A high wear-resistant 10kv high-voltage cable and a preparation method thereof

Abstract

The application discloses a kind of 10kV high-voltage cable of high wear resistance and preparation method thereof, it is related to wire and cable technical field, including the conductor, semi-conductive resistance band, conductor shield layer, insulating layer, insulating shield layer, water barrier layer, smooth metal sleeve layer and outer sheath that are sequentially covered from inside to outside;The raw material of outer sheath includes wear-resistant component, and wear-resistant component includes the mass ratio of (8-14) : (4-6) ultrahigh molecular weight polyethylene fiber and ternary layered ceramic particles;Smooth metal sleeve layer and outer sheath are also provided with buffer layer in the middle;Buffer layer includes the following mass fraction of raw materials: ethylene-vinyl alcohol copolymer 60-80 parts;Maleic anhydride grafted POE 15-25 parts and carbon nanotube 3-6 parts.Form enhanced network between wear-resistant components, combined with self-lubricating properties, reduce the friction coefficient of outer sheath, improve wear resistance;And introduce buffer layer, absorb and disperse stress, with heat conduction network can reduce local heat accumulation, improve thermal cycle stability.

Description

Technical Field

[0001] This invention relates to the field of wire and cable technology, and in particular to a highly wear-resistant 10kV high-voltage cable and its preparation method. Background Technology

[0002] A 10kV high-voltage power cable is a power transmission cable with a rated voltage of 10 kV. It is a key power transmission device in urban power distribution networks and industrial and mining enterprise power supply systems, undertaking the important task of power distribution and transmission. Its typical structure mainly includes a conductor, a conductor shielding layer, an insulation layer, an insulation shielding layer, a metal shielding / sheathing layer, and an outermost outer sheath. The insulation layer is usually cross-linked polyethylene, making it a cross-linked polyethylene insulated power cable. The synergistic effect between its multiple layers helps ensure the electrical performance and mechanical reliability of the cable.

[0003] During the laying and long-term operation of high-voltage cables, friction or scratching with pipes, supports, the ground, or other cables is inevitable. This is especially true in complex environments such as mining areas, forest areas, and areas with frequent construction activity, where the cable's outer surface is highly susceptible to mechanical damage. Therefore, abrasion resistance is a key indicator of the cable's outer sheath quality. Wear on the outer sheath not only directly weakens its mechanical protection but can also damage the cable's waterproof and corrosion-resistant barriers, leading to internal insulation dampness, metal sheath corrosion, and ultimately, decreased insulation performance, partial discharge, or even breakdown—serious faults. Therefore, improving the abrasion resistance of high-voltage cables is crucial for ensuring the safe and stable operation of power systems, reducing maintenance costs, and extending cable lifespan.

[0004] However, in existing technologies, the common method to improve the abrasion resistance of cables is to modify the outermost sheath material, using high-density polyethylene or adding abrasion-resistant fillers such as carbon black and mineral fillers to enhance its surface hardness and scratch resistance. However, the interfacial bonding performance between the outer sheath material and the metal sheath is often overlooked during the modification process. Furthermore, during long-term operation of high-voltage cables, it has been found that changes in current load cause periodic temperature fluctuations within the cable. During this long-term heating and cooling thermal cycle, due to the difference in thermal expansion coefficients, coupled with the higher hardness and reduced flexibility of the modified abrasion-resistant outer sheath, the bonding interface between the outer sheath and the metal sheath is prone to fatigue, leading to decreased bonding strength and reciprocating shear stress at the interface. When delamination occurs at the interface, moisture can more easily corrode the cable interior, reducing the mechanical protective function of the outer sheath and compromising the overall structural integrity of the cable, thus affecting its service life and safety.

[0005] Therefore, it is of great significance to obtain a high-voltage cable with good wear resistance and long-term stability under thermal cycling conditions. Summary of the Invention

[0006] The purpose of this invention is to provide a highly wear-resistant 10kV high-voltage cable and its preparation method, so as to solve the technical problems of poor wear resistance and difficulty in taking into account the thermal cycling fatigue performance of high-voltage cables in the prior art.

[0007] The technical problem to be solved by this invention can be achieved through the following technical solution: In a first aspect, the present invention provides a highly wear-resistant 10kV high-voltage cable, comprising, from the inside out, a conductor, a semi-conductive resistance strip, a conductor shielding layer, an insulation layer, an insulation shielding layer, a water-blocking layer, a smooth metal sheath, and an outer sheath; the outer sheath is made of a wear-resistant component, which comprises ultra-high molecular weight polyethylene fiber and ternary layered ceramic particles in a mass ratio of (8-14):(4-6); A buffer layer is also provided between the smooth metal sleeve and the outer sheath; the buffer layer comprises the following raw materials in parts by weight: 60-80 parts of ethylene-vinyl alcohol copolymer; 15-25 parts of maleic anhydride grafted onto POE; 3 to 6 parts of carbon nanotubes.

[0008] Preferably, the outer sheath comprises the following parts by weight of raw material: 20-30 parts of low-density polyethylene; 70-80 parts of high-density polyethylene; 12-20 parts of wear-resistant component; 8-12 parts of ethylene-vinyl acetate copolymer; Other adjuvants: 2-6 parts.

[0009] More preferably, other additives include antioxidants and lubricants in a mass ratio of (1-3):(1-3).

[0010] Preferably, the strength of the ultra-high molecular weight polyethylene fiber is 30-40 cN / dtex.

[0011] Preferably, the ternary layered ceramic particles include one or more combinations of Ti2AlC, Ti2AlN, Ti3SiC2, Cr2AlC, Nb2AlC and Ti2SnC.

[0012] Preferably, the insulation layer is a cross-linked polyethylene insulation layer.

[0013] Preferably, the conductor is a segmented conductor formed by splicing together five sector-shaped aluminum conductors.

[0014] By adopting the above technical solution, the present invention introduces a wear-resistant component into the outer sheath. The wear-resistant component is a blend of ultra-high molecular weight polyethylene fiber and ternary layered ceramic particles. The ultra-high molecular weight polyethylene fiber has good dispersibility in the polyethylene matrix of the outer sheath and can form physical entanglement during melt blending, achieving a relatively good interfacial bond. Furthermore, the ultra-high molecular weight polyethylene fiber itself has excellent self-lubricating properties, which can not only improve the overall tensile strength and modulus of the outer sheath material and enhance puncture resistance, but also greatly improve the wear resistance of the outer sheath and reduce the wear rate.

[0015] Ternary layered ceramic particles possess a graphite-like layered crystal structure, which facilitates crystal plane slippage during friction, forming a continuous solid lubricating film. This significantly reduces the friction coefficient and wear rate of the outer sheath. Compared to traditional mineral fillers or hard ceramic fillers, although they have high hardness, they lack self-lubricating ability. During long-term use, they may detach or precipitate, potentially exacerbating cable wear. Furthermore, ternary layered ceramic particles combine the thermal conductivity of metals with the high-temperature resistance and oxidation resistance of ceramics. This helps to quickly dissipate heat from within the cable and from friction, reducing static electricity accumulation, improving thermal stability, and ensuring that the outer sheath does not develop internal microcracks due to material brittleness when subjected to impact or thermal cycling stress.

[0016] The composite of ultra-high molecular weight polyethylene fiber and ternary layered ceramic particles can form a three-dimensional interwoven reinforcement network in the outer sheath. The fiber skeleton plays a load-bearing role, and the ternary layered ceramic particles are evenly distributed and interspersed in the skeleton, which also reduces the movement of ceramic particles and prevents them from falling off the matrix, thereby further improving the mechanical strength and wear resistance of the outer sheath.

[0017] Meanwhile, a buffer layer is introduced between the smooth metal sheath and the outer sheath of the present invention. When the cable is subjected to external compression, bending or impact, the buffer layer can undergo elastic deformation to absorb and disperse stress, thereby preventing stress from being directly and rigidly transmitted. This not only protects the bonding interface between the layers, but also reduces the accelerated wear of the outer sheath caused by local stress concentration. Specifically, the buffer layer mainly uses ethylene-vinyl alcohol copolymer as the continuous phase, and maleic anhydride grafted POE (polyolefin elastomer) as a toughening agent and compatibilizer. Maleic anhydride can chemically react with the hydroxyl groups in ethylene-vinyl alcohol to form a strong interfacial bond, thereby greatly improving the toughness of the blend, enabling it to withstand repeated deformation without becoming brittle, thereby improving the wear resistance of the cable.

[0018] Furthermore, due to the changes in current load during the operation of high-voltage cables, the internal temperature of the cables exhibits periodic fluctuations, which can cause thermal shear stress between the metal sheath and the outer sheath. Over a long period of time, this can lead to interlayer delamination and cracking. The buffer layer of this invention has high elastic recovery capability, enabling it to undergo reversible deformation during multiple thermal cycles. It converts shear stress into elastic potential energy and dissipates it as heat, thereby significantly reducing interlayer stress. In addition, carbon nanotubes are introduced. Carbon nanotubes have extremely high thermal conductivity, which can rapidly diffuse the generated heat laterally, making the temperature distribution of the cable more uniform, reducing the overall operating temperature, and thus effectively resisting the periodic stress problem caused by thermal cycling.

[0019] The buffer layer uses ethylene-vinyl alcohol copolymer as the matrix material, which itself is a high barrier material. It can effectively prevent external moisture or corrosive gases from penetrating the surface of the metal sheath along the cracks or interface gaps of the outer sheath, thereby reducing interface loosening and peeling caused by corrosion. The addition of carbon nanotubes can also make the buffer layer semi-conductive, improving the safety of the cable.

[0020] The buffer layer acts as a bridge between the smooth metal sheath and the outer sheath. Its anhydride groups coordinate with the metal surface, while its hydroxyl groups form hydrogen bonds with the ethylene-vinyl acetate in the outer sheath, significantly improving interlayer bonding. This results in more uniform stress distribution, reduced stress concentration, and enhanced cable compressive strength. The introduction of the buffer layer can address the problem of thermally cycle-induced interfacial fatigue delamination failure while improving wear resistance, significantly improving the long-term structural stability and service life of high-voltage cables under variable load operating conditions.

[0021] Preferably, the carbon nanotubes are modified; the modified carbon nanotubes are grafted with polyvinyl alcohol segments.

[0022] Preferably, the modified carbon nanotubes include the following process steps: Pretreatment of carbon nanotubes: Carbon nanotubes are heated under reflux at 40-50°C for 8-12 hours in an acidic solution, and then washed and dried after centrifugation to obtain pretreated carbon nanotubes. Modification of carbon nanotubes: An emulsifier is added to water and stirred to dissolve at 60–70°C. Vinyl acetate is then added to obtain an emulsion. An initiator solution is added to the emulsion and stirred at 70–75°C for 1–2 hours to perform prepolymerization, yielding a prepolymer. Pretreated carbon nanotubes, an emulsifier, and an initiator are added to the prepolymer, and the reaction continues for 1–2 hours to obtain a polymer emulsion. The polymer emulsion is added to a saturated sodium hydroxide solution at 30–40°C for demulsification, followed by filtration to precipitate, washing, and drying to obtain a crude graft product. The crude graft product is dissolved in methanol and subjected to alcoholysis under alkaline conditions. Finally, the precipitate is precipitated, washed, and dried to obtain the final product.

[0023] Preferably, the mass-to-volume ratio of carbon nanotubes, vinyl acetate, emulsifier, and initiator is 1 mg: (0.15–0.25) mL: (5–7) mg: (1.5–2) mg.

[0024] More preferably, the acidic solution includes an aqueous solution of nitric acid or sulfuric acid with a mass fraction of 15-25%.

[0025] More preferably, the emulsifier includes one or a combination of two of anionic and nonionic emulsifiers; the anionic emulsifier includes one or a combination of sodium dodecyl sulfate, sodium dodecylbenzene sulfonate and sodium hexadecyl sulfate; and the nonionic emulsifier includes any one of alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether.

[0026] More preferably, the initiator includes one or a combination of two of potassium persulfate and ammonium persulfate.

[0027] By adopting the above technical solution, the carbon nanotubes in the buffer layer of this invention can be further modified. Specifically, the carbon nanotubes are first surface activated in an acidic solution, which introduces oxygen-containing groups such as carboxyl groups onto the surface of the carbon nanotubes, providing reactive sites for subsequent grafting. Then, through free radical emulsion polymerization, vinyl acetate is converted into polyvinyl acetate prepolymer under the action of an initiator. Then, emulsifiers and initiators are added, and the oxygen-containing groups on the surface of the carbon nanotubes act as free radical sites to connect the polyvinyl acetate prepolymer and initiate further polymerization. Then, the product is precipitated by demulsification. Finally, through alcoholysis, under alkaline conditions, the acetate groups on the polyvinyl acetate molecular chain undergo transesterification with methanol to generate polyvinyl alcohol, thus obtaining carbon nanotubes with polyvinyl alcohol grafted onto their surface.

[0028] Introducing modified carbon nanotubes into the buffer layer can effectively improve the dispersion of carbon nanotubes in the matrix. The grafted polyvinyl alcohol segments can form a hydrogen bond network with the ethylene-vinyl alcohol matrix, which, together with maleic anhydride grafted POE, improves the toughness of the buffer layer. The carbon nanotubes can also effectively bear and dissipate stress, thereby improving the overall wear resistance.

[0029] Furthermore, after modification, the thermally conductive network constructed by carbon nanotubes is more complete, resulting in a more uniform thermal conductivity and higher isotropy of the buffer layer. During the thermal cycling heating process, it can reduce the temperature difference between the metal smooth sheath and the outer sheath. Moreover, the constructed hydrogen bond network can help the buffer layer maintain good structural stability after multiple compression thermal cycles, greatly improving the fatigue resistance and durability of high-voltage cables.

[0030] Modified carbon nanotubes can enhance the crack propagation resistance and high-temperature bonding stability of the buffer layer under thermal cycling conditions, forming an efficient anti-fatigue and wear-resistant protection with the outer sheath, ensuring the long-term structural stability of high-voltage cables.

[0031] Secondly, the present invention provides a method for preparing a highly wear-resistant 10kV high-voltage cable, which includes the following process steps: S1. Weigh the raw materials for the outer sheath and the buffer layer separately and mix them evenly. Then, obtain the outer sheath functional masterbatch and the buffer layer functional masterbatch by melt extrusion and granulation, respectively. S2. Overlapping semiconducting resistance strips are wrapped around the conductor, and then three layers are co-extruded to form a conductor shielding layer, an insulation layer, and an insulation shielding layer in sequence. After extrusion, the material is placed in a cross-linking pipe for cross-linking. After cooling and degassing, a water-blocking strip is wrapped around it to form a water-blocking layer. Then, a smooth metal sheath is extruded. Finally, a buffer layer functional masterbatch and an outer sheath functional masterbatch are extruded sequentially outside the smooth metal sheath to form a buffer layer and an outer sheath. After cooling and setting, the desired product is obtained.

[0032] The beneficial effects of this invention are: 1. The outer sheath of the high wear-resistant 10kV high-voltage cable of the present invention contains wear-resistant components. Ultra-high molecular weight polyethylene fibers and ternary layered ceramic particles can work together to form a reinforcing network. Combined with their self-lubricating properties, the friction coefficient of the outer sheath can be significantly reduced, while ensuring good mechanical strength and greatly improving the wear resistance of the high-voltage cable.

[0033] 2. In the high wear-resistant 10kV high-voltage cable of the present invention, a buffer layer is further provided between the smooth metal sheath and the outer sheath. The buffer layer uses ethylene-vinyl alcohol copolymer as the matrix material and is composited with maleic anhydride-grafted POE and carbon nanotubes. It can effectively absorb and disperse the interfacial shear stress generated by thermal cycling. After modification, the carbon nanotubes can further improve the stress diffusion ability by forming a hydrogen bond network, improve the structural stability of the high-voltage cable, and maintain the interfacial bonding force. In addition, its thermally conductive network can also synergistically dissipate heat and reduce local heat accumulation, thereby solving the problem of interfacial failure caused by thermal fatigue in conventional wear-resistant cables, resulting in a high-voltage cable with excellent comprehensive performance, good wear resistance, and long service life. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the cross-section of a 10kV high-voltage cable obtained in Embodiment 1 of the present invention. Detailed Implementation

[0035] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0036] Preparation Example Preparation Example 1: A carbon nanotube, after modification treatment, includes the following steps: Pretreatment of carbon nanotubes: Take 100 mg of carbon nanotubes (single-walled carbon nanotubes with a diameter of 1-2 nm and a length of 1-3 μm) and add them to a 20% nitric acid aqueous solution. Heat and reflux at 45 °C for 10 h. After centrifugation, wash and dry to obtain pretreated carbon nanotubes. Modification of carbon nanotubes: 200 mg sodium dodecyl sulfate and 300 mg alkylphenol polyoxyethylene ether emulsifier OP-10 were added to water and stirred at 65 °C to dissolve. 20 mL of vinyl acetate was added to obtain an emulsion. A 2.5 mg / mL potassium persulfate aqueous solution was added to the emulsion, with 150 mg of potassium persulfate added. The mixture was stirred at 70 °C for 2 h to perform prepolymerization, obtaining a prepolymer. The pretreated carbon nanotubes and 100 mg dodecyl sulfate were then added to the prepolymer. Sodium persulfate and 50 mg of potassium persulfate were reacted for 2 hours to obtain a polymer emulsion. The polymer emulsion was then added to a saturated sodium hydroxide solution at 35°C for demulsification. The precipitate was then filtered, washed, and dried to obtain the crude graft product. The crude graft product was dissolved in methanol and subjected to alcoholysis under alkaline conditions. Specifically, a 5% (w / w) mixed solution of sodium hydroxide and methanol was added dropwise at 25°C, and the mixture was stirred for 1 hour. The mixture of sodium hydroxide and methanol was then added dropwise for another 1 hour. Finally, the precipitate was precipitated, washed, and dried to obtain the final product.

[0037] Example Example 1: A highly wear-resistant 10kV high-voltage cable was prepared according to the following method: S1. Weigh the raw materials for the outer sheath and the buffer layer separately and mix them evenly. Then, obtain the outer sheath functional masterbatch and the buffer layer functional masterbatch by melt extrusion and granulation, respectively. Specifically: Weigh out 25 parts of low-density polyethylene (melt flow rate 0.35 g / 10 min @ 190 ℃ / 2.16 kg), 75 parts of high-density polyethylene (melt flow rate 0.48 g / 10 min @ 190 ℃ / 2.16 kg), 16 parts of wear-resistant component, which includes ultra-high molecular weight polyethylene fiber (strength 30 cN / dtex) and ternary layered ceramic particles Ti2AlC with a mass ratio of 11:5, 10 parts of ethylene-vinyl acetate copolymer (melt flow rate 6 g / 10 min @ 190 ℃ / 2.16 kg), 2 parts of antioxidant 1035 and 2 parts of lubricant polyethylene wax. Mix all raw materials except ultra-high molecular weight polyethylene fiber evenly, and then melt extrude at 160-185 ℃. During the process, ultra-high molecular weight polyethylene fiber is added from the side feed. Finally, cool and granulate to obtain the outer sheath functional masterbatch. Weigh 70 parts of ethylene-vinyl alcohol copolymer (melt flow rate 3.8 g / 10 min @ 210 ℃ / 2.16 kg), 20 parts of maleic anhydride-grafted POE (maleic anhydride content 0.6-1.0%) and 5 parts of carbon nanotubes (single-walled carbon nanotubes, diameter 1-2 nm, length 1-3 μm), mix them evenly, and then melt extrude and granulate them at 175-195 ℃ to obtain the buffer layer functional masterbatch; S2. According to Figure 1 Semiconductor resistor 2 is wrapped around conductor 1, and then three layers are co-extruded to form conductor shielding layer 3, insulation layer 4 and insulation shielding layer 5 in sequence. After extrusion, it is placed in a cross-linking pipe for cross-linking, and then cooled and degassed before being wrapped with water-blocking tape to form water-blocking layer 6. Then, smooth metal aluminum sheath layer 7 is extruded. Finally, buffer layer functional masterbatch and outer sheath functional masterbatch are extruded in sequence outside the smooth metal sheath layer to form buffer layer 8 and outer sheath 9. After cooling and shaping, the product is obtained.

[0038] Examples 2 and 3 describe a highly wear-resistant 10kV high-voltage cable. The only difference between Example 1 and Example 2 is the adjustment of the raw material ratios for the outer sheath and buffer layer, as shown in Table 1. Table 1 Formulation of Outer Sheath and Cushion Layer

[0039] In Example 2, the wear-resistant component includes ultra-high molecular weight polyethylene fiber and ternary layered ceramic particles Ti2AlC in a mass ratio of 8:4; in Example 3, the wear-resistant component includes ultra-high molecular weight polyethylene fiber and ternary layered ceramic particles Ti2AlC in a mass ratio of 14:6.

[0040] Example 4: A highly wear-resistant 10kV high-voltage cable, the only difference from Example 1 is that the carbon nanotubes in Example 1 are replaced with an equal amount of carbon nanotubes prepared in Example 1.

[0041] Example 5: A highly wear-resistant 10kV high-voltage cable, which differs from Example 1 only in that the amount of wear-resistant component added to the outer sheath is 25 parts.

[0042] Comparative Example Comparative Example 1 is a 10kV high-voltage cable with high wear resistance. The only difference from Example 1 is that the wear-resistant components in the outer sheath include ultra-high molecular weight polyethylene fibers and ternary layered ceramic particles Ti2AlC in a mass ratio of 14:2.

[0043] Comparative Example 2, a highly wear-resistant 10kV high-voltage cable, differs from Example 1 only in that the wear-resistant components in the outer sheath include ultra-high molecular weight polyethylene fibers and ternary layered ceramic particles Ti2AlC in a mass ratio of 8:8.

[0044] Comparative Example 3 is a highly wear-resistant 10kV high-voltage cable, which differs from Example 1 only in that the wear-resistant component in the outer sheath is only ultra-high molecular weight polyethylene fiber.

[0045] Comparative Example 4 is a highly wear-resistant 10kV high-voltage cable, which differs from Example 1 only in that an equal amount of glass fiber (linear density of 2400 tex) is used to replace ultra-high molecular weight polyethylene fiber.

[0046] Comparative Example 5, a highly wear-resistant 10kV high-voltage cable, differs from Example 1 only in that an equal amount of carbon black is used to replace the ternary layered ceramic particles Ti2AlC.

[0047] Comparative Example 6 is a highly wear-resistant 10kV high-voltage cable, which differs from Example 1 only in that a buffer layer is not squeezed between the smooth metal sheath and the outer sheath.

[0048] Performance testing methods 1. Abrasion resistance test: According to the relevant records in industry standard JB / T 10696.6-2007 "Mechanical and physical and chemical properties test methods for wires and cables - Part 6: Extrusion sheath scratch test", the 10kV high voltage cable samples obtained in the examples and comparative examples were subjected to scratch resistance test. 2. Thermal cycling fatigue performance test: Referring to the relevant records in industry standard JB / T 10696.3-2007 "Mechanical and physical and chemical properties test methods for electric wires and cables - Part 3: Bending test", and maintaining current transmission to simulate heat storage conditions, dynamic bending fatigue tests were conducted on the 10kV high-voltage cable samples obtained in the examples and comparative examples, and the test results were recorded.

[0049] The results of the above experiments are shown in Table 2:

[0050] According to Table 2, combined with Examples 1 and 4, it can be seen that the wear resistance and thermal cycling fatigue resistance of Example 4 are enhanced compared to Example 1. The reason is that the carbon nanotubes in the buffer layer in Example 4 are modified and grafted with polyvinyl alcohol, which can improve the ability of the buffer layer to absorb and disperse stress, and make the carbon nanotubes more uniformly dispersed in the buffer layer. They can form a hydrogen bond network with the ethylene-vinyl alcohol copolymer matrix, improve the crack propagation resistance and thermomechanical fatigue life of the buffer layer, and enhance the structural stability.

[0051] Combining Examples 1 and 5, it can be seen that the performance of Examples 5 is lower than that of Examples 1. The reason is that the outer sheath of Examples 5 contains an excessive amount of wear-resistant components. Excessive fibers and ceramic particles will increase the brittleness of the outer sheath and make it easier to generate microcracks during dynamic bending.

[0052] In conjunction with Example 1, Comparative Examples 1 to 5 show that the performance of Comparative Examples 1 to 5 is significantly lower than that of Example 1. This is because Comparative Example 1 added a small amount of ternary layered ceramic particles, leading to a decrease in the self-lubricating and anti-wear capabilities of the outer sheath, as well as a reduction in its resistance to bending deformation. Comparative Example 3, which did not add ternary layered ceramic particles, showed an even more significant performance decline. Comparative Example 5 used conventional fillers to replace the ternary layered ceramic particles, lacking the layered structure characteristics and exhibiting low thermal conductivity, resulting in decreased thermal cycling stability. Comparative Example 2, with its excessive addition of ternary layered ceramic particles, easily led to excessive rigidity and increased brittleness of the outer sheath, making it prone to cracking during bending. Comparative Example 4 used conventional glass fibers to replace ultra-high molecular weight polyethylene fibers. However, due to the limited compatibility between glass fibers and the polyethylene matrix, the interfacial bonding is weak, and it is difficult to form an interpenetrating network with the ternary layered ceramic particles, thus leading to a performance decline.

[0053] Combining Example 1 and Comparative Example 6, it can be seen that the thermal cycling fatigue resistance of Comparative Example 6 is significantly lower than that of Example 1. The reason is that no buffer layer is set in Comparative Example 6. The lack of stress buffering and interface bonding effect of the buffer layer leads to stress concentration during long-term thermal cycling and bending, which can cause cracks or delamination.

[0054] To facilitate understanding of the embodiments of this solution by those skilled in the art, the working principle of this solution will now be briefly explained in conjunction with specific application scenarios: The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A highly wear-resistant 10kV high-voltage cable, comprising, from the inside out, a conductor, a semi-conductive resistance strip, a conductor shielding layer, an insulation layer, an insulation shielding layer, a water-blocking layer, a smooth metal sheath, and an outer sheath, characterized in that, The outer sheath is made of a wear-resistant component, which includes ultra-high molecular weight polyethylene fiber and ternary layered ceramic particles in a mass ratio of (8-14):(4-6). A buffer layer is further provided between the smooth metal sleeve and the outer sheath; the buffer layer comprises the following raw materials in parts by weight: 60-80 parts of ethylene-vinyl alcohol copolymer; 15-25 parts of maleic anhydride grafted onto POE; 3 to 6 parts of carbon nanotubes.

2. The high wear-resistant 10kV high-voltage cable according to claim 1, characterized in that, The outer sheath comprises the following parts by weight of raw materials: 20-30 parts of low-density polyethylene; 70-80 parts of high-density polyethylene; 12-20 parts of wear-resistant component; 8-12 parts of ethylene-vinyl acetate copolymer; Other adjuvants: 2-6 parts.

3. The high wear-resistant 10kV high-voltage cable according to claim 1, characterized in that, The strength of the ultra-high molecular weight polyethylene fiber is 30-40 cN / dtex.

4. The high wear-resistant 10kV high-voltage cable according to claim 1, characterized in that, The ternary layered ceramic particles include one or more combinations of Ti2AlC, Ti2AlN, Ti3SiC2, Cr2AlC, Nb2AlC, and Ti2SnC.

5. The high wear-resistant 10kV high-voltage cable according to claim 1, characterized in that, The carbon nanotubes have undergone modification treatment; The modified carbon nanotubes are grafted with polyvinyl alcohol segments.

6. The high wear-resistant 10kV high-voltage cable according to claim 5, characterized in that, The modified carbon nanotubes include the following process steps: Pretreatment of carbon nanotubes: Carbon nanotubes are heated under reflux at 40-50°C for 8-12 hours in an acidic solution, and then washed and dried after centrifugation to obtain pretreated carbon nanotubes. Modification of carbon nanotubes: An emulsifier is added to water and stirred to dissolve at 60–70°C. Vinyl acetate is then added to obtain an emulsion. An initiator solution is added to the emulsion and stirred at 70–75°C for 1–2 hours to perform prepolymerization, yielding a prepolymer. Pretreated carbon nanotubes, an emulsifier, and an initiator are added to the prepolymer, and the reaction continues for 1–2 hours to obtain a polymer emulsion. The polymer emulsion is added to a saturated sodium hydroxide solution at 30–40°C for demulsification, followed by filtration to precipitate, washing, and drying to obtain a crude graft product. The crude graft product is dissolved in methanol and subjected to alcoholysis under alkaline conditions. Finally, the precipitate is precipitated, washed, and dried to obtain the final product.

7. The high wear-resistant 10kV high-voltage cable according to claim 6, characterized in that, The mass-volume ratio of the carbon nanotubes, vinyl acetate, emulsifier, and initiator is 1 mg: (0.15–0.25) mL: (5–7) mg: (1.5–2) mg.

8. The high wear-resistant 10kV high-voltage cable according to claim 1, characterized in that, The insulation layer is a cross-linked polyethylene insulation layer.

9. The high wear-resistant 10kV high-voltage cable according to claim 1, characterized in that, The conductor is a segmented conductor formed by splicing together five sector-shaped aluminum conductors.

10. A method for preparing a highly wear-resistant 10kV high-voltage cable, used to prepare the highly wear-resistant 10kV high-voltage cable according to any one of claims 1 to 9, characterized in that, The process includes the following steps: S1. Weigh the raw materials for the outer sheath and the buffer layer separately and mix them evenly. Then, obtain the outer sheath functional masterbatch and the buffer layer functional masterbatch by melt extrusion and granulation, respectively. S2. Overlapping semiconducting resistance strips are wrapped around the conductor, and then three layers are co-extruded to form a conductor shielding layer, an insulation layer, and an insulation shielding layer in sequence. After extrusion, the material is placed in a cross-linking pipe for cross-linking. After cooling and degassing, a water-blocking strip is wrapped around it to form a water-blocking layer. Then, a smooth metal sheath is extruded. Finally, a buffer layer functional masterbatch and an outer sheath functional masterbatch are extruded sequentially outside the smooth metal sheath to form a buffer layer and an outer sheath. After cooling and setting, the desired product is obtained.

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