described in claim 6, characterized in that, A displacement sensor is also installed on the top of the air plug to detect changes in air plug displacement under different air pressures.

10. The test method for the airtightness testing device of the surrounding rock-structure interface of the compressed gas energy storage chamber as described in any one of claims 1-9, characterized in that, Step 1. Check that all connections of the test apparatus are secure; open the air valve, turn on the air compressor switch, and slowly fill the unfilled air storage chamber with compressed air through the air injection line; at the same time, observe the real-time reading changes of the pressure display screen, and record the pressure and time data of the pressure sensor and flow meter, as well as the air injection volume; Step 2. When the pressure display reading reaches the preset value, immediately turn off the compressor switch, cut off the gas supply, stop the gas filling, and close the gas valve; conduct the test and observe the change in gas pressure in the gas storage chamber; the average leakage rate and leakage amount are obtained through the changes in the pressure sensor and flow meter; Step 3. Calculate the leakage within the set time. Confirm that the pressure in the air storage chamber is stable at the preset value and that the leakage at the interface between the air plug and the concrete or steel block is less than the first set value within the set time. Continue to increase the atmospheric pressure to carry out the test. Start the air compressor loading system, open the air valve, and increase the pressure by the second set value for each stage until the maximum pressure value is reached. After each stage of pressure is maintained at a set time and the gas leakage is less than the first set value, increase the pressure to the next stage. Step 4. During the set time of each pressure level, record the real-time reading of the pressure display screen, and at the same time record the real-time data of the displacement sensor, air pressure sensor, flow meter, and air pressure sensor. Step 5. Plot the data change curves of each sensor based on the test records, and calculate the deformation and leakage rate of the air plug.

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