CN2485760Y

CN2485760Y - Electric power cable with waterproof high pressure polyethylene insulation

Info

Publication number: CN2485760Y
Application number: CN 01237930
Authority: CN
Inventors: 史建东; 胡剑虹; 吴春中
Original assignee: BAOSHENG BICC UNIVERSAL CABLE Co Ltd
Current assignee: BAOSHENG BICC UNIVERSAL CABLE Co Ltd
Priority date: 2001-05-23
Filing date: 2001-05-23
Publication date: 2002-04-10
Anticipated expiration: 2011-05-23

Abstract

The utility model provides an electric power cable with waterproof high pressure polyethylene insulation, belonging to cable, comprising a conductor 1, a conductor waterproof belt 2, a semiconductor waterproof belt, a conductor shield layer 4, an insulation layer 5 and an insulation shield layer 6; furthermore, a semiconductor waterproof expansion buffer layer 7, a bamboo node type ring metal aluminium protection sleeve 8, an asphalt anticorrosion layer 9 and a nonmetal protection sleeve as well as a conductive coating 10 of the outer layer are also provided. Compared with the prior art, the cable has perfect waterproof performance of radial, longitudinal and conductor waterproof, overall preventing water from immerging and penetrating, being safe and reliable and having long service life, which can be produced by use of the prior devices with low cost.

Description

High-voltage cross-linking polythene insulated power cable entirely blocks water

The utility model belongs to the cable technology field.

Existing high-voltage cross-linking polythene insulated power cable is made up of block water zone of swelling, metallic aluminium sheath and non metallic sheath etc. of normal conductor, insulating barrier, semiconductive, this construction of cable in fact only has good effect in the radially waterproof of cable, rather than cable stops immersion and the infiltration of external moisture content to cable in all directions.

Cable is being made, is being laid, moisture content immersed in the insulating barrier in installation and the running, when polymer contacts with moisture content, moisture content is diffused into gradually in the polymer with fine impurities in the polymer and contacts, if the diffusion rate of moisture content is increased to certain value, impurity begins dissolving.If polymer at high temperature water-filling reaches saturatedly, then after cooling, will become supersaturation.Salt grain, hole etc. all can play the effect of cooling nuclear in the polymer.The unnecessary water in cooling back is the cooling nuclear proliferation in the polymer at once, as long as the pressure that produces is greater than some values, the pressure of water just may surpass the mechanical strength of polymer, cause the micropore fission and then produce the water tree, under effect of electric field, water tree aging phenomenon can take place, and causes cable breakdown at last.The water tree is that diameter is in the space set of 0.1mm to several microns full waters.The local high electric field position that the inhomogeneous place of the impurity that exists in the insulation, pore and insulation and interior outer semiconducting layer faying face forms is the starting point that the water tree is taken place.The evolution of water tree is generally more than 8 years, and humidity, temperature, voltage are high more, and contained ion is many more in the water, and then the development of water tree is fast more.

Branchization is the guide that polymeric media punctures, and is the great potential safety hazard of power network operation, and after the cable insulation medium branchization, greatly reduce the useful life of cable.Therefore, the waterproof measure of cable is one of basic assurance of cable running safety, and high-tension cable especially is because of line voltage grade height, involving a wide range of knowledge seems particularly important.

The design that blocks water of general high-pressure cross-linking cable is to adopt the cable design that vertically and radially blocks water outside insulated wire cores.Radially block water and all adopt metal sheath, the common metal with good molecule compactness is lead and aluminium.Plumbous softness but density is big, unless at special occasions, aluminium is low with its density, low price more and more is subjected to liking of user.The general structure that all on metal sheath inner cable insulated wire cores, adopts the wrapped zone of swelling that blocks water of the design that vertically blocks water of cable.Metal sheath has two kinds of extruded type and welded types.The welding type metallic sheath can not guarantee to prevent fully the immersion of moisture content owing to there is factors such as leaking weldering or not prison welding.Extruded type metallic sheath commonly used at present adopts spiral formula structure, and the extruded type metallic sheath has then prevented the radially possibility of moisture content immersion of cable fully.But the spiral structure, under the situation of contingency cable socket water inlet, moisture content can be along the crest infiltration extension in cable promptly of spiral.When the contingency sheath had damage, damage can not become hole shape in the aluminium cover, do not have good water resistance.In fact this can not play the effect that cable vertically blocks water.

In addition, the function that conductor does not block water fully, in case immerse moisture content in the cable conductor, consequence will be more serious, the generation meeting of accident is rapider.This is because in the process that cable conductor is made, and impossible compacting always exists the space between the single line between the single line layer of conductor and the layer.

The purpose of this utility model is to prevent that at being difficult in the existing cable technology moisture content from immersing the shortcoming in the cable, and a kind of high-voltage cross-linking polythene insulated power cable that blocks water entirely that can prevent effectively that moisture content from immersing is provided.

The formation that blocks water the high-voltage cross-linking polythene insulated power cable entirely of the present utility model is, core part is made up of the conductor of conductor waterstop wrapping, and it is non metallic sheath and conductive coating that the core skin extrudes block water expansion resilient coating, pitch lumarith, outermost layer of conductor shield, insulating barrier, insulation screen, wrapped semiconductive respectively successively by nexine to skin.Be characterized in that also wrapping up the semiconductive water blocking layer between the conductor layer in core and blocking water set between expansion resilient coating and the pitch lumarith at semiconductive is that the bamboo joint type ring grain is extruded the metallic aluminium sheath.

Accompanying drawing 1, high-voltage cross-linking polythene insulated power cable cross section structure schematic diagram entirely blocks water.

Accompanying drawing 2, bamboo joint type ring grain are extruded metallic aluminium sheath schematic diagram.

By accompanying drawing as seen, the formation of this cable is that core part is made up of the conductor 1 of conductor waterstop 2 the several layers wrapping, the core part skin extrudes conductor shield 4 by nexine respectively successively to skin, insulating barrier 5, insulation screen 6, the wrapped semiconductive expansion resilient coating 7 that blocks water, pitch lumarith 9 and outermost non metallic sheath and conductive coating 10.Be characterized at the wrapped or vertical bag semiconductive of the interlayer of core part conductor water blocking layer 3, and adopt the normal circle of conductor to press, make not have the space between conductor layer, blocking water at semiconductive, set sheath is that the bamboo joint type ring grain is extruded metallic aluminium sheath 8 between expansion resilient coating 7 and the pitch lumarith 9.

Adopt circle to press the wrapped semiconductive water blocking layer 3 of mode between the core part conductor layer, and do not leave the purpose in space, be to suppress effectively moisture content from vertical immersion or permeate in cable conductor.If just in case moisture content is arranged when cable socket immerses, the zone of swelling that blocks water can expand rapidly, especially at the trough place of ring grain, moisture content more is difficult to infiltration, moisture content is limited in certain scope effectively, has played the effect that blocks water well.Each annular of aluminium cover all forms water blocking layer one, and when the contingency sheath had damage, damage became hole shape in the aluminium cover, have good water resistance.The purpose that makes whole cable reach vertically, radially block water and block water fully with conductor in a word has favorable waterproof property.

Accompanying drawing 2 is schematic diagrames that the bamboo joint type ring grain is extruded the metallic aluminium sheath.

Claims

1, a kind of formation of the high-voltage cross-linking polythene insulated power cable that blocks water is entirely formed core by the wrapped or vertical conductor (1) that is surrounded by conductor waterstop (2), the core skin extrudes conductor shield (4) respectively successively by nexine to skin, insulating barrier (5), insulation screen (6), the wrapped semiconductive expansion resilient coating (7) that blocks water, pitch lumarith (9) and outermost non metallic sheath and conductive coating (10), it is characterized in that, layer at the core part conductor has semiconductive water blocking layer (3) with interlayer wrapping, extrudes the metallic aluminium sheath at the block water sheath (8) of setting between expansion resilient coating (7) and the pitch lumarith (9) of semiconductive for the bamboo joint type ring grain.