CN110994437A

CN110994437A - High-voltage cable water inlet treatment method

Info

Publication number: CN110994437A
Application number: CN201911154248.2A
Authority: CN
Inventors: 余臣斌; 宋国林; 郭翔宇; 李新平
Original assignee: Chongqing Taishan Cable Co Ltd
Current assignee: Chongqing Taishan Cable Co Ltd
Priority date: 2019-11-22
Filing date: 2019-11-22
Publication date: 2020-04-10

Abstract

The invention discloses a high-voltage cable water inlet treatment method, which comprises the steps of connecting one end of a high-voltage cable with an air inlet device, connecting the other end of the high-voltage cable with an air exhaust device, simultaneously utilizing the air exhaust device for vacuumizing and utilizing nitrogen flushed by the air inlet device to suck out inlet water in the high-voltage cable, continuously vacuumizing the air exhaust device, and secondarily filling nitrogen when no water exists in the air exhaust device to evacuate water in a buffer layer.

Description

High-voltage cable water inlet treatment method

Technical Field

The invention relates to the technical field of repairing after water enters a cable due to improper treatment in the laying and using processes of high-voltage cables, in particular to a high-voltage cable water inlet treatment method.

Background

With the development of economy, the dosage of the crosslinked cable is increased explosively, the technical quality of a construction team is far lagged behind the development requirement, and the water inflow of the cable is often caused. The water inflow of the cross-linked cable is divided into two situations in a large range, the first situation is that in the cable laying process, a joint is not installed, and the water inflow of the cable is caused by weather or construction and other reasons; the second is that the cable is already put into operation or the accessories at both ends are already manufactured, and the outer layer of the cable is broken to cause water inflow due to construction, artificial damage or the protection sleeve is punctured by a hard object. The first case occurs with a relatively high probability, about 90% or more, and includes the case where the cable is laid without a splice being made or where one end is spliced and the other end is found to be flooded. In these cases, the water is divided into the core water inlet, the buffer layer (filling layer) water inlet or the core and the buffer layer (filling layer) water inlet at the same time. In order to solve the potential safety hazard of the cable caused by water inflow of the buffer layer (filling layer), the technical personnel in the field are dedicated to develop a method and a device for treating the water inflow of the buffer layer (filling layer) of the cable. The device for treating the high-voltage cable water inlet is a vacuumizing device for treating the high-voltage cable water inlet, which is portable in use, convenient to operate, effective in use in engineering, small in engineering amount, low in cost, and capable of improving the working efficiency and reducing the cost.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention provides a method for pumping out water from a high-voltage cable after water is introduced into the cable, so as to restore the cable to a normal operating environment. In order to achieve the purpose, the invention discloses a method for treating high-voltage cable inlet water, which is characterized by comprising the following steps: comprises the following steps

1) Connecting one end of a high-voltage cable with an air inlet device, and connecting the other end of the high-voltage cable with an air exhaust device;

2) starting the air extractor to suck vacuum, introducing nitrogen for the first time when the pressure value of the buffer layer reaches-0.25 MPa to-0.15 MPa, so that the pressure value of the buffer layer reaches negative pressure of-0.07 MPa to-0.03 MPa, stopping introducing the nitrogen when no water is sucked from the air extractor, and continuously vacuumizing the air extractor; when no water gas appears in the air extractor, nitrogen is filled for the second time, so that the pressure value of the buffer layer is kept between-0.07 MPa and-0.03 MPa;

3) and (4) observing whether the high-speed expansion water-absorbing resin placed on the buffer layer is dried or not, stopping the treatment if the high-speed expansion water-absorbing resin is dried, and returning to the step 2 to continue the treatment until the high-speed expansion water-absorbing resin is dried.

Furthermore, the time for filling nitrogen for the first time is calculated according to the following mode, the air inlet time is not less than 4 hours when the length of the high-voltage cable is less than 400m, the air inlet time is calculated according to 1 hour per 100 m-150 m when the length of the high-voltage cable exceeds 400m, a part of inlet water of the high-voltage cable is volatilized to form water vapor to be adsorbed in the buffer layer after the inlet water of the high-voltage cable, the time of the pumping process is too short, only the liquid inlet water is pumped, and the water vapor part can be completely pumped after being pumped for multiple times.

Further, air inlet unit includes that the nitrogen cylinder links to each other with relief pressure valve one end through first intake pipe, the relief pressure valve other end passes through the second intake pipe and links to each other with the suction nozzle, and the purpose of relief pressure valve is regulation and control nitrogen gas inlet pressure.

Further, air exhaust device includes the vacuum pump is connected with the overflow jar through first exhaust tube, the overflow jar passes through the second exhaust tube and is connected with the suction nozzle, can directly observe the inflow of suction through the overflow jar, helps operating personnel to judge high tension cable reason of intaking according to the inflow, also helps operating personnel to predict nitrogen gas and pour into quantity.

Furthermore, a sealing tape is wound and sealed between the air inlet nozzle and the second air inlet pipe.

Furthermore, the first air inlet pipe and the second air inlet pipe are made of multilayer rubber pipes.

Furthermore, install second valve and third valve on the first exhaust tube, the case aperture of adjusting second valve and third valve of installing on first exhaust tube can effectually block the intaking that the suction was come, prevents to get into the vacuum pump and influences the suction effect, install first valve on the second exhaust tube, the water backflow high tension cable of overflow jar when preventing to dismantle air exhaust device, the drain valve is installed to overflow jar bottom for get rid of too much intaking.

Furthermore, a sealing tape is wound and sealed between the air suction nozzle and the second air suction pipe.

Furthermore, the first air exhaust pipe and the second air exhaust pipe are made of multiple layers of rubber pipes.

The invention has the beneficial effects that: the cable vacuumizing device is simple in structural design, scientific in design, convenient and portable, simple to maintain and high in practicability.

Drawings

Fig. 1 shows an intake system according to the present embodiment.

FIG. 2 shows the air suction device of the present embodiment.

Figure 3 is a water treatment device with the attachment installed.

Reference numbers in the figures: 1 a conductor; 2 insulating the wire core; 3, sheathing; 401 a first sealing means; 402 a second sealing device; 501, an air exhaust nozzle; 502 an air inlet nozzle; 601 a first valve; 602 a second valve; 603 a third valve; 7, a water overflow cylinder; 8, a drain valve; 9 a vacuum pump; 10 vacuum gauge; 11 nitrogen gas cylinder; 12 a pressure reducing valve; 1301 a first exhaust pipe; 1302 a second extraction duct; 1401 a first intake duct; 1402 second intake manifold.

Detailed Description

The invention will be further illustrated with reference to the following examples in figures 1 to 3:

as shown in the figures 1 to 3 of the drawings,

one end of a treated high-voltage cable is connected with an air inlet device, the treated high-voltage cable conductor 1 is equal to the insulation wire core 2 in length or the conductor 1 is longer than the insulation wire core 2, the insulation wire core 2 is longer than the sheath 3, so that a sealing device can be conveniently installed, one end of the air inlet nozzle 502 is connected with the second sealing device 402, the other end of the air inlet nozzle 502 is connected with one end of a second air inlet pipe 1402, the other end of the second air inlet pipe 1402 is connected with one end of a pressure reducing valve 12, and the other end of the pressure reducing valve 12 is connected with a nitrogen gas bottle 11 through a.

Connecting the other end of the treated high-voltage cable inlet with an air extraction device, connecting one end of an air extraction nozzle 402 with a first sealing device 401, installing a valve 601 on a second air extraction pipe 1302, and respectively connecting the two ends of the second air extraction pipe 1302 with an overflow cylinder 7 and the air extraction nozzle 501; the

valves

602 and 603 are installed on the first suction pipe 1301, and then both ends of the first suction pipe 1301 are connected to the overflow tank 7 and the vacuum pump 9, respectively.

Starting the vacuum pump 9, introducing nitrogen when the pressure value of the buffer layer reaches-0.25 MPa to-0.15 MPa, adjusting the pressure reducing valve 12 to enable the pressure value of the vacuum meter 10 to reach-0.07 MPa to-0.03 MPa, stopping introducing the nitrogen when no water is sucked in the air extraction device, continuously vacuumizing the vacuum pump 9, and introducing the nitrogen for the second time when no water exists in the air extraction device to enable the pressure value of the buffer layer to be maintained at-0.07 MPa to-0.03 MPa.

After the buffer layer is treated according to the method, the drying degree of the buffer layer is checked, the sheath of the high-voltage cable at the end of the air extracting device is cut off by 10-15 cm, whether the high-speed expansion water-absorbing resin placed on the buffer layer is dried or not is observed, if the high-speed expansion water-absorbing resin is dried, the treatment is stopped, otherwise, the method is returned to the method for continuous treatment until the requirement is met.

For a running high-voltage cable or a cable with accessories at two ends, the metal sheath of the cable is usually damaged in other engineering construction, so that water enters into a buffer layer, if no water enters between the insulation wire core 2 and the conductor 1, the high-voltage cable can be filled in the mode of fig. 3 for water inlet treatment, the two ends of the high-voltage cable with the accessories are connected in the mode of the above-mentioned, nitrogen is flushed into the two ends of the high-voltage cable, and the middle part of the high-voltage cable is vacuumized to carry out the water inlet treatment of the buffer layer of the high-voltage cable.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims

1. A method for treating water entering a high-voltage cable is characterized by comprising the following steps: the method comprises the following steps:

connecting one end of a high-voltage cable with an air inlet device, and connecting the other end of the high-voltage cable with an air exhaust device;

starting the air extractor to suck vacuum, introducing nitrogen for the first time when the pressure value of the buffer layer reaches-0.25 MPa to-0.15 MPa, so that the pressure value of the buffer layer reaches-0.07 MPa to-0.03 MPa, stopping introducing the nitrogen when no water is sucked from the air extractor, and continuously vacuumizing the air extractor; when no water gas appears in the air extractor, nitrogen is filled for the second time, so that the pressure value of the buffer layer is kept between-0.07 MPa and-0.03 MPa;

and (4) observing whether the high-speed expansion water-absorbing resin placed on the buffer layer is dried or not, stopping the treatment if the high-speed expansion water-absorbing resin is dried, and returning to the step 2 to continue the treatment until the high-speed expansion water-absorbing resin is dried.

2. The method for water inlet treatment of high-voltage cable as claimed in claim 1, wherein: the time for filling nitrogen for the first time is calculated according to the following mode, the air inlet time is not less than 4 hours when the length of the high-voltage cable is less than 400m, and the air inlet time is calculated according to 1 hour of every 100 m-150 m when the length of the high-voltage cable exceeds 400 m.

3. The method for water inlet treatment of high-voltage cable as claimed in claim 1, wherein: the air inlet device comprises a second sealing device (402), the second sealing device (402) seals the high-voltage cable buffer layer, and the second sealing device (402) is sequentially connected with an air inlet nozzle (502), a second air inlet pipe (1402), a pressure reducing valve (12), a first air inlet pipe (1401) and a nitrogen gas bottle (11).

4. The method for water inlet treatment of high-voltage cable as claimed in claim 1, wherein: the air extracting device comprises a first sealing device (401), the first sealing device (401) seals the high-voltage cable buffer layer, and the first sealing device (401) is sequentially connected with an air extracting nozzle (501), a second air extracting pipe (1302), an overflow cylinder (7), a first air extracting pipe (1301) and a vacuum pump (9).

5. The method for water inlet treatment of high-voltage cables as claimed in claim 3, wherein the method comprises the following steps: and a sealing tape is adopted to wind and seal between the air inlet nozzle (502) and the second air inlet pipe (1402).

6. The method for water inlet treatment of high-voltage cables as claimed in claim 3, wherein the method comprises the following steps: the first air inlet pipe (1401) and the second air inlet pipe (1402) adopt multilayer rubber pipes.

7. The method for water inlet treatment of high-voltage cables as claimed in claim 4, wherein the method comprises the following steps: the first air suction pipe (1301) is provided with a second valve (602) and a third valve (603), the second air suction pipe (1302) is provided with a first valve (601), and the bottom of the overflow tank (7) is provided with a drain valve (8).

8. The method for water inlet treatment of high-voltage cables as claimed in claim 4, wherein the method comprises the following steps: and a sealing tape is wound and sealed between the air suction nozzle (501) and the second air suction pipe (1302).

9. The method for water inlet treatment of high-voltage cables as claimed in claim 4, wherein the method comprises the following steps: the first air exhaust pipe (1301) and the second air exhaust pipe (1302) are made of multilayer rubber pipes.