Self-supporting medium-voltage water-blocking overhead insulated cable

Abstract

The utility model provides a self-supporting medium-voltage water-blocking overhead insulated cable which comprises a cable core and an insulating layer, composite fiber filling ropes and tension-bearing steel wires are twisted on the outer side of the insulating layer, more than one composite fiber filling rope is arranged on each of the two sides of each group of tension-bearing steel wires, and the composite fiber filling ropes are twisted on the outer side of the insulating layer. The outer sides of the insulating layers, the composite fiber filling ropes and the tension-bearing steel wires are wrapped with a composite wrapping tape, and the outer side of the composite wrapping tape is extruded with a sheath layer. The tensile steel wires are arranged on the outer sides of the insulating layers of the cable core, and the composite fiber filling ropes are twisted on the two sides of the tensile steel wires, so that on one hand, smooth transition between the tensile steel wires and the insulating layers is achieved, grooves are avoided, and meanwhile, the overall tensile capacity of the cable body is improved; and the composite fiber filling rope is matched, so that the overall axial waterproof and radial waterproof capabilities of the cable can be improved, the surface of the cable body is smooth, and the wind resistance and the rain and snow adhesion amount are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of electric wires and cables, in particular to a self-supporting medium-voltage water-blocking overhead insulated cable. Background Art

[0002] Self-supporting overhead cables are self-load-bearing cables. Compared with ordinary cables that require separate poles and towers for support, self-supporting overhead cables adopt a special structural design, usually including a main cable core and tensile steel wires outside the cross-sectional profile of the main cable core, which enhances the self-supporting performance of the cable.

[0003] The tensile steel wire is usually made of 7-strand galvanized steel strands with two nominal outer diameters of 6.3mm and 4.75mm. Its tensile strength is not less than 3000kg and 1800kg to ensure that the cable can withstand a certain amount of tension and pressure. In addition, the surface of the tensile steel wire is coated with thermoplastic paint to prevent the steel wire from rusting.

[0004] In some schemes, in order to further improve the corrosion resistance of the tensile steel wire, an insulating layer is also coated on the outside of the steel wire. Since this part protrudes from the circular cross-section of the cable body, a groove is formed between the tensile steel wire and the cable body or the stress area of ​​the overhead cable in the air is increased, which is undesirable. Utility Model Content

[0005] The utility model provides a self-supporting medium-voltage water-blocking overhead insulated cable, comprising:

[0006] A cable core, comprising a plurality of sets of mutually twisted conductors;

[0007] An insulating layer, covering the outer side of the cable core;

[0008] Among them, three groups of composite fiber filling ropes and three groups of tensile steel wires are twisted on the outside of the insulating layer, and at least one composite fiber filling rope is arranged on both sides of each group of tensile steel wires. The outer sides of the insulating layer, composite fiber filling rope and tensile steel wire are wrapped with a composite wrapping tape, and the outer side of the composite wrapping tape is extruded with a sheath layer, so that the cross-section of the cable body is a rounded triangle or rounded hexagonal structure.

[0009] Preferably, the composite fiber filling rope comprises mutually twisted tensile-resistant fibers and water-blocking fibers, wherein the ratio of the cross-sectional areas of the tensile-resistant fibers to the water-blocking fibers is set to [0.5-2]:1.

[0010] Preferably, the cross-section of the composite fiber filling rope is constructed to be circular or elliptical, and the wire diameter of the composite fiber filling rope is smaller than the wire diameter of the tensile steel wire.

[0011] Preferably, the tensile-resistant fiber yarn comprises aramid fiber yarn.

[0012] Preferably, the composite wrapping tape comprises a water-blocking yarn located in an inner layer and a wrapping tape located in an outer layer, the water-blocking yarn and the wrapping tape are wrapped in opposite directions, and a water-blocking sealant is provided between the water-blocking yarn and the wrapping tape.

[0013] Preferably, the wrapping tape comprises silicone rubber glass fiber cloth.

[0014] Preferably, the cable core comprises a first cable core and a second cable core, the diameter of the first cable core is larger than the diameter of the second cable core, and the second cable core is twisted in a gap between the first cable cores.

[0015] Preferably, the first cable core comprises aluminum alloy monofilaments, and the second cable core comprises steel wires.

[0016] Preferably, the insulating layer comprises three co-extruded insulating layers.

[0017] Preferably, the sheath layer comprises a polyethylene or a cross-linked polyethylene sheath.

[0018] Compared with the prior art, the advantages of the utility model are:

[0019] The utility model arranges the tensile steel wire on the outside of the insulating layer of the cable core, and twists the composite fiber filling rope on both sides of the tensile steel wire, so as to make a smooth transition between the tensile steel wire and the insulating layer to avoid the formation of grooves, and at the same time improve the overall tensile capacity of the cable body, and arrange a water-blocking composite wrapping tape on the inner side of the sheath layer, which, together with the composite fiber filling rope, can improve the overall axial waterproof and radial waterproof capabilities of the cable, make the surface of the cable body smooth, and reduce wind resistance and the amount of rain and snow adhesion. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are not intended to be drawn to scale. In the accompanying drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For the sake of clarity, not every component is labeled in each figure. Now, embodiments of various aspects of the utility model will be described by way of example and with reference to the accompanying drawings, in which:

[0021] Figure 1 It is a schematic diagram of the end structure of the self-supporting medium-voltage water-blocking overhead insulated cable shown in the embodiment of the utility model;

[0022] Figure 2 It is a schematic cross-sectional structure diagram of a self-supporting medium-voltage water-blocking overhead insulated cable shown in an embodiment of the utility model;

[0023] Figure 3 It is a schematic diagram of the hierarchical structure of a self-supporting medium-voltage water-blocking overhead insulated cable shown in an embodiment of the utility model;

[0024] 10. Cable core; 11. First cable core; 12. Second cable core; 20. Insulation layer; 30. Composite fiber filling rope; 31. Tensile fiber filament; 32. Water-blocking fiber filament; 40. Tensile steel wire; 50. Composite wrapping tape; 51. Water-blocking yarn; 52. Wrapping tape; 60. Sheath layer. DETAILED DESCRIPTION

[0025] In order to better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0026] At present, self-supporting cables place the steel wire used for tension on the outside of the cable body and cover it with an insulating layer at the same time. Due to the diameter difference between the steel wire and the cable body, a groove is formed between the steel wire and the cable body. The existence of the groove makes it easy to store rainwater. Long-term accumulation of rainwater will penetrate into the insulating material, accelerate insulation aging, and cause water to leak into the conductor. Therefore, the utility model proposes a self-supporting medium-voltage water-blocking overhead insulated cable, which aims to improve the weather resistance of the cable and extend the service life of the cable. The cable mainly includes a cable core 10, an insulating layer 20, a composite fiber filling rope 30, a tension steel wire 40, a composite wrapping tape 50 and a sheath layer 60.

[0027] like Figure 1 and Figure 2 As shown, the cable core 10 includes a plurality of mutually twisted conductors, and an insulating layer 20 is coated on the outside of the cable core 10 .

[0028] Furthermore, the cable core 10 includes a first cable core 11 and a second cable core 12 , wherein the diameter of the first cable core 11 is greater than the diameter of the second cable core 12 , and the second cable core 12 is twisted in the gap between the first cable cores 11 .

[0029] In an optional embodiment, the first cable core 11 adopts highly conductive annealed aluminum alloy monofilaments, and the second cable core 12 adopts fine steel wires. The fine steel wires and the annealed aluminum alloy monofilaments are twisted together to form a cable core 10. The tensile strength of the cable core 10 can be improved and the roundness of the cable core 10 can be made higher. The insulating layer 20 adopts a three-layer co-extruded insulating layer, which, from the inside to the outside, are a conductor shielding layer, an insulating layer, and an insulating shielding layer, respectively, which can improve the electric field distribution of the cable core 10.

[0030] Furthermore, three groups of composite fiber filling ropes 30 and three groups of tensile steel wires 40 are twisted together on the outer side of the insulating layer 20 , and at least one composite fiber filling rope 30 is arranged on both sides of each group of tensile steel wires 40 .

[0031] In a specific embodiment, three groups of tensile steel wires 40 are distributed on the outside of the insulating layer 20 in a centrally symmetrical manner. The tensile steel wires 40 play a tensile resistance role and jointly protect the inner cable core 10 to prevent cracks or breaks in the cable core 10 when it is pulled by wind. The cross-section of the composite fiber filling rope 30 is constructed to be circular or elliptical. The wire diameter of the composite fiber filling rope 30 is smaller than the wire diameter of the tensile steel wire 40. The composite fiber filling rope 30 is used to fill the space on both sides of the tensile steel wire 40 to make a smooth transition between the tensile steel wire 40 and the insulating layer 20 to avoid grooves.

[0032] Furthermore, the composite fiber filling rope 30 includes mutually twisted tensile-resistant fiber filaments 31 and water-blocking fiber filaments 32, wherein the tensile-resistant fiber filaments 31 can be made of aramid fiber filaments, which have excellent properties such as ultra-high strength, high modulus, high temperature resistance, acid and alkali resistance, and light weight, and can cooperate with the tensile steel wire 40 to play a tensile role. The water-blocking fiber filaments 32 can be made of a water-blocking rope, which is woven with water-blocking powder, water-absorbing and swelling ointment, etc., which can absorb moisture entering from the outside and block water from penetrating radially or axially.

[0033] In an optional embodiment, the ratio of the cross-sectional areas of the tensile-resistant fiber filaments 31 and the water-blocking fiber filaments 32 is set to [0.5-2]:1, and the tensile-resistant fiber filaments 31 and the water-blocking fiber filaments 32 are mixed and woven into a rope structure using fiber filaments of the same diameter. When the cross-sectional area of ​​the tensile-resistant fiber filaments 31 is relatively large, for example, the ratio of the cross-sectional areas of the tensile-resistant fiber filaments 31 and the water-blocking fiber filaments 32 is set to 2:1, the overall tensile resistance of the composite fiber-filled rope 30 is better. When the cross-sectional area of ​​the water-blocking fiber filaments 32 is relatively large, for example, the ratio of the cross-sectional areas of the tensile-resistant fiber filaments 31 and the water-blocking fiber filaments 32 is set to 1:2, the overall water-blocking performance of the composite fiber-filled rope 30 is better.

[0034] like Figure 3 As shown, the outer sides of the insulating layer 20, the composite fiber filling rope 30 and the tensile steel wire 40 are wrapped with a composite wrapping tape 50, and the outer side of the composite wrapping tape 50 is extruded with a sheath layer 60, so that the cross section of the cable body is a rounded triangle or rounded hexagon structure.

[0035] In this way, there is no groove structure on the surface of the cable body, and the surface of the cable body is relatively smooth, which can prevent rain and snow from accumulating on the surface of the cable body. The cable body with a rounded triangle or rounded hexagonal structure can guide the wind blowing on the surface of the cable body, disperse the wind force, and reduce the swing amplitude of the cable under the action of wind force.

[0036] Furthermore, the composite wrapping tape 50 includes a water-blocking yarn 51 located in an inner layer and a wrapping tape 52 located in an outer layer, wherein the water-blocking yarn 51 and the wrapping tape 52 are wrapped in opposite directions, wherein the water-blocking yarn 51 of the inner layer contains expanded fibers or expanded powder of polyacrylate, and the fiber body of the water-blocking yarn can rapidly expand when it meets water to form a large gel-like substance, and the gel-like substance has a very strong water-retaining capacity, which can effectively prevent the growth of water trees, thereby preventing water from continuing to penetrate and diffuse, thereby achieving the purpose of water blocking, and a water-blocking sealant is provided between the water-blocking yarn 51 and the wrapping tape 52 to isolate the inner layer from the outer side by water, and the wrapping tape 52 can be made of silicone rubber glass fiber cloth, which has good electrical insulation and fire resistance.

[0037] Furthermore, the sheath layer 60 includes a polyethylene or a cross-linked polyethylene sheath, wherein polyethylene is a commonly used sheath material, and the cross-linked polyethylene sheath has a longer service life, better aging resistance, better wear resistance, etc. compared with the polyethylene sheath, and is suitable for medium voltage overhead insulated cables.

[0038] In combination with the above embodiments, the tensile steel wire 40 is arranged on the outside of the insulating layer 20 of the cable core 10, and the composite fiber filling rope 30 is twisted on both sides of the tensile steel wire 40. On the one hand, a smooth transition is made between the tensile steel wire 40 and the insulating layer 20 to avoid the formation of grooves, while at the same time improving the overall tensile capacity of the cable body. A water-blocking composite wrapping tape 50 is arranged on the inner side of the sheath layer 60. In combination with the composite fiber filling rope 30, the overall axial and radial waterproof capabilities of the cable can be improved, the surface of the cable body can be smooth, and the wind resistance and the amount of rain and snow adhesion can be reduced.

[0039] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A self-supporting medium-voltage water-blocking overhead insulated cable, characterized in that: include: A cable core (10) comprising a plurality of groups of mutually twisted conductors; An insulating layer (20) covering the outer side of the cable core (10); Specifically, three groups of composite fiber filling ropes (30) and three groups of tensile steel wires (40) are twisted on the outer side of the insulating layer (20), and at least one composite fiber filling rope (30) is arranged on both sides of each group of tensile steel wires (40). The outer sides of the insulating layer (20), the composite fiber filling rope (30) and the tensile steel wires (40) are wrapped with a composite wrapping tape (50), and the outer side of the composite wrapping tape (50) is extruded with a sheath layer (60), so that the cross-section of the cable body is a rounded triangle or a rounded hexagonal structure.

2. The self-supporting medium-voltage water-blocking overhead insulated cable according to claim 1, characterized in that: The composite fiber filling rope (30) comprises mutually twisted tensile-resistant fiber yarns (31) and water-blocking fiber yarns (32), wherein the ratio of the cross-sectional area of ​​the tensile-resistant fiber yarns (31) to the water-blocking fiber yarns (32) is set to [0.5-2]:

1.

3. The self-supporting medium-voltage water-blocking overhead insulated cable according to claim 2, characterized in that: The cross section of the composite fiber filling rope (30) is configured to be circular or elliptical, and the wire diameter of the composite fiber filling rope (30) is smaller than the wire diameter of the tensile steel wire (40).

4. The self-supporting medium-voltage water-blocking overhead insulated cable according to claim 2, characterized in that: The tensile-resistant fiber yarn (31) comprises aramid fiber yarn.

5. The self-supporting medium-voltage water-blocking overhead insulated cable according to claim 1, characterized in that: The composite wrapping tape (50) comprises a water-blocking yarn (51) located in an inner layer and a wrapping tape (52) located in an outer layer, the water-blocking yarn (51) and the wrapping tape (52) are wrapped in opposite directions, and a water-blocking sealant is provided between the water-blocking yarn (51) and the wrapping tape (52).

6. The self-supporting medium-voltage water-blocking overhead insulated cable according to claim 5, characterized in that: The wrapping tape (52) comprises silicone rubber glass fiber cloth.

7. The self-supporting medium-voltage water-blocking overhead insulated cable according to any one of claims 1 to 6, characterized in that: The cable core (10) comprises a first cable core (11) and a second cable core (12); the diameter of the first cable core (11) is greater than the diameter of the second cable core (12), and the second cable core (12) is twisted in the gap between the first cable cores (11).

8. The self-supporting medium-voltage water-blocking overhead insulated cable according to claim 7, characterized in that: The first cable core (11) comprises aluminum alloy monofilaments, and the second cable core (12) comprises steel wires.

9. The self-supporting medium-voltage water-blocking overhead insulated cable according to claim 1, characterized in that: The insulating layer (20) comprises three co-extruded insulating layers.

10. The self-supporting medium-voltage water-blocking overhead insulated cable according to claim 1, characterized in that: The sheath layer (60) comprises a polyethylene or cross-linked polyethylene sheath.

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