CN205751636U - A medium voltage waterproof single core cable - Google Patents

Abstract

The utility model belongs to the field of cable technology, and particularly relates to a medium-voltage waterproof single-core cable, comprising a prefabricated cable core, wherein the prefabricated cable core is sequentially provided with a conductor, a composite layer, an outer semiconducting water-blocking tape, an aluminum-plastic composite tape and a flame-retardant sheath from the inside to the outside, and the outer side of the prefabricated cable core is sequentially wrapped with an inner sheath, an armor layer, a wrapping layer and an outer sheath from the inside to the outside, and a filling layer is filled between the prefabricated cable core and the inner sheath, and the composite layer is sequentially provided with a conductor shielding layer, an insulating layer, an insulating shielding layer and a metal shielding layer from the inside to the outside, and an inner semiconducting water-blocking tape is provided between the insulating shielding layer and the metal shielding layer. The medium-voltage waterproof single-core cable of the utility model is provided with multiple shielding layers, double water-blocking tapes, a fully sealed armor layer and a high-density polyethylene outer sheath, and uses a full-surface waterproof structure, that is, radial waterproofing is combined with longitudinal waterproofing, so that the waterproof effect is better.

Description

A medium voltage waterproof single core cable

technical field

The utility model relates to the cable technology, in particular to a medium-voltage waterproof single-core cable.

Background technique

With the development of the national economy and the acceleration of the urbanization process, the use of high-voltage power cables for power transmission is becoming the trend of urban power grid construction today. Due to the needs of the laying environment, more and more medium-voltage cables need to be laid in ponds, groundwater, and even seawater. Most of the commonly produced medium-voltage cables use plastic materials such as PVC and PE as sheath materials. Although plastic materials such as PVC and PE have excellent electrical and mechanical properties, they have poor water resistance. The cables are placed in water for a long time. Water will slowly seep into the plastic material, forming a water tree and causing breakdown of the cable. The known medium-voltage waterproof cable technologies in the prior art all have some problems of poor fire resistance and poor waterproof performance. According to statistics, in the 10-35kV power system of the domestic urban network, ordinary XLPE insulated cables used underground will generally grow a large number of water trees after 8 to 12 years of operation, resulting in a breakdown of a large number of XLPE cables due to water trees. It affects the safe operation of the power grid, so it is necessary to develop a medium-voltage waterproof single-core cable.

Contents of the invention

The purpose of this utility model is to provide a medium-voltage waterproof single-core cable for the above-mentioned deficiencies in the prior art, by adding conductor shielding layer, insulating layer, insulating shielding layer, metal shielding layer, , aluminum-plastic composite tape and flame-retardant sheath, which can effectively prevent the diffusion of moisture to the insulated core and along the length of the insulated core, isolate the electromagnetic interference in the power cable, and ensure the bending performance of the cable while avoiding external mechanical damage. It can meet the normal use of the cable under long-term sunlight exposure, and at the same time prevent the diffusion of moisture to the inner direction of the cable and affect the service life of the cable.

The purpose of this utility model is achieved through the following technical solutions:

A medium-voltage waterproof single-core cable, including a pre-formed cable core, the pre-formed cable core is sequentially provided with a conductor, a composite layer, an outer semi-conductive resistance water tape, an aluminum-plastic composite tape, and a flame-retardant sheath from the inside to the outside. The outer side of the cabled core is wrapped with inner sheath, armor layer, wrapping layer and outer sheath in sequence from inside to outside, and the filling layer is filled between the pre-cabled core and the inner sheath, and the composite layer is arranged in sequence from inside to outside There is a conductor shielding layer, an insulating layer, an insulating shielding layer and a metal shielding layer, and an inner semiconducting resistance water belt is arranged between the insulating shielding layer and the metal shielding layer.

Wherein, the conductor is an oxygen-free copper conductor, specifically an oxygen-free copper conductor with a circular compact structure of the second type in GB/T3956-2008.

Wherein, the conductor shielding layer is a galvanized copper wire braiding layer with a weaving density of 80%-95%.

Wherein, the insulating layer is a cross-linked polyethylene insulating layer, and the insulating shielding layer is a semiconductive material layer.

Wherein, the metal shielding layer is a braided tinned copper mesh shielding layer with a thickness of 4.0-4.5mm.

Wherein, the filling layer is a polypropylene filling layer.

Wherein, the flame-retardant sheath is a low-smoke halogen-free sheath.

Wherein, the inner sheath is a polyethylene sheath, and the outer surface of the inner sheath is provided with grooves.

Wherein, the inner surface of the armor layer is provided with a convex strip matching with the groove.

Wherein, the wrapping layer is a polyester fiber layer, and the outer sheath is a high-density polyethylene sheath with a thickness of 3.0-4.0mm.

The utility model can effectively solve the waterproof and moisture-proof problems:

(1) Longitudinal waterproof and moisture-proof: ①During the stranding process of aluminum alloy conductors, electrostatic spraying technology is used to make the water-blocking powder better adhere to the single wires of the conductors, and the conductors are wrapped with semi-conductive resistance hoses. ②The gap between the insulated wire cores and cables is filled with water-blocking yarn, and the cable core is wrapped with semi-conductive resistance water tape.

(2) Radial waterproof and moisture-proof: ① Conductors, insulation shields, and cable cores are wrapped with semi-conductive resistance hoses. ②The cable core tape is extruded with a layer of polyethylene (with excellent waterproof performance) isolation sleeve, the isolation sleeve is interlocked with armored aluminum alloy tape, and the armored layer is extruded with a polyethylene outer sheath. The above two structures from the longitudinal and radial directions have achieved all-round waterproof and moisture-proof performance. It effectively solves the water tree branch and electric tree branch caused by the cable being damp or soaked in water, and improves the service life and reliability of the cable.

In view of the influence of XLPE cables on the reliability and service life of cables after water and damp, many cable water blocking technologies have been developed at home and abroad. These water blocking technologies can be roughly classified as follows: ①According to the water blocking materials used, they can be divided into active water blocking technology and passive water blocking technology; ②According to the water blocking mechanism adopted, they can be divided into longitudinal water blocking technology and radial water blocking technology. Water blocking technology. The development and research on the structure of water-blocking cables is earlier in foreign countries.

It is composed of longitudinally wrapped aluminum-plastic composite tape and extruded low-smoke and halogen-free combined sheath. The longitudinal wrap is completed by heating and baking by professional equipment, so that the surface films of the overlapping parts of the aluminum-plastic composite tape are bonded together to form a complete seamless aluminum alloy sheath. In addition, when extruding the low-smoke and zero-halogen sheath, due to the high temperature and pressure of the low-smoke and zero-halogen sheath melt, the low-smoke and zero-halogen sheath film on the surface of the aluminum-plastic composite tape and the inner layer of the polyethylene sheath The surface is well pasted, and at the same time, the overlapping part of the aluminum-plastic tape is further bonded when it is wrapped vertically, thus completely blocking the way for moisture (gas) to penetrate into the cable, and achieving good radial water resistance requirements.

The beneficial effects of the utility model:

1. The utility model uses a multi-layer shielding layer to effectively ensure the transmission of the signal, and prevent the high-order harmonics contained in the power cable from causing strong interference to other electronic equipment and automatic processing equipment around it when the cable goes to the line. As a result, the equipment may malfunction and cause consequences.

2. The utility model uses a high-density polyethylene sheath as a protective device for the entire cable to protect its internal structure from external mechanical force collisions, friction, etc., to ensure long-term effective operation of the cable.

3. The utility model innovatively arranges grooves and convex lines in the internal structure, and the two are used together to prevent the cable from causing secondary rotation of the internal structure during use, causing excessive twisting of the cable and causing damage.

4. The material of the armor layer of the utility model adopts aluminum alloy, and the advanced technology of chain armor can not only improve the mechanical safety and electrical safety performance of the traditional cable, reduce the loss of the line, but also can play a certain resistance Water and flame retardant effect. The aluminum alloy belt is a non-magnetic material, even if there is a three-phase unbalanced current, it will not generate eddy current, which can reduce the loss of the line. And once a fire occurs, the internal insulated wire core can be well isolated from the external fire source, which has a certain flame retardant effect. In addition, since the armor layer is in the form of self-locking, it has good sealing performance and certain radial water resistance.

5. The electric field on the surface of the conductor is more uniform due to the inner and outer semi-conductive shielding of the utility model, and no local electric field concentrated discharge phenomenon will occur.

6. The utility model is designed from two kinds of waterproof structures, longitudinal and radial, to achieve all-round waterproof and moisture-proof effects. It effectively solves the water tree branch and electric tree branch caused by the cable being damp or soaked in water, and improves the service life and reliability of the cable.

Description of drawings

Utilize accompanying drawing to further illustrate the utility model, but the embodiment in the accompanying drawing does not constitute any restriction to the present utility model, for those of ordinary skill in the art, under the premise of not paying creative work, also can obtain according to following accompanying drawing Additional drawings.

Fig. 1 is a structural representation of the utility model;

Fig. 2 is a schematic structural view of the pre-cable core of the present invention.

Reference signs include:

1 pre-cable core, 2 filling layer, 3 inner sheath, 4 armor layer, 5 wrapping layer, 6 outer sheath, 7 conductor, 8 conductor shielding layer, 9 insulating layer, 10 insulating shielding layer, 11 inner half Conductive resistance hose, 12 metal shielding layer, 13 outer semi-conductive resistance hose, 14 aluminum-plastic composite belt, 15 flame-retardant sheath.

detailed description

The utility model is further described in conjunction with the following examples.

Example 1

As shown in Figures 1 and 2, a medium-voltage waterproof single-core cable of this embodiment includes a pre-formed cable core 1, and the pre-formed cable core 1 is sequentially provided with a conductor 11, a composite layer, and an outer semi-conductor from the inside to the outside. Conductive resistance water tape 13, aluminum-plastic composite tape 14 and flame-retardant sheath 15, the outside of pre-cabled core 1 is wrapped with inner sheath 3, armor layer 4, wrapping layer 5 and outer sheath 6 in sequence from inside to outside The filling layer 2 is filled between the pre-cabled core 1 and the inner sheath 3, and the composite layer is sequentially provided with a conductor shielding layer 8, an insulating layer 9, an insulating shielding layer 10 and a metal shielding layer 12 from the inside to the outside. An inner semiconductive resistance water belt 11 is arranged between the layer 10 and the metal shielding layer 12 .

The conductor 7 of this embodiment is an oxygen-free copper conductor having a type 2 circular compression structure of GB/T3956-2008.

The conductor shielding layer 8 of this embodiment is a braided layer of galvanized copper wire, and the braiding density is 80%.

The insulating layer 9 in this embodiment is a cross-linked polyethylene insulating layer with a shrinkage rate of 0.5%, and the insulating shielding layer 10 is a semiconductive material layer.

The metal shielding layer 12 in this embodiment is a braided tinned copper mesh shielding layer with a thickness of 4.0 mm.

The filling layer 2 of this embodiment is a polypropylene filling layer.

The flame-retardant sheath 15 in this embodiment is a low-smoke, halogen-free sheath.

The inner sheath 3 in this embodiment is a polyethylene sheath, and the outer surface of the inner sheath 3 is provided with grooves.

In this embodiment, the inner surface of the armor layer 4 is provided with a convex strip matching the groove.

In this embodiment, the wrapping layer 5 is a polyester fiber layer, and the outer sheath 6 is a high-density polyethylene sheath with a thickness of 3.0 mm.

Example 2

As shown in Figure 1 and Figure 2, a medium-voltage waterproof single-core cable of this embodiment, the metal shielding layer 12 is a tinned copper mesh braided shielding layer, the thickness is 4.5mm; the outer sheath 6 is a high-density polyethylene sheath The cover has a thickness of 4.0mm; a plastic layer is also arranged between the armor layer 4 and the wrapping layer 5, and the plastic layer is a commercially available phenolic material layer, commonly known as a bakelite layer.

The rest of the content of this embodiment is the same as that of Embodiment 1, and will not be repeated here.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model, rather than limiting the protection scope of the present utility model. Although the utility model has been described in detail with reference to the preferred embodiments, those skilled in the art Personnel should understand that the technical solution of the utility model can be modified or equivalently replaced without departing from the essence and scope of the technical solution of the utility model.

Claims (9)

1. one kind is pressed waterproof single-core cable, it is characterised in that: including a preformation cable core, preformation cable core sets the most successively It is equipped with conductor, composite bed, outer semiconductor waterstop, aluminium-plastic tape and fire retardant jacket, outside preformation cable core the most successively Be enclosed with inner sheath, armor, lapping layer and oversheath, between preformation cable core and inner sheath, be filled with packed layer, composite bed from Interior to being disposed with outward conductor shield, insulating barrier, insulation screen and metal screen layer, at insulation screen and metal screen Cover and between layer, be provided with interior semiconductor waterstop；Described inner sheath is pe sheath, and described inner sheath outer surface is provided with recessed Groove, described armor inner surface is provided with the raised line with groove fit, and described lapping layer is layer of polyester fiber, and described oversheath is High density polyethylene (HDPE) sheath, thickness is 3.0-4.0mm.

One the most according to claim 1 is pressed waterproof single-core cable, it is characterised in that: described conductor is that oxygen-free copper is led Body.

One the most according to claim 1 is pressed waterproof single-core cable, it is characterised in that: described conductor shield is braiding Density is the zinc-plated copper wire braid of 80%-95%.

One the most according to claim 1 is pressed waterproof single-core cable, it is characterised in that: described insulating barrier is for cross-linking poly-second Alkene insulating barrier, described insulation screen is semiconducting material.

One the most according to claim 1 is pressed waterproof single-core cable, it is characterised in that: described metal screen layer is tin plating Copper mesh woven shield, thickness is 4.0-4.5mm.

One the most according to claim 1 is pressed waterproof single-core cable, it is characterised in that: described packed layer is reclaimed polypropylene Fill layer.

One the most according to claim 1 is pressed waterproof single-core cable, it is characterised in that: described fire retardant jacket be low cigarette without Halogen sheath.

One the most according to claim 1 is pressed waterproof single-core cable, it is characterised in that: described armor inner surface is arranged There is the raised line with groove fit.

One the most according to claim 1 is pressed waterproof single-core cable, it is characterised in that: described lapping layer is polyester fiber Layer, described oversheath is high density polyethylene (HDPE) sheath, and thickness is 3.0-4.0mm.