CN115359963A

CN115359963A - Medium-voltage cable for high-performance high-capacity transformer and preparation method thereof

Info

Publication number: CN115359963A
Application number: CN202211041741.5A
Authority: CN
Inventors: 刘家朝; 王凤勤; 何明涛; 周志浩; 冯耀才
Original assignee: WUXI MINGZHU CABLE CO Ltd
Current assignee: WUXI MINGZHU CABLE CO Ltd
Priority date: 2022-08-29
Filing date: 2022-08-29
Publication date: 2022-11-18

Abstract

The invention relates to the technical field of wires and cables, in particular to a medium-voltage cable for a high-performance high-capacity transformer and a preparation method thereof, wherein the medium-voltage cable comprises a wire core, a filling layer, an inner sheath, an armor layer and an outer sheath, the conductor core comprises a plurality of layers of stranded wires distributed from inside to outside, and a heat-conducting filling layer is filled between each layer of wires, so that gaps among the wires are filled; the filling layer comprises a plurality of strands of filling ropes, and the filling ropes comprise filling ropes and composite heat conductors uniformly distributed in the filling ropes; through the inside at the conductor core set up the heat conduction filling layer, can effectually improve the electrically conductive heat conductivity of conductor core, avoid steam to invade in the conductor gap simultaneously, play the guard action, compound heat conductor adheres to in the outer packing rope, and the insulation of avoiding long-time heat accumulation to lead to is ageing, prolongs the life of cable insulation layer, improves the factor of safety of transformer operation, reduces the safe risk because of the cable is ageing to be brought.

Description

Medium-voltage cable for high-performance high-capacity transformer and preparation method thereof

Technical Field

The invention relates to the technical field of wires and cables, in particular to a medium-voltage cable for a high-performance high-capacity transformer and a preparation method thereof.

Background

The voltage class of the medium-voltage cable is generally in a range between 6KV and 33KV, the structure of the medium-voltage cable is more complex than that of the low-voltage cable, the used materials and the production process are different, the insulating layer of the medium-voltage cable generally consists of three layers, namely a conductor shielding layer, an insulating material and an insulating shielding layer, the medium-voltage cable for the transformer generally continuously bears larger current-carrying capacity for a long time, and higher requirements are provided for the voltage-resistant and temperature-resistant performances of the cable.

In the prior art, a typical medium-voltage power cable is generally formed by twisting a plurality of power wire cores which are twisted with each other, and filling ropes and the like are arranged on the peripheral sides of the power wire cores so as to enable the cable core of the cable to be round, such as halogen-free filling ropes, and meanwhile, the tensile strength, flame retardance, heat resistance and aging resistance of the cable are improved.

Disclosure of Invention

In combination with the drawbacks of the prior art, according to a first aspect of the object of the present invention, a medium voltage cable for a high performance high capacity transformer is proposed, comprising:

the cable comprises three groups of cable cores twisted in a pairwise tangent mode, wherein each group of cable cores comprises a conductor core, and an insulating layer and a metal shielding layer which are sequentially coated outside the conductor core from inside to outside;

the filling layers are filled between the adjacent wire cores, and wrapping layers are wrapped on the outer sides of the wire cores and the filling layers, so that the wire cores and the filling layers are fixedly formed into circular sections;

the inner sheath is extruded on the outer side of the wrapping layer;

the armor layer is wrapped on the outer side of the inner sheath;

the outer sheath is extruded on the outer side of the armor layer;

the conductor core comprises a plurality of layers of stranded wires distributed from inside to outside, a heat-conducting filling layer is filled between every two layers of wires, so that gaps among the wires are filled, and the heat-conducting filling layer comprises conductive silicone grease;

the filling layer comprises a plurality of strands of filling ropes, composite heat conductors are uniformly distributed on the filling ropes, and the composite heat conductors comprise phase change heat conductors.

Preferably, the conductive silicone grease comprises copper oxide powder, modified graphene powder, heat-conducting silicone grease and a water retention agent.

Preferably, the copper oxide powder accounts for 20-30 wt%, the modified graphene powder accounts for 8-15 wt%, the water-retaining agent accounts for 0.2-1 wt%, and the balance is the heat-conducting silicone grease.

Preferably, the filling rope comprises a glass fiber rope, and the composite heat conductor comprises heat-conducting silicone grease, expanded graphite and a water-retaining agent.

Preferably, the expanded graphite accounts for 30-35 wt%, the water-retaining agent accounts for 0.2-1 wt%, and the balance is the heat-conducting silicone grease.

Preferably, the diameter of the glass fiber rope is set to be 2-5 mm.

Preferably, the wrapping layer comprises a mica tape or a glass fiber wrapping tape.

Preferably, the armor layer comprises an armor tape and a water-resistant layer, the armor tape comprises a steel tape or an aluminum alloy tape, the water-resistant layer comprises water-resistant paste, and the water-resistant layer is sprayed and attached to the inner side face of the armor tape.

Preferably, the inner and outer sheaths each comprise a cross-linked polyethylene sheath.

According to a second aspect of the object of the present invention, there is provided a method for preparing a medium voltage cable for a high performance high capacity transformer, comprising the steps of:

step 1, manufacturing a wire core:

1.1): stranding a conductor core: stranding a plurality of layers of wires in a regular manner by using a stranding machine to form a conductor core;

1.2): spraying a heat-conducting filling layer: in the process of stranding the wires, spraying conductive silicone grease on each layer of wire by using a spraying machine, compacting the conductor cores after spraying, compressing gaps among the wires, and filling the gaps among the conductor cores with the conductive silicone grease to form a heat-conducting filling layer;

1.3): extruding and coating an insulating layer: extruding inner semiconductive polyolefin, middle crosslinked polyethylene and outer semiconductive polyolefin materials on the outer side of the conductor core by using an extruder in a three-layer coextrusion mode to form the insulating layer;

1.4): wrapping a metal shielding layer: wrapping a copper strip with the width of 30-35 mm by using a wrapping machine, wherein the average overlapping rate of the copper strip is not less than 15% of the width of the copper strip to form the metal shielding layer;

1.5): twisting the wire cores, and twisting the three groups of wire cores to the right in a pairwise tangent mode to form a wire cable core;

step 2, manufacturing a filling layer:

2.1): manufacturing a composite heat conductor: weighing 30-35 parts of expanded graphite, 0.2-1 part of water-retaining agent and 64-70 parts of heat-conducting silicone grease in parts by mass, and mixing in a mixer to form a composite heat conductor;

2.2): immersing a filling rope into the phase-change heat-conducting slurry, so that the phase-change heat-conducting slurry is immersed into a gap of the filling rope;

2.3): filling the filling rope with the composite heat conductor between the gaps of the three groups of wire cores which are tangent to each other;

step 3, manufacturing a lapping layer, namely selecting a mica tape or a glass fiber lapping tape to be lapped leftwards for two layers, wherein the lapping rate of each layer of lapping is not less than 50 percent to form the lapping layer;

step 4, manufacturing an inner sheath, and extruding a cross-linked polyethylene material by using an extruder to form the inner sheath;

step 5, manufacturing an armor layer:

5.1): selecting a steel belt or an aluminum alloy belt as an armor belt, and spraying a water-blocking paste on one side of the armor belt by using a spraying machine to form a water-blocking layer;

5.2): two layers of armor tapes are wound rightwards in a clearance mode to form the armor layer, and the overlapping rate of the upper armor tape and the lower armor tape is not less than 1/4 of the width of the armor tape;

and 6, manufacturing an outer sheath, and extruding a cross-linked polyethylene material by using an extruder to form the outer sheath.

By combining the technical scheme of the invention, the medium-voltage cable for the high-performance high-capacity transformer has the following remarkable beneficial effects:

according to the medium-voltage cable for the high-performance large-capacity transformer, the heat conduction filling layer is arranged in the conductor core, so that the electric conduction and heat conduction capability of the conductor core can be effectively improved, and meanwhile, water vapor is prevented from invading into a conductor gap, so that a protection effect is achieved.

The composite heat conductor is attached to the outer filling rope, so that heat generated by the wire core can be transferred in the axial direction and the radial direction of the cable, the heat dissipation of the cable is promoted, the insulation aging caused by long-time heat storage is avoided, the service life of the cable insulation layer is prolonged, the safety factor of the operation of the transformer is improved, and the safety risk caused by the aging of the cable is reduced.

Drawings

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. Embodiments of various aspects of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

fig. 1 is a schematic cross-sectional structure view of a medium voltage cable for a high performance large capacity transformer according to an embodiment of the present invention;

fig. 2 is a schematic perspective view of a medium voltage cable for a high performance large capacity transformer according to an embodiment of the present invention;

fig. 3 is a schematic view of a hierarchical structure of a medium voltage cable for a high performance large capacity transformer according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a filler rope in a medium voltage cable for a high performance and large capacity transformer according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a conductor core in a medium-voltage cable for a high-performance large-capacity transformer according to an embodiment of the present invention.

Detailed Description

In order to better understand the technical content of the present invention, specific embodiments are described below with reference to the accompanying drawings.

Because the prior medium-voltage cable has relatively poor heat dissipation performance, the medium-voltage cable applied to the transformer runs at high carrying capacity for a long time, the whole cable is easy to keep at high temperature for a long time, the aging of the insulating layer is accelerated, so that the insulativity of the sheath is poor, and water branches are formed in the insulation after the insulation is wetted or wetted, so that insulation breakdown, short circuit, fire and the like are caused.

Medium voltage cable for high performance and large capacity transformer

With reference to fig. 1 and 2, a first aspect of the present invention provides a technical solution, a medium voltage cable for a high performance and large capacity transformer, which is mainly applied to power transmission of a transformer and aims to improve the heat dissipation capability of the cable, and mainly includes a wire core 1, a filling layer 2, a wrapping layer 3, an inner sheath 4, an armor layer 5, and an outer sheath 6.

Wire core

The cable cores 1 comprise three groups twisted in a pairwise tangent mode, and each group of cable cores 1 comprises a conductor core 11, and an insulating layer 13 and a metal shielding layer 14 which are sequentially wrapped outside the conductor core 11 from inside to outside.

Further, the conductor core 11 includes a plurality of layers of stranded conductors distributed from inside to outside, a heat-conducting filling layer 12 is filled between each layer of conductors, so that gaps between the conductors are filled, and the heat-conducting filling layer 12 includes conductive silicone grease.

Specifically, the wire adopts the oxygen-free copper conductor, four layers are twisted in a normal twisting mode, wherein the conductive silicone grease contains copper oxide powder, modified graphene powder, heat-conducting silicone grease and a water-retaining agent, the copper oxide powder accounts for 20-30 wt%, the modified graphene powder accounts for 8-15 wt%, the water-retaining agent accounts for 0.2-1 wt%, and the balance is the heat-conducting silicone grease, the conductive silicone grease is in gaps between the conductors, gap space can be filled, effective contact surface is enlarged, contact conditions are improved, resistance reduction and high conduction effects are achieved, poor heat conduction at the gaps is avoided, electric and heat conduction capability is improved, the electric and heat conduction capability of the heat-conducting silicone grease can be improved due to the addition of the copper oxide powder and the modified graphene powder, and the water-retaining agent is used for absorbing moisture, so that the conductive silicone grease can avoid water vapor from invading into the gaps of the conductors, and electrochemical corrosion and oxidative corrosion of the conductors are reduced.

Therefore, the conductor core 11 filled with the heat-conducting filling layer 12 effectively improves the electric and heat conducting capacity of the conductor core 11, and meanwhile, vapor is prevented from invading into a conductor gap to play a role in protection.

Filling layer

With reference to fig. 2-4, further, the filling layer 2 is filled between the adjacent wire cores 1, and the wrapping layer 3 is wrapped around the outer sides of the wire cores 1 and the filling layer 2, so that the wire cores 1 and the filling layer 2 are fixed to form a circular cross section.

Specifically, the filling layer 2 includes a plurality of strands of filling ropes 21, composite heat conductors 22 are uniformly distributed on the filling ropes 21, and the composite heat conductors 22 include phase change heat conductors.

In a preferred embodiment, the filling rope 21 is a glass fiber rope, the composite heat conductor 22 is a heat conductive silicone grease, expanded graphite and a water retention agent, and the weight percentage of the expanded graphite is 30-35%, the weight percentage of the water retention agent is 0.2-1%, and the balance is the heat conductive silicone grease.

Wherein the glass fiber rope has better traction and fire resistance, and the surface of the braided rope has a multi-gap structure which can accommodate the composite heat conductor 22.

The heat-conducting silicone grease has good heat conductivity, can transmit heat generated by the conductor core 11 outwards along the radial direction and upwards along the axial direction, and has the effect of transmitting the heat in a diffusion mode.

The expanded graphite expands at high temperature (150-180 ℃) to become a worm shape with low density, and the expanded graphite can form a very good heat insulation layer on the surface of the flame retardant material, so that the heat insulation can be effectively realized, the heat release rate of the expanded graphite in a fire disaster is low, the mass loss is small, the generated smoke is less, and the good flame retardant effect is achieved.

In a preferred embodiment, the diameter of the glass fiber rope is set to be 2-5 mm, so that the glass fiber rope can be compactly filled between the wire cores 1, the composite heat conductor 22 is filled between the wire cores 1 and the wrapping layer 3, and heat can be transferred in the radial direction and the axial direction.

So, filling layer 2 can act as the heat-conducting layer between sinle silk 1 and sheath, with the heat of sinle silk 1 production at cable axial and radial direction transmission, avoids the inside or local overheat of cable, with the heat of cable outwards diffusion, promotes the cable heat dissipation, avoids the insulation ageing that long-time heat accumulation leads to.

Wrapping layer, inner sheath, armor layer and outer sheath

Further, the inner sheath 4 is extruded in the outside around covering 3, and armor 5 is around the outside of covering 4 in the outer sheath, and 6 extruded in the outside of armor 5 of oversheath.

The mica tape or the glass fiber wrapping tape is adopted as the wrapping layer 3, the mica tape or the glass fiber wrapping tape has excellent fire resistance, the inner sheath 4 and the outer sheath 6 both comprise crosslinked polyethylene sheaths, the performance of the polyethylene can be greatly improved after crosslinking modification, the polyethylene has excellent comprehensive performances such as mechanical property, environmental stress cracking resistance, chemical medicine corrosion resistance, creep resistance, electrical performance and the like, the temperature resistance grade is remarkably improved, and the heat resistance temperature of the sheaths can be improved from 70 ℃ to more than 100 ℃.

Further, armor layer 5 includes armor tape 51 and water barrier layer 52.

Armor tape 51 comprises a strip of steel or aluminum alloy, and water barrier 52 comprises a water barrier paste, with water barrier 52 spray-applied to the inside of armor tape 51.

Thus, the armor tape 51 forms a steel tape armor around the outer side of the inner sheath 4, the armor tape 51 is attached with water-blocking paste during wrapping, a tight water-blocking structure can be formed, and the armor tape can be matched with the composite heat conductor 22 and the heat-conducting filling layer 12 of the inner layer to play a water-blocking role in the axial direction and the radial direction of the cable.

Combine above embodiment, through set up heat conduction filling layer 12 in conductor core 11's inside, can effectually improve conductor core 11's electrically conductive heat conductivity, avoid steam to invade in the conductor gap simultaneously, play the guard action, adhere to compound heat conductor 22 in the outer packing rope 21, can be with the heat of sinle silk 1 production at cable axial and radial direction transmission, promote the cable heat dissipation, avoid the insulation ageing that long-time heat accumulation leads to.

Preparation method of medium-voltage cable for high-performance and high-capacity transformer

The second aspect of the invention provides a technical scheme, and a preparation method of a medium-voltage cable for a high-performance large-capacity transformer comprises the following steps:

step 1, manufacturing a wire core 1:

1.1): the conductor core 11 is stranded: four layers of oxygen free copper wire are stranded in a regular manner using a stranding machine to form the conductor core 11.

1.2): spraying the heat-conducting filling layer 12: as shown in fig. 5, in the wire twisting process, conductive silicone grease is sprayed on each layer of wires by a spraying machine, the conductor cores 11 are compressed after spraying, gaps between the wires are compressed, the gaps between the conductor cores 11 are filled with the conductive silicone grease to form the heat-conducting filling layer 12, gaps between the conductors are filled with the conductive silicone grease, the gap space can be filled, an effective contact surface is enlarged, the contact condition is improved, the resistance-reducing high-conductivity effect is achieved, poor heat conduction at the gaps is avoided, the electric and heat conduction capability is improved, meanwhile, the conductive silicone grease can avoid water vapor from invading into the gaps of the conductors, and the galvanic corrosion and the oxidative corrosion of the conductors are reduced.

1.3): extruding and coating an insulating layer 13: an extruder is used for extruding and wrapping inner layer semiconductive polyolefin, middle layer crosslinked polyethylene and outer layer semiconductive polyolefin materials on the outer side of the conductor core 11 in a three-layer coextrusion mode to form the insulating layer 13.

1.4): wrapping the metal shielding layer 14: a copper strip with the width of 30-35 mm is lapped by a lapping machine, the average lapping rate of the copper strip is not less than 15% of the width of the copper strip to form a metal shielding layer 14, and the metal shielding layer can shield an inner electromagnetic field and an outer electromagnetic field and play a role in homogenizing an electric field.

1.5): and twisting the cable cores 1, namely twisting the three groups of cable cores 1 to the right in a pairwise tangent mode to form a cable core.

Step 2, manufacturing a filling layer 2:

2.1): manufacturing the composite heat conductor 22: weighing 30-35 parts of expanded graphite, 0.2-1 part of water-retaining agent and 64-70 parts of heat-conducting silicone grease in parts by mass, putting the materials into a mixer to mix to form a composite heat conductor 22, wherein the composite heat conductor 22 is filled between the wire core 1 and the wrapping layer 3, and can transfer heat in the radial and axial directions and play a role in flame retardance.

2.2): the filling rope 21 is immersed in the phase-change heat-conducting paste, so that the phase-change heat-conducting paste is immersed in the gap of the filling rope 21.

2.3): the filling rope 21 with the composite heat conductor 22 is filled between the gaps tangent to each two of the three groups of wire cores 1.

And 3, manufacturing a wrapping layer 3, selecting a mica tape or a glass fiber wrapping tape, and wrapping the mica tape or the glass fiber wrapping tape for two layers leftwards, wherein the covering rate of each layer of wrapping tape is not less than 50% to form the wrapping layer 3, so that the effects of fixing the wire core and resisting fire are achieved.

And 4, manufacturing the inner sheath 4, and extruding the crosslinked polyethylene material by using an extruder to form the inner sheath 4.

Step 5, manufacturing an armor layer 5:

5.1): a steel belt or an aluminum alloy belt is selected as the armor belt 51, and a waterproof paste is sprayed on one side of the armor belt 51 by a spraying machine to form a waterproof layer 52.

5.2): the armor layer 5 is formed by wrapping two armor tapes 51 rightwards in a clearance manner, and the overlapping rate of the upper and lower armor tapes 51 is not less than 1/4 of the width of the armor tape 51.

The armor tape 51 forms a steel tape armor around the outer side of the inner sheath 4, the armor tape 51 is attached with water-blocking paste during wrapping, a tight water-blocking structure can be formed, and the armor tape can play a role in blocking water in the axial direction and the radial direction by matching with the composite heat conductor 22 and the heat-conducting filling layer 12 of the inner layer.

And 6, manufacturing the outer sheath 6, and extruding the cross-linked polyethylene material by using an extruder to form the outer sheath 6.

With the above embodiment, the heat conducting filling layer 12 is arranged inside the conductor core 11, so that the electric and heat conducting capability of the conductor core 11 can be effectively improved, the composite heat conductor 22 is attached to the outer filling rope 21, heat generated by the wire core 1 can be transferred in the axial direction and the radial direction of the cable, the insulation aging caused by long-time heat storage is avoided, and the cable has a good flame-retardant effect and is more suitable for being used in transformer equipment.

Although the present invention has been described with reference to the preferred embodiments, it is not intended to be limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. Medium voltage cable that high performance large capacity transformer was used, its characterized in that includes:

the cable comprises cable cores (1) which comprise three groups twisted in a pairwise tangent mode, wherein each group of cable cores (1) comprises a conductor core (11), and an insulating layer (13) and a metal shielding layer (14) which are sequentially coated outside the conductor core (11) from inside to outside;

the packing layer (2) is filled between the adjacent wire cores (1), and the wrapping layers (3) are wrapped on the outer sides of the wire cores (1) and the packing layer (2) to enable the wire cores (1) and the packing layer (2) to be fixed and form a circular cross section;

the inner sheath (4) is extruded on the outer side of the wrapping layer (3);

the armor layer (5) is wrapped on the outer side of the inner sheath (4);

the outer sheath (6) is extruded on the outer side of the armor layer (5);

the conductor core (11) comprises a plurality of layers of stranded wires distributed from inside to outside, a heat conduction filling layer (12) is filled between every two layers of wires, so that gaps between the wires are filled, and the heat conduction filling layer (12) comprises conductive silicone grease;

the filling layer (2) comprises a plurality of strands of filling ropes (21), composite heat conductors (22) are uniformly distributed on the filling ropes (21), and the composite heat conductors (22) comprise phase change heat conductors.

2. The medium voltage cable for a high performance large capacity transformer according to claim 1, wherein the electrically conductive silicone grease comprises copper oxide powder, modified graphene powder, thermally conductive silicone grease, and a water retaining agent.

3. The medium voltage cable for the high-performance high-capacity transformer as claimed in claim 2, wherein the copper oxide powder accounts for 20-30 wt%, the modified graphene powder accounts for 8-15 wt%, the water retention agent accounts for 0.2-1 wt%, and the balance is the heat-conducting silicone grease.

4. The medium voltage cable for a high performance high capacity transformer according to claim 1, wherein the filler rope (21) comprises a fiberglass rope and the composite heat conductor (22) comprises a thermally conductive silicone grease, expanded graphite and a water retention agent.

5. The medium voltage cable for a high performance large capacity transformer according to claim 4, wherein the expanded graphite is 30 to 35 wt%, the water retaining agent is 0.2 to 1 wt%, and the balance is the heat conductive silicone grease.

6. The medium voltage cable for a high performance large capacity transformer according to claim 4, wherein the diameter of the glass fiber rope is set at 2 to 5mm.

7. The medium voltage cable for a high performance high capacity transformer according to claim 1, wherein the wrapping layer (3) comprises a mica tape or a glass fiber wrapping tape.

8. A medium voltage cable for a high performance high capacity transformer according to claim 1, wherein the armouring layer (5) comprises an armouring tape (51) and a water blocking layer (52), the armouring tape (51) comprising a steel or aluminium alloy tape, the water blocking layer (52) comprising a water blocking paste, the water blocking layer (52) being spray-attached to the inner side of the armouring tape (51).

9. Medium voltage cable for a high performance high capacity transformer according to claim 1, characterized in that the inner sheath (4) and the outer sheath (6) each comprise a cross-linked polyethylene sheath.

10. A method for preparing a medium voltage cable for a high performance large capacity transformer as claimed in claim 1, comprising the steps of:

step 1, manufacturing a wire core (1):

1.1): twisting of the conductor core (11): stranding a plurality of layers of wires in a regular manner by using a stranding machine to form a conductor core (11);

1.2): spraying the heat-conducting filling layer (12): in the wire stranding process, spraying conductive silicone grease on each layer of wire by using a spraying machine, compacting the conductor cores (11) after spraying, compressing gaps among the wires, and filling the gaps among the conductor cores (11) with the conductive silicone grease to form a heat-conducting filling layer (12);

1.3): extrusion coating of an insulating layer (13): extruding inner layer semiconductive polyolefin, middle layer crosslinked polyethylene and outer layer semiconductive polyolefin materials on the outer side of the conductor core (11) by using an extruder in a three-layer coextrusion mode to form the insulating layer (13);

1.4): wrapping a metal shielding layer (14): a copper strip with the width of 30-35 mm is lapped by a lapping machine, and the average lapping rate of the copper strip is not less than 15% of the width of the copper strip to form the metal shielding layer (14);

1.5): twisting the wire cores (1), and twisting the three groups of wire cores (1) to the right in a pairwise tangent mode to form a wire cable core;

step 2, manufacturing a filling layer (2):

2.1): production of composite heat conductor (22): weighing 30-35 parts of expanded graphite, 0.2-1 part of water-retaining agent and 64-70 parts of heat-conducting silicone grease in parts by weight, and putting the materials into a mixer to mix to form a composite heat conductor (22);

2.2): immersing a filling rope (21) into the phase-change heat-conducting slurry, so that the phase-change heat-conducting slurry is immersed into a gap of the filling rope (21);

2.3): filling the filling ropes (21) with the composite heat conductors (22) in gaps between every two tangent wire cores (1) of the three groups;

step 3, manufacturing a lapping layer (3), selecting a mica tape or a glass fiber lapping tape for left lapping two layers, and forming the lapping layer (3) with the lapping rate of each layer of lapping not less than 50%;

step 4, manufacturing an inner sheath (4), and extruding a cross-linked polyethylene material by using an extruder to form the inner sheath (4);

step 5, manufacturing an armor layer (5):

5.1): selecting a steel belt or an aluminum alloy belt as an armor belt (51), and spraying a water-blocking paste on one side of the armor belt (51) by using a spraying machine to form a water-blocking layer (52);

5.2): two layers of armor belts (51) are wound rightwards in a clearance mode to form the armor layer (5), and the overlapping rate of the upper layer of armor belt (51) and the lower layer of armor belt (51) is not less than 1/4 of the width of the armor belt (51);

and 6, manufacturing the outer sheath (6), and extruding the cross-linked polyethylene material by using an extruder to form the outer sheath (6).