Micro-water detection device for high-voltage cable

Abstract

The utility model discloses a micro-water detection device of a high voltage cable, which comprises a cable (1) used for detection, the cable (1) is a cable (1) after water seepage, the cable (1) comprises a conductor (1.1), an insulating layer (1.2), a metal sleeve (1.3) and an outer sheath (1.4) from inside to outside, one end of the cable (1) is connected with a nitrogen pump (2), the output end of the nitrogen pump (2) is sleeved on the insulating layer (1.2), and the outer sheath (1.4) is sleeved on the outer sheath (1.4). The other end of the cable (1) is connected with a first humidity tester (3), and the input end of the first humidity tester (3) is sleeved on the insulating layer (1.2). The utility model provides the micro-water detection device for the high-voltage cable, which is low in maintenance cost, effective and small in work amount.

Description

Technical Field

[0001] This utility model relates to the field of cable inspection and maintenance, specifically a micro-moisture detection device for high-voltage cables. Background Technology

[0002] As the service life of land cables increases, even if the overall structure of the cable is not damaged, some water may seep into the conductor inside the cable, which can easily cause a decrease in the conductor's power transmission efficiency and conductor breakdown faults.

[0003] For the problem of water leakage in high-voltage cables, a more effective maintenance solution is to directly replace the original ground cable. However, this maintenance solution is costly and requires the ground cable to be re-laid, which involves a large amount of work and a long maintenance cycle. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a low-maintenance, effective, and minimally engineering-intensive micro-moisture detection device for high-voltage cables.

[0005] The technical solution adopted by this utility model to solve the above problems is as follows: a micro-water detection device for high-voltage cables, including a cable for detection, the cable being a cable after water seepage, the cable including a conductor, an insulation layer, a metal sleeve and an outer sheath from the inside out, one end of the cable is connected to a nitrogen pump, the output end of the nitrogen pump is sleeved on the insulation layer, and the other end of the cable is connected to a first humidity tester, the input end of the first humidity tester is sleeved on the insulation layer.

[0006] Compared with the prior art, the advantages of this utility model are as follows: First, this detection device is designed for water seepage maintenance of cables with intact overall structure and no obvious damage. During the maintenance process, a nitrogen pump at one end of the cable delivers high-pressure nitrogen to the cable conductor, and then the nitrogen carries the seeping water out of the cable from the other end, completing the water seepage maintenance of the cable conductor. To avoid nitrogen from entering the gap between the insulation layer and the metal sheath, causing separation between the insulation layer and the metal sheath, the metal sheath of the cable is first separated from the outer sheath when connecting the output end of the nitrogen pump to the cable, and then the output end of the nitrogen pump is connected to the insulation layer. The function of the first humidity tester is to detect the moisture content when the cable discharges nitrogen. When no moisture is discharged for a long time, it proves that the water seepage maintenance of the conductor has been completed.

[0007] As an improvement of this utility model, a second humidity tester is provided between the nitrogen pump and the cable. Through this improvement, the moisture content in the nitrogen output by the nitrogen pump can be checked, avoiding the situation where the nitrogen used for water seepage maintenance contains high moisture content, which not only fails to provide protection but also exacerbates the water seepage problem of the cable.

[0008] As an improvement of this utility model, a pressure reducing safety valve is provided between the nitrogen pump and the second humidity tester. This improvement is used to stabilize the output air pressure of the nitrogen pump, so that the air pressure can be steadily pushed inside the cable, without fluctuating pushing air pressure inside the cable. Fluctuating pushing air pressure can easily break up water molecules, making it more difficult to expel them from the cable. At the same time, it can also reduce air pressure noise.

[0009] As an improvement of this utility model, a first sealing sleeve is provided at the connection between the nitrogen pump and the cable. The first sealing sleeve is fitted onto the insulation layer of the cable. A nitrogen inlet hole for nitrogen flow is provided on the axis of the first sealing sleeve. Through this improvement, the sealing performance of the nitrogen pump is ensured. Because the cable is long and the input pressure is high, if the sealing performance between the output end of the nitrogen pump and the cable is poor, a large amount of nitrogen will be discharged from the output end of the nitrogen pump and the cable, and the purpose of drainage cannot be achieved. The nitrogen inlet hole is used to realize nitrogen delivery.

[0010] As an improvement of this utility model, a connecting sealing component is provided between the first sealing sleeve and the insulating layer. Through this improvement, the sealing performance between the first sealing sleeve and the insulating layer is guaranteed.

[0011] As an improvement of this utility model, the connecting sealing assembly includes a sealing tape and a sealing ring. The sealing tape is wrapped around the insulation layer, the inner side of the sealing ring is sealed to the sealing tape, and the outer side of the sealing ring is sealed to the inner wall of the first sealing sleeve. The sealing ring is inclined near the insertion end of the first sealing sleeve. Through this improvement, a high-strength seal of the connecting sealing assembly is achieved. Firstly, to avoid damage to the insulation layer during the sealing process and to repair the roughness of the insulation layer surface, the sealing tape is first wrapped around the insulation layer to ensure the effectiveness of the seal and the integrity of the insulation layer. After water seepage maintenance, the insulation layer can still be effectively connected. Then, through the compression of the first sealing sleeve and the sealing ring, a high-strength sealing structure is formed, thereby ensuring that the nitrogen gas input to the cable will be transported along the conductor and will not leak from the connecting sealing assembly. The inclined setting of the sealing ring near the insertion end of the first sealing sleeve facilitates the compression of the sealing ring by the first sealing sleeve, making it easier for the first sealing sleeve to complete the sealing connection with the sealing ring.

[0012] As an improvement of this utility model, the insertion end of the first sealing sleeve is provided with a fastening cap. The fastening cap is used to strengthen the sealing connection between the first sealing sleeve and the sealing ring. Through this improvement, during the sealing compression process between the first sealing sleeve and the sealing ring, the connection between the first sealing sleeve and the sealing ring is easily subjected to the reaction force of compression, causing the first sealing sleeve to flare and deform. By designing the fastening cap, the structural strength of the connection between the first sealing sleeve and the sealing ring can be increased, and deformation can be avoided.

[0013] As an improvement of this utility model, a second sealing sleeve is provided at the connection between the first humidity tester and the cable. The second sealing sleeve is also fitted onto the insulation layer of the cable. A nitrogen output hole for nitrogen gas flow is provided on the axis of the second sealing sleeve. Through the improvement, the design of the second sealing sleeve is used to ensure the sealing when nitrogen gas is discharged from the cable. The nitrogen output hole is used to realize the delivery of nitrogen gas, which facilitates the first humidity tester to detect water molecules in the nitrogen gas.

[0014] As an improvement of this utility model, a sealing tape is wrapped around the connection between the second sealing sleeve and the insulation layer. With this improvement, since the gas pressure has dropped significantly when nitrogen is discharged from the cable and no further work is required, a high-strength seal is not necessary. Only a simple seal is required, which is sufficient for the smooth detection of the first humidity tester. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall cross-sectional structure of this utility model.

[0016] Figure 2 This is a cross-sectional view of the connection structure of the connection and sealing assembly of this utility model.

[0017] The figure shows: 1. Cable, 1.1. Conductor, 1.2. Insulation layer, 1.3. Metal sheath, 1.4. Outer sheath, 2. Nitrogen pump, 3. First humidity tester, 4. Second humidity tester, 5. Pressure reducing safety valve, 6. First sealing sleeve, 6.1. Nitrogen inlet port, 6.2. Fastening cap, 7. Connecting sealing assembly, 7.1. Sealing tape, 7.2. Sealing ring, 8. Second sealing sleeve, 8.1. Nitrogen outlet port, 9. Sealing tape. Detailed Implementation

[0018] The embodiments of this utility model will be further described below with reference to the accompanying drawings.

[0019] like Figure 1 As shown, a micro-moisture detection device for a high-voltage cable includes a cable 1 for detection. The cable 1 is a cable 1 after water seepage. The cable 1 includes a conductor 1.1, an insulation layer 1.2, a metal sheath 1.3, and an outer sheath 1.4 from the inside out. One end of the cable 1 is connected to a nitrogen pump 2, and the output end of the nitrogen pump 2 is sleeved on the insulation layer 1.2. The other end of the cable 1 is connected to a first humidity tester 3, and the input end of the first humidity tester 3 is sleeved on the insulation layer 1.2.

[0020] A second humidity tester 4 is installed between the nitrogen pump 2 and the cable 1, and a pressure reducing safety valve 5 is installed between the nitrogen pump 2 and the second humidity tester 4. Both the first humidity tester 3 and the second humidity tester 4 are conventional dew point humidity testers. Humidity testing can be performed simply by inserting the test probe into the gas tube and sealing it properly.

[0021] like Figure 1 , Figure 2 As shown, a first sealing sleeve 6 is provided at the connection between the nitrogen pump 2 and the cable 1. The first sealing sleeve 6 is sleeved on the insulation layer 1.2 of the cable 1. A nitrogen inlet hole 6.1 for nitrogen flow is provided on the axis of the first sealing sleeve 6. A connecting sealing assembly 7 is provided between the first sealing sleeve 6 and the insulation layer 1.2. The connecting sealing assembly 7 includes a sealing strip 7.1 and a sealing ring 7.2. The sealing strip 7.1 is wrapped around the insulation layer 1.2. The inner side of the sealing ring 7.2 is sealed to the sealing strip 7.1, and the outer side of the sealing ring 7.2 is sealed to the inner wall of the first sealing sleeve 6. The sealing ring 7.2 is inclined near the insertion end of the first sealing sleeve 6. The insertion end of the first sealing sleeve 6 is provided with a fastening cap 6.2. The fastening cap 6.2 is used to strengthen the sealing connection between the first sealing sleeve 6 and the sealing ring 7.2. The connection surface between the fastening cap 6.2 and the first sealing sleeve 6 is inclined, and the fastening cap 6.2 and the first sealing sleeve 6 are connected by threads. When the fastening cap 6.2 is fixedly connected to the first sealing sleeve 6, the first sealing sleeve 6 can be compressed at the same time, causing the first sealing sleeve 6 to contract towards the sealing ring 7.2, thereby increasing the sealing strength.

[0022] like Figure 1 As shown, a second sealing sleeve 8 is provided at the connection between the first humidity tester 3 and the cable 1. The second sealing sleeve 8 is also fitted onto the insulation layer 1.2 of the cable 1. A nitrogen output hole 8.1 for nitrogen gas to flow is provided on the axis of the second sealing sleeve 8. A sealing tape 9 is wrapped around the connection between the second sealing sleeve 8 and the insulation layer 1.2.

[0023] During the inspection and maintenance process, the cable is directly processed according to the two ends of the land cable 1, and the first sealing sleeve 6 and the second sealing sleeve 8 are installed. If there is a height difference between the two ends of the cable 1, the first sealing sleeve 6 is placed at the higher end to facilitate better drainage of water that has seeped into conductor 1.1. During the drainage process, the dryness of the output nitrogen is ensured by the second humidity tester 4, while the adequacy of the maintenance drainage is ensured by the first humidity tester 3. The humidity of the first humidity tester 3 is recorded every two hours. When the data is lower than the specified standard for several consecutive times without fluctuation, the drainage operation is considered complete, and the two ends of the cable 1 can be reconnected.

[0024] This method has low inspection and maintenance costs, does not require re-laying of cable 1, involves a small amount of work, has low maintenance intensity, and can ensure the effectiveness and quality of maintenance.

[0025] The above description only illustrates the preferred embodiment of this utility model and should not be construed as limiting the scope of the claims. This utility model is not limited to the above embodiments, and variations in its specific structure are permitted. All changes made within the scope of the independent claims of this utility model are also within the scope of protection of this utility model.

Claims

1. A device for detecting micro water in a high voltage cable, characterized in that: The utility model provides a kind of cable (1) for detection, the cable (1) is waterlogged cable (1), the cable (1) includes conductor (1.1) from inside to outside, insulating layer (1.2), metal sleeve (1.3) and outer sheath (1.4), one end of the cable (1) is connected with nitrogen gas pump (2), the output of the nitrogen gas pump (2) is sleeved on insulating layer (1.2), the other end of the cable (1) is connected with first humidity tester (3), the input of the first humidity tester (3) is sleeved on insulating layer (1.2); The connection of the nitrogen gas pump (2) and the cable (1) is equipped with first sealing sleeve (6), the first sealing sleeve (6) is sleeved on the insulating layer (1.2) of the cable (1), nitrogen gas input hole (6.1) for nitrogen gas circulation is equipped on the axis of the first sealing sleeve (6), connecting sealing assembly (7) is equipped between the first sealing sleeve (6) and the insulating layer (1.2), the connecting sealing assembly (7) includes sealing strip (7.1) and sealing ring (7.2), the sealing strip (7.1) is wrapped on the insulating layer (1.2), the inner side of the sealing ring (7.2) is closedly connected with the sealing strip (7.1), the outer side of the sealing ring (7.2) is closedly connected with the inner wall of the first sealing sleeve (6), the sealing ring (7.2) is inclinedly arranged close to the insertion end of the first sealing sleeve (6), the insertion end of the first sealing sleeve (6) is equipped with fastening cap (6.2), the connecting surface between fastening cap (6.2) and the first sealing sleeve (6) is inclinedly arranged, and fastening cap (6.2) and the first sealing sleeve (6) are connected by screw thread, and the fastening cap (6.2) is used to strengthen the sealing connection between the first sealing sleeve (6) and the sealing ring (7.2); The connection of the first humidity tester (3) and the cable (1) is equipped with second sealing sleeve (8), the second sealing sleeve (8) is also sleeved on the insulating layer (1.2) of the cable (1), nitrogen gas output hole (8.1) for nitrogen gas circulation is equipped on the axis of the second sealing sleeve (8), and sealing band (9) is wound at the connection of the second sealing sleeve (8) and the insulating layer (1.2).

2. A device for detecting the presence of micro water in a high voltage cable according to claim 1, characterized in that: Second humidity tester (4) is equipped between the nitrogen gas pump (2) and the cable (1).

3. A device for detecting the presence of micro water in a high voltage cable according to claim 2, characterized in that: Pressure relief safety valve (5) is equipped between the nitrogen gas pump (2) and the second humidity tester (4).

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