Special aerial insulated cable and preparation method thereof

Abstract

The invention relates to the technical field of cable manufacturing, and discloses a special aerial insulated cable and a preparation method thereof, and the special aerial insulated cable comprises a metal conductive core, an inner insulating layer, an outer insulating layer and a composite protection layer which is used for carrying out axial limiting and extrusion compensation on the inner and outer layers of the cable; the composite protective layer comprises a winding strip wound around the outer wall of the inner insulating layer, the winding strip is of an inverted T shape, and a spiral interlayer groove is formed between every two adjacent circles of winding strips. According to the equipment, a spiral flowing hose filled with phase-change material suspension liquid is embedded into an interlayer groove, and conical-barrel-shaped throttling petals are arranged in the spiral flowing hose at intervals in the axial direction; when the cable is extruded in the radial direction, the spiral flowing hose is pressed and deformed to guide the phase-change material suspension liquid to flow along the pipe cavity so as to convert local concentrated pressure into axial evenly-distributed pressure, meanwhile, the throttling petals generate damping retardation when fluid rapidly impacts to form progressive buffering, and pressure transfer and graded dissipation of impact energy are achieved. Therefore, the cable is effectively protected from being damaged by external pressure.

Description

Technical Field

[0001] This invention relates to the field of cable manufacturing technology, and in particular to a special overhead insulated cable and its preparation method. Background Technology

[0002] Overhead insulated cables are widely used in urban power distribution networks, rural power grid upgrades, and inter-regional transmission lines. Their basic structure typically consists of a metal conductor, an inner insulation layer, a metal armor layer, and an outer sheath. The metal conductor carries the current, the inner insulation layer provides electrical insulation protection, the metal armor layer enhances the cable's mechanical strength to resist external tensile, compressive, and impact loads, and the outer sheath provides environmental protection for the internal structure. During cable laying and operation, to improve the cable's resistance to mechanical damage, existing technologies typically add a braided metal wire layer or a steel tape armor layer outside the insulation layer. The rigid constraints of the metal structure resist external shear forces and radial compressive forces, while the sealing performance of the outer sheath prevents the intrusion of moisture and corrosive media, thus ensuring the long-term stable operation of the cable in harsh outdoor environments.

[0003] However, the above-mentioned equipment still has the following shortcomings: First, when the cable is subjected to external radial compression, the rigid contact between the braided layer and the insulation layer causes the compressive force to be directly transmitted to the internal structure, which can easily lead to irreversible deformation or even damage of the insulation layer near the pressure point. In severe cases, it can cause local flattening or wire breakage of the conductor. Moreover, when the cable is subjected to axial tension or bending during laying, relative slippage can easily occur between the metal braided layer and the insulation layer, which makes it impossible for the braided layer to effectively transmit external loads. Local stress is concentrated in a single area and directly acts on the insulation layer and conductor, accelerating the fatigue aging of the insulation layer and increasing the risk of conductor breakage. Summary of the Invention

[0004] To address the shortcomings mentioned above, this invention proposes a special overhead insulated cable and its preparation method.

[0005] To achieve the above objectives, this application adopts the following technical solution: a special overhead insulated cable and its preparation method, comprising a metal conductor, an inner insulation layer, an outer insulation layer, and a composite protective layer for axial limiting and compression compensation of the inner and outer layers of the cable; the composite protective layer includes a winding strip coiled around the outer wall of the inner insulation layer, the winding strip having an inverted T-shape structure, and adjacent winding strips forming a spiral interlayer groove; a spiral flow hose coiled inside the interlayer groove and located on the outer wall of the inner insulation layer, the spiral flow hose having a hollow structure and being filled with a phase change material suspension; multiple sets of serrated strips are continuously arranged along the spiral shape on the top outer wall of the winding strip; wherein the composite protective layer further includes a metal mesh braided layer wrapped around the winding strip and the spiral flow hose, and the mesh surface of the metal mesh braided layer is embedded in the corresponding serrated strips, forming an interlocking structure with the winding strip; the outer insulation layer covers the outer wall of the metal mesh braided layer.

[0006] Preferably, the metal conductor core adopts a double-stranded structure of steel-cored aluminum stranded wire, and the inner insulation layer tightly covers the outer wall of the metal conductor core.

[0007] Preferably, the wrapping strip and the inner insulation layer are made of the same polymer insulating material, and the bottom of the wrapping strip and the outer wall of the inner insulation layer are integrally formed by thermal fusion.

[0008] Preferably, the serrated stripes on the outer wall of the wrapping strip are continuous triangular barbs, and the serrated stripes are in contact with the bottom of the mesh nodes of the metal mesh weave layer.

[0009] Preferably, the spiral flow hose is made of an elastic conductive polymer material, and the outer diameter of the spiral flow hose matches the depth and width of the interlayer groove, and the spiral flow hose is embedded in the interlayer groove.

[0010] The spiral flow hose has multiple throttling valves spaced axially inside, and each throttling valve is a cone-shaped tube with one end larger than the other.

[0011] Preferably, the phase change material suspension inside the spiral flow hose is an insulating fluid with antifreeze and pressure transfer properties, and the phase change material suspension is in a completely sealed state inside the spiral flow hose.

[0012] Preferably, the metal mesh weaving layer is made of high-strength metal composite wire, and the metal mesh weaving layer is formed by multi-spindle winding.

[0013] Preferably, the inner wall of the outer insulation layer has multiple sets of contact anchor points arranged in a spiral, and one end of the contact anchor point penetrates the mesh of the metal mesh braided layer and contacts the outer wall of the spiral flow hose.

[0014] Preferably, the inner wall of the adjacent metal mesh braided layer and the interlayer groove together form a limiting cavity.

[0015] A method for preparing a special overhead insulated cable includes the following steps: S1, forming a metal conductor core by re-stretching steel-cored aluminum stranded wire, and tightly covering the outer wall of the metal conductor core with an inner insulation layer to isolate the metal conductor core from the external layers and prevent partial discharge; S2, using the same polymer insulating material as the inner insulation layer, winding a strip with an inverted T-shaped cross-section around the outer wall of the inner insulation layer, and heat-melting the bottom of the strip with the outer wall of the inner insulation layer to form a spiral interlayer groove between adjacent coils of the strip to form an integral structure without interface gaps between the strip and the inner insulation layer to enhance axial fixing strength; S3, winding a spiral flow hose with conical throttling valves spaced axially and filled with a phase change material suspension inside the interlayer groove and located on the outer wall of the inner insulation layer, so that the spiral flow hose is embedded in the interlayer groove, and the outer diameter of the spiral flow hose matches the groove depth and groove width to form a stable positioning fit, so that the spiral flow hose is subjected to... The pressure is guided to flow the phase change material suspension to achieve pressure transfer, and the throttling valve generates damping and hindrance when the fluid is rapidly impacted to form a gradual buffer; S4, a metal mesh braided layer is made by winding high-strength metal composite wires, and the metal mesh braided layer is wrapped around the outside of the winding strip and the spiral flow hose, so that the mesh surface of the metal mesh braided layer is embedded in the spirally continuous sawtooth stripes on the top outer wall of the winding strip, forming an interlocking structure with the winding strip. Then, an outer insulation layer is wrapped around the outer wall of the metal mesh braided layer, so that multiple sets of contact anchor points arranged in a spiral on the inner wall of the outer insulation layer penetrate the mesh of the metal mesh braided layer and contact the outer wall of the spiral flow hose to form an intermittent local constraint. This is used to provide radial constraint on the winding strip and the spiral flow hose and enhance the overall structural strength. The contact anchor points retain the sliding ability of the spiral flow hose in the non-anchored area while providing axial positioning constraint, and the inner walls of adjacent metal mesh braided layers and the interlayer groove together form a limiting cavity to limit the excessive expansion of the spiral flow hose.

[0016] The technical effects and advantages of this invention are as follows: In this invention, the device embeds a spiral flow hose filled with a phase change material suspension into a jacketed groove, and sets conical throttling valves at axial intervals inside the spiral flow hose. When the cable is subjected to radial compression, the spiral flow hose deforms under pressure, guiding the phase change material suspension to flow along the cavity, thus converting the local concentrated pressure into axially distributed pressure. At the same time, the throttling valves generate damping and hindrance when the fluid is rapidly impacted, forming a gradual buffer, realizing pressure transfer and graded dissipation of impact energy, thereby effectively protecting the cable from damage by external pressure.

[0017] In this invention, the device forms an axial anchoring structure by thermally fusing the bottom of the wrapping strip with the outer wall of the inner insulation layer. The mesh surface of the metal mesh braided layer is embedded in the serrated stripes of the top outer wall of the wrapping strip to form an interlocking structure to prevent axial slippage of the metal mesh braided layer. Multiple sets of contact anchor points arranged in a spiral on the inner wall of the outer insulation layer penetrate the mesh holes of the metal mesh braided layer and contact the outer wall of the spiral flow hose to form an intermittent local constraint. Together, they form a triple axial limiting system, which realizes axial reinforcement and anti-slip of the cable during axial tension and bending laying, thereby enhancing the structural stability of the cable under complex stress conditions. Attached Figure Description

[0018] The disclosure of this invention is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings, the same reference numerals are used to refer to the same parts:

[0019] Figure 1 This is a schematic diagram of the main structure of the present invention; Figure 2 This is a partial cross-sectional view of the present invention; Figure 3 For the present invention Figure 2 Enlarged schematic diagram of the structure at point A in the middle; Figure 4 This is a schematic diagram of the spiral flow hose and serrated stripe structure of the present invention. Figure 5 This is a schematic diagram of the wrapping strip and serrated stripe structure of the present invention; Figure 6 This is a schematic diagram of the spiral flow hose structure of the present invention; Figure 7 This is a schematic diagram of the outer insulation layer and contact anchor point structure of the present invention; Figure 8 This is a partial cross-sectional schematic diagram of the throttling valve structure of the present invention.

[0020] Legend: 1. Metal conductor core; 11. Inner insulation layer; 2. Wrapping strip; 21. Serrated stripe; 22. Spiral flow hose; 23. Throttling valve; 3. Metal mesh braided layer; 4. Outer insulation layer; 41. Contact anchor point. Detailed Implementation

[0021] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0022] Reference Figure 1-8As shown, the present invention provides a technical solution: a special overhead insulated cable, comprising a metal conductor 1, an inner insulation layer 11, an outer insulation layer 4, and a composite protective layer for axial limiting and compression compensation of the inner and outer layers of the cable; the composite protective layer includes a winding strip 2 coiled around the outer wall of the inner insulation layer 11, which forms a spiral interlayer groove between adjacent winding strips 2 to accommodate a spiral flow hose 22. The winding strip 2 has an inverted T-shape structure, and a spiral interlayer groove is formed between adjacent winding strips 2; a spiral flow hose 22 is coiled inside the interlayer groove and located on the outer wall of the inner insulation layer 11, which guides the internal fluid flow to achieve pressure transfer when under pressure. The spiral flow hose 22 is a... The structure is hollow and filled with a phase change material suspension. The top outer wall of the wrapping strip 2 is continuously provided with multiple sets of serrated stripes 21 in a spiral shape, which are used to form an interlocking structure with the mesh surface of the metal mesh braided layer 3 to reduce axial slippage. The composite protective layer also includes a metal mesh braided layer 3 wrapped around the wrapping strip 2 and the spiral flow hose 22, which is used to provide radial constraint on the wrapping strip 2 and the spiral flow hose 22 and enhance the overall structural strength. The mesh surface of the metal mesh braided layer 3 is embedded in the corresponding serrated stripes 21, forming an interlocking structure with the wrapping strip 2. The outer insulation layer 4 covers the outer wall of the metal mesh braided layer 3, which is used to provide the outermost protection for each internal layer and enhance the overall sealing of the cable.

[0023] Reference Figure 1-4 As shown in this embodiment: the metal conductor 1 adopts a double-stranded structure of steel-cored aluminum stranded wire to withstand tensile loads during cable laying and operation and maintain stable conductivity. The inner insulation layer 11 tightly covers the outer wall of the metal conductor 1 to isolate current conduction between the metal conductor 1 and the external layers and prevent partial discharge. The wrapping strip 2 and the inner insulation layer 11 use the same polymer insulation material to ensure the consistency of interface bonding strength and insulation performance during hot-melt molding. The bottom of the wrapping strip 2 is integrally molded with the outer wall of the inner insulation layer 11 through hot-melt molding to form an integral structure without interface gaps between the wrapping strip 2 and the inner insulation layer 11 to enhance axial fixing strength.

[0024] Reference Figure 4-8 As shown in this embodiment: the serrated stripes 21 on the outer wall of the wrapping strip 2 are in the shape of continuous triangular barbs. The sharp ends of the serrated stripes 21 are in close contact with the inner wall of the metal mesh braided layer 3, increasing the friction between the stripes and the mesh surface of the metal mesh braided layer 3, forming a locking effect to reduce the phenomenon of axial slippage of the metal mesh braided layer 3. Furthermore, the serrated stripes 21 are in contact with the bottom of the mesh nodes of the metal mesh braided layer 3, and part of the mesh surface of the metal mesh braided layer 3 is embedded in the serrated stripes 21 to enhance the reliability of the interlocking.

[0025] The spiral flow hose 22 is made of elastic conductive polymer material, which is used to generate elastic deformation under pressure to absorb impact energy and convert local pressure into fluid flow. The outer diameter of the spiral flow hose 22 is matched with the depth and width of the interlayer groove to ensure that the spiral flow hose 22 forms a stable positioning fit with the wrapping strip 2 after being embedded in the interlayer groove. The spiral flow hose 22 is embedded in the interlayer groove.

[0026] The spiral flow hose 22 has multiple throttling valves 23 spaced axially inside, which are used to generate damping and hindrance when the fluid is rapidly impacted to form a gradual buffer. The throttling valves 23 are cone-shaped with one end larger than the other end, which are used to dampen and hindrance the fluid when it flows in the direction of the small end, and to smoothly return it in the direction of the large end to achieve directional pressure response.

[0027] Reference Figure 4-8 As shown in this embodiment: the phase change material suspension inside the spiral flow hose 22 is an insulating fluid with antifreeze and pressure transfer properties. It is used to release latent heat of crystallization at low temperatures to prevent the spiral flow hose 22 and the inner insulation layer 11 from becoming embrittled, and to absorb heat at high temperatures to suppress overheating of the insulation layer. At the same time, when the spiral flow hose 22 is pressurized, it flows along the cavity to convert the local concentrated pressure into an axially distributed pressure. The phase change material suspension is in a completely sealed state inside the spiral flow hose 22 to prevent fluid leakage and maintain the continuity of pressure transmission.

[0028] Reference Figure 1-3 As shown in this embodiment: the metal mesh braided layer 3 is made of high-strength metal composite wire material, which is used to provide high-strength radial constraint force to limit the excessive expansion of the spiral flow hose 22. The metal mesh braided layer 3 is formed by multi-spindle winding, which is used to make the metal mesh braided layer 3 form a uniform mesh structure and ensure the consistency of force in all directions.

[0029] Reference Figure 2-8 As shown in this embodiment: the inner wall of the outer insulation layer 4 has multiple sets of contact anchor points 41 arranged in a spiral pattern, which are used to provide intermittent local constraints along the winding path of the spiral flow hose 22 to prevent the hose from moving axially. One end of the contact anchor point 41 penetrates the mesh of the metal mesh braided layer 3 and contacts the outer wall of the spiral flow hose 22, which is used to provide axial positioning constraints while retaining the sliding ability of the spiral flow hose 22 in the non-anchored area.

[0030] Reference Figure 1-5 As shown in this embodiment: the inner wall of the adjacent metal mesh braided layer 3 and the interlayer groove together form a limiting cavity.

[0031] A method for preparing a special overhead insulated cable includes the following steps: S1, forming a metal conductor 1 by re-stranding steel-cored aluminum stranded wire, and tightly covering the outer wall of the metal conductor 1 with an inner insulation layer 11 to isolate the metal conductor 1 from the current conduction between the metal conductor 1 and the external layers and to prevent partial discharge; S2, using the same polymer insulating material as the inner insulation layer 11, winding a strip 2 with an inverted T-shaped cross-section around the outer wall of the inner insulation layer 11, and heat-melting the bottom of the strip 2 with the outer wall of the inner insulation layer 11 to form an integral structure, with adjacent turns of the strip... A spiral-shaped interlayer groove is formed between the two layers to create an integral structure without interface gaps between the wrapping strip 2 and the inner insulation layer 11, thereby enhancing axial fixing strength; S3, a spiral flow hose 22, which has conical throttling valves 23 spaced axially and is filled with a phase change material suspension, is coiled inside the interlayer groove and located on the outer wall of the inner insulation layer 11, so that the spiral flow hose 22 is embedded in the interlayer groove. The outer diameter of the spiral flow hose 22 matches the groove depth and groove width of the interlayer groove to form a stable positioning fit, which is used to ensure that the spiral flow hose 22 is under pressure. The flow of the phase change material suspension is guided to achieve pressure transfer, and the throttling valve 23 generates damping and stagnation during rapid fluid impact to form a gradual buffer; S4, a metal mesh braided layer 3 is formed by winding multiple spindles of high-strength metal composite wires, and the metal mesh braided layer 3 is wrapped around the outside of the winding strip 2 and the spiral flow hose 22, so that the mesh surface of the metal mesh braided layer 3 is embedded in the interior of the spirally continuous serrated stripes 21 on the top outer wall of the winding strip 2, forming an interlocking structure with the winding strip 2, and then the outer insulation layer 4 is wrapped around the outer wall of the metal mesh braided layer 3, so that the outer... Multiple sets of contact anchor points 41 arranged in a spiral on the inner wall of the insulation layer 4 penetrate the mesh of the metal mesh braided layer 3 and contact the outer wall of the spiral flow hose 22 to form an intermittent local constraint. This is used to provide radial constraint on the wrapping strip 2 and the spiral flow hose 22 by the metal mesh braided layer 3 and to enhance the overall structural strength. The contact anchor points 41 provide axial positioning constraint while retaining the sliding ability of the spiral flow hose 22 in the non-anchored area. The inner walls of adjacent metal mesh braided layers 3 and the interlayer groove together form a limiting cavity to limit the excessive expansion of the spiral flow hose 22.

[0032] Working principle: First, the outer wall of the metal conductor core 1 is tightly covered by the inner insulation layer 11, and the winding strip 2 with an inverted T-shaped cross-section is coiled around the outer wall of the inner insulation layer 11. During the production process, the bottom of the winding strip 2 and the outer wall of the inner insulation layer 11 are integrally formed by heat fusion, which creates a spiral interlayer groove between adjacent winding strips 2. Then, the spiral flow hose 22, filled with a phase change material suspension, is coiled inside the interlayer groove and located at the outer wall of the inner insulation layer 11. The spiral flow hose 22 is embedded in the interlayer groove, and its outer diameter matches the groove depth and width, ensuring the stability of the overall structure. Second, the metal mesh braided layer 3 is wrapped around the outside of the winding strip 2 and the spiral flow hose 22, and part of the mesh surface of the metal mesh braided layer 3 is embedded inside the spirally continuous serrated stripes 21 on the top outer wall of the winding strip 2, forming an "interlocking structure" together with the winding strip 2. Next, the outer insulation layer 4 covers the outer wall of the metal mesh braided layer 3. During this process, multiple sets of contact anchor points 41 arranged spirally on the inner wall of the outer insulation layer 4 penetrate the braided mesh holes (slots reserved during production) of the metal mesh braided layer 3 and come into contact with the outer wall of the spiral flow hose 22, further enhancing the stability of the entire cable structure. Furthermore, when the cable is subjected to radial extrusion pressure from the outside, the spiral flow hose 22 in the interlayer groove deforms under pressure, and the phase change material suspension inside begins to flow along the cavity. This flow process can convert locally concentrated pressure into uniformly distributed pressure along the cable axis. Simultaneously, the throttling valves 23 spaced axially inside the spiral flow hose 22 present a conical shape with a large opening at one end and a small opening at the other. This structural design dampens the fluid during rapid impact, creating a gradual buffering effect, thereby achieving pressure transfer and graded dissipation of impact energy, effectively protecting the cable from damage by external pressure. Meanwhile, when the cable is in a low-temperature environment, the phase change material suspension inside the spiral flow hose 22 will release latent heat of crystallization. This process can prevent the spiral flow hose 22 and the inner insulation layer 11 from becoming embrittled, ensuring that the cable can still work normally in a low-temperature environment. When the cable is in a high-temperature environment, the phase change material suspension can absorb heat, thereby suppressing the overheating of the insulation layer, realizing the adaptive adjustment of the cable operating temperature, and allowing the cable to maintain good performance in different temperature environments.Next, when the cable is subjected to axial tension or bending during installation, the thermofused structure between the bottom of the wrapping strip 2 and the outer wall of the inner insulation layer 11 provides axial fixation. The interlocking structure formed by the sawtooth stripes 21 embedded in the mesh of the metal mesh braided layer 3 can reduce the axial slippage of the metal mesh braided layer 3. The contact anchor point 41 on the inner wall of the outer insulation layer 4 provides local constraint after contacting the outer wall of the spiral flow hose 22. The wrapping strip 2, the metal mesh braided layer 3, and the outer insulation layer 4 together constitute three axial limiting structures, enhancing the stability of the cable under complex stress conditions. Through the cooperation between the above components, and utilizing the interaction between the inverted T-shaped wrapping strip 2, the spiral flow hose 22, the phase change material suspension, the throttling valve 23, the sawtooth stripes 21, the metal mesh braided layer 3, and the contact anchor point 41, multiple protective functions such as axial limiting, radial buffering, pressure transfer, thermal management, and impact energy dissipation are achieved. These functions work together to greatly improve the operational reliability and service life of the cable in harsh environments, enabling the cable to play a stable and long-lasting role in various complex usage scenarios.

[0033] The technical scope of this invention is not limited to the content described above. Those skilled in the art can make various modifications and variations to the above embodiments without departing from the technical concept of this invention, and all such modifications and variations should fall within the protection scope of this invention.

Claims

1. A special overhead insulated cable, characterized in that, The cable comprises a metal conductor core, an inner insulation layer, an outer insulation layer, and a composite protective layer for axial restraint and compression compensation of the inner and outer layers. The composite protective layer includes a winding strip coiled around the outer wall of the inner insulation layer. The winding strip has an inverted T-shape, and adjacent coils of the winding strip form a spiral interlayer groove. A spiral flow hose is coiled inside the interlayer groove and located on the outer wall of the inner insulation layer. The spiral flow hose has a hollow structure and is filled with a phase change material suspension. Multiple sets of serrated stripes are continuously arranged along the top outer wall of the winding strip in a spiral shape. The composite protective layer also includes a metal mesh braided layer wrapped around the winding strip and the spiral flow hose, with the mesh surface of the metal mesh braided layer embedded within the corresponding serrated stripes, forming an interlocking structure with the winding strip. The outer insulation layer covers the outer wall of the metal mesh braided layer.

2. The special overhead insulated cable according to claim 1, characterized in that: The metal conductor core adopts a double-stranded structure of steel-cored aluminum stranded wire, and the inner insulation layer tightly covers the outer wall of the metal conductor core.

3. The special overhead insulated cable according to claim 1, characterized in that: The wrapping strip and the inner insulation layer are made of the same polymer insulating material, and the bottom of the wrapping strip and the outer wall of the inner insulation layer are integrally formed by thermal fusion.

4. The special overhead insulated cable according to claim 1, characterized in that: The serrated stripes on the outer wall of the wrapping strip are continuous triangular barbs, and the serrated stripes are in contact with the bottom of the mesh nodes of the metal mesh weave layer.

5. The special overhead insulated cable according to claim 1, characterized in that: The spiral flow hose is made of elastic conductive polymer material. The outer diameter of the spiral flow hose matches the depth and width of the interlayer groove. The spiral flow hose is embedded in the interlayer groove. The spiral flow hose has multiple throttling valves spaced axially inside, and each throttling valve is a cone-shaped tube with one end larger than the other.

6. The special overhead insulated cable according to claim 1, characterized in that: The phase change material suspension inside the spiral flow hose is an insulating fluid with antifreeze and pressure transfer properties, and the phase change material suspension is in a completely sealed state inside the spiral flow hose.

7. The special overhead insulated cable according to claim 1, characterized in that: The metal mesh weave layer is made of high-strength metal composite wire, and the metal mesh weave layer is formed by multiple spindles winding together.

8. The special overhead insulated cable according to claim 1, characterized in that: The inner wall of the outer insulation layer has multiple sets of contact anchors arranged in a spiral, and one end of the contact anchor penetrates the mesh of the metal mesh braided layer and contacts the outer wall of the spiral flow hose.

9. The special overhead insulated cable according to claim 1, characterized in that: The inner walls of the adjacent metal mesh braided layers and the interlayer grooves together form a limiting cavity.

10. The method for preparing the special overhead insulated cable as described in any one of claims 1-9, characterized in that: Includes the following steps: S1. A metal conductor core is formed by re-stretching steel-cored aluminum stranded wire. An inner insulation layer is tightly wrapped around the outer wall of the metal conductor core to isolate the metal conductor core from the external layers and prevent partial discharge. S2. Using the same polymer insulating material as the inner insulation layer, a T-shaped strip is coiled around the outer wall of the inner insulation layer. The bottom of the strip is thermally fused to the outer wall of the inner insulation layer, forming a spiral interlayer groove between adjacent coils. This creates a seamless, interfacial structure between the strip and the inner insulation layer. Enhance axial fixation strength; S3, a spiral flow hose with conical throttling valves spaced axially and filled with phase change material suspension is coiled inside the interlayer groove and located on the outer wall of the inner insulation layer, so that the spiral flow hose is embedded in the interlayer groove. The outer diameter of the spiral flow hose matches the groove depth and groove width of the interlayer groove to form a stable positioning fit, which is used to guide the flow of phase change material suspension when the spiral flow hose is under pressure to achieve pressure transfer, and to make the throttling valve generate damping and hindrance when the fluid is rapidly impacted to form a gradual buffer; S4. A metal mesh braided layer is formed by winding high-strength metal composite wire. The metal mesh braided layer is wrapped around the outside of the winding strip and the spiral flow hose, so that the mesh surface of the metal mesh braided layer is embedded in the spirally continuous serrated stripes on the top outer wall of the winding strip, forming an interlocking structure with the winding strip. Then, an outer insulation layer is wrapped around the outer wall of the metal mesh braided layer, so that multiple sets of contact anchor points arranged in a spiral on the inner wall of the outer insulation layer penetrate the mesh of the metal mesh braided layer and contact the outer wall of the spiral flow hose to form an intermittent local constraint. This is used to provide radial constraint on the winding strip and the spiral flow hose by the metal mesh braided layer and enhance the overall structural strength. The contact anchor points retain the sliding ability of the spiral flow hose in the non-anchored area while providing axial positioning constraint. The inner walls of adjacent metal mesh braided layers and the interlayer groove together form a limiting cavity to limit the excessive expansion of the spiral flow hose.

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