CN205751674U - A medium voltage waterproof multi-core cable - Google Patents

Abstract

The utility model belongs to a cable technical field especially relates to a waterproof multicore cable of middling pressure, cable core is preformed including two to five, every cable core from interior to exterior has set gradually the conductor in advance, the composite bed, outer semiconduction waterproofing area, aluminum-plastic composite belt and fire-retardant sheath, it has the inner sheath to wrap up in proper order outside the cable core from interior to exterior in advance, the armor, around covering and oversheath, it has the filling layer to fill between cable core and the inner sheath in advance, the composite bed has set gradually the conductor shield from interior to exterior, an insulating layer, insulation shield and metallic shield, be provided with interior semiconduction waterproofing area between insulation shield and metallic shield. The utility model discloses a waterproof multicore cable of middling pressure sets up many shielding layers, two water blocking tapes, totally enclosed armor and high density polyethylene oversheath, uses the waterproof structure of full text face, and radial waterproof combines with vertical waterproof promptly, makes water-proof effects better.

Description

A medium voltage waterproof multi-core cable

technical field

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

Contents of the invention

The purpose of this utility model is to address the above-mentioned deficiencies in the prior art, to provide a medium-voltage waterproof multi-core cable, by adding a conductor shielding layer, an insulating layer, an insulating shielding layer, a metal shielding layer, and a semiconducting resistance hose to the cable. , 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 multi-core cable, including two to five pre-formed cable cores, each pre-formed cable core is sequentially provided with a conductor, a composite layer, an outer semiconducting resistance water belt, an aluminum-plastic composite belt and a flame-retardant cable. Sheath, the outside of the pre-formed cable core is wrapped with inner sheath, armor layer, wrapping layer and outer sheath in turn from inside to outside, the filling layer is filled between the pre-formed cable core and the inner sheath, and the composite layer is from the inner A conductor shielding layer, an insulating layer, an insulating shielding layer and a metal shielding layer are sequentially arranged on the outside, 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 having a type 2 circular compression structure of 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 4.0-4.5 mm.

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 wrapping layer is a polyester fiber layer.

Wherein, the outer sheath is a high-density polyethylene sheath with a thickness of 3.0-4.0mm.

Wherein, the high-density polyethylene sheath is provided with a waterproof coating layer.

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 made of longitudinally wrapped aluminum-plastic composite tape and extruded low-smoke and halogen-free combined sheath. The longitudinal wrap is heated and baked 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. 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 material of the armor layer of this utility model is aluminum alloy, and the advanced technology of chain armor is used, which can not only improve the mechanical safety and electrical safety performance of traditional cables, reduce the loss of lines, but also play a certain role in 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.

4. The electric field on the surface of the conductor is made more uniform by the inner and outer semi-conductive shielding of the utility model at the same time, and there will be no concentrated discharge phenomenon of the local electric field.

5. 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 schematic structural view of Embodiment 1 of the present utility model.

Fig. 2 is a structural schematic diagram of Embodiment 2 of the present utility model.

Fig. 3 is a schematic structural view of Embodiment 3 of the present utility model.

Fig. 4 is a schematic structural view of Embodiment 4 of the present utility model.

Fig. 5 is a structural schematic 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 semiconducting resistance hose, 12 metal shielding layer, 13 outer semiconducting 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 Figure 1 and Figure 5, a medium-voltage waterproof multi-core cable of this embodiment includes two pre-formed cable cores 1, and each pre-formed cable core 1 is sequentially provided with a conductor 7, a composite layer, Outer semi-conductive resistance water belt 13, aluminum-plastic composite belt 14 and flame-retardant sheath 15, the outer side of pre-formed cable core 1 is wrapped with inner sheath 3, armor layer 4, wrapping layer 5 and outer sheath in sequence from inside to outside. The sleeve 6 is filled with a filling layer 2 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 hose 11 is arranged between the insulating shielding 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 9 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 2 .

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

The inner sheath 3 of this embodiment is a polyethylene sheath.

The wrapping layer 5 of this embodiment is a polyester fiber layer.

The outer sheath 6 of this embodiment is a high-density polyethylene sheath with a thickness of 3.0 mm.

The material of the waterproof coating layer in this embodiment is an acrylic waterproof coating, which is a one-component water-emulsion type waterproof coating prepared with pure acrylic acid polymer emulsion as the base material and adding other additives. The waterproof film formed after the waterproof coating is cured has certain extensibility, elastic-plasticity, crack resistance, impermeability and weather resistance, and can play the role of waterproof, anti-seepage and protection. The waterproof coating has good temperature adaptability, easy operation, easy repair and maintenance.

Example 2

As shown in FIG. 2 and FIG. 5 , a medium-voltage waterproof multi-core cable of this embodiment has three pre-assembled cores 1 .

The metal shielding layer 12 in this embodiment is a braided tinned copper mesh shielding layer with a thickness of 4.2 mm.

The outer sheath 6 of this embodiment is a high-density polyethylene sheath with a thickness of 3.5 mm.

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

Example 3

As shown in FIG. 3 and FIG. 5 , a medium-voltage waterproof multi-core cable of this embodiment has four pre-assembled cores 1 .

The metal shielding layer 12 in this embodiment is a braided tinned copper mesh shielding layer with a thickness of 4.5 mm.

The outer sheath 6 of this embodiment is a high-density polyethylene sheath with a thickness of 4.0 mm.

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

Example 4

A medium-voltage waterproof multi-core cable of this embodiment as shown in FIGS. 4-5 has five pre-assembled cores 1 .

In this embodiment, a plastic layer is provided 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. A medium-voltage waterproof multi-core cable, characterized in that: it includes two to five pre-formed cable cores, and each pre-formed cable core is sequentially provided with a conductor, a composite layer, an outer semiconducting resistance hose, an aluminum Plastic composite tape and flame-retardant sheath, the outside of the pre-formed cable core is wrapped with inner sheath, armor layer, wrapping layer and outer sheath in turn from inside to outside, and the pre-formed cable core and inner sheath are filled with filler 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 resistance hose is arranged between the insulating shielding layer and the metal shielding layer; the outer sheath It is a high-density polyethylene sheath with a thickness of 3.0-4.0mm. 2. A medium-voltage waterproof multi-core cable according to claim 1, wherein the conductor is an oxygen-free copper conductor. 3. A medium-voltage waterproof multi-core cable according to claim 1, wherein the conductor shielding layer is a galvanized copper wire braiding layer with a weaving density of 80%-95%. 4. A medium-voltage waterproof multi-core cable according to claim 1, characterized in that: the insulating layer is a cross-linked polyethylene insulating layer, and the insulating shielding layer is a semi-conductive material layer. 5. A medium-voltage waterproof multi-core cable according to claim 1, wherein the metal shielding layer is a braided tinned copper mesh shielding layer with a thickness of 4.0-4.5 mm. 6. A medium-voltage waterproof multi-core cable according to claim 1, wherein the filling layer is a polypropylene filling layer. 7. A medium-voltage waterproof multi-core cable according to claim 1, wherein the flame-retardant sheath is a low-smoke, halogen-free sheath. 8. A medium-voltage waterproof multi-core cable according to claim 1, characterized in that: the inner sheath is a polyethylene sheath, and the wrapping layer is a polyester fiber layer. 9. A medium-voltage waterproof multi-core cable according to claim 1, characterized in that a waterproof coating layer is arranged outside the high-density polyethylene sheath.