Compressed air energy storage underground cavern flexible sealing layer leakage point detection method

Abstract

The invention discloses a compressed air energy storage underground cavern flexible sealing layer leakage point detection method comprising the following steps: brushing a conductive coating on the surface of a concrete lining of a compressed air energy storage underground cavern, and installing a flexible sealing layer on the surface of the concrete lining in a fragmented manner; a detection device is prepared and comprises a host and an electric spark detector composed of a probe brush, a telescopic rod and an alarm, the host is used for converting external low-voltage current into high-voltage current in a working state and conveying the high-voltage current to the probe brush, and the probe brush is used for detecting leakage points; after the metal objects on the surface of the flexible sealing layer are checked and processed, an operator takes protective measures, carries out leakage point detection with an electric spark detector and records the position of the leakage point; and repairing the leakage point by adopting a leakage repairing means, and then carrying out leakage point retest on the position of the repaired leakage point. The method is high in detection efficiency, adjustable and controllable in detection precision, convenient to operate and small in damage to the flexible sealing layer, and is an ideal method for detecting the leakage point of the flexible sealing layer of the compressed air energy storage underground cavern.

Description

Technical Field

[0001] The present invention belongs to the technical field of underground chamber sealing layer detection, and particularly relates to a method for detecting leakage points of a flexible sealing layer in an underground chamber for compressed air energy storage. Background Art

[0002] The underground chamber compressed air energy storage technology is a new type of environmentally friendly, safe and efficient long-term energy storage technology. Its technical feature is to compress air into the underground chamber for energy storage. Therefore, the airtightness of the underground chamber is very important. A concrete lining is provided on the surface of the surrounding rock of the underground chamber, and a flexible sealing layer is provided on the surface of the concrete lining. The flexible sealing layer technology makes full use of the bearing capacity of the concrete lining and the surrounding rock. Materials such as rubber and polyurethane are used as the flexible sealing layer, which not only improves the construction efficiency of the underground chamber for compressed air energy storage, but also reduces the cost, and has great application prospects. However, splicing joints will inevitably exist during the installation process of the flexible sealing layer. The splicing quality of the joints and the disturbances during the construction process will affect the sealing performance of the flexible sealing layer. There is no effective detection method for the leakage points of the flexible sealing layer in the existing technology. Therefore, it is urgent to develop a targeted detection method for the leakage points of the flexible sealing layer in the underground chamber for compressed air energy storage. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for detecting leakage points of a flexible sealing layer in an underground chamber for compressed air energy storage, which has high detection efficiency, adjustable detection accuracy, is easy to operate and causes little damage to the flexible sealing layer, aiming at the deficiencies of the existing technology.

[0004] The technical solution adopted by the present invention to solve the above technical problem is as follows: A method for detecting leakage points of a flexible sealing layer in an underground chamber for compressed air energy storage, the detection method comprising the following steps: (1) Apply a conductive coating on the surface of the concrete lining of the underground chamber for compressed air energy storage, and then install the flexible sealing layer in pieces on the surface of the concrete lining; (2) Prepare a detection device, the detection device comprising a main unit and a spark detector. The spark detector is composed of a probe brush, a telescopic rod and an alarm. The probe brush is installed on the telescopic rod. The surface of the telescopic rod is covered with an insulating layer. The telescopic movement of the telescopic rod is controlled by the main unit. The alarm is installed on the telescopic rod. The probe brush and the alarm are respectively electrically connected to the main unit. The main unit is connected to an external power supply outside the underground chamber for compressed air energy storage through a power cord. The main unit is used to convert an externally connected low-voltage current into a high-voltage current and transmit it to the probe brush in the working state. The probe brush is used to detect the leakage points of the flexible sealing layer, generate a spark and a sound signal when detecting a leakage point and send a signal to the main unit. The main unit converts the received signal into an alarm signal to make the alarm sound an alarm; (3) After inspecting and handling the metal objects on the surface of the flexible sealing layer, the operator takes protective measures and uses a spark detector to detect leaks in the compressed air energy storage underground cavern and records the leak locations; (4) Use leak repair methods to repair the leak point, and then re-test the leak point after the repair.

[0005] The method of the present invention enhances the conductivity of the concrete lining by brushing a conductive coating on the surface of the concrete lining of the compressed air energy storage underground cavern. When there are defects such as tiny holes, cracks or corrosion damage on the surface or inside of the flexible sealing layer, the high voltage electricity introduced by the probe brush will form a discharge channel at these defects, generate electric sparks and sound signals to send signals to the host, and the host converts the received signal into an alarm signal, causing the alarm to sound an alarm, thereby realizing accurate positioning of the defect.

[0006] During the leak detection process, the probe brush, telescopic rod and alarm work together. When a leak is detected in the flexible sealing layer, an alarm will be immediately sounded because the high voltage electricity passes through the leak and connects with the conductive coating, reminding the operator that there is a leak in the area swept by the probe brush.

[0007] For compressed air energy storage underground caverns of different sizes, different specifications of brushes can be equipped to achieve the regulation of detection efficiency and detection accuracy. To increase the efficiency of leak detection, a large-sized brush with sparse bristles can be used, for example, the width of the brush is at least 1 meter; to increase the detection accuracy, a small-sized brush with dense bristles can be used, for example, the width of the brush is less than 0.5 meters.

[0008] The method of the invention has high detection efficiency, adjustable detection accuracy, is easy to operate and causes little damage to the flexible sealing layer. It is an ideal method for leak detection of the flexible sealing layer of an underground cavern for compressed air energy storage.

[0009] Preferably, in step (1), the conductive coating is applied to the surface of the concrete lining corresponding to the joint of the flexible sealing layer, or the conductive coating is applied to the entire surface of the concrete lining.

[0010] Preferably, in step (1), the conductive coating is liquid carbon fiber coating or metal coating.

[0011] Preferably, the probe brush is a metal brush head with a convex curvature.

[0012] Preferably, the host includes a chassis, a transformer, an operating mainboard, a leakage counter, a display and a grounding wire. Four rubber wheels are installed at the bottom of the chassis. The leakage point counter is used to record the number of leakage points in the working state and display the number of leakage points on the display.

[0013] Preferably, during the construction of the flexible sealing layer, the operator steps on the bottom of the hole where the flexible sealing layer is not installed for leak detection. During the leak detection process, the grounding wire is connected to the surface of the concrete lining.

[0014] Preferably, leak detection is carried out after the entire construction of the flexible sealing layer is completed. During the leak detection process, the grounding wire is connected to the adjacent rock mass outside the compressed air energy storage underground chamber.

[0015] Preferably, the operator starts leak detection from the far end of the compressed air energy storage underground chamber, moves backward along the axis of the compressed air energy storage underground chamber to the exit of the compressed air energy storage underground chamber, and conducts leak detection on the stepped-on part of the flexible sealing layer while moving backward. If a leak point is detected, leakage repair measures are used to repair the leak point and the leak point is retested at the repaired leak point location.

[0016] Preferably, during the operation period of the compressed air energy storage underground chamber, if it is monitored that the flexible sealing layer leaks air, leak detection is carried out as follows: first, slowly release the air pressure in the compressed air energy storage underground chamber to atmospheric pressure, then let it stand for 24 hours. During the standing process, monitor data including deformation, displacement, and pressure are observed in real time to determine the leaking area. If the monitoring data is normal, the grounding wire is connected to the adjacent rock mass outside the compressed air energy storage underground chamber, and the operator and the detection device enter the cave; after the operator reaches the leaking area, first deal with the metal objects in the leaking area and use tools to dry the leaking area, then the operator holds an electric spark detector to conduct leak detection in the leaking area and record the leak point location, then use leakage repair measures to repair the leak point, and finally retest the leak point at the repaired leak point location; after the leak repair is completed, the operator and the detection device retreat to the outside of the cave, and leak detection is carried out on the stepped-on part of the flexible sealing layer while retreating. If a leak point is detected, leakage repair measures are used to repair the leak point and the leak point is retested at the repaired leak point location.

[0017] Compared with the prior art, the present invention has the following advantages: By applying a conductive coating on the surface of the concrete lining of the underground chamber for compressed air energy storage, the conductivity of the concrete lining is enhanced. When there are defects such as tiny holes, cracks or corrosion damage on the surface or inside of the flexible sealing layer, the high-voltage electricity introduced by the detection brush will form a discharge channel at these defects, generating electric sparks and sound signals to send signals to the host. The host converts the received signals into alarm signals, causing the alarm to sound, thereby achieving precise positioning of the defects. The method of the present invention can detect flexible sealing layers spliced by various methods including glue pasting, vulcanization bonding and bolt connection. The detection method of the present invention has high detection efficiency, adjustable detection accuracy, is easy to operate and causes little damage to the flexible sealing layer, and is an ideal method for detecting leakage points of the flexible sealing layer of the underground chamber for compressed air energy storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the leakage point detection state in Embodiment 1; Figure 2 is Figure 1 the enlarged view at A in Figure 3 It is a schematic diagram of the leakage point detection state in Embodiments 2 and 3; Figure 4 It is a front view schematic diagram of the host used in Embodiments 1 to 3; The specific reference numerals in the drawings are as follows: 1 - Host, 10 - Chassis, 11 - Transformer, 12 - Operation main board, 13 - Leakage counter, 14 - Display, 15 - Grounding wire, 16 - Rubber wheel, 17 - Power cord, 2 - Electric spark detector, 21 - Detection brush, 22 - Telescopic rod, 23 - Alarm, 3 - Concrete lining, 4 - Flexible sealing layer, 5 - Conductive coating, 6 - Surrounding rock; Figure 1 、 Figure 3 The direction indicated by the arrow in is the detection direction in Embodiments 1 to 3 (i.e., the moving direction of the operator during the leakage point detection process in the cave). DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The present invention will be further described in detail below in conjunction with the embodiments of the drawings. The processes, devices or structures not defined in the present invention all adopt the prior art.

[0020] Embodiment 1: See Figure 1 and Figure 2 , during the construction process of the flexible sealing layer, the leakage points are detected, and the detection method includes the following steps: (1) A conductive coating 5 is applied to the surface of the concrete lining 3 corresponding to the joint of the flexible sealing layer 4. The concrete lining 3 is arranged on the surface of the surrounding rock 6. The conductive coating 5 is made of liquid carbon fiber coating. Then, the flexible sealing layer 4 is installed in pieces on the surface of the concrete lining 3. (2) Prepare a detection device, which includes a host 1 and a spark detector 2. The spark detector 2 consists of a probe brush 21, a telescopic rod 22 and an alarm 23. The probe brush 21 is a metal brush head with a convex arc. The probe brush 21 is installed on the telescopic rod 22 to facilitate the detection of the flexible sealing layer 4 on the side wall and top of the cavern. The surface of the telescopic rod 22 is covered with an insulating layer to protect the safety of the operator. The extension and retraction of the telescopic rod 22 is controlled by the host 1. The alarm 23 is installed on the telescopic rod 22. The probe brush 21 and the alarm 23 are electrically connected to the host 1 respectively. The host 1 is connected to the external power supply of the compressed air energy storage underground cavern through a power cord 17, as shown in FIG. Figure 4 As shown, the host 1 includes a chassis 10, a transformer 11, an operating mainboard 12, a leakage counter 13, a display 14 and a grounding wire 15. Four rubber wheels 16 are installed at the bottom of the chassis 10. The leakage counter 13 is used to record the number of leakage points in the working state and display the number of leakage points on the display 14. The host 1 is used to convert the external low-voltage current into a high-voltage current and transmit it to the detection brush 21 in the working state. The detection brush 21 is used to detect the leakage point of the flexible sealing layer 4. When the leakage point is detected, an electric spark and a sound signal are generated and sent to the host 1. The host 1 converts the received signal into an alarm signal, so that the alarm 23 sends a visual or audible alarm; (3) After inspecting and treating (by covering with polyurethane or spraying with liquid rubber, etc.) the metal objects on the surface of the flexible sealing layer 4, the operator takes protective measures, connects the grounding wire 15 to the surface of the concrete lining 3, steps on the bottom of the hole where the flexible sealing layer 4 is not installed, and carries out leakage detection in the compressed air energy storage underground cavern with the spark detector 2. If the alarm 23 sounds an alarm and the number of leakage points is displayed on the display 14, the operator records the leakage point location; (4) Use leak repair methods to repair the leak, and then re-test the leak location after repair to ensure that the leak repair effect is good.

[0021] The detection method of Example 1 has relatively low requirements on the conductive coating 5 and is suitable for the case where the thickness of the flexible sealing layer 4 is relatively thick.

[0022] Example 2: See Figure 3 After the flexible sealing layer is fully constructed, the leak point is detected. The detection method includes the following steps: (1) A conductive coating 5 is applied to the entire surface of a concrete lining 3 of a compressed air energy storage underground cavern. The conductive coating 5 is made of a metallic coating, and then a flexible sealing layer 4 is installed in pieces on the surface of the concrete lining 3; (2) Prepare the same detection device as in Example 1; (3) After checking and dealing with the metal objects on the surface of the flexible sealing layer 4, the operator takes protective measures, connects the grounding wire 15 to the adjacent rock mass outside the compressed air energy storage underground chamber, and the operator starts the leak detection from the far end of the compressed air energy storage underground chamber, along the axis of the compressed air energy storage underground chamber, retreats to the exit of the compressed air energy storage underground chamber, and conducts leak detection on the trampled part of the flexible sealing layer 4 while retreating. If a leak point is detected, adopt leak repair means to repair the leak point and conduct leak re-detection on the position of the leak point after repair.

[0023] The detection efficiency of the detection method of Example 2 is relatively high, and it is applicable to the leak detection of flexible sealing layers 4 with different thicknesses.

[0024] Example 3: See Figure 3 , during the operation period of the compressed air energy storage underground chamber, conduct leak detection. The flexible sealing layer 4 is installed in sections on the entire surface of the concrete lining 3 of the compressed air energy storage underground chamber. A conductive coating 5 is applied between the concrete lining 3 and the flexible sealing layer 4, and the conductive coating 5 uses a metal coating; during the operation period, mainly monitor the sealing performance of the flexible sealing layer 4. If it is monitored that the flexible sealing layer 4 has a gas leakage phenomenon, use the same detection device as in Example 1 to conduct leak detection, and the operation is as follows: (1) First, slowly release the air pressure in the compressed air energy storage underground chamber to atmospheric pressure, and then let it stand for 24 hours. During the standing process, monitor the data including deformation, displacement, and pressure in real time and determine the leaking area. If the monitoring data is normal, connect the grounding wire 15 to the adjacent rock mass outside the compressed air energy storage underground chamber, and the operator and the detection device enter the cave; (2) After the operator arrives at the leaking area, first deal with the metal objects in the leaking area and use tools such as a blower to dry the leaking area, then the operator holds an electric spark detector to conduct leak detection in the leaking area and record the position of the leak point, then adopt leak repair means to repair the leak point, and finally conduct leak re-detection on the position of the leak point after repair; (3) After the leak repair is completed, the operator and the detection device retreat to the outside of the cave, and conduct leak detection on the trampled part of the flexible sealing layer 4 while retreating. If a leak point is detected, adopt leak repair means to repair the leak point and conduct leak re-detection on the position of the leak point after repair.

[0025] In specific applications, the thickness of the flexible sealing layer has a great influence on the detection voltage. Before detecting leakage points using the method of the present invention, it is possible to refer to the specification requirements of the "Technical Standard for Polyolefin Adhesive Tape Anti-corrosion Coating of Steel Pipelines" (SY / T 0414-2017), and select an appropriate detection voltage in combination with the test results to ensure the accuracy and safety of leakage point detection.

Claims

1. A method for detecting leakage points of a flexible sealing layer in an underground chamber for compressed air energy storage, characterized in that, The detection method comprises the following steps: (1) Apply a conductive coating on the surface of the concrete lining of the compressed air energy storage underground cavern, and then install the flexible sealing layer in pieces on the surface of the concrete lining; (2) Prepare a detection device, which includes a host and an electric spark detector, the electric spark detector consists of a probe brush, a telescopic rod and an alarm, the probe brush is installed on the telescopic rod, the surface of the telescopic rod is covered with an insulating layer, the extension and retraction of the telescopic rod is controlled by the host, the alarm is installed on the telescopic rod, the probe brush and the alarm are electrically connected to the host respectively, the host is connected to the external power supply of the compressed air energy storage underground cavern through a power cord, the host is used to convert the external low-voltage current into high-voltage current and transmit it to the probe brush in the working state, the probe brush is used to detect the leakage point of the flexible sealing layer, and when the leakage point is detected, it generates electric sparks and sound signals and sends signals to the host, and the host converts the received signal into an alarm signal, so that the alarm sounds an alarm; (3) After inspecting and handling the metal objects on the surface of the flexible sealing layer, the operator takes protective measures and uses a spark detector to detect leaks in the compressed air energy storage underground cavern and records the leak locations; (4) Use leak repair methods to repair the leak point, and then re-test the leak point after the repair.

2. The method for detecting leakage points of the flexible sealing layer of the underground chamber for compressed air energy storage according to claim 1, wherein In step (1), the conductive coating is applied to the surface of the concrete lining corresponding to the joint of the flexible sealing layer.

3. The method for detecting leakage points of the flexible sealing layer of the underground chamber for compressed air energy storage according to claim 1, wherein In step (1), the conductive coating is applied to the entire surface of the concrete lining.

4. The leak point detection method for the flexible sealing layer of the underground chamber for compressed air energy storage according to claim 1, wherein In step (1), the conductive coating is liquid carbon fiber coating or metal coating.

5. The method for detecting leakage points of the flexible sealing layer of the underground chamber for compressed air energy storage according to claim 1, wherein The exploration brush is a metal brush head with an outwardly convex curvature.

6. The method for detecting leakage points of the flexible sealing layer of the underground chamber for compressed air energy storage according to claim 1, characterized in that, The host comprises a chassis, a transformer, an operating mainboard, a leakage counter, a display and a grounding wire. Four rubber wheels are installed at the bottom of the chassis. The leakage point counter is used to record the number of leakage points in a working state and display the number of leakage points on the display.

7. The method for detecting leakage points of the flexible sealing layer of the underground chamber for compressed air energy storage according to claim 6, characterized in that, During the construction of the flexible sealing layer, an operator steps on the bottom of the hole where the flexible sealing layer is not installed to perform a leak detection. During the leak detection, the grounding wire is connected to the surface of the concrete lining.

8. The method for detecting leakage points of the flexible sealing layer of the underground chamber for compressed air energy storage according to claim 6, wherein After the flexible sealing layer is completely constructed, a leak detection is performed. During the leak detection process, the grounding wire is connected to the adjacent rock mass outside the compressed air energy storage underground cavern.

9. The method for detecting leakage points of the flexible sealing layer of the underground cavern for compressed air energy storage according to claim 7, characterized in that, The operator starts the leakage detection from the far end of the compressed air energy storage underground cavern, and moves backward along the axis of the compressed air energy storage underground cavern to the exit of the compressed air energy storage underground cavern, while moving backward to detect the leakage of the stepped part of the flexible sealing layer. If a leakage is found during the detection, the leakage is repaired by means of leak repairing means and the repaired leakage position is retested.

10. The method for detecting leakage points of the flexible sealing layer of the underground chamber for compressed air energy storage according to claim 6, wherein, During the operation period of the underground chamber for compressed air energy storage, if it is monitored that air leakage occurs in the flexible sealing layer, leak point detection shall be carried out as follows: First, slowly release the air pressure in the underground chamber for compressed air energy storage to the atmospheric pressure, and then let it stand for 24 hours. During the standing process, monitor data including deformation, displacement, and pressure shall be observed in real time to determine the leaking area. If the monitoring data is normal, connect the grounding wire to the adjacent rock mass outside the underground chamber for compressed air energy storage, and the operator and the detection device enter the chamber; After the operator reaches the leaking area, first deal with the metal objects in the leaking area and dry the leaking area with tools. Then, the operator holds an electric spark detector to detect the leak points in the leaking area and record the positions of the leak points. After that, adopt leak repair measures to repair the leak points, and finally conduct a re-detection of the leak points at the repaired positions; After the leak point repair is completed, the operator and the detection device retreat outside the chamber. At the same time of retreating, detect the leak points at the trampled parts of the flexible sealing layer. If leak points are detected, adopt leak repair measures to repair the leak points and conduct a re-detection of the leak points at the repaired positions.

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