CN114123092A

CN114123092A - Be used for prosthetic power cable intermediate head that wets of cable

Info

Publication number: CN114123092A
Application number: CN202111337455.9A
Authority: CN
Inventors: 何嘉兴; 方健; 杨帆; 莫文雄
Original assignee: Guangzhou Power Supply Bureau of Guangdong Power Grid Co Ltd
Current assignee: Guangzhou Power Supply Bureau of Guangdong Power Grid Co Ltd
Priority date: 2021-11-09
Filing date: 2021-11-09
Publication date: 2022-03-01

Abstract

The invention discloses a power cable intermediate joint for cable damp repair, the cable includes exposed conductive core and external insulating layer, the intermediate joint includes: the connector comprises an outer connector and an inner connector arranged inside the outer connector, wherein the outer connector is used for being electrically insulated from the outside, and the inner connector is used for electrically connecting a first cable and a second cable; the inner connector comprises a port assembly, a connector main body, a sealing piece, a liquid storage cavity and a conductive connecting piece; wherein, port subassembly detachably is connected to the joint main part, and the sealing member is connected with joint main part, port subassembly, sets up the liquid storage chamber in the electrically conductive connecting piece outside for connecting the seal structure of first cable, the outside insulating layer of second cable, and inside is provided with the electrically conductive connecting piece and the electrically conductive core electrical connection of through-hole. The invention utilizes the liquid storage cavity of the inner connector to wrap the exposed conductive parts of the two independent cables, thereby forming a fluid channel and a fluid storage chamber which can bear the pressure higher than the atmospheric pressure, and smoothly carrying out pressure type injection repair on the cables.

Description

Be used for prosthetic power cable intermediate head that wets of cable

Technical Field

The invention relates to the technical field of power cable accessories, in particular to a power cable intermediate joint for cable damp repair.

Background

With the rapid development of urban construction, the application of power cables has also increased rapidly. The power cable intermediate joint is a common cable accessory, is used for realizing the electrical connection of two independent cables, and has the functions of water resistance, insulation and the like. A typical underground cable comprises inner and outer semiconductive layers, an insulating layer and copper or aluminium strands. Such underground cables have a service life of 20 to 40 years, and in some cases, the life is shortened when water enters the cable and forms micro-pores in the insulation layer. These pores are distributed in a tree-like fashion over the insulating layer, the collection of which is commonly referred to as a water tree. In the presence of water and ions and the like, water treeing is easily formed in the cable insulation when a medium high voltage ac voltage is applied to the polymer medium (insulator). The water tree area grows gradually and expands, so that the dielectric property of the insulating layer is reduced until breakdown occurs. Water tree growth can be generally inhibited by preventing or reducing invasion of moisture and ions, reducing electrical stress, and the like; in addition, water can be removed and water tree holes can be filled in a mode of injecting a medium reinforcing liquid into gaps among the cable conductive stranded wires, and the insulating property of the cable is improved.

However, the existing intermediate joint cannot meet the cable repair method of injecting the medium reinforcing fluid or repair fluid, for example, the typical cold-shrink type and hot-shrink type intermediate joints cannot bear the air pressure applied during injection, and phenomena such as bulging, air leakage and liquid leakage are generated. Most of medium-voltage underground cables in the power distribution network are provided with more than one intermediate joint, and if the intermediate joints cannot bear the air pressure applied by the cable repairing method, operations such as intermediate joint searching, excavation and dismantling need to be additionally carried out, so that the labor, material and financial resources are consumed.

Disclosure of Invention

The invention aims to provide a power cable intermediate joint for repairing a cable affected with damp so as to solve the technical problem that a large amount of manpower, material resources and financial resources are consumed for repairing the power cable intermediate joint.

The purpose of the invention can be realized by the following technical scheme:

a power cable intermediate joint for moisture repair of a cable, the cable including an exposed conductive core and an outer insulating layer, the intermediate joint comprising:

an outer connector for electrical insulation from the outside and an inner connector disposed inside the outer connector for electrically connecting a first cable and a second cable;

the inner connector comprises a port assembly, a connector main body, a sealing piece, a liquid storage cavity and a conductive connecting piece; the port assembly is detachably connected to the connector main body, the sealing element is connected with the connector main body and the port assembly, the liquid storage cavity arranged on the outer side of the conductive connecting piece is a sealing structure for connecting the external insulating layers of the first cable and the second cable, and a through hole is formed inside the conductive connecting piece and electrically connected with the conductive core.

Optionally, the outer connector comprises an outer housing, an inner housing and an intermediate insulating layer disposed between the outer housing and the inner housing.

Optionally, the port assembly comprises a first port assembly and a second port assembly disposed at the first cable and the second cable port, respectively.

Optionally, the seal comprises a first seal and a second seal disposed on the first cable and the second cable, respectively.

Optionally, the reservoir chamber comprises a plurality of expansion cells for storing liquid.

Optionally, the conductive connector is a tubing structure.

Optionally, two ends of the liquid storage cavity are respectively fixed on the outer insulating layers of the first cable and the second cable.

Optionally, the liquid storage cavity is a cavity made of a semiconductive elastic material, an insulating material or a rigid material.

Optionally, the outer housing is a housing made of a semiconductor material.

Optionally, the inner housing is a housing made of a semiconductor material.

The invention provides a power cable intermediate joint for cable moisture repair, the cable comprising an exposed conductive core and an outer insulating layer, the intermediate joint comprising: an outer connector for electrical insulation from the outside and an inner connector disposed inside the outer connector for electrically connecting a first cable and a second cable; the inner connector comprises a port assembly, a connector main body, a sealing piece, a liquid storage cavity and a conductive connecting piece; the port assembly is detachably connected to the connector main body, the sealing element is connected with the connector main body and the port assembly, the liquid storage cavity arranged on the outer side of the conductive connecting piece is a sealing structure for connecting the external insulating layers of the first cable and the second cable, and a through hole is formed inside the conductive connecting piece and electrically connected with the conductive core.

The power cable intermediate joint for cable moisture repair provided by the invention has the following beneficial effects:

the power cable intermediate joint for damp repair of the cable comprises an outer connector and an inner connector, wherein the outer connector has the functions of uniform electric field and sealing and electrically insulates an internal conductive core from the outside; the female connector electrically connects two independent power cables and functions as both a fluid passageway and a fluid reservoir. The conductive connecting piece in the inner connector is electrically connected with the conductive core, the liquid storage cavity arranged at the outer side of the conductive connecting piece wraps two independent power cables, namely the exposed conductive parts of the first cable and the second cable, so that a fluid channel and a fluid storage chamber which can bear the pressure atmosphere are formed.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

fig. 2 is a schematic view of an inner connector according to an embodiment of the present invention.

The connector comprises a first cable 11, a second cable 12, a conductive core 13, an external insulating layer 14, an external connector 21, an outer shell, an inner shell and an

intermediate insulating layer

22, 23 and 24 of the external connector 21, an internal connector 31, a first port assembly, a second port assembly and a connector

main body

32, 33 and 34 of the internal connector 31, a first sealing element and a

second sealing element

35 and 36, a groove 37, a steel hoop 38, a liquid storage cavity 39 and a conductive connecting piece 40.

Detailed Description

The embodiment of the invention provides a power cable intermediate joint for repairing a cable affected with damp, and aims to solve the technical problem that a large amount of manpower, material resources and financial resources are consumed for repairing the power cable intermediate joint.

To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The invention can provide the power cable intermediate joint with the liquid storage cavity aiming at the defects of the prior art, can smoothly carry out pressure injection repair on the power cable with the intermediate joint, can safely and reliably complete the pressure injection repair on the power cable, can avoid the phenomena of bulging, air leakage, liquid leakage and the like of the intermediate joint, and improves the service quality and the service life of the power cable.

Referring to fig. 1, the present invention provides an embodiment of an intermediate joint for a power cable for moisture repair of the cable, the cable including an exposed conductive core 13 and an outer insulating layer 14, the intermediate joint comprising:

an outer connector 21 and an inner connector 31 disposed inside the outer connector 21, the outer connector 21 for electrical insulation from the outside, the inner connector 31 for electrically connecting the first cable 11 and the second cable 12;

the female connector 31 includes a port assembly, a connector body 34, a sealing member, a reservoir 39, and a conductive connector 40; the port assembly is detachably connected to the connector main body 34, the sealing member is connected to the connector main body 34 and the port assembly, the liquid storage cavity 39 arranged outside the conductive connecting member 40 is a sealing structure for connecting the external insulating layers 14 of the first cable 11 and the second cable 12, and the conductive connecting member 40 provided with a through hole inside is electrically connected with the conductive core 13.

In this embodiment, the power cable includes an exposed conductive core 13 and an outer insulating layer 14, and the conductive core 13 is required to have a gap therein, such as a stranded conductor. The intermediate connector comprises an outer connector 21 and an inner connector 31, and the openings at two ends of the outer connector 21 and the inner connector 31 form a sealing structure with the insulating surface of the cable.

The outer connector 21 includes an outer housing 22, an inner housing 23, and an intermediate insulating layer 24, the intermediate insulating layer 24 is disposed between the outer housing 22 and the inner housing 23, both the outer housing 22 and the inner housing 23 may be made of a semi-conductive material, and the intermediate insulating layer 24 is made of an insulating material. The outer connector 21 has a uniform electric field, seals, and electrically insulates the inner conductive core 13 from the outside.

In this embodiment, the inner connector 31 includes a port assembly, a connector body 34, a sealing member, a liquid storage cavity 39 and a conductive connecting member 40, the sealing member is connected to the connector body 34 and the port assembly, the liquid storage cavity disposed outside the conductive connecting member 40 is a sealing structure for connecting the external insulating layer 14 of the first cable 11 and the second cable 12, and the conductive connecting member 40 having a through hole inside is electrically connected to the conductive core 13.

Specifically, the port assembly and the joint body 34 are made of an insulating material, the port assembly includes a first port assembly 32 and a second port assembly 33 provided at the ports of the first cable 11 and the second cable 12, respectively, the first port assembly 32 and the second port assembly 33 are engaged by mating threads, and the first port assembly 32 and the second port assembly 33 are detachably connected to the joint body 34.

Specifically, the sealing member 35 is connected to the connector body 34 and the port assembly, and the sealing member 35 is used to further seal the inner cavity of the inner connector 31 and includes a first sealing member 35 and a second sealing member 36 respectively disposed on the first cable 11 and the second cable 12. In the preferred embodiment, the seal 35 comprises a resilient disc and two rigid discs, the resilient disc being sandwiched between the two rigid discs, the seal 35 sealing the inner connector 31 by applying pressure through a groove 37 in the body 34 to the first port assembly 32 and the second port assembly 33.

Specifically, the liquid storage cavity 39 is provided with a sealing structure connected with the external insulating layer 14 of the two independent power cables, the liquid storage cavity 39 is arranged at the outer sides of the conductive core 13 and the conductive connecting piece 40, wraps the exposed conductive parts of the two independent power cables, and can bear certain air pressure so as to limit the fluid to flow in the conductive core 13, and the specific air pressure bearing capacity can be determined according to engineering requirements; the two ends of the liquid storage cavity 39 are respectively and tightly fixed on the external insulating layers 14 of the first cable 11 and the second cable 12, and a liquid storage cavity is arranged in the liquid storage cavity, and the size of the liquid storage cavity can be selected according to actual needs.

In this embodiment, the reservoir 39 may be made of a rigid material, an elastic material, or an insulating material, and in a preferred embodiment, the reservoir 39 is made of a semiconductive elastic material, and is capable of controlling electrical stress and receiving air pressure when pressure injection is performed from the conductive core 13 to form a fluid passage and a fluid reservoir. On one hand, the cable containing the intermediate joint can safely and reliably complete pressure injection type repair, on the other hand, a storage space is provided for the medium reinforcing liquid, and after the medium reinforcing liquid of the cable core part which is not exposed out of the cable is diffused to the insulating layer, the medium reinforcing liquid in the intermediate joint can provide certain supplement for the medium reinforcing liquid, so that the pressure injection type repair can be smoothly carried out.

In this embodiment, the two ends of the reservoir 39 are sealed by fixing the steel ferrules 38, and in a preferred embodiment, the reservoir 39 includes two expansion units and is fixed by four steel ferrules 38.

In one embodiment, the two ends of the reservoir 39 are fixed to the outer insulating layers 14 of the first and

second cables

11 and 12 by steel ferrules 38, so as to ensure that the fluid inside the reservoir does not leak. Of course, other possible ways may be used.

In another embodiment, the reservoir 39 may include one or more expansion units, and the number of the steel ferrules 38 may be selected according to the requirement, or other sealing means may be adopted.

Specifically, the conductive connecting member 40 is a pipe structure, has a through hole inside, and is tightly attached to the conductive core 13 by crimping, welding, and the like, and the conductive connecting member 40 and the conductive core 13 can be tightly electrically connected. The ends of the conductive connector 40 are spaced a small distance, for example 1-2cm, from the edges of the outer insulating layer 14 to allow the medium enhancing fluid to flow smoothly out into the reservoir chamber 39.

It should be noted that basic components such as a metal shield mesh, a ground wire, and the like may be attached to the outside of the female connector 31 according to the attachment requirements of the conventional intermediate joint.

The power cable intermediate joint for cable damp repair provided by the embodiment is a power cable intermediate joint with a liquid storage cavity, and is provided with a three-level sealing structure:

the first stage is a liquid storage cavity, and the flow of the medium reinforcing liquid is limited to enable the medium reinforcing liquid to flow from the inner flow of the cable core of the previous stage to the cable core of the next stage;

the second level is an inner connector, when the liquid storage cavity is made of elastic materials, the liquid storage cavity is limited to be over-expanded, and when the liquid storage cavity is damaged accidentally, the inner connector can bear air pressure and limit the outflow of medium reinforcing liquid;

the third level is an external connector, and the main function is to seal the whole joint and prevent invasion of moisture, impurities and the like. It should be noted that, because the first-stage structure and the second-stage structure both have sealing performance, they also have the function of preventing intrusion of moisture, impurities, etc., and this embodiment is superior to the prior art in terms of performance of preventing intrusion of moisture, impurities, etc.

The power cable intermediate joint for cable moisture restoration provided by the embodiment comprises an outer connector and an inner connector, wherein the outer connector has the functions of uniform electric field and sealing and electrically insulates an internal conductive core from the outside; the female connector electrically connects two independent power cables and functions as both a fluid passageway and a fluid reservoir. The inner connector is electrically connected with the conductive core, the liquid storage cavity arranged outside the conductive connecting piece is wrapped by two independent power cables, namely a first cable and a conductive part of a second cable exposed outside, and a fluid channel and a fluid storage chamber capable of bearing the atmospheric pressure are formed.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

Claims

1. A power cable intermediate joint for moisture repair of a cable, the cable including an exposed conductive core and an outer insulating layer, the intermediate joint comprising:

2. A power cable intermediate joint for cable moisture repair as claimed in claim 1, wherein the outer connector includes an outer housing, an inner housing and an intermediate insulating layer disposed between the outer and inner housings.

3. A power cable intermediate joint for cable moisture repair according to claim 1, wherein the port assemblies include a first port assembly and a second port assembly disposed at the first cable and second cable ports, respectively.

4. A power cable intermediate joint for cable moisture repair according to claim 1, wherein the seal comprises a first seal and a second seal provided on the first cable, respectively the second cable.

5. A power cable intermediate joint for cable moisture restoration according to claim 1, wherein the reservoir chamber comprises a plurality of expansion units for storing liquid.

6. A power cable intermediate joint for cable moisture repair according to claim 1, wherein the conductive connecting member is a pipe structure.

7. The intermediate joint for power cables used in cable moisture repair of claim 1, wherein the two ends of the reservoir are fixed on the outer insulating layer of the first cable and the second cable respectively.

8. The intermediate joint for power cables used in cable moisture restoration according to any one of claims 1-7, wherein the reservoir is a cavity made of a semi-conductive elastic material or an insulating material or a rigid material.

9. A power cable intermediate joint for cable moisture restoration according to any one of claims 1-7, wherein the outer housing is a housing made of a semi-conductive material.

10. An intermediate joint for power cables used in the repair of cables affected by moisture according to any of claims 1 to 7, characterized in that said inner casing is a casing made of a semi-conductive material.