A 10 kV overhead insulated cable

Abstract

The application discloses a 10kV overhead insulated cable, a tin layer is plated on the surface of a copper single wire to obtain a tin-plated copper single wire, the tin-plated copper single wire is twisted to obtain a conductor; an insulating layer mixture is extruded on the conductor and a steel wire rope respectively to form an insulating layer, a core and a tensile rope are obtained; one tensile rope is taken as an axis, and a plurality of cores are twisted with the tensile rope to obtain a cable core; a tin-plated copper single wire is woven outside the cable core to form a shielding layer; a sheath mixture is extruded on the outside of the shielding layer to form a sheath, and the overhead insulated cable is obtained. The overhead insulated cable has excellent mechanical properties and high and low temperature resistance, and can meet the 10kV power transmission requirement.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cable processing, and particularly relates to a 10kV overhead insulated cable. BACKGROUND

[0002] The overhead insulated cable is a wiring method for power or signal transmission by supporting the cable on the ground at a certain height through a support such as a telegraph pole. It is a new power transmission method between overhead conductors and underground cables. The overhead insulated cable has high power supply reliability and high safety, and is convenient and economical to erect and maintain, with obvious advantages. It is widely used for power transmission in cities, towns and green belts, and is suitable for long-distance and large-capacity power transmission. In particular, in complex terrain areas such as mountains and hills, the overhead insulated cable can cross valleys, rivers and other obstacles to provide power supply for remote areas, and is a key part of the power network.

[0003] Since the overhead insulated cable operates in the external environment for a long time, it is affected by ultraviolet light, wind, high temperature and low temperature, etc. Therefore, the mechanical properties in various extreme environments are directly related to the service life and power transmission safety of the overhead insulated cable.

[0004] The core material of the insulated overhead cable is usually aluminum alloy or metal copper, and the insulation material is usually chlorosulfonated polyethylene, silicone rubber, polyvinyl chloride, cross-linked polyethylene, etc. Among them, cross-linked polyethylene is the most common insulation material, which has good heat resistance, with a long-term working temperature range of -40℃ to 90℃, and a short-time resistance temperature of up to 150℃, but poor light and oxygen aging resistance. At present, the problem of poor light and oxygen aging resistance of cross-linked polyethylene as an insulation material is generally solved by adding anti-ultraviolet agents and carbon black, but there are problems such as poor compatibility, which affects the mechanical properties of the cable.

[0005] 10kV belongs to high voltage, and compared with low voltage cables, the performance requirements of 10kV overhead insulated cables are higher. How to improve the mechanical properties, high and low temperature resistance, etc. of 10kV overhead insulated cables is the current research focus.

[0006] Patent CN118126436B discloses an insulated overhead cable and a preparation method thereof, which comprises a conductor, a shielding layer and an insulation layer from inside to outside, wherein the insulation layer is made of polyethylene, plasticizer, initiator, antioxidant, light stabilizer, modified carbon black, catalyst, HDPE-g-MAH, etc. The modified carbon black includes mercaptosiloxane modified carbon black and / or amino chloroimidazole compound modified carbon black. The patent technology improves the dispersibility of carbon black in the polymer matrix, has good compatibility, and improves the mechanical properties of the insulated overhead cable. However, its high temperature aging resistance is general, and cannot meet the increasing application requirements.

[0007] Patent CN116189989B discloses an insulating overhead cable, which comprises a conductor, a shielding layer and an insulating layer from inside to outside, wherein the insulating layer is made of PVC resin, flame retardant, plasticizer, coupling agent, antioxidant, crosslinking agent, p-aminobenzamide and inorganic filler. The patent technology mainly improves the flame retardance of the cable, although the mechanical properties of the insulating layer are improved by introducing p-aminobenzamide, but the mechanical properties of the finally obtained cable are not ideal. SUMMARY

[0008] In view of the deficiencies of the prior art, the purpose of the present application is to provide a 10kV overhead insulated cable with excellent mechanical properties and high and low temperature resistance.

[0009] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0010] A processing technology of a 10kV overhead insulated cable, the specific steps are as follows:

[0011] (1) Preparation of filler: silicon carbide modified graphene oxide is prepared by taking graphite and nano silicon powder as raw materials; the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber, and graphene is grown on the surface of the silicon carbide modified graphene oxide to obtain a graphene composite material; the graphene composite material is modified by sulfur hexafluoride to obtain the filler;

[0012] (2) The following components are blended and extruded to obtain a sheath mixture: 50-60 parts of crosslinked polyethylene, 15-20 parts of ethylene-tetrafluoroethylene copolymer, 8-10 parts of epoxy resin, 4-5 parts of filler, 1-2 parts of antioxidant, 1-2 parts of plasticizer, 1-2 parts of lubricant, and 1-2 parts of polychlorotrifluoroethylene-vinylidene fluoride copolymer;

[0013] (3) The following components are blended and extruded to obtain an insulating layer mixture: 50-60 parts of crosslinked polyethylene, 15-20 parts of ethylene-tetrafluoroethylene copolymer, 8-10 parts of ethylene-propylene-diene rubber, 4-5 parts of filler, 1-2 parts of antioxidant, 1-2 parts of plasticizer, and 1-2 parts of polychlorotrifluoroethylene-vinylidene fluoride copolymer;

[0014] (4) A tinned copper monofilament is obtained by plating a tinned layer on the surface of a copper monofilament, and is twisted to obtain a conductor; the insulating layer mixture is extruded around the conductor and the steel wire rope to form an insulating layer, and a core and a tensile rope are obtained; a tensile rope is taken as an axis, and a plurality of cores are twisted with the tensile rope to form a cable core;

[0015] (5) The tinned copper monofilament is woven outside the cable core to form a shielding layer;

[0016] (6) The sheath mixture is extruded around the outside of the shielding layer to form a sheath, and the overhead insulated cable is obtained.

[0017] Preferably, in step (1), the specific preparation method of the silicon carbide modified graphene oxide is as follows: first, the graphite is made into graphite oxide by Hummers method, the graphite oxide is added into deionized water, and ultrasonic oscillation treatment is performed to obtain a graphene oxide dispersion liquid; then, the nanometer silicon is added into the graphene oxide dispersion liquid, stirring at room temperature (25℃) for 6-8h to obtain a mixed solution, vacuum drying to obtain nanometer silicon modified graphene oxide; finally, the nanometer silicon modified graphene oxide is placed in an atmospheric resistance furnace, argon is introduced, the temperature is raised to 800-900℃ at a rate of 15-20℃ / min, and the temperature is kept for 1-2h, the temperature is raised to 1300-1320℃ at a rate of 5-8℃ / min, and the temperature is kept for 3-4h, and then it is ground into fine powder.

[0018] Further preferably, the mass ratio of graphite oxide, deionized water and nanometer silicon is 5-7:40-50:1.

[0019] Further preferably, the ultrasonic oscillation conditions are as follows: ultrasonic oscillation treatment at 300-400W for 40-50min.

[0020] Preferably, in step (1), the specific method for growing graphene on the surface of the silicon carbide modified graphene oxide is as follows: the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber which is vacuumed to below 0.003Pa, hydrogen gas is introduced at a flow rate of 220-240cm 3 / min, the temperature is raised to 1000-1050℃ under hydrogen atmosphere, the chamber pressure is kept at 3-4kPa for 30-40min, methane is introduced at a flow rate of 15-20cm 3 / min, argon is introduced at a flow rate of 230-260cm 3 / min, hydrogen is introduced at a flow rate of 1000-1020cm 3 / min, and after 10min, the introduction of methane and hydrogen is stopped, and the argon atmosphere is used for natural cooling to room temperature.

[0021] Preferably, in step (1), the specific method for modification treatment is as follows: the graphene composite material is placed in the chamber of a tube furnace, and is thinned to a thickness of not more than 1mm, sulfur hexafluoride is introduced into the chamber, a voltage of 1500-1700kV is applied, and the graphene composite material is irradiated with ultraviolet light with a wavelength of 220-240nm for 5-7min, the material is mixed and thinned again, the above-mentioned treatment method is repeated, and the material is irradiated again for 5-7min.

[0022] Preferably, in steps (2) and (3), the antioxidant is selected from any one of antioxidant 1010, antioxidant 300 or antioxidant 1076; the plasticizer is selected from diisodecyl phthalate or dibutyl phthalate; and the lubricant is polyethylene wax or sodium stearate.

[0023] Preferably, in step (2), the sheath mixture is extruded by a double screw, and the temperature of each zone is 180-190 DEG C, 210-220 DEG C, 240-250 DEG C, 200-210 DEG C in turn, and the screw rotation speed is 250-300 r / min.

[0024] Preferably, in step (3), the insulation layer mixture is extruded by a double screw, and the temperature of each zone is 180-190 DEG C, 210-220 DEG C, 240-250 DEG C, 200-210 DEG C in turn, and the screw rotation speed is 250-300 r / min.

[0025] Preferably, in step (4), the diameter of the copper single wire is 0.5-0.7 mm, the thickness of the tin layer is 0.7-0.9 mu m, the twisting direction of the tinned copper single wire is left, and the pitch ratio of the twisting is 20-22 times; the steel wire rope is twisted by 40-50 steel wires with a nominal diameter of 0.17 mm, and the pitch ratio of the twisting is 20-22 times; the cable twisting direction is left, and the pitch ratio is 10-12 times.

[0026] Preferably, in step (4), the thickness of the insulation layer is 0.4-0.6 mm.

[0027] Preferably, in step (5), the braiding density is greater than or equal to 85%, and the braiding pitch is 30 mm. The tinned copper single wire used in this step is the same as that in step (4).

[0028] Preferably, in step (6), the thickness of the sheath is 1.0-1.2 mm.

[0029] A 10kV overhead insulated cable is obtained by the above processing process.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] The present application provides a processing process of a 10kV overhead insulated cable, a tin layer is plated on the surface of a copper single wire to obtain a tinned copper single wire, which is twisted to obtain a conductor; an insulation layer mixture is extruded around the conductor and a steel wire rope to form an insulation layer, thereby obtaining a core and a tensile rope; a plurality of cores are twisted with the tensile rope as an axis to obtain a cable core; a tinned copper single wire is braided around the cable core to form a shielding layer; and a sheath mixture is extruded around the shielding layer to form a sheath, thereby obtaining an overhead insulated cable. The overhead insulated cable has excellent mechanical properties and high and low temperature resistance, and can meet the 10kV power transmission requirements.

[0032] The key of the present application lies in the preparation of the filler, taking graphite and nano silicon powder as raw materials to prepare silicon carbide modified graphene oxide; transferring the silicon carbide modified graphene oxide into a chemical vapor deposition chamber to grow graphene on the surface of the silicon carbide modified graphene oxide to obtain a graphene composite material; and then modifying the graphene composite material by using sulfur hexafluoride to obtain the same. The filler combines silicon carbide, graphene oxide and graphene, and the graphene is insulated by sulfur hexafluoride, so that the mechanical properties and high and low temperature resistance are improved, and the insulation is ensured. The introduction of sulfur hexafluoride realizes fluorine doping, and the polychlorotrifluoroethylene-vinylidene fluoride copolymer in the sheath mixture and the insulating layer mixture is combined to improve the compatibility with crosslinked polyethylene and the like, so as to avoid affecting the mechanical properties of the product.

[0033] On this basis, the present application blends and extrudes crosslinked polyethylene, ethylene-tetrafluoroethylene copolymer, epoxy resin, filler, antioxidant, plasticizer, lubricant, polychlorotrifluoroethylene-vinylidene fluoride copolymer and other components to obtain a sheath mixture, and blends and extrudes crosslinked polyethylene, ethylene-tetrafluoroethylene copolymer, ethylene-propylene rubber, filler, antioxidant, plasticizer, polychlorotrifluoroethylene-vinylidene fluoride copolymer and other components to obtain an insulating layer mixture. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0035] Crosslinked polyethylene, brand LS4201S, North Europe Chemical;

[0036] Ethylene-tetrafluoroethylene copolymer, brand CF-5020X, Japan Asahi;

[0037] Epoxy resin, brand E-44, Shandong Poly Chemical;

[0038] Ethylene-propylene rubber, brand NORDEL 3430, USA Dow;

[0039] Polychlorotrifluoroethylene-vinylidene fluoride copolymer, item number HC0307, Tianmen Hengchang Chemical.

[0040] Example 1

[0041] A processing process of a 10kV overhead insulated cable, the specific steps are as follows:

[0042] (1) Preparation of the filler: taking graphite and nano-silicon powder as raw materials, silicon carbide modified graphene oxide is prepared; the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber, and graphene is grown on the surface of the silicon carbide modified graphene oxide to obtain a graphene composite material; the graphene composite material is modified by sulfur hexafluoride to obtain the graphene composite material;

[0043] (2) The following components are blended and extruded to obtain a sheath mixture: crosslinked polyethylene 5 kg, ethylene-tetrafluoroethylene copolymer 1.5 kg, epoxy resin 0.8 kg, filler 0.4 kg, antioxidant 0.1 kg, plasticizer 0.1 kg, lubricant 0.1 kg, and polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.1 kg;

[0044] (3) The following components are blended and extruded to obtain an insulation layer mixture: crosslinked polyethylene 5 kg, ethylene-tetrafluoroethylene copolymer 1.5 kg, ethylene-propylene-diene rubber 0.8 kg, filler 0.4 kg, antioxidant 0.1 kg, plasticizer 0.1 kg, and polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.1 kg;

[0045] (4) A tin layer is plated on the surface of the copper monofilament to obtain a tinned copper monofilament, which is twisted to obtain a conductor; the insulation layer mixture is extruded around the conductor and the steel wire rope to form an insulation layer, thereby obtaining a core and a tensile rope; a tensile rope is taken as an axis, and a plurality of cores are twisted with the tensile rope to obtain a cable core;

[0046] (5) The tinned copper monofilament is woven around the cable core to form a shielding layer;

[0047] (6) The sheath mixture is extruded around the shielding layer to form a sheath, thereby obtaining the overhead insulated cable.

[0048] In step (1), the specific preparation method of the silicon carbide modified graphene oxide is as follows: first, the graphite is made into graphene oxide by the Hummers method, the graphene oxide is added to deionized water, and ultrasonic oscillation treatment is performed to obtain a graphene oxide dispersion liquid; then, the nano-silicon is added to the graphene oxide dispersion liquid, stirred at room temperature (25℃) for 6h, vacuum dried to obtain nano-silicon modified graphene oxide; finally, the nano-silicon modified graphene oxide is placed in an atmosphere resistance furnace, argon is introduced, the temperature is raised to 800℃ at a rate of 15℃ / min, kept for 1h, the temperature is raised to 1300℃ at a rate of 5℃ / min, kept for 3h, and ground into fine powder.

[0049] The mass ratio of graphene oxide, deionized water and nano-silicon is 5:40:1.

[0050] The ultrasonic oscillation conditions are as follows: 300W ultrasonic oscillation treatment for 40min.

[0051] In step (1), the specific method for growing graphene on the surface of silicon carbide modified graphene oxide is as follows: the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber which is vacuumed to below 0.003 Pa, 220 cm 3 / min of hydrogen is introduced, the temperature is raised to 1000℃ under the hydrogen atmosphere, the chamber pressure is 3 kPa, the temperature and pressure are maintained for 30 min, 15 cm 3 / min of methane, 230 cm 3 / min of argon, and 1000 cm 3 / min of hydrogen are introduced, the introduction of methane and hydrogen is stopped after 10 min, and the argon atmosphere is used for natural cooling to room temperature.

[0052] In step (1), the specific method for modification treatment is as follows: the graphene composite material is placed in the chamber of a tube furnace, is thinned to a thickness of not more than 1 mm, sulfur hexafluoride is introduced into the chamber, a voltage of 1500 kV is applied, the graphene composite material is irradiated with ultraviolet light of a wavelength of 220 nm, the irradiation is performed for 5 min, the material is mixed and thinned again, the foregoing treatment method is repeated, and the irradiation is performed for 5 min again.

[0053] In steps (2) and (3), the antioxidant is antioxidant 1010, the plasticizer is diisodecyl phthalate, and the lubricant is polyethylene wax.

[0054] In step (2), the sheath mixture is extruded by a double screw, and the temperature of each zone is 180℃, 210℃, 240℃, and 200℃ in sequence, and the screw rotation speed is 250 r / min.

[0055] In step (3), the insulation layer mixture is extruded by a double screw, and the temperature of each zone is 180℃, 210℃, 240℃, and 200℃ in sequence, and the screw rotation speed is 250 r / min.

[0056] In step (4), the diameter of the copper monofilament is 0.5 mm, the thickness of the tin layer is 0.7 μm, the twisting direction of the tinned copper monofilament is leftward, and the twisting pitch ratio is 20 times; the steel wire rope is twisted by 40 steel wires with a nominal diameter of 0.17 mm, the twisting pitch ratio is 20 times, the cabling twisting direction is leftward, and the pitch ratio is 10 times.

[0057] In step (4), the thickness of the insulation layer is 0.4 mm.

[0058] In step (5), the braiding density is greater than or equal to 85%, and the braiding pitch is 30 mm. The tinned copper monofilament used in this step is the same as that in step (4).

[0059] In step (6), the thickness of the sheath is 1.0 mm.

[0060] Example 2

[0061] A processing process of a 10kV overhead insulated cable, the specific steps are as follows:

[0062] (1) Preparation of filler: silicon carbide modified graphene oxide is prepared by taking graphite and nano silicon powder as raw materials; the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber, and graphene is grown on the surface of the silicon carbide modified graphene oxide to obtain a graphene composite material; the graphene composite material is modified by sulfur hexafluoride to obtain the graphene composite material.

[0063] (2) The following components are blended and extruded to obtain a sheath mixture: crosslinked polyethylene 6kg, ethylene-tetrafluoroethylene copolymer 2kg, epoxy resin 1kg, filler 0.5kg, antioxidant 0.2kg, plasticizer 0.2kg, lubricant 0.2kg, polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.2kg;

[0064] (3) The following components are blended and extruded to obtain an insulation layer mixture: crosslinked polyethylene 6kg, ethylene-tetrafluoroethylene copolymer 2kg, ethylene-propylene-diene rubber 1kg, filler 0.5kg, antioxidant 0.2kg, plasticizer 0.2kg, polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.2kg;

[0065] (4) A tin layer is plated on the surface of the copper monofilament to obtain a tinned copper monofilament, which is twisted to obtain a conductor; the insulation layer mixture is extruded around the conductor and the steel wire rope to form an insulation layer, and a core and a tensile rope are obtained; a tensile rope is taken as an axis, and a plurality of cores are twisted with the tensile rope to form a cable core;

[0066] (5) The tinned copper monofilament is woven outside the cable core to form a shielding layer;

[0067] (6) The sheath mixture is extruded outside the shielding layer to form a sheath, and the overhead insulated cable is obtained.

[0068] In step (1), the specific preparation method of the silicon carbide modified graphene oxide is as follows: first, the graphite is made into graphene oxide by Hummers method, the graphene oxide is added to deionized water, and ultrasonic oscillation treatment is carried out to obtain a graphene oxide dispersion liquid; then nano silicon is added to the graphene oxide dispersion liquid, stirred at room temperature (25℃) for 8h, vacuum dried to obtain nano silicon modified graphene oxide; finally, the nano silicon modified graphene oxide is placed in an atmosphere resistance furnace, argon is introduced, the temperature is raised to 900℃ at a rate of 20℃ / min, and kept for 2h, then the temperature is raised to 1320℃ at a rate of 8℃ / min, and kept for 4h, and then ground into fine powder.

[0069] The mass ratio of graphene oxide, deionized water and nano silicon is 7:50:1.

[0070] The ultrasonic oscillation conditions are as follows: 400W ultrasonic oscillation treatment for 50min.

[0071] In step (1), the specific method of growing graphene on the surface of silicon carbide modified graphene oxide is as follows: the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber which is vacuumed to below 0.003 Pa, 240 cm 3 / min of hydrogen is introduced, the temperature is raised to 1050℃ under the hydrogen atmosphere, the chamber pressure is 4 kPa, the temperature and pressure are maintained for 40 min, 20 cm 3 / min of methane, 260 cm 3 / min of argon, and 1020 cm 3 / min of hydrogen are introduced, the introduction of methane and hydrogen is stopped after 10 min, and the argon atmosphere is used for natural cooling to room temperature.

[0072] In step (1), the specific method of modification treatment is as follows: the graphene composite material is placed in the chamber of a tube furnace, is thinned to a thickness of not more than 1 mm, sulfur hexafluoride is introduced into the chamber, a voltage of 1700 kV is applied, the graphene composite material is irradiated with ultraviolet light with a wavelength of 240 nm, the irradiation is performed for 7 min, the material is mixed and thinned again, the foregoing treatment method is repeated, and the graphene composite material is irradiated again for 7 min.

[0073] In steps (2) and (3), the antioxidant is antioxidant 300, the plasticizer is dibutyl phthalate, and the lubricant is sodium stearate.

[0074] In step (2), the sheath mixed material is extruded by a double screw, and the temperature of each zone is 190℃, 220℃, 250℃, and 210℃ in sequence, and the screw rotation speed is 300 r / min.

[0075] In step (3), the insulation layer mixed material is extruded by a double screw, and the temperature of each zone is 190℃, 220℃, 250℃, and 210℃ in sequence, and the screw rotation speed is 300 r / min.

[0076] In step (4), the diameter of the copper single wire is 0.7 mm, the thickness of the tin layer is 0.9 μm, the twisting direction of the tinned copper single wire is left, and the twisting pitch ratio is 22 times; the steel wire rope is twisted by 50 steel wires with a nominal diameter of 0.17 mm, the twisting pitch ratio is 22 times, the cable twisting direction is left, and the pitch ratio is 12 times.

[0077] In step (4), the thickness of the insulation layer is 0.6 mm.

[0078] In step (5), the braiding density is greater than or equal to 85%, and the braiding pitch is 30 mm. The tinned copper single wire used in this step is the same as that in step (4).

[0079] In step (6), the thickness of the sheath is 1.2 mm.

[0080] Example 3

[0081] A processing process of a 10kV overhead insulated cable, the specific steps are as follows:

[0082] (1) Preparation of filler: silicon carbide modified graphene oxide is prepared by taking graphite and nano silicon powder as raw materials; the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber, and graphene is grown on the surface of the silicon carbide modified graphene oxide to obtain a graphene composite material; the graphene composite material is modified by sulfur hexafluoride to obtain the graphene composite material.

[0083] (2) The following components are blended and extruded to obtain a sheath mixture: crosslinked polyethylene 5kg, ethylene-tetrafluoroethylene copolymer 2kg, epoxy resin 0.8kg, filler 0.5kg, antioxidant 0.1kg, plasticizer 0.2kg, lubricant 0.1kg, polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.2kg;

[0084] (3) The following components are blended and extruded to obtain an insulation layer mixture: crosslinked polyethylene 5kg, ethylene-tetrafluoroethylene copolymer 2kg, ethylene-propylene-diene rubber 0.8kg, filler 0.5kg, antioxidant 0.1kg, plasticizer 0.2kg, polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.1kg;

[0085] (4) A tin layer is plated on the surface of the copper monofilament to obtain a tinned copper monofilament, which is twisted to obtain a conductor; the insulation layer mixture is extruded around the conductor and the steel wire rope to form an insulation layer, and a core and a tensile rope are obtained; a tensile rope is taken as an axis, and a plurality of cores are twisted with the tensile rope to form a cable core;

[0086] (5) The tinned copper monofilament is woven outside the cable core to form a shielding layer;

[0087] (6) The sheath mixture is extruded outside the shielding layer to form a sheath, and the overhead insulated cable is obtained.

[0088] In step (1), the specific preparation method of the silicon carbide modified graphene oxide is as follows: first, the graphite is made into graphene oxide by Hummers method, the graphene oxide is added into deionized water, and ultrasonic oscillation treatment is carried out to obtain a graphene oxide dispersion liquid; then nano silicon is added into the graphene oxide dispersion liquid, stirred at room temperature (25℃) for 8h, vacuum dried to obtain nano silicon modified graphene oxide; finally, the nano silicon modified graphene oxide is placed in an atmosphere resistance furnace, argon is introduced, the temperature is raised to 900℃ at a rate of 15℃ / min, kept for 1h, the temperature is raised to 1300℃ at a rate of 8℃ / min, kept for 4h, and ground into fine powder.

[0089] The mass ratio of graphene oxide, deionized water and nano silicon is 5:50:1.

[0090] The ultrasonic oscillation condition is: 300W ultrasonic oscillation treatment for 50min.

[0091] In step (1), the specific method for growing graphene on the surface of silicon carbide modified graphene oxide is as follows: the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber which is vacuumed to below 0.003Pa, 220cm 3 / min of hydrogen is introduced, the temperature is raised to 1050℃ under the hydrogen atmosphere, the chamber pressure is 3kPa, the temperature and pressure are maintained for 40min, 15cm 3 / min of methane, 260cm 3 / min of argon, and 1000cm 3 / min of hydrogen are introduced, the introduction of methane and hydrogen is stopped after 10min, and the argon atmosphere is used for natural cooling to room temperature.

[0092] In step (1), the specific method for modification treatment is as follows: the graphene composite material is placed in the chamber of a tube furnace, is thinned to a thickness of not more than 1mm, sulfur hexafluoride is introduced into the chamber, a voltage of 1700kV is applied, the graphene composite material is irradiated by ultraviolet light with a wavelength of 220nm, the irradiation is performed for 7min, the material is mixed and thinned again, the foregoing treatment method is repeated, and the irradiation is performed for 5min again.

[0093] In steps (2) and (3), the antioxidant is antioxidant 1076, the plasticizer is diisodecyl phthalate, and the lubricant is sodium stearate.

[0094] In step (2), the sheath mixed material is extruded by a double screw, and the temperature of each zone is 180℃, 220℃, 240℃ and 210℃ in sequence; the screw rotation speed is 250r / min.

[0095] In step (3), the insulation layer mixed material is extruded by a double screw, and the temperature of each zone is 190℃, 210℃, 250℃ and 200℃ in sequence; the screw rotation speed is 300r / min.

[0096] In step (4), the diameter of the copper single wire is 0.5mm, the thickness of the tin layer is 0.9μm, the twisting direction of the tinned copper single wire is left, and the twisting pitch ratio is 20 times; the steel wire rope is twisted by 50 steel wires with a nominal diameter of 0.17mm, the twisting pitch ratio is 20 times, the cable twisting direction is left, and the pitch ratio is 12 times.

[0097] In step (4), the thickness of the insulation layer is 0.4mm.

[0098] In step (5), the braiding density is greater than or equal to 85%, and the braiding pitch is 30mm. The tinned copper single wire used in this step is the same as that in step (4).

[0099] In step (6), the sheath thickness is 1.2 mm.

[0100] Example 4

[0101] A processing process of a 10kV overhead insulated cable, the specific steps are as follows:

[0102] (1) Preparation of filler: graphene oxide modified with silicon carbide is prepared by taking graphite and nano silicon powder as raw materials; graphene oxide modified with silicon carbide is transferred into a chemical vapor deposition chamber, and graphene is grown on the surface of graphene oxide modified with silicon carbide to obtain a graphene composite material; the graphene composite material is modified by sulfur hexafluoride to obtain the graphene composite material.

[0103] (2) The following components are blended and extruded to obtain a sheath mixture: crosslinked polyethylene 5.5 kg, ethylene-tetrafluoroethylene copolymer 1.8 kg, epoxy resin 0.9 kg, filler 0.45 kg, antioxidant 0.15 kg, plasticizer 0.15 kg, lubricant 0.15 kg, and polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.15 kg;

[0104] (3) The following components are blended and extruded to obtain an insulation layer mixture: crosslinked polyethylene 5.5 kg, ethylene-tetrafluoroethylene copolymer 1.8 kg, ethylene-propylene-diene rubber 0.9 kg, filler 0.45 kg, antioxidant 0.15 kg, plasticizer 0.15 kg, and polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.15 kg;

[0105] (4) A tin layer is plated on the surface of the copper monofilament to obtain a tinned copper monofilament, which is twisted to obtain a conductor; the insulation layer mixture is extruded around the conductor and the steel wire rope to form an insulation layer, and a core and a tensile rope are obtained; a tensile rope is taken as an axis, and a plurality of cores are twisted with the tensile rope to form a cable core;

[0106] (5) The tinned copper monofilament is woven around the cable core to form a shielding layer;

[0107] (6) The sheath mixture is extruded around the shielding layer to form a sheath, and an overhead insulated cable is obtained.

[0108] In step (1), the specific preparation method of graphene oxide modified with silicon carbide is as follows: first, the graphite is made into graphite oxide by Hummers method, the graphite oxide is added into deionized water, and ultrasonic oscillation treatment is carried out to obtain a graphene oxide dispersion liquid; then, nano silicon is added into the graphene oxide dispersion liquid, stirred at room temperature (25℃) for 7h, vacuum dried to obtain graphene oxide modified with nano silicon; finally, the graphene oxide modified with nano silicon is placed in an atmosphere resistance furnace, argon is introduced, the temperature is raised to 850℃ at a rate of 17℃ / min, kept for 1.5h, the temperature is raised to 1310℃ at a rate of 7℃ / min, kept for 3h, and ground into fine powder.

[0109] The mass ratio of the oxidized graphite, deionized water and nano-silicon is 6:45:1.

[0110] The ultrasonic oscillation condition is 400W ultrasonic oscillation treatment for 45min.

[0111] In step (1), the specific method for growing graphene on the surface of silicon carbide modified graphene oxide is as follows: the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber which is vacuumed to below 0.003Pa, 230cm 3 / min of hydrogen is introduced, the temperature is raised to 1020℃ under the hydrogen atmosphere, the chamber pressure is 3kPa, the temperature and pressure are maintained for 35min, 18cm 3 / min of methane, 250cm 3 / min of argon and 1010cm 3 / min of hydrogen are introduced, the introduction of methane and hydrogen is stopped after 10min, and the argon atmosphere is used for natural cooling to room temperature.

[0112] In step (1), the specific method for modification treatment is as follows: the graphene composite material is placed in the chamber of a tube furnace, is thinned to a thickness of not more than 1mm, sulfur hexafluoride is introduced into the chamber, a voltage of 1600kV is applied, the graphene composite material is irradiated by ultraviolet light with a wavelength of 230nm, the irradiation is performed for 6min, the material is mixed and thinned again, the foregoing treatment method is repeated, and the irradiation is performed for 6min again.

[0113] In step (2) and step (3), the antioxidant is antioxidant 1010, the plasticizer is dibutyl phthalate, and the lubricant is polyethylene wax.

[0114] In step (2), the double-screw extrusion sheath mixed material is used, and the temperature of each zone is 185℃, 215℃, 245℃ and 205℃ in sequence; the screw rotation speed is 280r / min.

[0115] In step (3), the double-screw extrusion insulation layer mixed material is used, and the temperature of each zone is 185℃, 215℃, 245℃ and 205℃ in sequence; the screw rotation speed is 280r / min.

[0116] In step (4), the diameter of the copper monofilament is 0.6mm, the thickness of the tin layer is 0.8μm, the twisting direction of the tinned copper monofilament is left, and the twisting pitch ratio is 21 times; the steel wire rope is twisted by 45 steel wires with a nominal diameter of 0.17mm, and the twisting pitch ratio is 21 times; the cabling twisting direction is left, and the pitch ratio is 11 times.

[0117] In step (4), the thickness of the insulation layer is 0.5mm.

[0118] In step (5), the braiding density is ≥85% and the braiding pitch is 30mm. The tin-plated copper monofilament used in this step is the same as that used in step (4).

[0119] In step (6), the thickness of the sheath is 1.1 mm.

[0120] Comparative Example 1

[0121] A processing technology for a 10kV overhead insulated cable, the specific steps of which are as follows:

[0122] (1) Preparation of filler: Silicon carbide modified graphene oxide was prepared using graphite and nano-silicon powder as raw materials; the silicon carbide modified graphene oxide was transferred to the chemical vapor deposition chamber, and graphene was grown on the surface of the silicon carbide modified graphene oxide to obtain graphene composite material; the graphene composite material was modified by sulfur hexafluoride.

[0123] (2) The following components are blended and extruded to obtain a sheath mixture: 5 kg of cross-linked polyethylene, 1.5 kg of ethylene-tetrafluoroethylene copolymer, 0.8 kg of epoxy resin, 0.4 kg of filler, 0.1 kg of antioxidant, 0.1 kg of plasticizer, and 0.1 kg of lubricant;

[0124] (3) The following components are blended and extruded to obtain an insulating layer mixture: 5 kg of cross-linked polyethylene, 1.5 kg of ethylene-tetrafluoroethylene copolymer, 0.8 kg of EPDM rubber, 0.4 kg of filler, 0.1 kg of antioxidant, and 0.1 kg of plasticizer;

[0125] (4) A tin-plated layer is applied to the surface of the copper monofilament to obtain a tin-plated copper monofilament, which is then stranded to obtain a conductor; an insulating layer mixture is extruded over the conductor and the steel wire rope to form an insulating layer, thus obtaining a wire core and a tensile rope; a tensile rope is taken as the axis, and multiple wire cores are stranded with the tensile rope to obtain a cable core;

[0126] (5) A shielding layer is formed by braiding tin-plated copper monofilaments outside the cable core;

[0127] (6) Extruding sheath mixture on the outside of the shielding layer to form a sheath, thus obtaining an overhead insulated cable.

[0128] In step (1), the specific preparation method of silicon carbide modified graphene oxide is as follows: First, graphite is converted into graphene oxide by the Hummers method. The graphene oxide is added to deionized water and ultrasonically oscillated to obtain a graphene oxide dispersion. Then, nano-silicon is added to the graphene oxide dispersion and stirred at room temperature (25℃) for 6 hours to obtain a mixed solution. The solution is then vacuum dried to obtain nano-silicon modified graphene oxide. Finally, the nano-silicon modified graphene oxide is placed in an atmosphere resistance furnace, argon gas is introduced, and the temperature is increased to 800℃ at 15℃ / min and held for 1 hour. The temperature is then increased to 1300℃ at 5℃ / min and held for 3 hours. The solution is then ground into fine powder to obtain the final product.

[0129] The mass ratio of the oxidized graphite, the deionized water and the nano-silicon is 5:40:1.

[0130] The ultrasonic oscillation condition is 300W ultrasonic oscillation treatment for 40min.

[0131] In step (1), the specific method for growing graphene on the surface of the silicon carbide modified graphene oxide is as follows: the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber which is vacuumed to below 0.003Pa, 220cm 3 / min of hydrogen is introduced, the temperature is raised to 1000℃ under the hydrogen atmosphere, the chamber pressure is 3kPa, the temperature and pressure are maintained for 30min, 15cm 3 / min of methane, 230cm 3 / min of argon and 1000cm 3 / min of hydrogen are introduced, 10min later, the introduction of methane and hydrogen is stopped, and the argon atmosphere is used for natural cooling to room temperature.

[0132] In step (1), the specific method for modification treatment is as follows: the graphene composite material is placed in the chamber of a tube furnace, and is thinned to a thickness of not more than 1mm, sulfur hexafluoride is introduced into the chamber, a voltage of 1500kV is applied, the graphene composite material is irradiated by ultraviolet light with a wavelength of 220nm, the irradiation is performed for 5min, the material is mixed and thinned again, the foregoing treatment method is repeated, and the irradiation is performed for 5min again.

[0133] In step (2) and step (3), the antioxidant is antioxidant 1010, the plasticizer is diisodecyl phthalate, and the lubricant is polyethylene wax.

[0134] In step (2), the double-screw extrusion sheath mixed material is used, and the temperature of each zone is 180℃, 210℃, 240℃ and 200℃ in sequence; the screw rotation speed is 250r / min.

[0135] In step (3), the double-screw extrusion insulation layer mixed material is used, and the temperature of each zone is 180℃, 210℃, 240℃ and 200℃ in sequence; the screw rotation speed is 250r / min.

[0136] In step (4), the diameter of the copper monofilament is 0.5mm, the thickness of the tin layer is 0.7μm, the twisting direction of the tinned copper monofilament is left, and the twisting pitch ratio is 20 times; the steel wire rope is twisted by 40 steel wires with a nominal diameter of 0.17mm, the twisting pitch ratio is 20 times, the cable twisting direction is left, and the pitch ratio is 10 times.

[0137] In step (4), the thickness of the insulation layer is 0.4mm.

[0138] In step (5), the braiding density is ≥ 85%, and the braiding pitch is 30 mm. The tinned copper monofilament used in this step is the same as that in step (4).

[0139] In step (6), the sheath thickness is 1.0 mm.

[0140] Comparative Example 2

[0141] A processing process of a 10 kV overhead insulated cable, the specific steps are as follows:

[0142] (1) Preparation of filler: graphene oxide is prepared from graphite as raw material; graphene oxide is transferred to a chemical vapor deposition chamber, and graphene is grown on the surface of graphene oxide to obtain a graphene composite material; the graphene composite material is modified by sulfur hexafluoride to obtain the filler;

[0143] (2) The following components are blended and extruded to obtain a sheath mixture: crosslinked polyethylene 5 kg, ethylene-tetrafluoroethylene copolymer 1.5 kg, epoxy resin 0.8 kg, filler 0.4 kg, antioxidant 0.1 kg, plasticizer 0.1 kg, lubricant 0.1 kg, and polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.1 kg;

[0144] (3) The following components are blended and extruded to obtain an insulation layer mixture: crosslinked polyethylene 5 kg, ethylene-tetrafluoroethylene copolymer 1.5 kg, ethylene-propylene-diene rubber 0.8 kg, filler 0.4 kg, antioxidant 0.1 kg, plasticizer 0.1 kg, and polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.1 kg;

[0145] (4) A tinned copper monofilament is obtained by plating a tin layer on the surface of a copper monofilament, and is twisted to obtain a conductor; the insulation layer mixture is extruded around the conductor and the steel wire rope to form an insulation layer, and a core and a tensile rope are obtained; a tensile rope is taken as an axis, and a plurality of cores are twisted with the tensile rope to form a cable core;

[0146] (5) A tinned copper monofilament is braided around the cable core to form a shielding layer;

[0147] (6) The sheath mixture is extruded around the outside of the shielding layer to form a sheath, and an overhead insulated cable is obtained.

[0148] In step (1), the specific preparation method of graphene oxide is as follows: first, graphite is made into graphite oxide by Hummers method, and then the graphite oxide is added to deionized water and treated by ultrasonic oscillation to obtain a graphene oxide dispersion liquid, which is dried to obtain the graphene oxide.

[0149] The mass ratio of graphite oxide to deionized water is 1:8.

[0150] The ultrasonic oscillation condition is 300 W ultrasonic oscillation treatment for 40 min.

[0151] In step (1), the specific method for growing graphene on the surface of graphene oxide is as follows: the graphene oxide is transferred into a chemical vapor deposition chamber which is vacuumed to below 0.003 Pa, 220 cm 3 / min of hydrogen is introduced, the temperature is raised to 1000℃ under the hydrogen atmosphere, the chamber pressure is 3 kPa, and the temperature and pressure are maintained for 30 min; 15 cm 3 / min of methane, 230 cm 3 / min of argon, and 1000 cm 3 / min of hydrogen are introduced, the introduction of methane and hydrogen is stopped after 10 min, and the argon atmosphere is used for natural cooling to room temperature.

[0152] In step (1), the specific method for modification treatment is as follows: the graphene composite material is placed in the chamber of a tube furnace, is thinned to a thickness of not more than 1 mm, sulfur hexafluoride is introduced into the chamber, a voltage of 1500 kV is applied, the graphene composite material is irradiated with ultraviolet light of a wavelength of 220 nm, the irradiation is performed for 5 min, the material is mixed and thinned again, the foregoing treatment method is repeated, and the irradiation is performed for 5 min again.

[0153] In steps (2) and (3), the antioxidant is antioxidant 1010; the plasticizer is diisodecyl phthalate; and the lubricant is polyethylene wax.

[0154] In step (2), the sheath mixture is extruded by a double-screw extruder, and the temperature of each zone is 180℃, 210℃, 240℃, and 200℃ in sequence; the screw rotation speed is 250 r / min.

[0155] In step (3), the insulation layer mixture is extruded by a double-screw extruder, and the temperature of each zone is 180℃, 210℃, 240℃, and 200℃ in sequence; the screw rotation speed is 250 r / min.

[0156] In step (4), the diameter of the copper monofilament is 0.5 mm, the thickness of the tin layer is 0.7 μm, the twisting direction of the tinned copper monofilament is leftward, and the pitch ratio of the twisting is 20 times; the steel wire rope is twisted by 40 steel wires with a nominal diameter of 0.17 mm, the pitch ratio of the twisting is 20 times, the twisting direction of the cable is leftward, and the pitch ratio is 10 times.

[0157] In step (4), the thickness of the insulation layer is 0.4 mm.

[0158] In step (5), the braiding density is greater than or equal to 85%, and the braiding pitch is 30 mm. The tinned copper monofilament used in this step is the same as that in step (4).

[0159] In step (6), the thickness of the sheath is 1.0 mm.

[0160] Comparative Example 3

[0161] A processing process of a 10kV overhead insulated cable, the specific steps are as follows:

[0162] (1) Preparation of filler: silicon carbide modified graphene oxide is prepared by taking graphite and nano silicon powder as raw materials; the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber, and graphene is grown on the surface of the silicon carbide modified graphene oxide to obtain a graphene composite material as a filler;

[0163] (2) The following components are blended and extruded to obtain a sheath mixture: crosslinked polyethylene 5kg, ethylene-tetrafluoroethylene copolymer 1.5kg, epoxy resin 0.8kg, filler 0.4kg, antioxidant 0.1kg, plasticizer 0.1kg, lubricant 0.1kg, polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.1kg;

[0164] (3) The following components are blended and extruded to obtain an insulation layer mixture: crosslinked polyethylene 5kg, ethylene-tetrafluoroethylene copolymer 1.5kg, ethylene-propylene-diene rubber 0.8kg, filler 0.4kg, antioxidant 0.1kg, plasticizer 0.1kg, polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.1kg;

[0165] (4) A tin layer is plated on the surface of the copper monofilament to obtain a tinned copper monofilament, which is stranded to obtain a conductor; the insulation layer mixture is extruded around the conductor and the steel wire rope respectively to form an insulation layer, and a core and a tensile rope are obtained; a tensile rope is taken as an axis, and a plurality of cores are stranded with the tensile rope to obtain a cable core;

[0166] (5) The tinned copper monofilament is woven outside the cable core to form a shielding layer;

[0167] (6) The sheath mixture is extruded outside the shielding layer to form a sheath, and an overhead insulated cable is obtained.

[0168] In step (1), the specific preparation method of the silicon carbide modified graphene oxide is as follows: first, the graphite is made into graphite oxide by Hummers method, the graphite oxide is added into deionized water, and ultrasonic oscillation treatment is carried out to obtain a graphene oxide dispersion liquid; then, the nano silicon is added into the graphene oxide dispersion liquid, stirred at room temperature (25℃) for 6h, vacuum dried to obtain nano silicon modified graphene oxide; finally, the nano silicon modified graphene oxide is placed in an atmosphere resistance furnace, argon is introduced, heated to 800℃ at a rate of 15℃ / min, kept for 1h, heated to 1300℃ at a rate of 5℃ / min, kept for 3h, and ground into fine powder.

[0169] The mass ratio of graphite oxide, deionized water and nano silicon is 5:40:1.

[0170] The ultrasonic oscillation condition is 300W ultrasonic oscillation treatment for 40min.

[0171] In step (1), the specific method of growing graphene on the surface of silicon carbide modified graphene oxide is as follows: the silicon carbide modified graphene oxide is transferred into a chemical vapor deposition chamber which is vacuumed to below 0.003 Pa, 220 cm 3 / min of hydrogen is introduced, the temperature is raised to 1000℃ under the hydrogen atmosphere, the chamber pressure is 3 kPa, the temperature and pressure are maintained for 30 min, 15 cm 3 / min of methane, 230 cm 3 / min of argon, and 1000 cm 3 / min of hydrogen are introduced, the introduction of methane and hydrogen is stopped after 10 min, and the argon atmosphere is naturally cooled to room temperature.

[0172] In steps (2) and (3), the antioxidant is antioxidant 1010; the plasticizer is diisodecyl phthalate; and the lubricant is polyethylene wax.

[0173] In step (2), the sheath mixture is mixed by a double-screw extruder, and the temperature of each zone is 180℃, 210℃, 240℃, and 200℃ in sequence; the screw rotation speed is 250 r / min.

[0174] In step (3), the insulation layer mixture is mixed by a double-screw extruder, and the temperature of each zone is 180℃, 210℃, 240℃, and 200℃ in sequence; the screw rotation speed is 250 r / min.

[0175] In step (4), the diameter of the copper monofilament is 0.5 mm, the thickness of the tin layer is 0.7 μm, the twisting direction of the tinned copper monofilament is left, and the pitch ratio of the twisting is 20 times; the steel wire rope is twisted by 40 steel wires with a nominal diameter of 0.17 mm, the pitch ratio of the twisting is 20 times, the twisting direction of the cable is left, and the pitch ratio is 10 times.

[0176] In step (4), the thickness of the insulation layer is 0.4 mm.

[0177] In step (5), the braiding density is ≥85%, and the braiding pitch is 30 mm. The tinned copper monofilament used in this step is the same as that in step (4).

[0178] In step (6), the thickness of the sheath is 1.0 mm.

[0179] Comparative Example 4

[0180] A processing process of a 10 kV overhead insulated cable is as follows:

[0181] (1) Preparation of the filler: silicon carbide modified graphene oxide is prepared by using graphite and nano silicon powder as raw materials, as the filler;

[0182] (2) The sheath mixture is obtained by blending and extruding the following components: crosslinked polyethylene 5 kg, ethylene-tetrafluoroethylene copolymer 1.5 kg, epoxy resin 0.8 kg, filler 0.4 kg, antioxidant 0.1 kg, plasticizer 0.1 kg, lubricant 0.1 kg, polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.1 kg;

[0183] (3) The insulation layer mixture is obtained by blending and extruding the following components: crosslinked polyethylene 5 kg, ethylene-tetrafluoroethylene copolymer 1.5 kg, ethylene-propylene-diene rubber 0.8 kg, filler 0.4 kg, antioxidant 0.1 kg, plasticizer 0.1 kg, polychlorotrifluoroethylene-vinylidene fluoride copolymer 0.1 kg;

[0184] (4) A tin layer is plated on the surface of the copper monofilament to obtain a tinned copper monofilament, which is twisted to obtain a conductor; the insulation layer mixture is extruded around the conductor and the steel wire rope respectively to form an insulation layer, thereby obtaining a core and a tensile rope; one tensile rope is taken as an axis, and a plurality of cores are twisted with the tensile rope to form a cable core;

[0185] (5) The tinned copper monofilament is woven outside the cable core to form a shielding layer;

[0186] (6) The sheath mixture is extruded around the outside of the shielding layer to form a sheath, thereby obtaining the overhead insulated cable.

[0187] In step (1), the specific preparation method of the silicon carbide modified graphene oxide is as follows: first, the graphite is made into graphite oxide by the Hummers method, the graphite oxide is added to deionized water, and ultrasonic oscillation treatment is performed to obtain a graphene oxide dispersion liquid; then, the nano silicon is added to the graphene oxide dispersion liquid, stirred at room temperature (25℃) for 6h, to obtain a mixed solution, vacuum dried to obtain nano silicon modified graphene oxide; finally, the nano silicon modified graphene oxide is placed in an atmospheric resistance furnace, argon is introduced, heated to 800℃ at a rate of 15℃ / min, kept for 1h, heated to 1300℃ at a rate of 5℃ / min, kept for 3h, and ground into fine powder.

[0188] The mass ratio of graphite oxide, deionized water and nano silicon is 5:40:1.

[0189] The ultrasonic oscillation condition is 300W ultrasonic oscillation treatment for 40min.

[0190] In steps (2) and (3), the antioxidant is antioxidant 1010; the plasticizer is diisodecyl phthalate; and the lubricant is polyethylene wax.

[0191] In step (2), the sheath mixture is extruded by a double screw extruder, and the temperature of each zone is 180℃, 210℃, 240℃ and 200℃ in turn; the screw speed is 250r / min.

[0192] In step (3), the insulation layer mixture is extruded by a double screw, and the temperature of each zone is 180°C, 210°C, 240°C and 200°C in sequence, and the screw rotation speed is 250 r / min.

[0193] In step (4), the diameter of the copper single wire is 0.5 mm, the thickness of the tin layer is 0.7 μm, the twisting direction of the tinned copper single wire is left, and the pitch ratio of the twisting is 20 times; the steel wire rope is twisted by 40 steel wires with a nominal diameter of 0.17 mm, and the pitch ratio of the twisting is 20 times; the cable twisting direction is left, and the pitch ratio is 10 times.

[0194] In step (4), the thickness of the insulation layer is 0.4 mm.

[0195] In step (5), the braiding density is ≥85%, and the braiding pitch is 30 mm. The tinned copper single wire used in this step is the same as that in step (4).

[0196] In step (6), the thickness of the sheath is 1.0 mm.

[0197] Test Example

[0198] The mechanical properties and high and low temperature resistance of the overhead cables obtained in Examples 1-4 and Comparative Examples 1-4 are investigated.

[0199] 1. Mechanical property test

[0200] The mechanical properties of the sheath (tensile strength and elongation at break) are tested according to GB / T 2951.11-2008 "Cables and optical fibers-Insulation and sheath materials-General test methods-Part 11: General test methods-Thickness and outer dimension measurement-Mechanical property test".

[0201] 2. High and low temperature resistance

[0202] The high temperature resistance test (250°C, 240h) is carried out according to GB / T 2951.12-2008 "Cables and optical fibers-Insulation and sheath materials-General test methods-Part 12: General test methods-Thermal aging test methods", and the elongation at break is tested.

[0203] The low temperature resistance test (-40°C, 24h) is carried out according to GB / T 2951.14-2008 "Cables and optical fibers-Insulation and sheath materials-General test methods-Part 14: General test methods-Low temperature test methods", and the elongation at break is tested.

[0204] The test results are shown in Table 1.

[0205] Table 1. Cable performance investigation

[0206]

[0207] From Table 1, it can be seen that the cables obtained in Examples 1-4 have excellent mechanical properties and high and low temperature resistance.

[0208] Comparative Example 1 omits the poly chlorotrifluoroethylene-vinylidene fluoride copolymer in preparing the sheath mixture or the insulation layer mixture, Comparative Example 2 omits the silicon carbide modification in preparing the filler, Comparative Example 3 omits the sulfur hexafluoride modification treatment in preparing the filler, and Comparative Example 4 uses silicon carbide modified graphene oxide as the filler, which shows that the poly chlorotrifluoroethylene-vinylidene fluoride copolymer promotes the compatibility between the components, and the silicon carbide modification, sulfur hexafluoride modification treatment and the like in preparing the filler have a synergistic effect, thereby improving the mechanical properties and high and low temperature resistance of the product.

[0209] The technical concept of the present application is illustrated by the above examples, but the present application is not limited to the above examples, i.e. it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of individual raw materials of the product of the present application, addition of auxiliary ingredients, selection of specific modes, etc. all fall within the protection scope and disclosure scope of the present application.

Claims

1. A processing technology for a 10kV overhead insulated cable, characterized in that, The specific steps are as follows: (1) Preparation of filler: Silicon carbide modified graphene oxide was prepared using graphite and nano-silicon powder as raw materials; the silicon carbide modified graphene oxide was transferred to the chemical vapor deposition chamber, and graphene was grown on the surface of the silicon carbide modified graphene oxide to obtain graphene composite material; the graphene composite material was modified by sulfur hexafluoride. (2) The following components are blended and extruded to obtain a sheath mixture: 50-60 parts of cross-linked polyethylene, 15-20 parts of ethylene-tetrafluoroethylene copolymer, 8-10 parts of epoxy resin, 4-5 parts of filler, 1-2 parts of antioxidant, 1-2 parts of plasticizer, 1-2 parts of lubricant, and 1-2 parts of polyvinyl chloride-vinylidene fluoride copolymer. (3) The following components are blended and extruded to obtain an insulating layer mixture: 50-60 parts of cross-linked polyethylene, 15-20 parts of ethylene-tetrafluoroethylene copolymer, 8-10 parts of ethylene propylene diene monomer (EPDM) rubber, 4-5 parts of filler, 1-2 parts of antioxidant, 1-2 parts of plasticizer, and 1-2 parts of polyvinyl chloride-vinylidene fluoride copolymer. (4) A tin-plated layer is applied to the surface of the copper monofilament to obtain a tin-plated copper monofilament, which is then stranded to obtain a conductor; an insulating layer mixture is extruded over the conductor and the steel wire rope to form an insulating layer, thus obtaining a wire core and a tensile rope; a tensile rope is taken as the axis, and multiple wire cores are stranded with the tensile rope to obtain a cable core; (5) A shielding layer is formed by braiding tin-plated copper monofilaments outside the cable core; (6) Extruding sheath mixture on the outside of the shielding layer to form a sheath, thus obtaining the overhead insulated cable.

2. The processing technology for a 10kV overhead insulated cable according to claim 1, characterized in that, In step (1), the specific preparation method of the silicon carbide modified graphene oxide is as follows: First, graphite is converted into graphene oxide by the Hummers method. The graphene oxide is added to deionized water and ultrasonically oscillated to obtain a graphene oxide dispersion. Then, nano-silicon is added to the graphene oxide dispersion and stirred at room temperature for 6-8 hours to obtain a mixed solution. The solution is then vacuum dried to obtain nano-silicon modified graphene oxide. Finally, the nano-silicon modified graphene oxide is placed in an atmosphere resistance furnace, argon gas is introduced, and the temperature is raised to 800-900℃ at 15-20℃ / min and held for 1-2 hours. The temperature is then raised to 1300-1320℃ at 5-8℃ / min and held for 3-4 hours. The solution is then ground into fine powder to obtain the final product.

3. The processing technology for a 10kV overhead insulated cable according to claim 1, characterized in that, In step (1), the specific method for growing graphene on the surface of silicon carbide-modified graphene oxide is as follows: the silicon carbide-modified graphene oxide is transferred to a chemical vapor deposition chamber evacuated to below 0.003 Pa, and grown at 220–240 cm⁻¹ 3 Hydrogen gas is introduced at a rate of 15-20 cm³ / min, and the temperature is raised to 1000-1050℃ in a hydrogen atmosphere. The chamber pressure is 3-4 kPa, and the temperature and pressure are maintained for 30-40 min. 3 methane concentration per minute, 230–260 cm⁻¹ 3 Argon gas at a flow rate of 1000–1020 cm⁻¹ / min 3 After 10 minutes, stop the flow of methane and hydrogen and allow the mixture to cool naturally to room temperature under an argon atmosphere.

4. The processing technology for a 10kV overhead insulated cable according to claim 1, characterized in that, In step (1), the specific method of modification treatment is as follows: place the graphene composite material in the chamber of the tube furnace, spread it thinly with a thickness not exceeding 1 mm, introduce sulfur hexafluoride into the chamber, apply a voltage of 1500-1700 kV, irradiate the graphene composite material with ultraviolet light with a wavelength of 220-240 nm for 5-7 min, mix the material, spread it thinly again, repeat the above treatment method, and irradiate it again for 5-7 min.

5. The processing technology for a 10kV overhead insulated cable according to claim 1, characterized in that, In steps (2) and (3), the antioxidant is selected from any one of antioxidant 1010, antioxidant 300 or antioxidant 1076; the plasticizer is selected from diisodecyl phthalate or dibutyl phthalate; and the lubricant is polyethylene wax or sodium stearate.

6. The processing technology of a 10kV overhead insulated cable according to claim 1, characterized in that, In step (2), the sheath mixture is extruded using a twin-screw extruder, and the temperatures of each zone are as follows: 180~190℃, 210~220℃, 240~250℃, and 200~210℃; the screw speed is 250~300r / min.

7. The processing technology for a 10kV overhead insulated cable according to claim 1, characterized in that, In step (3), the insulation layer mixture is extruded using a twin-screw extruder, with the temperatures of each zone being 180~190℃, 210~220℃, 240~250℃, and 200~210℃ respectively; the screw speed is 250~300r / min.

8. The processing technology of a 10kV overhead insulated cable according to claim 1, characterized in that, In step (4), the diameter of the copper monofilament is 0.5-0.7 mm, the thickness of the tin layer is 0.7-0.9 μm, the twisting direction of the tin-plated copper monofilament is to the left, and the twisting pitch ratio is 20-22 times; the steel wire rope is made of 40-50 steel wires with a nominal diameter of 0.17 mm twisted together, and the twisting pitch ratio is 20-22 times; the cable twisting direction is to the left, and the pitch ratio is 10-12 times.

9. The processing technology of a 10kV overhead insulated cable according to claim 1, characterized in that, In step (4), the thickness of the insulation layer is 0.4–0.6 mm; In step (5), the weaving density is ≥85% and the weaving pitch is 30mm; In step (6), the thickness of the sheath is 1.0 to 1.2 mm.

10. A 10kV overhead insulated cable, characterized in that, It is prepared by the processing technology of any one of claims 1 to 9 for a 10kV overhead insulated cable.

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