A detection method for double-membrane structure cyclic gas injection in underground rock cavern gas storage cavity

Abstract

The present invention discloses a method for detecting cyclical gas injection within a double-membrane structure within an underground rock cavern gas storage cavity. The method comprises the following steps: 1. constructing the double-membrane structure on the surrounding rock mass; 2. detecting gas injection between the inner and outer membrane layers; and 3. injecting and detecting compressed air within the cavity. The present invention detects the cyclical gas injection and degassing within the double-membrane structure, minimizing damage to the double-membrane structure and thereby improving the durability and safety of the double-membrane sealing structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of compressed air energy storage, and in particular relates to a method for detecting cyclic gas injection of a double-membrane structure in a cavity of an underground rock cavern gas storage reservoir. Background Art

[0002] Compressed air energy storage effectively solves the long-distance energy consumption, high utilization efficiency, low capacity cost, and has no resource development bottleneck, cycle life limit, high environmental friendliness and other problems, and is widely promoted and used.

[0003] However, for now, the safety and stability of compressed air energy storage during operation have always been a concern. During the operation of compressed air energy storage structures, factors such as high pressure, high temperature and instability caused by gas injection have a significant impact on the sealing layer of the underground rock gas storage cavity, causing the sealing layer inside the cavity to be squeezed under the action of high pressure. The high temperature generated by gas injection also has a certain impact on the durability of the cavity sealing layer. Due to the sharp drop in pressure inside the cavity caused by degassing, the cavity is prone to cracks, separation, and peeling of the sealing layer under the action of reduced pressure, which can cause cavity gas leakage, sealing layer failure, economic losses, and serious unsafe accidents. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned prior art and provide a method for detecting the cyclic gas injection of a double-membrane structure in the cavity of an underground cavern gas storage reservoir. The method has a reasonable design and performs detection during the gas injection and degassing cycle of the double-membrane structure cavity, thereby reducing damage to the double-membrane structure and improving the durability and safety of the double-membrane sealing structure.

[0005] To solve the above technical problems, the present invention adopts a technical solution: a method for detecting cyclic gas injection of a double-membrane structure in an underground cavern gas storage cavity, characterized in that the method comprises the following steps:

[0006] Step 1: Construction of double membrane structure on surrounding rock mass:

[0007] Step 101: constructing a waterproof layer on the surrounding rock mass;

[0008] Step 102: constructing a lining layer on the waterproof layer; wherein a plurality of connecting rods are embedded at the bottom of the lining layer;

[0009] Step 103: constructing an anti-seepage layer on the lining layer; wherein the connecting rod passes through the anti-seepage layer;

[0010] Step 104: Lower the double membrane structure through the hole in the surrounding rock mass, and extend the outer gas injection pipe and outer gas exhaust pipe on the outer membrane layer and the inner gas injection pipe and inner gas exhaust pipe on the inner membrane layer through the hole in the surrounding rock mass. The double membrane structure includes an inner membrane layer and an outer membrane layer arranged from inside to outside, the outer membrane layer being located between the inner membrane layer and the impermeable layer, a cavity being provided in the inner membrane layer, an inner gas injection valve and an inner pressure gauge being provided on the inner gas injection pipe, an outer gas exhaust valve being provided on the outer gas exhaust pipe, and an inner gas exhaust valve being provided on the inner gas exhaust pipe.

[0011] Step 105: Connect the bottom of the outer membrane layer to the protruding end of the connecting rod to fix the bottom of the double membrane structure;

[0012] Step 106: Connect an extended gas injection pipe to the external gas injection pipe; wherein the extended gas injection pipe is provided with an external gas injection valve and an external pressure gauge;

[0013] Step 2: Gas injection detection between the inner and outer membrane layers:

[0014] Step 201: Close the inner gas injection valve, the inner gas exhaust valve, and the outer gas exhaust valve, connect the compressor to the extended gas injection pipe, and open the outer gas injection valve to inject gas between the inner and outer membrane layers.

[0015] Step 202: During the process of injecting air between the inner membrane layer and the outer membrane layer, the outer pressure gauge detects the pressure of the outer cavity between the inner membrane layer and the outer membrane layer until the outer cavity pressure obtained by the outer pressure gauge reaches the set outer cavity pressure value P. sw When the gas is injected, close the external gas injection valve to stop the gas injection;

[0016] Step 203: After the inner membrane layer and the outer membrane layer are stationary for 24 to 32 hours, the outer cavity pressure is obtained by an external pressure gauge until the outer cavity pressure remains constant and is greater than 0.90P. sw , the seal between the inner film layer and the outer film layer is qualified;

[0017] Step 3: Injection and testing of compressed air into the cavity:

[0018] Step 301: Open the inner gas injection valve, open the inner gas exhaust valve, close the outer gas injection valve and the outer gas exhaust valve, and inject compressed air into the cavity through the inner gas injection pipe;

[0019] Step 302: During the process of injecting compressed air into the cavity through the inner air injection tube, the inner pressure gauge detects the inner cavity pressure in the cavity in real time. At the same time, the outer pressure gauge detects the outer cavity pressure between the inner membrane layer and the outer membrane layer in real time. The inner temperature sensor detects the inner temperature of the cavity in real time, and the outer temperature sensor detects the outer temperature between the inner membrane layer and the outer membrane layer in real time. The inner cavity pressure obtained at the i-th detection moment is recorded as The external cavity pressure obtained at the i-th detection moment is recorded as The internal temperature obtained at the i-th detection moment is recorded as The external temperature obtained at the i-th detection moment is recorded as i is a positive integer;

[0020] Step 303: If Less than 1 / 3 of the set inner cavity pressure value, Less than the internal temperature setting value T n,s ,and Less than the external temperature setting value T w,s , continue to inject compressed air into the cavity until When the pressure in the inner cavity reaches 1 / 3 of the set value, the inner exhaust valve is closed;

[0021] Step 304: Continue to inject compressed air into the cavity for the second time, and during the second injection of compressed air, record the inner cavity pressure obtained at the jth detection moment as The external cavity pressure obtained at the jth detection moment is recorded as The internal temperature obtained at the jth detection moment is recorded as The external temperature obtained at the jth detection moment is recorded as Wherein, j is a positive integer;

[0022] Step 305: If Less than the set inner cavity pressure value, Less than the internal temperature setting value T n,s , Less than the external temperature setting value T w,s ,and Greater than 0.90P sw , continue to inject compressed air into the cavity until the inner cavity pressure meets the inner cavity set pressure value, then stop injecting into the cavity and close the inner air injection valve.

[0023] The above-mentioned method for detecting the circulating gas injection of a double-membrane structure in the cavity of an underground rock gas storage reservoir is characterized in that: the outlet of the inner gas injection pipe is connected to the cavity, the inner gas injection pipe passes through the outer membrane layer and the outer gas injection pipe, and the inner gas injection pipe and the outer gas injection pipe are coaxially arranged, the inlet of the inner gas injection pipe is located outside the outer gas injection pipe, the inner gas injection valve and the internal pressure gauge are located on the inner gas injection pipe on the protruding end of the outer gas injection pipe, and the top of the outer gas injection pipe and the outer side wall of the inner gas injection pipe are sealed.

[0024] The above-mentioned method for detecting cyclic gas injection of a double-membrane structure in an underground rock cavern gas storage cavity is characterized in that: the inner exhaust pipe passes through the outer membrane layer and the outer exhaust pipe, and the inner exhaust pipe and the outer gas injection pipe are coaxially arranged, and the inner exhaust valve is located at the end of the inner exhaust pipe extending out of the outer exhaust pipe;

[0025] An opening is formed between the top end of the outer exhaust pipe and the outer side wall of the inner exhaust pipe, and the outer exhaust valve is used to seal or open a passage between the outer exhaust pipe and the inner exhaust pipe.

[0026] The above-mentioned method for detecting cyclic gas injection of a double-membrane structure in the cavity of an underground cavern gas storage reservoir is characterized in that the inner temperature sensor is located at the bottom of the inner membrane layer, and the outer temperature sensor is located at the bottom of the outer membrane layer.

[0027] The above-mentioned underground rock cave gas storage cavity has a built-in circulating double-membrane structure, which is characterized in that the inner membrane layer and the outer membrane layer are both fire-proof and anti-static PVDF membranes.

[0028] The above-mentioned method for detecting cyclic gas injection of a double-membrane structure in the cavity of an underground rock gas storage reservoir is characterized in that both the internal temperature sensor and the external temperature sensor are wireless temperature sensors.

[0029] The above-mentioned method for detecting cyclic gas injection of a double-membrane structure in an underground rock cavern gas storage cavity is characterized in that: after the compressed air injection into the cavity is completed in step 3, the external pressure gauge performs real-time detection of the external cavity pressure between the inner membrane layer and the outer membrane layer; when the external cavity pressure is greater than the external cavity pressure value, the external exhaust valve is operated to open until the external cavity pressure meets the external cavity pressure value;

[0030] The internal pressure gauge detects the internal cavity pressure in the cavity in real time. When the internal cavity pressure is greater than the internal cavity set pressure value, the internal exhaust valve is operated to open until the internal cavity pressure meets the internal cavity set pressure value.

[0031] The above-mentioned detection method for double-membrane structure cyclic gas injection in the cavity of underground cavern gas storage is characterized in that: the set external cavity pressure value P sw The set inner cavity pressure value is 8MPa~10MPa, and the set inner cavity pressure value is 9MPa~11MPa;

[0032] The internal temperature setting value T n,s The external temperature setting value T is 100℃~150℃. w,s It is 70℃~120℃.

[0033] The above-mentioned detection method for cyclic gas injection of a double-membrane structure in an underground cavern gas storage cavity is characterized in that: when degassing is required, the inner gas injection valve, the outer gas injection valve and the outer exhaust valve are closed, the inner exhaust valve is opened, and the compressed air in the cavity is degassed through the inner exhaust valve. During the degassing process of the cavity, the outer pressure gauge performs real-time detection on the outer cavity pressure between the inner membrane layer and the outer membrane layer, so that the outer cavity pressure remains unchanged and is greater than 0.90P sw ;

[0034] The internal pressure gauge detects the internal cavity pressure in the cavity in real time, so that when the internal cavity pressure meets the set deflation pressure value, the internal exhaust valve is operated to close and the deflation ends.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] 1. The present invention is rationally designed and only changes the inner cavity pressure of the double membrane structure during air injection and air release, thereby preventing the pressure change from directly acting on the cavity sealing layer, thereby avoiding the weakening of stability caused by structural changes of the cavity sealing layer, i.e., the waterproof layer, lining layer, and anti-seepage layer.

[0037] 2. The present invention adopts a double-membrane structure for sealing, which can not only adapt to the shape of the inner wall of the surrounding rock body, but also ensure the integrity of the double-mode structure, improve the volume rate of compressed air energy storage in the cavity, and thus increase the utilization rate of the cavity.

[0038] 3. The present invention is provided with an internal pressure gauge and an external pressure gauge to detect the internal cavity pressure and the external cavity pressure in real time.

[0039] 4. The detection method of the underground rock gas storage cavity built-in circulating double membrane structure of the present invention has simple steps, convenient implementation and simple operation, ensuring the safety of the cavity double membrane structure during the compressed air injection and release process.

[0040] 5. The detection method of the underground rock gas storage cavity with a built-in circulating double-membrane structure of the present invention is simple to operate and has good use effect. First, the double-membrane structure is constructed on the surrounding rock mass, and then the gas injection detection is carried out between the inner membrane layer and the outer membrane layer; finally, the compressed air is injected into the cavity and detected.

[0041] In summary, the present invention has a reasonable design and performs detection during the gas injection and gas release cycle of the double-membrane structure cavity, thereby reducing damage to the double-membrane structure and improving the durability and safety of the double-membrane sealing structure.

[0042] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a flowchart of the present invention.

[0044] Figure 2 It is a structural schematic diagram of the present invention.

[0045] Description of the accompanying drawings:

[0046] 1—surrounding rock mass; 2—waterproof layer; 3—lining layer;

[0047] 4—impermeable layer; 5—outer membrane layer; 5-1—inner gas injection tube;

[0048] 5-2—Internal gas injection valve; 5-3—Internal exhaust pipe; 5-4—Internal exhaust valve;

[0049] 6—intima layer; 6-1—external gas injection tube; 6-2—external gas injection valve;

[0050] 6-3—External exhaust pipe; 6-4—External exhaust valve;

[0051] 7—External pressure gauge; 8—Internal pressure gauge; 9—Internal temperature sensor;

[0052] 10—External temperature sensor; 11—Cavity; 12—Extended gas injection pipe;

[0053] 13-Connecting rod. DETAILED DESCRIPTION

[0054] like Figure 1 and 2 The method for detecting cyclic gas injection of a double-membrane structure in an underground cavern gas storage cavity shown includes the following steps:

[0055] Step 1: Construction of double membrane structure on surrounding rock mass:

[0056] Step 101: constructing a waterproof layer 2 on the surrounding rock mass 1;

[0057] Step 102: construct a lining layer 3 on the waterproof layer 2; wherein, a plurality of connecting rods 13 are embedded at the bottom of the lining layer 3;

[0058] Step 103: constructing an anti-seepage layer 4 on the lining layer 3; wherein the connecting rod 13 passes through the anti-seepage layer 4;

[0059] Step 104: lower the double membrane structure through the hole in the surrounding rock mass 1, and extend the outer gas injection pipe 6-1 and the outer exhaust pipe 6-3 on the outer membrane layer 5, and the inner gas injection pipe 5-1 and the inner exhaust pipe 5-3 on the inner membrane layer 6 through the hole in the surrounding rock mass 1. The double membrane structure includes an inner membrane layer 6 and an outer membrane layer 5 arranged from the inside to the outside, the outer membrane layer 5 is located between the inner membrane layer 6 and the anti-seepage layer 4, a cavity 11 is provided in the inner membrane layer 6, an inner gas injection valve 5-2 and an inner pressure gauge 8 are provided on the inner gas injection pipe 5-1, an outer exhaust valve 6-4 is provided on the outer exhaust pipe 6-3, and an inner exhaust valve 5-4 is provided on the inner exhaust pipe 5-3.

[0060] Step 105: Connect the bottom of the outer membrane layer 5 to the protruding end of the connecting rod 13 to fix the bottom of the double membrane structure;

[0061] Step 106: Connect the extended gas injection pipe 12 to the external gas injection pipe 6-1; wherein, the extended gas injection pipe 12 is provided with an external gas injection valve 6-2 and an external pressure gauge 7;

[0062] Step 2: Gas injection detection between the inner and outer membrane layers:

[0063] Step 201: Close the inner gas injection valve 5-2, the inner gas exhaust valve 5-4, and the outer gas exhaust valve 6-4, connect the compressor to the extended gas injection pipe 12, and open the outer gas injection valve 6-2 to inject gas between the inner membrane layer 6 and the outer membrane layer 5;

[0064] Step 202: During the process of injecting air between the inner membrane layer 6 and the outer membrane layer 5, the outer pressure gauge 7 detects the pressure of the outer cavity between the inner membrane layer 6 and the outer membrane layer 5 until the outer cavity pressure obtained by the outer pressure gauge 7 reaches the set outer cavity pressure value P. sw When the gas injection valve 6-2 is closed, the gas injection is stopped;

[0065] Step 203: After the inner membrane layer 6 and the outer membrane layer 5 are stationary for 24 to 32 hours, the outer cavity pressure is obtained through the outer pressure gauge 7 until the outer cavity pressure remains constant and is greater than 0.90P. sw , then the seal between the inner film layer 6 and the outer film layer 5 is qualified;

[0066] Step 3: Injection and testing of compressed air into the cavity:

[0067] Step 301: Open the inner gas injection valve 5-2, open the inner gas exhaust valve 5-4, close the outer gas injection valve 6-2 and the outer gas exhaust valve 6-4, and inject compressed air into the cavity 11 through the inner gas injection pipe 5-1;

[0068] Step 302: During the process of injecting compressed air into the cavity 11 through the inner air injection pipe 5-1, the inner pressure gauge 8 detects the inner cavity pressure of the cavity 11 in real time. At the same time, the outer pressure gauge 7 detects the outer cavity pressure between the inner membrane layer 6 and the outer membrane layer 5 in real time. The inner temperature sensor 9 detects the inner temperature of the cavity 11 in real time. The outer temperature sensor 10 detects the outer temperature between the inner membrane layer 6 and the outer membrane layer 5 in real time. The inner cavity pressure obtained at the i-th detection moment is recorded as The external cavity pressure obtained at the i-th detection moment is recorded as The internal temperature obtained at the i-th detection moment is recorded as The external temperature obtained at the i-th detection moment is recorded as i is a positive integer;

[0069] Step 303: If Less than 1 / 3 of the set inner cavity pressure value, Less than the internal temperature setting value T n,s ,and Less than the external temperature setting value T w,s , continue to inject compressed air into the cavity 11 until When the pressure in the inner cavity reaches 1 / 3 of the set value, the inner exhaust valve 5-4 is operated to close;

[0070] Step 304: Continue to inject compressed air into the cavity 11 for the second time, and during the second injection of compressed air, record the inner cavity pressure obtained at the jth detection moment as The external cavity pressure obtained at the jth detection moment is recorded as The internal temperature obtained at the jth detection moment is recorded as The external temperature obtained at the jth detection moment is recorded as Wherein, j is a positive integer;

[0071] Step 305: If Less than the set inner cavity pressure value, Less than the internal temperature setting value T n,s , Less than the external temperature setting value T w,s ,and Greater than 0.90P sw , continue to inject compressed air into the cavity 11 until the inner cavity pressure meets the inner cavity set pressure value, then stop injecting into the cavity 11 and close the inner gas injection valve 5-2.

[0072] In this embodiment, the outlet of the inner gas injection pipe 5-1 is connected to the cavity 11, the inner gas injection pipe 5-1 passes through the outer membrane layer 5 and the outer gas injection pipe 6-1, and the inner gas injection pipe 5-1 and the outer gas injection pipe 6-1 are coaxially arranged, the inlet of the inner gas injection pipe 5-1 is located outside the outer gas injection pipe 6-1, the inner gas injection valve 5-2 and the internal pressure gauge 8 are located on the inner gas injection pipe 5-1 and on the protruding end of the outer gas injection pipe 6-1, and the top of the outer gas injection pipe 6-1 and the outer wall of the inner gas injection pipe 5-1 are sealed.

[0073] In this embodiment, the inner exhaust pipe 5-3 passes through the outer film layer 5 and the outer exhaust pipe 6-3, and the inner exhaust pipe 5-3 and the outer gas injection pipe 6-1 are coaxially arranged. The inner exhaust valve 5-4 is located at the end of the inner exhaust pipe 5-3 extending out of the outer exhaust pipe 6-3;

[0074] The top end of the outer exhaust pipe 6-3 and the outer side wall of the inner exhaust pipe 5-3 are opened, and the outer exhaust valve 6-4 is used to seal or open the passage between the outer exhaust pipe 6-3 and the inner exhaust pipe 5-3.

[0075] In this embodiment, the inner temperature sensor 9 is located in the bottom of the inner film layer 6 , and the outer temperature sensor 10 is located in the bottom of the outer film layer 5 .

[0076] In this embodiment, the inner film layer 6 and the outer film layer 5 are both fireproof and antistatic PVDF films.

[0077] In this embodiment, the internal temperature sensor 9 and the external temperature sensor 10 are both wireless temperature sensors.

[0078] In this embodiment, after the compressed air is injected into the cavity 11 in step 3, the external pressure gauge 7 detects the external cavity pressure between the inner membrane layer 6 and the outer membrane layer 5 in real time. When the external cavity pressure is greater than the external cavity pressure value, the external exhaust valve 6-4 is operated to open until the external cavity pressure meets the external cavity pressure value;

[0079] The internal pressure gauge 8 detects the internal cavity pressure in the cavity 11 in real time. When the internal cavity pressure is greater than the internal cavity set pressure value, the internal exhaust valve 5-4 is operated to open until the internal cavity pressure meets the internal cavity set pressure value.

[0080] In this embodiment, the set external cavity pressure value P sw The set inner cavity pressure value is 8MPa~10MPa, and the set inner cavity pressure value is 9MPa~11MPa;

[0081] The internal temperature setting value T n,s The external temperature setting value T is 100℃~150℃. w,s It is 70℃~120℃.

[0082] In this embodiment, when deflation is required, the inner air injection valve 5-2, the outer air injection valve 6-2 and the outer exhaust valve 6-4 are closed, and the inner exhaust valve 5-4 is opened to deflate the compressed air in the cavity 11 through the inner exhaust valve 5-4. During the deflation process of the cavity 11, the outer pressure gauge 7 detects the outer cavity pressure between the inner membrane layer 6 and the outer membrane layer 5 in real time to ensure that the outer cavity pressure remains unchanged and is greater than 0.90P. sw ;

[0083] The internal pressure gauge 8 detects the internal cavity pressure in the cavity 11 in real time, so that when the internal cavity pressure meets the set deflation pressure value, the internal exhaust valve 5-4 is operated to close and the deflation is completed.

[0084] In this embodiment, during actual use, it is necessary to initially inject air according to step three, followed by a deflation and inflation cycle.

[0085] In this embodiment, in actual use, the deflation pressure value is set to 20% to 30% of the set inner cavity pressure value.

[0086] In this embodiment, in actual use, after the deflation is completed, step three is repeated to perform the gas injection, and the process is repeated in sequence.

[0087] In this embodiment, in actual use, the waterproof layer 2 is a plain concrete waterproof layer or a cement waterproof layer, and the thickness of the waterproof layer 2 is 1.5 mm to 2 mm;

[0088] The lining layer 3 is a reinforced concrete layer, the thickness of the lining layer 3 is 25 cm to 30 cm, and the concrete strength grade is C20.

[0089] In this embodiment, in actual use, the surrounding rock grade of the surrounding rock mass 1 is Grade II or above for construction.

[0090] In this embodiment, in actual use, the anti-seepage layer 4 is an anti-seepage membrane with a thickness of 2 mm.

[0091] In this embodiment, in actual use, the double membrane structure can be provided as a single double membrane cavity or multiple double membrane cavities in parallel according to the cavity structure of the inner wall of the surrounding rock mass 1 of the underground cavern gas storage or the energy storage capacity requirement.

[0092] In this embodiment, in actual use, the inner and outer double membrane structures adopted by the present invention both adopt PVDF air membranes, which have the advantages of large span, heat insulation, economy, speed, light weight, etc. The energy consumption is 10%-25% of traditional buildings, and the overall energy saving is more than 75%. It can be well applied to the sealing of underground rock cave gas storage.

[0093] In this embodiment, in actual use, the inner gas injection pipe 5-1 and the outer gas injection pipe 6-1 are coaxially nested, and the inner exhaust pipe 5-3 and the outer exhaust pipe 6-3 are coaxially nested, which reduces the gas pipe layout space and thus adapts to the narrow space of the surrounding rock body 1 hole.

[0094] In this embodiment, in actual use, the waterproof layer 2 is mainly used to isolate moisture, waterproof and damp-proof the inner wall of the surrounding rock mass 1. The lining layer 3 is mainly used to solve the internal morphology of the surrounding rock mass 1 and the transition of the surrounding rock mass 1 structure.

[0095] In this embodiment, during actual use, the dual-mode structure effectively blocks the conduction of temperature and pressure in the cavity 11 to the surrounding rock mass 1 .

[0096] In this embodiment, in actual use, the external exhaust valve 6 - 4 can refer to a valve structure for an annular channel in the CN219035595U patent, or other valves that can achieve the same function.

[0097] In summary, the present invention has a reasonable design and performs detection during the gas injection and gas release cycle of the double-membrane structure cavity, thereby reducing damage to the double-membrane structure and improving the durability and safety of the double-membrane sealing structure.

[0098] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for detecting cyclic gas injection of a double-membrane structure in an underground rock cavern gas storage cavity, characterized in that: The method comprises the following steps: Step 1: Construction of double membrane structure on surrounding rock mass: Step 101: constructing a waterproof layer (2) on the surrounding rock mass (1); Step 102: constructing a lining layer (3) on the waterproof layer (2); wherein a plurality of connecting rods (13) are embedded at the bottom of the lining layer (3); Step 103: constructing an anti-seepage layer (4) on the lining layer (3); wherein the connecting rod (13) passes through the anti-seepage layer (4); Step 104: lowering the double membrane structure through the hole of the surrounding rock mass (1), and extending the outer gas injection pipe (6-1) and the outer exhaust pipe (6-3) on the outer membrane layer (5) and the inner gas injection pipe (5-1) and the inner exhaust pipe (5-3) on the inner membrane layer (6) through the hole of the surrounding rock mass (1); wherein the double membrane structure comprises an inner membrane layer (6) and an outer membrane layer (5) arranged from the inside to the outside, the outer membrane layer (5) being located between the inner membrane layer (6) and the anti-seepage layer (4), a cavity (11) being provided in the inner membrane layer (6), an inner gas injection valve (5-2) and an inner pressure gauge (8) being provided on the inner gas injection pipe (5-1), an outer exhaust valve (6-4) being provided on the outer exhaust pipe (6-3), and an inner exhaust valve (5-4) being provided on the inner exhaust pipe (5-3); Step 105: Connect the bottom of the outer membrane layer (5) to the protruding end of the connecting rod (13) to fix the bottom of the double membrane structure; Step 106: Connect the extended gas injection pipe (12) to the external gas injection pipe (6-1); wherein the extended gas injection pipe (12) is provided with an external gas injection valve (6-2) and an external pressure gauge (7); Step 2: Gas injection detection between the inner and outer membrane layers: Step 201: Close the inner gas injection valve (5-2), the inner gas exhaust valve (5-4), and the outer gas exhaust valve (6-4), connect the compressor to the extended gas injection pipe (12), and open the outer gas injection valve (6-2) to inject gas between the inner membrane layer (6) and the outer membrane layer (5); Step 202: During the process of injecting air between the inner membrane layer (6) and the outer membrane layer (5), the outer pressure gauge (7) detects the pressure of the outer cavity between the inner membrane layer (6) and the outer membrane layer (5) until the outer cavity pressure obtained by the outer pressure gauge (7) reaches the set outer cavity pressure value P. sw When the gas injection valve (6-2) is closed, stop the gas injection; Step 203: After the inner membrane layer (6) and the outer membrane layer (5) are stationary for 24 to 32 hours, the outer cavity pressure is obtained through the outer pressure gauge (7) until the outer cavity pressure remains unchanged and is greater than 0.90P. sw , the seal between the inner film layer (6) and the outer film layer (5) is qualified; Step 3: Injection and testing of compressed air into the cavity: Step 301: Open the inner gas injection valve (5-2), open the inner gas exhaust valve (5-4), close the outer gas injection valve (6-2) and the outer gas exhaust valve (6-4), and inject compressed air into the cavity (11) through the inner gas injection pipe (5-1); Step 302: During the process of injecting compressed air into the cavity (11) through the inner air injection pipe (5-1), the inner pressure gauge (8) detects the inner cavity pressure in the cavity (11) in real time. At the same time, the outer pressure gauge (7) detects the outer cavity pressure between the inner film layer (6) and the outer film layer (5) in real time. The inner temperature sensor (9) detects the inner temperature in the cavity (11) in real time. The outer temperature sensor (10) detects the outer temperature between the inner film layer (6) and the outer film layer (5) in real time. The inner cavity pressure obtained at the i-th detection moment is recorded as The external cavity pressure obtained at the i-th detection moment is recorded as The internal temperature obtained at the i-th detection moment is recorded as The external temperature obtained at the i-th detection moment is recorded as i is a positive integer; Step 303: If Less than 1 / 3 of the set inner cavity pressure value, Less than the internal temperature setting value T n,s ,and Less than the external temperature setting value T w,s , continue to inject compressed air into the cavity (11) until When the pressure in the inner cavity reaches 1 / 3 of the set value, the inner exhaust valve (5-4) is operated to close; Step 304: Continue to inject compressed air into the cavity (11) for the second time, and during the second injection of compressed air, record the inner cavity pressure obtained at the jth detection moment as The external cavity pressure obtained at the jth detection moment is recorded as The internal temperature obtained at the jth detection moment is recorded as The external temperature obtained at the jth detection moment is recorded as Wherein, j is a positive integer; Step 305: If Less than the set inner cavity pressure value, Less than the internal temperature setting value T n,s , Less than the external temperature setting value T w,s ,and Greater than 0.90P sw , continue to inject compressed air into the cavity (11) until the pressure in the cavity meets the set pressure value of the cavity, then stop injecting air into the cavity (11) and close the internal air injection valve (5-2).

2. A method for detecting double-membrane structure cyclic gas injection in an underground rock cavern gas storage cavity according to claim 1, characterized in that: The outlet of the inner gas injection pipe (5-1) is connected to the cavity (11), the inner gas injection pipe (5-1) passes through the outer membrane layer (5) and the outer gas injection pipe (6-1), and the inner gas injection pipe (5-1) and the outer gas injection pipe (6-1) are coaxially arranged. The inlet of the inner gas injection pipe (5-1) is located outside the outer gas injection pipe (6-1), the inner gas injection valve (5-2) and the inner pressure gauge (8) are located on the protruding end of the inner gas injection pipe (5-1) from the outer gas injection pipe (6-1), and the top end of the outer gas injection pipe (6-1) and the outer side wall of the inner gas injection pipe (5-1) are sealed.

3. The method for detecting double-membrane structure cyclic gas injection in an underground cavern gas storage cavity according to claim 1, characterized in that: The inner exhaust pipe (5-3) passes through the outer film layer (5) and the outer exhaust pipe (6-3), and the inner exhaust pipe (5-3) and the outer gas injection pipe (6-1) are coaxially arranged, and the inner exhaust valve (5-4) is located at the end of the inner exhaust pipe (5-3) extending out of the outer exhaust pipe (6-3); An opening is formed between the top end of the outer exhaust pipe (6-3) and the outer side wall of the inner exhaust pipe (5-3), and the outer exhaust valve (6-4) is used to seal or open the passage between the outer exhaust pipe (6-3) and the inner exhaust pipe (5-3).

4. A method for detecting double-membrane structure cyclic gas injection in an underground rock cavern gas storage cavity according to claim 1, characterized in that: The inner temperature sensor (9) is located inside the bottom of the inner film layer (6), and the outer temperature sensor (10) is located inside the bottom of the outer film layer (5).

5. The method for detecting double-membrane structure cyclic gas injection in an underground rock cavern gas storage cavity according to claim 1, characterized in that: The inner film layer (6) and the outer film layer (5) are both fireproof and antistatic PVDF films.

6. A method for detecting cyclic gas injection of a double-membrane structure in an underground rock cavern gas storage cavity according to claim 4, characterized in that: The internal temperature sensor (9) and the external temperature sensor (10) are both wireless temperature sensors.

7. A method for detecting double-membrane structure cyclic gas injection in an underground cavern gas storage cavity according to claim 1, characterized in that: Step 3: After the compressed air is injected into the cavity (11), the external pressure gauge (7) detects the external cavity pressure between the inner membrane layer (6) and the outer membrane layer (5) in real time. When the external cavity pressure is greater than the external cavity pressure value, the external exhaust valve (6-4) is operated to open until the external cavity pressure meets the external cavity pressure value; The internal pressure gauge (8) detects the internal cavity pressure in the cavity (11) in real time. When the internal cavity pressure is greater than the internal cavity set pressure value, the internal exhaust valve (5-4) is operated to open until the internal cavity pressure meets the internal cavity set pressure value.

8. The method for detecting double-membrane structure cyclic gas injection in an underground rock cavern gas storage cavity according to claim 1, characterized in that: The set external cavity pressure value P sw The set inner cavity pressure value is 8MPa~10MPa, and the set inner cavity pressure value is 9MPa~11MPa; The internal temperature setting value T n,s The external temperature setting value T is 100℃~150℃. w,s It is 70℃~120℃.

9. The method for detecting double-membrane structure cyclic gas injection in an underground rock cavern gas storage cavity according to claim 1, characterized in that: When deflation is required, the inner air injection valve (5-2), the outer air injection valve (6-2) and the outer exhaust valve (6-4) are closed, and the inner exhaust valve (5-4) is opened to deflate the compressed air in the cavity (11) through the inner exhaust valve (5-4). During the deflation of the cavity (11), the outer pressure gauge (7) detects the outer cavity pressure between the inner membrane layer (6) and the outer membrane layer (5) in real time to ensure that the outer cavity pressure remains unchanged and is greater than 0.90P sw ; The internal pressure gauge (8) detects the internal cavity pressure in the cavity (11) in real time, so that when the internal cavity pressure meets the set deflation pressure value, the internal exhaust valve (5-4) is operated to close, and deflation ends; Repeat step 3 to inject gas, and repeat the process in a cycle.

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