CN-122000122-A - Special overhead insulated cable and preparation method thereof

CN122000122ACN 122000122 ACN122000122 ACN 122000122ACN-122000122-A

Abstract

The invention relates to the technical field of cable manufacture, and discloses a special overhead insulated cable and a preparation method thereof, wherein the special overhead insulated cable comprises a metal guide core, an inner insulating layer, an outer insulating layer and a composite protective layer for axially limiting and extrusion compensating the inner and outer layers of the cable; the composite protective layer comprises winding strips coiled on the outer wall of the inner insulating layer, the winding strips are of inverted T-shaped structures, and spiral interlayer grooves are formed between the winding strips in adjacent circles. According to the device, the spiral flow hose filled with the phase change material suspension is embedded into the interlayer groove, cone-shaped throttle flaps are arranged in the spiral flow hose at intervals along the axial direction, when a cable is radially extruded, the spiral flow hose is compressed and deformed to guide the phase change material suspension to flow along a pipe cavity, local concentrated pressure is converted into axial uniform pressure, meanwhile, the throttle flaps generate damping retardation to form progressive buffering when fluid is rapidly impacted, pressure transfer and graded dissipation of impact energy are achieved, and therefore the cable is effectively protected from being damaged by external pressure.

Inventors

XU HAOBO
JIANG HAITAO
REN DONGDONG
Lv Jianlei
PENG LINLIN

Assignees

东北塑力电缆有限公司

Dates

Publication Date: 20260508
Application Date: 20260401

Claims (10)

1. A special overhead insulated cable is characterized by comprising a metal guide core, an inner insulating layer, an outer insulating layer and a composite protective layer for axially limiting and extrusion compensating the inner layer and the outer layer of the cable, wherein the composite protective layer comprises winding strips coiled on the outer wall of the inner insulating layer, the winding strips are of inverted T-shaped structures, a spiral interlayer groove is formed between every two adjacent winding strips, a spiral flowing hose is coiled inside the interlayer groove and is positioned on the outer wall of the inner insulating layer, the spiral flowing hose is of a hollow structure and is filled with phase change material suspension liquid, a plurality of groups of sawtooth stripes are continuously arranged on the top outer wall of the winding strips along the spiral shape, the composite protective layer further comprises a metal mesh weaving layer wrapped outside the winding strips and the spiral flowing hose, the mesh surface of the metal mesh weaving layer is embedded into the corresponding sawtooth stripes to form an interlocking structure with the winding strips, and the outer insulating layer is wrapped on the outer wall of the metal mesh weaving layer.
2. The special overhead insulated cable of claim 1, wherein the metal guide core is of a twisted structure of steel-cored aluminum strand wires, and the inner insulating layer is tightly coated on the outer wall of the metal guide core.
3. The special aerial insulated cable according to claim 1, wherein the winding strip and the inner insulating layer are made of the same polymer insulating material, and the bottom of the winding strip and the outer wall of the inner insulating layer are integrally formed through hot melting.
4. The special aerial insulated cable according to claim 1, wherein the saw-tooth strips of the outer wall of the winding are in the shape of continuous triangular barbs, and the saw-tooth strips are contacted with the mesh node bottoms of the metal mesh braiding layer.
5. The special overhead insulated cable of claim 1, wherein the spiral flow hose is made of elastic conductive polymer material, the outer diameter of the spiral flow hose is matched with the groove depth and the groove width of the interlayer groove, and the spiral flow hose is embedded into the interlayer groove; the spiral flow hose is internally provided with a plurality of throttle petals at intervals along the axial direction, and the throttle petals are cone-shaped with a large opening at one end and a small opening at the other end.
6. The special aerial insulated cable according to claim 1, wherein the phase change material suspension inside the spiral flow hose is an insulating base fluid with anti-freezing and pressure transfer characteristics, and the phase change material suspension is in a completely sealed state inside the spiral flow hose.
7. The special aerial insulated cable of claim 1, wherein the metal mesh braiding layer is made of high-strength metal composite wires, and is formed by winding a plurality of ingots.
8. The special aerial insulated cable of claim 1, wherein a plurality of groups of contact anchor points are spirally arranged on the inner wall of the outer insulating layer, and one end of each contact anchor point penetrates through a mesh of the metal mesh braid and is contacted with the outer wall of the spiral flow hose.
9. The special aerial insulated cable of claim 1, wherein the inner walls of the adjacent metal mesh braiding layers and the interlayer grooves form a limiting cavity together.
10. The method for preparing the special overhead insulated cable according to any one of claims 1 to 9, which is characterized by comprising the following steps of S1, forming a steel-cored aluminum strand into a metal guide core by re-twisting, S3, arranging conical throttle flaps in an axial interval manner inside the sandwich groove and fully filling phase change material suspension inside the sandwich groove to enable the inner insulating layer to isolate current conduction between the metal guide core and each layer outside and prevent partial discharge, S2, adopting a high polymer insulating material which is the same as the inner insulating layer, coiling the formed section of the outer wall of the inner insulating layer into a reverse T-shaped winding strip, forming a sandwich groove between the bottom of the winding strip and the outer wall of the inner insulating layer into a hot melt integral shape, forming a spiral interlayer groove between adjacent winding strips, forming a whole structure without an interfacial gap between the winding strips and the inner insulating layer, enhancing axial fixed strength, S3, coiling the spiral flow hose which is internally filled with phase change material suspension along the axial interval inside the sandwich groove and is positioned inside the inner insulating layer, enabling the outer diameter of the spiral flow hose to be matched with the groove deep groove and the groove of the groove to form stable positioning fit, forming a transfer match with the spiral flow hose, enabling the spiral flow layer to be rapidly embedded into a metal wire suspension layer to be embedded into a woven layer, forming a continuous layer of the metal mesh, forming a continuous layer by winding layer, forming a continuous layer, forming a layer by winding buffer layer, and embedding the phase change material into a composite damping layer, forming a continuous layer, forming a layer, and a continuous layer, and forming a layer by winding layer, and a layer by winding layer by winding layer, the inner wall of the outer insulating layer is spirally arranged with multiple groups of contact anchor points penetrating through meshes of the metal mesh weaving layer and contacting with the outer wall of the spiral flow hose to form interval type local constraint, and the metal mesh weaving layer is used for providing radial constraint for winding strips and the spiral flow hose and enhancing the overall structural strength, so that the contact anchor points provide axial positioning constraint while retaining the sliding capacity of the spiral flow hose in a non-anchoring area part, and the inner wall of the adjacent metal mesh weaving layer and the interlayer groove form a limiting cavity together to limit the excessive expansion of the spiral flow hose.

Description

Special overhead insulated cable and preparation method thereof Technical Field The invention relates to the technical field of cable manufacturing, in particular to a special overhead insulated cable and a preparation method thereof. Background The overhead insulated cable is widely applied to urban distribution networks, rural power network transformation and trans-regional transmission lines, the basic structure of the overhead insulated cable is generally composed of a metal conductor, an inner insulating layer, a metal armor layer and an outer sheath, wherein the metal conductor bears a current transmission function, the inner insulating layer provides electric insulation protection, the metal armor layer is used for enhancing the mechanical strength of the cable to resist external stretching, extrusion and impact loads, and the outer sheath provides environmental protection for the internal structure. In the cable laying and operation process, in order to improve the mechanical damage resistance of the cable, a metal wire weaving layer or a steel tape armor layer is usually additionally arranged outside an insulating layer in the prior art, external shearing force and radial extrusion force are resisted through rigid constraint of a metal structure, and meanwhile, moisture and corrosive media are prevented from entering by utilizing the sealing performance of an outer sheath, so that long-term stable operation of the cable in an outdoor severe environment is ensured. However, the above-mentioned device still has the following disadvantages that firstly, when the cable is subjected to external radial extrusion, the rigid contact between the braid and the insulating layer enables extrusion force to be directly transmitted to the internal structure, so that irreversible deformation and even breakage of the insulating layer are easily caused near the pressed point, partial flattening or wire breakage of the conductor is easily caused when the cable is seriously caused, and when the cable is subjected to axial stretching or bending laying, relative sliding is easily caused between the metal braid and the insulating layer, so that external load cannot be effectively transmitted by the braid, local stress is concentrated in a single area to directly act on the insulating layer and the conductor, fatigue aging of the insulating layer is accelerated, and the fracture risk of the conductor is increased. Disclosure of Invention The invention aims to solve the defects, and provides a special overhead insulated cable and a preparation method thereof. The special overhead insulated cable comprises a metal guide core, an inner insulating layer, an outer insulating layer and a composite protective layer for axially limiting and extruding and compensating the inner layer and the outer layer of the cable, wherein the composite protective layer comprises winding strips coiled on the outer wall of the inner insulating layer, the winding strips are of inverted T-shaped structures, spiral interlayer grooves are formed between adjacent windings of the winding strips, spiral flowing hoses are coiled on the outer wall of the inner insulating layer and inside the interlayer grooves, the spiral flowing hoses are of hollow structures and filled with phase change material suspension liquid, a plurality of groups of saw-tooth strips are continuously arranged on the top outer wall of the winding strips along the spiral direction, the composite protective layer further comprises a metal net weaving layer wrapped outside the winding strips and the spiral flowing hoses, the net surface of the metal net weaving layer is embedded into the corresponding saw-tooth strips to form an interlocking structure with the winding strips, and the outer insulating layer is wrapped on the outer wall of the metal net weaving layer. Preferably, the metal guide core adopts a compound twisted structure of a steel-cored aluminum strand, and the inner insulating layer is tightly coated on the outer wall of the metal guide core. Preferably, the winding strip and the inner insulating layer are made of the same polymer insulating material, and the bottom of the winding strip and the outer wall of the inner insulating layer are integrally formed through hot melting. Preferably, the saw-tooth strips on the outer wall of the winding strip are in a continuous triangle barb shape, and the saw-tooth strips are contacted with the mesh knot bottoms of the metal mesh weaving layer. Preferably, the spiral flow hose is made of elastic conductive polymer materials, the outer diameter of the spiral flow hose is matched with the groove depth and the groove width of the interlayer groove, and the spiral flow hose is embedded into the interlayer groove; the spiral flow hose is internally provided with a plurality of throttle petals at intervals along the axial direction, and the throttle petals are cone-shaped with a large opening at one end and a small opening at the other