Physical model test system of gas storage structure capable of conveniently applying crustal stress

Abstract

The invention discloses a physical model test system of a gas storage structure capable of conveniently applying ground stress. The system comprises a gas storage chamber, the gas storage chamber comprises a sealing layer arranged in a cavity, and a longitudinal optical fiber sensor and an annular optical fiber sensor are pasted to the outer side of the sealing layer; a concrete lining layer is arranged on the periphery of the sealing layer, and a cylindrical steel bar pipe network is pre-embedded in the concrete lining layer; concrete surrounding rock is arranged on the periphery of the gas storage chamber, and a cubic reinforcing mesh used for applying ground stress is pre-buried in the concrete surrounding rock. The top end and the bottom end of the gas storage chamber communicate with a gas inlet pipeline and a gas outlet pipeline extending to the outer side of the concrete surrounding rock correspondingly. An air inlet of the air inlet pipeline is connected with an air compressor and a water pressure system, and the air compressor and the water pressure system are connected with the control system. According to the invention, the unused position change condition of each structural layer of the underground gas storage under the coupling action of internal force and external force can be reflected more truly.

Description

Technical Field

[0001] The present invention relates to the technical field of underground energy storage, and in particular to a physical model test system for a gas storage structure for conveniently applying ground stress. Background Art

[0002] Compressed air energy storage has attracted much attention as an ideal energy storage method. Artificial underground gas storage has become a hot topic in various industries, and the stability of the gas storage itself is one of the research hotspots.

[0003] Artificial underground gas storage is a technology that uses compressed air as a medium to store surplus electrical energy. During low-power periods, excess electricity from wind power and the power grid drives air compressors, converts electrical energy into the internal energy of compressed air and stores it in underground caverns. During peak power consumption, high-pressure air is released to convert the potential energy of compressed air into mechanical energy that drives the generator, thereby generating electricity.

[0004] In the existing technology, most of the stability analysis of surrounding rocks and chambers uses theoretical analysis and numerical simulation methods. Only a few studies use large-scale physical tests, which are very costly. The physical test simulates the gas storage reservoir by making a self-made similar system to study the changes in the internal sealing layer and external surrounding rock of the gas storage reservoir during the different stages of inflation, gas storage, and gas release. However, the physical test system of gas storage reservoirs in the existing technology has the following problems:

[0005] First, due to the high simulated air pressure, the test system is at risk of being damaged by high-pressure gas, and safety is difficult to guarantee.

[0006] Second, it is difficult for relevant experiments to effectively simulate the magnitude of ground stress that underground chambers are subjected to at different depths and in different directions, and there is little consideration of the connection positions of the internal sealing layers. Therefore, the conclusions drawn may not be accurate. Summary of the invention

[0007] In view of the shortcomings of the prior art, the present invention proposes a physical model test system for a gas storage structure that conveniently applies geostress, which not only adds a preliminary safety performance test experiment to provide a guarantee for the safety of subsequent compressed air energy storage experiments, but also can safely, simply, efficiently and economically apply geostress loads in physical tests of gas storage, making up for the fact that existing physical tests ignore the magnitude of geostress at different depths and in different directions, and can more realistically reflect the stress, strain, displacement and temperature changes of different positions of the sealing layer, lining and surrounding rock structural layers of the underground gas storage under the coupling of internal and external forces in the stages of inflation, gas storage and degassing, thereby determining the sealing and stability of the gas storage structure.

[0008] To achieve the above-mentioned purpose, the present invention is a physical model test system for a gas storage structure for applying ground stress conveniently, comprising a gas storage chamber, which is particularly characterized in that: the gas storage chamber comprises a sealing layer arranged inside the cavity, and a longitudinal optical fiber sensor and a circumferential optical fiber sensor for detecting stress, strain, displacement, and temperature changes at different positions are attached to the outside of the sealing layer;

[0009] A concrete lining layer is arranged on the outer periphery of the sealing layer, and a cylindrical steel pipe network is pre-buried inside the concrete lining layer, wherein the steel pipe network includes a plurality of longitudinal steel bars and annular steel bars formed by binding;

[0010] The outer periphery of the gas storage chamber is provided with a concrete surrounding rock, and a cubic steel mesh for applying ground stress is embedded in the concrete surrounding rock. The cubic steel mesh includes a plurality of transverse prestressed steel bars, longitudinal prestressed steel bars, and axial prestressed steel bars formed by binding, and both ends of each transverse prestressed steel bar, longitudinal prestressed steel bar, and axial prestressed steel bar extend to the outside of the concrete surrounding rock; the gas storage chamber is placed inside the cubic steel mesh, and the tensioning force of each steel bar is adjusted according to the actual ground stress situation, and the concrete surrounding rock is deformed by the steel bars, and the stress, strain, and displacement are transmitted to the gas storage chamber, thereby simulating the ground stress acting on the gas storage chamber in different directions and at different depths;

[0011] The longitudinal optical fiber sensor and the circumferential optical fiber sensor extension section are connected to a control system located outside the concrete surrounding rock;

[0012] The top of the gas storage chamber is connected to an air inlet pipe extending to the outside of the concrete surrounding rock, and the bottom of the gas storage chamber is connected to an air outlet pipe extending to the outside of the concrete surrounding rock;

[0013] The air inlet of the air inlet pipeline is respectively connected to an air compressor and a water pressure system, and the air compressor and the water pressure system are respectively connected to a control system.

[0014] Furthermore, the sealing layer is in the shape of a cylinder which is connected and sealed at both ends.

[0015] Furthermore, the longitudinal optical fiber sensors extend axially along the sealing layer and are spaced apart circumferentially around the sealing layer, and the circumferential optical fiber sensors are spaced apart axially along the sealing layer.

[0016] Furthermore, the longitudinal steel bars extend axially along the gas storage chamber and are arranged at intervals around the circumference of the gas storage chamber, and the annular steel bars are arranged at intervals along the axial direction of the gas storage chamber.

[0017] Furthermore, the transverse prestressed steel bars, the longitudinal prestressed steel bars, and the axial prestressed steel bars are in three mutually perpendicular directions.

[0018] Furthermore, the spacing between adjacent transverse prestressed steel bars, longitudinal prestressed steel bars, and axial prestressed steel bars in the same direction is 20 to 40 cm.

[0019] Furthermore, the concrete in the concrete lining layer is C40 high-strength concrete, and the concrete in the concrete surrounding rock is C40 high-strength concrete.

[0020] Furthermore, an air intake valve is provided at the inlet of the air intake pipe, and an air intake pressure gauge is provided between the air intake valve and the gas storage chamber; an air outlet valve is provided at the outlet of the air outlet pipe, and an air outlet pressure gauge is provided between the air outlet valve and the gas storage chamber.

[0021] Furthermore, the air inlet pipe and the air outlet pipe are high-pressure steel pipes.

[0022] Furthermore, the pressure variation range in the gas storage chamber is 7-20MPa.

[0023] The advantages of the present invention are:

[0024] 1. The present invention connects the air compressor and the water pressure system at the top of the gas storage chamber respectively. During the test, the water pressure system is used to replace the air pressure system for a preliminary safety performance test. The water pressure system injects liquid into the gas storage through the air intake pipe. A pressure gauge is connected to the end of the air intake pipe to control the maximum pressure in the gas storage to not exceed the specified pressure. Water filling, water discharge, and water storage are used instead of air filling, air discharge, and air storage to check the sealing and safety stability of the system device at each stage, so as to provide a guarantee for the safety of the subsequent compressed air energy storage experiment;

[0025] 2. After the preliminary test is completed, the internal liquid is discharged through the air outlet pipe, and then an air compressor is used to replace the water pressure system. The air compressor injects gas into the gas storage reservoir through the air inlet pipe to control the inflation, deflation and storage time of a single test. The stress, strain, displacement and temperature changes at different stages and positions of the gas storage reservoir are recorded through the test recording device, and the overall stability of the gas storage reservoir structure and the stability of the sealing layer are judged based on the corresponding data;

[0026] 3. The present invention embeds a cubic steel mesh inside the concrete surrounding rock, and extends both ends of the transverse prestressed steel bars, the longitudinal prestressed steel bars, and the axial prestressed steel bars to the outside of the concrete surrounding rock for applying ground stress. Compared with the existing physical model test, the present invention can safely, simply, effectively and economically load the external surrounding rock ground stress load into the gas storage system, and can more truly reflect the stability of the overall structure when the gas storage is subjected to the coupling of internal and external loads in the actual state, as well as the interference of the filling and degassing process of the gas storage on the external surrounding rock, collect various sensor data, and determine the sealing and stability of the gas storage chamber;

[0027] 4. Ideally, the sealing layer inside the gas storage reservoir is not subjected to stress. However, since the elastic modulus of the sealing layer is different from that of concrete, the sealing layer in the actual gas storage reservoir may be subjected to a part of the stress, especially the stress at the connection position of the sealing layer may not be uniform. The gas storage chamber in the present invention adopts the installation method of the sealing layer of the actual gas storage reservoir, connecting the sheet-shaped sealing layer to form a cylindrical shape with sealed ends, which can more accurately reflect the stability of the sealing layer structure in the actual gas storage reservoir;

[0028] 5. Compared with the actual cave simulation, the present invention can significantly reduce the cost and is not restricted by hydrogeological conditions; compared with the existing physical test model system, it can more realistically reflect the actual working conditions of the gas storage reservoir;

[0029] The physical model test system of the gas storage structure for conveniently applying ground stress of the present invention can more realistically reflect the stress, strain, displacement and temperature changes of different positions of the sealing layer, lining and surrounding rock structural layers of the underground gas storage in each stage of inflation, gas storage and degassing under the coupling of internal and external forces, and further determine the sealing and stability of the gas storage structure; at the same time, a preliminary safety performance detection experiment is added to provide guarantee for the safety of subsequent compressed air energy storage experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the gas pressure experiment for testing the gas storage chamber in the present invention;

[0031] Figure 2 It is a schematic diagram of a water pressure experiment for testing a gas storage chamber in the present invention;

[0032] Figure 3 It is a schematic diagram of the structure of the cubic steel mesh in the present invention;

[0033] Figure 4 It is a schematic diagram of the overall longitudinal section of the test specimen in the present invention;

[0034] Figure 5 It is a schematic diagram of the overall cross section of the test specimen in the present invention;

[0035] Figure 6 It is a schematic cross-sectional view of the gas storage chamber in the present invention;

[0036] Figure 7 It is a schematic diagram of the structure of the outer side of the sealing layer in the present invention;

[0037] In the figure: air compressor 1, water pressure system 2, gas storage chamber 3, concrete surrounding rock 4, control system 5, air inlet pipe 6, air outlet pipe 7;

[0038] The gas storage chamber 3 includes: a sealing layer 3-1, a concrete lining layer 3-2, longitudinal steel bars 3-3, annular steel bars 3-4, longitudinal optical fiber sensors 3-5, and annular optical fiber sensors 3-6;

[0039] The concrete surrounding rock 4 includes: transverse prestressed steel bars 4-1, longitudinal prestressed steel bars 4-2, and axial prestressed steel bars 4-3;

[0040] The air intake pipe 6 includes: an air intake valve 6-1 and an air intake pressure gauge 6-2;

[0041] The air outlet pipeline 7 includes: an air outlet valve 7-1 and an air outlet pressure gauge 7-2. DETAILED DESCRIPTION

[0042] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0043] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention.

[0044] like Figures 1 to 7 As shown, a physical model test system for a gas storage structure for conveniently applying ground stress includes a gas storage chamber 3, wherein the gas storage chamber 3 includes a sealing layer 3-1 arranged inside the cavity, and a longitudinal optical fiber sensor 3-5 and a circumferential optical fiber sensor 3-6 for detecting stress, strain, displacement, and temperature changes at different positions are adhered to the outer side of the sealing layer 3-1.

[0045] Specifically, the pressure variation range in the gas storage chamber 3 is 7-20 MPa, which is used to simulate the actual gas storage chamber.

[0046] Specifically, the sealing layer 3-1 is a cylindrical shape that is connected and sealed at both ends. Ideally, the sealing layer inside the gas storage reservoir is not subjected to force, but because the elastic modulus of the sealing layer is different from that of concrete, the sealing layer in the actual gas storage reservoir may be subjected to a part of the force, especially the force at the connection position of the sealing layer may not be uniform. The gas storage chamber in the present invention adopts the installation method of the actual gas storage sealing layer, connecting the sheet-shaped sealing layer to form a cylindrical shape with both ends sealed, which can more accurately reflect the stability of the sealing layer structure in the actual gas storage reservoir.

[0047] Specifically, the longitudinal optical fiber sensor 3-5 extends axially along the sealing layer 3-1 and is arranged at intervals around the sealing layer 3-1, and the circumferential optical fiber sensor 3-6 is arranged at intervals along the axial direction of the sealing layer 3-1. The longitudinal optical fiber sensor 3-5 and the circumferential optical fiber sensor 3-6 include a stress sensor, a strain sensor, a displacement sensor, and a temperature sensor.

[0048] A concrete lining layer 3-2 is arranged on the periphery of the sealing layer 3-1, and a cylindrical steel pipe network is pre-buried inside the concrete lining layer 3-2. The steel pipe network includes a plurality of longitudinal steel bars 3-3 and annular steel bars 3-4 formed by binding.

[0049] Specifically, the longitudinal steel bars 3 - 3 extend axially along the gas storage chamber 3 and are arranged at intervals around the circumferential direction of the gas storage chamber 3 , and the annular steel bars 3 - 4 are arranged at intervals axially along the gas storage chamber 3 .

[0050] The gas storage chamber 3 is provided with a concrete surrounding rock 4 (simulating the actual concrete surrounding rock), and a cubic steel mesh for applying ground stress is embedded inside the concrete surrounding rock 4. The cubic steel mesh includes a plurality of transverse prestressed steel bars 4-1, longitudinal prestressed steel bars 4-2, and axial prestressed steel bars 4-3 formed by binding, and both ends of each transverse prestressed steel bar 4-1, longitudinal prestressed steel bar 4-2, and axial prestressed steel bar 4-3 extend to the outside of the concrete surrounding rock 4; the gas storage chamber 3 is placed inside the cubic steel mesh, and the tensioning force of each steel bar is adjusted according to the actual ground stress conditions, and the concrete surrounding rock 4 is deformed by the steel bars, and the stress, strain, and displacement are transmitted to the gas storage chamber 3, thereby simulating the ground stress acting on the gas storage chamber 3 in different directions and at different depths.

[0051] The present invention embeds a cubic steel mesh inside the concrete surrounding rock, and extends both ends of the transverse prestressed steel bars, the longitudinal prestressed steel bars, and the axial prestressed steel bars to the outside of the concrete surrounding rock for applying ground stress. Compared with the existing physical model test, the present invention can safely, simply, effectively and economically load the external surrounding rock ground stress load into the gas storage system, and can more truly reflect the stability of the overall structure when the gas storage is subjected to the coupling of internal and external loads under actual conditions, as well as the interference of the filling and degassing process of the gas storage on the external surrounding rock, collect various sensor data, and determine the sealing and stability of the gas storage chamber.

[0052] Preferably, the transverse prestressed steel bars 4-1, the longitudinal prestressed steel bars 4-2, and the axial prestressed steel bars 4-3 are in three mutually perpendicular directions.

[0053] Specifically, the spacing between adjacent transverse prestressed steel bars 4 - 1 , longitudinal prestressed steel bars 4 - 2 , and axial prestressed steel bars 4 - 3 in the same direction is 20 to 40 cm.

[0054] The concrete in the concrete lining layer 3 - 2 is C40 high-strength concrete, and the concrete in the concrete surrounding rock 4 is C40 high-strength concrete.

[0055] The extended sections of the longitudinal optical fiber sensor 3 - 5 and the circumferential optical fiber sensor 3 - 6 are connected to a control system 5 located outside the concrete surrounding rock 4 .

[0056] The top end of the gas storage chamber 3 is connected to an air inlet pipe 6 extending to the outside of the concrete surrounding rock 4, and the bottom end of the gas storage chamber 3 is connected to an air outlet pipe 7 extending to the outside of the concrete surrounding rock 4.

[0057] The air inlet of the air inlet pipe 6 is respectively connected to the air compressor 1 and the water pressure system 2, and the air compressor 1 and the water pressure system 2 are respectively connected to the control system 5.

[0058] The function of the water pressure system 2 is to inject water with high lift into the gas storage reservoir, and the function of the air compressor 1 is to inject high-pressure air into the gas storage reservoir.

[0059] The air inlet pipe 6 and the air outlet pipe 7 are the water or high-pressure air inlet and outlet channels inside the gas storage reservoir. Preferably, the air inlet pipe 6 and the air outlet pipe 7 are high-pressure steel pipes.

[0060] Preferably, an intake valve 6-1 is provided at the inlet of the intake pipe 6, and an intake pressure gauge 6-2 is provided between the intake valve 6-1 and the gas storage chamber 3; an outlet valve 7-1 is provided at the outlet of the outlet pipe 7, and an outlet pressure gauge 7-2 is provided between the outlet valve 7-1 and the gas storage chamber 3.

[0061] In the system of the present invention, the air compressor 1 presses high-pressure air into the gas storage chamber 3 through the air inlet pipe 6 and the air outlet pipe 7, and the pressure variation range in the gas storage chamber 3 is controlled to be 7-20MPa. The gas storage system consists of three parts: the exterior is composed of high-strength prestressed concrete surrounding rock 4 formed by prestressed steel bars in the longitudinal, transverse and axial directions. The tension of each steel bar is adjusted according to the actual ground stress conditions, and the concrete is deformed by the steel bars to transmit the force to the test specimens, thereby simulating the ground stress acting on the gas storage chamber 3 in different directions and at different depths; the middle part is the reinforced concrete lining, which is a hollow cylindrical structure. The lining contains axial steel bars and annular stirrups. The internal pressure of the gas storage chamber 3 will be transmitted to the external concrete surrounding rock 4 through the concrete lining layer 3-2; the interior is the gas storage sealing layer 3-1. The temperature, humidity, pressure and displacement changes at both ends and around the sealing layer 3-1 during the inflation, storage and deflation stages are transmitted to the computer for recording through corresponding sensors.

[0062] Compared with actual cave simulation, the present invention can significantly reduce costs and is not restricted by hydrogeological conditions; compared with existing physical test model systems, it can more realistically reflect the actual working conditions of the gas storage reservoir.

[0063] Before the test, it is necessary to complete the production of the physical model test system. The specific operations are as follows:

[0064] ①: Connect the sealing layer 3-1 into a cylindrical shape with sealed ends, and stick optical fiber sensors around the outside and at both ends of the sealing layer 3-1 as sensors, such as Figure 7 As shown; the sealing layer 3-1 is placed inside a specific cylindrical mold, and a fixing device is placed inside the cylindrical sealing layer to prevent the structure from deforming. Axial steel bars are inserted into the gap between the specific cylindrical mold and the sealing layer, and annular stirrups are used to tie them to form a cylindrical steel pipe network; C40 concrete is filled in the gap between the specific cylindrical mold and the sealing layer, and after curing and demoulding, a gas storage chamber 3 with a sealing layer on the inner wall is formed, as shown Figure 6 As shown;

[0065] ②: Use high-strength and high-toughness steel bars, arrange them at equal intervals in the horizontal, vertical and axial directions, and tie them to form a cubic steel mesh. The spacing between adjacent steel bars in the same direction is 20cm to 40cm, and sufficient length is reserved for the ends of the steel bars. Figure 3 As shown;

[0066] ③: Splice the mold around the cubic steel mesh, and place the prepared gas storage chamber 3 with a sealing layer on the inner wall in the middle of the cubic steel mesh, then fill the gaps between the steel bars with C40 high-strength concrete, maintain and demould, and form a high-strength reinforced concrete gas storage model after demoulding, as shown in the figure. Figure 4 , 5 As shown;

[0067] ④: Connect one end of the air inlet pipe 6 to the top of the gas storage chamber 3, seal it with a concrete plug, connect the other end to the air compressor 1, and connect the optical fiber sensor and the control system 5; connect one end of the air outlet pipe 7 to the bottom of the gas storage chamber 3, as shown in the figure. Figure 1 , 2 As shown;

[0068] ⑤: Apply prestress to the transverse, axial and longitudinal steel bars to simulate ground stress for sealing and stability tests.

[0069] In addition, during the test, the water pressure system 2 is used instead of the air pressure system to conduct preliminary safety performance test experiments. The water pressure system 2 injects liquid into the gas storage reservoir through the air intake pipe 6. A pressure gauge is connected to the end of the air intake pipe 6 to control the maximum pressure in the gas storage reservoir not to exceed the specified pressure. Water filling, water discharge, and water storage are used instead of inflation, deflation, and air storage to check the sealing and safety stability of the system devices at each stage, so as to provide protection for the safety of subsequent compressed air energy storage experiments.

[0070] After the preliminary test is completed, the internal liquid is discharged through the air outlet pipe, and then the air compressor 1 is used to replace the water pressure system. The air compressor 1 injects gas into the gas storage reservoir through the air inlet pipe to control the inflation, deflation and storage time of a single test. The stress, strain, displacement and temperature changes at different stages and positions of the gas storage reservoir are recorded through the test recording device, and the overall stability of the gas storage reservoir structure and the stability of the sealing layer are judged based on the corresponding data.

[0071] The physical model test system of the gas storage structure for conveniently applying ground stress of the present invention can more realistically reflect the stress, strain, displacement and temperature changes of different positions of the sealing layer, lining and surrounding rock structural layers of the underground gas storage in each stage of inflation, gas storage and degassing under the coupling of internal and external forces, and further determine the sealing and stability of the gas storage structure; at the same time, a preliminary safety performance detection experiment is added to provide guarantee for the safety of subsequent compressed air energy storage experiments.

[0072] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A physical model test system for a gas storage structure for conveniently applying ground stress, comprising a gas storage chamber (3), characterized in that: The gas storage chamber (3) comprises a sealing layer (3-1) arranged inside the cavity, and a longitudinal optical fiber sensor (3-5) and a circumferential optical fiber sensor (3-6) for detecting stress, strain, displacement, and temperature changes at different positions are attached to the outside of the sealing layer (3-1); A concrete lining layer (3-2) is arranged on the outer periphery of the sealing layer (3-1), a cylindrical steel pipe network is pre-buried inside the concrete lining layer (3-2), and the steel pipe network includes a plurality of longitudinal steel bars (3-3) and annular steel bars (3-4) formed by binding; The gas storage chamber (3) is provided with a concrete surrounding rock (4) on the periphery thereof. A cubic steel mesh for applying ground stress is embedded in the concrete surrounding rock (4). The cubic steel mesh comprises a plurality of transverse prestressed steel bars (4-1), longitudinal prestressed steel bars (4-2), and axial prestressed steel bars (4-3) formed by binding. Both ends of each transverse prestressed steel bar (4-1), longitudinal prestressed steel bar (4-2), and axial prestressed steel bar (4-3) extend to the outside of the concrete surrounding rock (4). The gas storage chamber (3) is placed inside the cubic steel mesh. The tension of each steel bar is adjusted according to the actual ground stress. The concrete surrounding rock (4) is deformed by the steel bars, and the stress, strain, and displacement are transmitted to the gas storage chamber (3), thereby simulating the ground stress acting on the gas storage chamber (3) in different directions and at different depths. The extension sections of the longitudinal optical fiber sensor (3-5) and the circumferential optical fiber sensor (3-6) are connected to a control system (5) located outside the concrete surrounding rock (4); The top end of the gas storage chamber (3) is connected to an air inlet pipe (6) extending to the outside of the concrete surrounding rock (4), and the bottom end of the gas storage chamber (3) is connected to an air outlet pipe (7) extending to the outside of the concrete surrounding rock (4); The air inlet of the air inlet pipeline (6) is respectively connected to an air compressor (1) and a water pressure system (2), and the air compressor (1) and the water pressure system (2) are respectively connected to a control system (5).

2. The physical model test system for gas storage structure with convenient application of ground stress according to claim 1 is characterized in that: The sealing layer (3-1) is in the shape of a cylinder which is connected and sealed at both ends.

3. The physical model test system for gas storage structure with convenient application of ground stress according to claim 2 is characterized by: The longitudinal optical fiber sensors (3-5) extend axially along the sealing layer (3-1) and are arranged at intervals in the circumferential direction around the sealing layer (3-1); and the circumferential optical fiber sensors (3-6) are arranged at intervals in the axial direction along the sealing layer (3-1).

4. The physical model test system for gas storage structure with convenient application of ground stress according to claim 3 is characterized by: The longitudinal steel bars (3-3) extend axially along the gas storage chamber (3) and are arranged at intervals around the circumference of the gas storage chamber (3); and the annular steel bars (3-4) are arranged at intervals along the axial direction of the gas storage chamber (3).

5. The physical model test system for gas storage structure with convenient application of ground stress according to claim 4 is characterized by: The transverse prestressed steel bars (4-1), the longitudinal prestressed steel bars (4-2), and the axial prestressed steel bars (4-3) are in three mutually perpendicular directions.

6. The physical model test system for gas storage structure with convenient application of ground stress according to claim 5 is characterized by: The spacing between adjacent transverse prestressed steel bars (4-1), longitudinal prestressed steel bars (4-2), and axial prestressed steel bars (4-3) in the same direction is 20 to 40 cm.

7. The physical model test system for gas storage structure with convenient application of ground stress according to claim 1 is characterized by: The concrete in the concrete lining layer (3-2) is C40 high-strength concrete, and the concrete in the concrete surrounding rock (4) is C40 high-strength concrete.

8. The physical model test system for gas storage structure with convenient application of ground stress according to claim 1 is characterized by: The inlet of the air inlet pipeline (6) is provided with an air inlet valve (6-1), and an air inlet pressure gauge (6-2) is provided between the air inlet valve (6-1) and the gas storage chamber (3); the outlet of the air outlet pipeline (7) is provided with an air outlet valve (7-1), and an air outlet pressure gauge (7-2) is provided between the air outlet valve (7-1) and the gas storage chamber (3).

9. The physical model test system for gas storage structure with convenient application of ground stress according to claim 8 is characterized by: The air inlet pipe (6) and the air outlet pipe (7) are high-pressure steel pipes.

10. The physical model test system for gas storage structure with convenient application of ground stress according to claim 1 is characterized by: The pressure variation range in the gas storage chamber (3) is 7-20 MPa.

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