Anti-aging high-temperature-resistant environment-friendly power cable and preparation method thereof

Abstract

The invention relates to the technical field of power transmission, and discloses an anti-aging high-temperature-resistant environment-friendly power cable and a preparation method thereof.The anti-aging high-temperature-resistant environment-friendly power cable comprises a cross-linked polyethylene insulating cylinder, a copper strip shielding layer is arranged in the cross-linked polyethylene insulating cylinder, and a multi-layer composite filling structure is arranged between the copper strip shielding layer and the cross-linked polyethylene insulating cylinder; the multi-layer composite filling structure sequentially comprises elastic buffer cotton, a carbon nano tube reinforced aerogel layer and an ultra-high molecular weight polyethylene woven layer from inside to outside. According to the scheme, the anti-aging requirement is fully considered on material selection and structural design; the cross-linked polyethylene insulating cylinder is prepared from weather-resistant materials such as ethylene-tetrafluoroethylene copolymer and propylene-tetrafluoroethylene copolymer, and is matched with antioxidants such as nickel dibutyldithiocarbamate, so that erosion of oxygen, ultraviolet rays and the like to the insulating layer can be effectively resisted; and the aramid fiber bundles are uniformly distributed in the chloroprene rubber protective sleeve, so that the service life of the cable is prolonged by multiple designs.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power transmission, in particular to an anti-aging high-temperature-resistant environment-friendly power cable and a preparation method thereof. BACKGROUND

[0002] In the field of power transmission, power cables are the key carriers to ensure stable energy supply, and their performance is directly related to the safe operation of the power system. With the diversified development of industrial production and the increasing demand for power in complex outdoor environments, more stringent requirements are placed on the anti-aging, high-temperature resistance, and environmental performance of power cables.

[0003] At present, traditional power cables on the market are easily affected by external environmental factors during long-term use. For example, in high-temperature industrial environments, the insulation layer of the cable is prone to softening and cracking due to high temperatures, resulting in a decrease in insulation performance. In outdoor long-term exposure to sunlight or humid environments, cable materials are prone to aging, exhibiting surface cracking, reduced mechanical strength, and other phenomena, which severely shortens the service life of the cable. At the same time, some cables use materials containing halogen, heavy metals, and other harmful substances in pursuit of performance, which can pollute the soil, water, and air during production, use, and post-disposal, and do not meet modern environmental protection concepts. In addition, the structural design of traditional cables often has shortcomings, such as poor cushioning and heat insulation performance of the filling structure, and unsatisfactory shielding effect, which makes it difficult for the overall performance of the cable to meet the needs of special working conditions, and therefore an anti-aging high-temperature-resistant environment-friendly power cable is needed. SUMMARY

[0004] To solve the problems raised in the background art, the present application provides an anti-aging high-temperature-resistant environment-friendly power cable and a preparation method thereof.

[0005] The anti-aging high-temperature-resistant environment-friendly power cable and the preparation method thereof provided by the present application adopt the following technical solutions:

[0006] The application discloses an anti-aging high-temperature-resistant environment-friendly power cable and a preparation method thereof.

[0007] Preferably, the magnesium hydroxide composite fireproof pad is composed of nano magnesium hydroxide particles and epoxy resin, wherein the mass percentage of the nano magnesium hydroxide particles is 60%-70%.

[0008] Preferably, the thickness of the carbon nanotube reinforced aerogel layer is 1.2-1.8 mm, the inner carbon nanotube has a tube diameter of 20-50 nm, and the porosity of the aerogel is not less than 95%.

[0009] Preferably, the application further provides a preparation method of the anti-aging high-temperature-resistant environment-friendly power cable.

[0010] 1) Preparation of the crosslinked polyethylene insulating cylinder: ethylene-tetrafluoroethylene copolymer 12-18 parts by mass, propylene-tetrafluoroethylene copolymer 3-7 parts by mass (weight ratio 3-5:4), polyethylene 50-80 parts by mass, polypropylene 20-50 parts by mass, and glass fiber 5-10 parts by mass are taken, the above materials are stirred in a blender for 15-30 min, and then are put into a double-screw extruder, the screw length-diameter ratio is set to 10-18:1, the temperature of the first zone is 165-175°C, the temperature of the second zone is 185-195°C, the temperature of the third zone is 200-205°C, the temperature of the fourth zone is 210-215°C, and the temperature of the die head is 155-165°C, and after melt extrusion, the crosslinked polyethylene insulating cylinder is formed;

[0011] 2) Carbon nanotube reinforced aerogel layer preparation: Take 3-10 parts of silane coupling agent into a flask in a water bath, add appropriate amount of anhydrous ethanol and heat to 70-90°C to dissolve, add 15-25 parts of dried nano calcium carbonate and stir evenly, then add 1-2 parts of polyvinyl alcohol, heat and stir reflux for 0.5-1.5h, after the reaction is completed, filter several times, wash with alcohol, and dry in an oven at 110-150°C. Take carbon nanotubes (tube diameter 20-50nm) and the above prepared product according to the mass ratio of 2:1, add 5-8 parts of bisphenol F type epoxy resin and stir evenly, freeze-dried to prepare a carbon nanotube reinforced aerogel layer with a thickness of 1.2-1.8mm and a porosity of not less than 95%;

[0012] 3) Preparation of magnesium hydroxide composite fireproof pad: Take nano-sized magnesium hydroxide particles and epoxy resin, mix according to the mass ratio of nano-sized magnesium hydroxide particles 60%-70%, add 1-3 parts of zinc borate, 10-15 parts of red phosphorus, 10-15 parts of flame retardant (one of triphenyl phosphate, flame retardant RC200 or triethyl phosphate), stir evenly and then press into shape by calender to obtain a magnesium hydroxide composite fireproof pad;

[0013] 4) Preparation of chlorobutyl rubber protective sleeve: Take chlorobutyl rubber raw material, add 0.4-0.6 parts of diphenyl disulfide, 1-1.5 parts of active agent magnesium oxide, 0.5-1 part of nickel dibutyl dithiocarbamate, mix, then add aramid fiber bundle, melt and plasticize in an open type plasticizing machine at 160-170°C, then add 2-5 parts of plasticizer (tris (nonyl) trimellitate), 1-3 parts of stabilizer (calcium-zinc composite stabilizer), 1-2 parts of lubricant (one of stearic acid, calcium stearate or polyethylene wax), roll and pass through multiple times, then injection molding to obtain a chlorobutyl rubber protective sleeve with aramid fiber bundle uniformly distributed inside;

[0014] 5) Preparation of graphene heat-conducting pad: Take 1-3 parts of silicon carbide and 1-3 parts of boron nitride particles, mix them to prepare boron nitride composite silicon carbide particle material, take graphene slurry and the particle material according to the mass ratio of 1:4, stir evenly and reserve;

[0015] 6) Cable assembly: Place the tinned copper cable core in the copper tape shielding layer, wrap the elastic buffer cotton, the carbon nanotube reinforced aerogel layer prepared in step 2, and the ultra-high molecular weight polyethylene woven layer outside the copper tape shielding layer in sequence, and symmetrically arrange the ground wire and power line in the elastic buffer cotton; Put the above combination into the cross-linked polyethylene insulation cylinder prepared in step 1, and sequentially coat the glass fiber cloth, halogen-free flame-retardant polyolefin insulation sleeve, magnesium hydroxide composite fireproof pad prepared in step 3, and chlorobutyl rubber protective sleeve prepared in step 4 outside; evenly coat the mixed slurry prepared in step 5 outside the chlorobutyl rubber protective sleeve, and after curing, form a graphene heat-conducting pad to complete the preparation of the cable.

[0016] Preferably, the high-speed mixer of the twin-screw extruder in step 1 rotates at a speed of 200-500 r / min.

[0017] Preferably, the temperature of the freeze-drying in step 2 is -50 to -40°C, and the drying time is 12-16 h.

[0018] Preferably, the mass ratio of the boron nitride particles to silicon carbide in step 5 is 1:1.5.

[0019] In summary, the present application includes the following beneficial technical effects:

[0020] 1. Excellent anti-aging performance: The power cable fully considers the anti-aging requirements in material selection and structural design. The cross-linked polyethylene insulating cylinder is made of weather-resistant materials such as ethylene-tetrafluoroethylene copolymer and propylene-tetrafluoroethylene copolymer, and is used in combination with antioxidants such as nickel dibutyl dithiocarbamate, which can effectively resist the erosion of oxygen, ultraviolet light, and other factors on the insulating layer. The uniformly distributed aramid fiber bundles inside the neoprene protective sleeve enhance the mechanical strength and anti-aging ability of the protective sleeve, and the multiple designs jointly prolong the service life of the cable.

[0021] 2. Outstanding high-temperature resistance: The carbon nanotube reinforced aerogel layer has extremely low thermal conductivity and a porosity of not less than 95%, which can effectively block heat transfer, and the internal carbon nanotubes ensure the heat insulation effect while not affecting the overall structural compactness of the cable. The nano-sized magnesium hydroxide particles in the magnesium hydroxide composite fireproof pad are combined with epoxy resin to form a stable heat shield, which can play a good fireproof and heat insulation role in high-temperature environments, making the cable adaptable to high-temperature working conditions.

[0022] 3. Good environmental performance: The materials used in the cable all comply with environmental protection standards, and materials such as halogen-free flame-retardant polyolefin insulating sleeves avoid pollution caused by halogen release, and substances containing heavy metals such as lead and mercury are not used. In the preparation process, the process design of each step is reasonable, which reduces energy consumption and waste emissions, conforms to the environmental protection concept of sustainable development, and reduces the negative impact on the environment.

[0023] 4. Comprehensive overall performance: In the multi-layer composite filling structure, the elastic buffer cotton plays a good buffering role, and the ultra-high molecular weight polyethylene woven layer improves the tensile properties of the cable. The copper strip shielding layer effectively reduces electromagnetic interference, and the ground wire and power line are symmetrically arranged about the copper strip shielding layer, which optimizes the electric field distribution and improves the power transmission efficiency. The combination of the graphene heat-conducting pad and the boron nitride composite silicon carbide particles enhances the heat dissipation capacity of the cable, ensuring stable operation of the cable in complex environments. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a front view structural schematic diagram of the application embodiment.

[0025] Figure 2 yes Figure 1 A magnified schematic diagram of the structure in the middle.

[0026] Explanation of the accompanying symbols: 1. Cross-linked polyethylene insulation tube; 2. Copper tape shielding layer; 3. Elastic buffer cotton; 4. Carbon nanotube reinforced aerogel layer; 5. Polyethylene braided layer; 6. Ground wire; 7. Power cord; 8. Tinned copper cable core; 9. Glass fiber cloth; 10. Halogen-free flame-retardant polyolefin insulation sleeve; 11. Magnesium hydroxide composite fireproof pad; 12. Neoprene protective sleeve; 13. Graphene thermal pad. DETAILED DESCRIPTION

[0027] The following is combined with Figures 1-2 This application is described in further detail.

[0028] The present application discloses an anti-aging, high-temperature resistant and environmentally friendly power cable and its preparation method. Figures 1-2 , including a cross-linked polyethylene insulating tube 1, a copper tape shielding layer 2 is arranged inside the cross-linked polyethylene insulating tube 1, and a multi-layer composite filling structure is arranged between the copper tape shielding layer 2 and the cross-linked polyethylene insulating tube 1, and the multi-layer composite filling structure is composed of elastic buffer cotton 3, carbon nanotube reinforced aerogel layer 4 and ultra-high molecular weight polyethylene braided layer 5 from the inside to the outside; a ground wire 6 and a power line 7 are arranged inside the elastic buffer cotton 3, and the ground wire 6 and the power line 7 are symmetrically arranged about the copper tape shielding layer 2, a tinned copper cable core 8 is arranged inside the copper tape shielding layer 2, and the tinned copper cable core 8 is tightly fitted with the copper tape shielding layer 2; glass fiber cloth 9, halogen-free flame retardant polyolefin insulating sleeve 10, magnesium hydroxide composite fireproof pad 11, chloroprene rubber protective sleeve 12, and graphene thermal conductive pad 13 are arranged on the outside of the cross-linked polyethylene insulating tube 1 in sequence, aramid fiber bundles are evenly distributed inside the chloroprene rubber protective sleeve 12, and the graphene thermal conductive pad 13 is filled with boron nitride composite silicon carbide granular material.

[0029] Reference Figure 1 -,2. The magnesium hydroxide composite fireproof pad 11 is made of nano-scale magnesium hydroxide particles and epoxy resin, in which the mass proportion of nano-scale magnesium hydroxide particles is 60%-70%.

[0030] Reference Figures 1-2 The thickness of the carbon nanotube-reinforced aerogel layer 4 is 1.2-1.8 mm, the diameter of the internal carbon nanotubes is 20-50 nm, and the porosity of the aerogel is not less than 95%.

[0031] Another technical problem to be solved by the present invention is to provide a method for preparing an anti-aging, high-temperature, and environmentally friendly power cable, comprising the following steps:

[0032] 1) Cross-linked polyethylene insulation cylinder preparation: take ethylene-tetrafluoroethylene copolymer 12-18 parts by mass, propylene-tetrafluoroethylene copolymer 3-7 parts (weight ratio 3-5:4), polyethylene 50-80 parts, polypropylene 20-50 parts, glass fiber 5-10 parts, add the above materials to the blender and stir for 15-30 min, then put into a twin-screw extruder, set the screw length-diameter ratio to 10-18:1, zone 1 temperature 165-175°C, zone 2 temperature 185-195°C, zone 3 temperature 200-205°C, zone 4 temperature 210-215°C, die head temperature 155-165°C, melt extrusion, and then shape into a cross-linked polyethylene insulation cylinder 1;

[0033] 2) Carbon nanotube reinforced aerogel layer preparation: take silane coupling agent 3-10 parts and place it in a flask in a water bath, add an appropriate amount of anhydrous ethanol and heat to 70-90°C to dissolve, add dried nano calcium carbonate 15-25 parts and stir evenly, then add polyvinyl alcohol 1-2 parts, heat and stir to reflux for 0.5-1.5 h, after the reaction is completed, filter several times, wash with alcohol, and dry in an oven at 110-150°C and grind for use; take carbon nanotubes (tube diameter 20-50 nm) and mix with the above prepared product according to a mass ratio of 2:1, add bisphenol F type epoxy resin 5-8 parts and stir evenly, freeze-dry to form a carbon nanotube reinforced aerogel layer 4 with a thickness of 1.2-1.8 mm and a porosity of not less than 95%;

[0034] 3) Magnesium hydroxide composite fireproof pad preparation: take nano-sized magnesium hydroxide particles and epoxy resin, mix according to a mass ratio of 60%-70% of nano-sized magnesium hydroxide particles, add zinc borate 1-3 parts, red phosphorus 10-15 parts, and flame retardant 10-15 parts (one of triphenyl phosphate, flame retardant RC200 or triethyl phosphate), stir evenly, and then press into shape by a calender to obtain a magnesium hydroxide composite fireproof pad 11;

[0035] 4) Chlorobutyl rubber protective sleeve preparation: take chlorobutyl rubber raw material, add diphenyl disulfide 0.4-0.6 parts, active agent magnesium oxide 1-1.5 parts, and nickel dibutyldithiocarbamate 0.5-1 part, mix, then add aramid fiber bundle in an open type plastic mixing machine and melt plasticize at 160-170°C, then add plasticizer 2-5 parts (tris (nonyl) trimellitate), stabilizer 1-3 parts (calcium-zinc composite stabilizer), and lubricant 1-2 parts (one of stearic acid, calcium stearate or polyethylene wax), roll and pass through multiple times, and then injection mold to obtain a chlorobutyl rubber protective sleeve 12 with aramid fiber bundle uniformly distributed inside;

[0036] 5) Preparation of graphene heat-conducting pad: take 1-3 parts of silicon carbide and boron nitride particles by mass, mix them to prepare boron nitride composite silicon carbide particulate matter, take graphene slurry and the particulate matter in a mass ratio of 1:4, mix and stir uniformly for standby use;

[0037] 6) Cable assembly: place the tinned copper cable core 8 in the copper tape shielding layer 2, wrap the elastic buffer cotton 3, the carbon nanotube reinforced aerogel layer 4 prepared in step 2, the ultrahigh molecular weight polyethylene braid layer 5 outside the copper tape shielding layer 2 in turn, and symmetrically arrange the ground wire 6 and the power line 7 in the elastic buffer cotton 3; put the above combination into the cross-linked polyethylene insulation cylinder prepared in step 1, and externally wrap the glass fiber cloth 9, the halogen-free flame-retardant polyolefin insulation sleeve 10, the magnesium hydroxide composite fireproof pad 11 prepared in step 3, and the chloroprene rubber protective sleeve 12 prepared in step 4; uniformly coat the mixed slurry prepared in step 5 outside the chloroprene rubber protective sleeve 12, and form the graphene heat-conducting pad 13 after solidification, thereby completing the preparation of the cable.

[0038] The high-speed blender of the double-screw extruder in step 1 rotates at 200-500 r / min, the temperature of the freeze-drying in step 2 is-50 to-40°C, the drying time is 12-16 h, and the mass ratio of boron nitride particles to silicon carbide in step 5 is 1:1.5.

[0039] The implementation principle of the anti-aging high-temperature-resistant environment-friendly power cable and the preparation method thereof is as follows: the working principle of the anti-aging high-temperature-resistant environment-friendly power cable is based on the multi-layer synergistic structural design and scientific preparation process. From the structural function, the core tinned copper cable core 8 is responsible for power transmission, the outer copper tape shielding layer 2 can effectively shield electromagnetic interference and ensure transmission stability; the multi-layer composite filling structure between the copper tape shielding layer 2 and the cross-linked polyethylene insulating cylinder 1 has clear division of labor, the elastic buffer cotton 3 provides buffer protection, the carbon nanotube reinforced aerogel layer 4 forms an efficient heat shielding barrier by virtue of the carbon nanotubes with a pipe diameter of 20-50 nm and a porosity of not less than 95%, the ultra-high molecular weight polyethylene woven layer 5 enhances the overall tensile property, and the symmetrical arrangement of the ground wire 6 and the power line 7 optimizes the electric field distribution. The protective structure outside the cross-linked polyethylene insulating cylinder 1 is progressive, the glass fiber cloth 9 strengthens the structural stability, the halogen-free flame-retardant polyolefin insulating sleeve 10 improves the insulation, the magnesium hydroxide composite fireproof pad 11 realizes fireproofing and heat insulation by compounding nano magnesium hydroxide particles with a mass fraction of 60%-70% and epoxy resin, the aramid fiber bundle in the neoprene protective sleeve 12 enhances the mechanical strength, and the graphene heat-conducting pad 13 efficiently dissipates heat through the internal boron nitride composite silicon carbide particulate matter. From the preparation, the components are sequentially assembled after being made by precise process, the cross-linked polyethylene insulating cylinder 1 is extruded into shape by a double-screw extruder at a set temperature parameter, the carbon nanotube reinforced aerogel layer 4 is made by mixing carbon nanotubes, bisphenol F type epoxy resin and nano calcium carbonate treated by silane coupling agent after cold freeze drying, the magnesium hydroxide composite fireproof pad 11 is calendered into shape by corresponding materials, the neoprene protective sleeve 12 is injection molded after plasticizing and adding auxiliary materials, the graphene heat-conducting pad 13 is made by mixing silicon carbide, boron nitride particles and graphene paste in a specific proportion, and finally the complete cable is formed by sequentially coating and assembling, and the cooperation of each structure and preparation process endows the cable with anti-aging, high-temperature resistance, environmental protection and good comprehensive performance.

[0040] Finally, it should be pointed out that: first, in the description of the present application, it should be pointed out that unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, which can be mechanical connection or electrical connection, or the communication between the two elements, or direct connection, "up", "down", "left", "right" and the like are only used to indicate the relative positional relationship, when the absolute position of the described object changes, the relative positional relationship may change;

[0041] Secondly: the present application discloses the structure involved in the embodiment of the present application, other structures can refer to the usual design, in the case of no conflict, the same embodiment and different embodiments of the present application can be combined with each other;

[0042] Finally: the above only for the preferred embodiments of the present application, and not for limiting the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application, should be included in the scope of protection of the present application.

[0043] The above are the preferred embodiments of the present application, and do not limit the protection scope of the present application, therefore: any equivalent changes made according to the structure, shape, principle of the present application, should be covered within the protection scope of the present application.

Claims

1. An anti-aging, high-temperature resistant and environmentally friendly power cable, comprising a cross-linked polyethylene insulation barrel (1), characterized in that: A copper tape shielding layer (2) is provided inside the cross-linked polyethylene insulating tube (1), and a multi-layer composite filling structure is provided between the copper tape shielding layer (2) and the cross-linked polyethylene insulating tube (1), wherein the multi-layer composite filling structure comprises, from the inside to the outside, an elastic buffer cotton (3), a carbon nanotube reinforced aerogel layer (4), and an ultra-high molecular weight polyethylene braided layer (5); a ground wire (6) and a power wire (7) are provided inside the elastic buffer cotton (3), and the ground wire (6) and the power wire (7) are symmetrically arranged with respect to the copper tape shielding layer (2). The layer (2) is provided with a tinned copper cable core (8), and the tinned copper cable core (8) is tightly fitted with the copper tape shielding layer (2); the outside of the cross-linked polyethylene insulation tube (1) is provided with glass fiber cloth (9), a halogen-free flame-retardant polyolefin insulation sleeve (10), a magnesium hydroxide composite fireproof pad (11), a chloroprene rubber protective sleeve (12), and a graphene thermal conductive pad (13) in sequence, the inside of the chloroprene rubber protective sleeve (12) is evenly distributed with aramid fiber bundles, and the inside of the graphene thermal conductive pad (13) is filled with boron nitride composite silicon carbide granular material.

2. The anti-aging, high-temperature resistant and environmentally friendly power cable according to claim 1, characterized in that: The magnesium hydroxide composite fireproof pad (11) is formed by compounding nano-magnesium hydroxide particles and epoxy resin, wherein the mass proportion of the nano-magnesium hydroxide particles is 60%-70%.

3. The anti-aging, high-temperature resistant and environmentally friendly power cable according to claim 1, characterized in that: The thickness of the carbon nanotube-reinforced aerogel layer (4) is 1.2-1.8 mm, the diameter of the internal carbon nanotubes is 20-50 nm, and the porosity of the aerogel is not less than 95%.

4. The method for preparing an anti-aging, high-temperature resistant and environmentally friendly power cable according to claim 1, characterized in that: The following steps are involved: 1) Preparation of cross-linked polyethylene insulation tube: 12-18 parts of ethylene-tetrafluoroethylene copolymer, 3-7 parts of propylene-tetrafluoroethylene copolymer (the weight ratio of the two is 3-5:4), 50-80 parts of polyethylene, 20-50 parts of polypropylene, and 5-10 parts of glass fiber are added to a mixer and stirred for 15-30 minutes. The mixture is then put into a twin-screw extruder with a screw length-diameter ratio of 10-18:1, a zone 1 temperature of 165-175°C, a zone 2 temperature of 185-195°C, a zone 3 temperature of 200-205°C, a zone 4 temperature of 210-215°C, and a die head temperature of 155-165°C. The mixture is melt-extruded and formed into a cross-linked polyethylene insulation tube (1); 2) Preparation of carbon nanotube-enhanced aerogel layer: 3-10 parts of silane coupling agent are placed in a flask in a water bath, an appropriate amount of anhydrous ethanol is added and the temperature is raised to 70-90°C to dissolve, 15-25 parts of dried nano-calcium carbonate are added and stirred evenly, and then 1-2 parts of polyvinyl alcohol are added, heated and stirred under reflux for 0.5-1.5h, and after the reaction is completed, the mixture is filtered and washed with alcohol several times, dried and ground in an oven at 110-150°C for later use; carbon nanotubes (tube diameter 20-50nm) are mixed with the above-mentioned spare product in a mass ratio of 2:1, 5-8 parts of bisphenol F epoxy resin are added and stirred evenly, and freeze-dried to prepare a carbon nanotube-enhanced aerogel layer (4) with a thickness of 1.2-1.8mm and a porosity of not less than 95%; 3) Preparation of magnesium hydroxide composite fireproof mat: Take nano-magnesium hydroxide particles and epoxy resin, mix them according to the mass ratio of nano-magnesium hydroxide particles to 60%-70%, add 1-3 parts of zinc borate, 10-15 parts of red phosphorus, and 10-15 parts of flame retardant (one of triphenyl phosphate, flame retardant RC200 or triethyl phosphate), stir evenly and press into shape through a calender to obtain a magnesium hydroxide composite fireproof mat (11); 4) Preparation of chloroprene rubber protective cover: take chloroprene rubber raw material, add 0.4-0.6 parts of dibenzothiazole disulfide, 1-1.5 parts of magnesium oxide as an active agent, and 0.5-1 parts of nickel dibutyl dithiocarbamate, mix and add aramid fiber bundle, melt and plasticize in an open plasticizer at 160-170°C, then add 2-5 parts of plasticizer (trinonyl trimellitate), 1-3 parts of stabilizer (calcium zinc composite stabilizer), 1-2 parts of lubricant (one of stearic acid, calcium stearate or polyethylene wax), roll and thin pass for multiple times, and then injection mold to obtain a chloroprene rubber protective cover with aramid fiber bundles evenly distributed inside (12); 5) Preparation of graphene thermal pad: Mix 1-3 parts of silicon carbide and boron nitride particles by mass to form a boron nitride-silicon carbide composite particle material. Mix the graphene slurry with the particle material at a mass ratio of 1:4, stir well, and set aside. 6) Cable assembly: Place the tinned copper cable core (8) in the copper tape shielding layer (2), wrap the copper tape shielding layer (2) with elastic buffer cotton (3), the carbon nanotube reinforced aerogel layer (4) prepared in step 2, and the ultra-high molecular weight polyethylene braided layer (5) in sequence, and symmetrically arrange the ground wire (6) and the power line (7) in the elastic buffer cotton (3); insert the above-mentioned assembly into the cross-linked polyethylene insulation tube prepared in step 1, and wrap the outside with glass fiber cloth (9), halogen-free flame-retardant polyolefin insulation sleeve (10), magnesium hydroxide composite fireproof pad (11) prepared in step 3, and chloroprene rubber protective sleeve (12) prepared in step 4 in sequence; evenly apply the mixed slurry prepared in step 5 on the outside of the chloroprene rubber protective sleeve (12), and form a graphene thermal conductive pad (13) after curing, thereby completing the cable preparation.

5. The preparation method according to claim 4, characterized in that: The high-speed mixer speed of the twin-screw extruder described in step 1 is 200-500r / min.

6. The preparation method according to claim 4, characterized in that: The freeze-drying temperature in step 2 is -50 to -40°C, and the drying time is 12-16 hours.

7. The preparation method according to claim 4, characterized in that: The mass ratio of the boron nitride particles to the silicon carbide in step 5 is 1:1.5.

Images