Flame-retardant environment-friendly cross-linked polyethylene insulated steel tape armored heavy power cable

Abstract

The utility model discloses a flame-retardant environment-friendly cross-linked polyethylene insulated steel tape armored heavy power cable, which relates to the technical field of cables, is made of oxygen-free copper materials and sequentially comprises an insulating layer, an inner protective layer, a steel tape armored layer and an outer protective layer outwards, and a semi-conductive shielding layer is arranged between the insulating layer and the inner protective layer. The insulating layer is made of a cross-linked polyethylene material and contains auxiliaries such as a flame retardant and the like in a specific proportion, and the flame retardant is a compound of a phosphorus-nitrogen intumescent flame retardant and aluminum hydroxide; the inner protection layer is made of a polyolefin material; the steel tape armoring layer is composed of two layers of galvanized steel tapes which are different in thickness, are wound in opposite directions and are provided with gaps; the outer protective layer is a thermoplastic elastomer with shore hardness of 80 and contains an ultraviolet light absorber and an antistatic agent; the semi-conductive shielding layer is made of a carbon black filled polyethylene material. Compared with the prior art, the performance of each layer of the cable is improved, safe, stable and long-acting power transmission is cooperatively ensured, and the cable has remarkable beneficial effects in the aspects of flame retardance, protection, mechanical strength, weather resistance, static electricity resistance, uniform electric field and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to cable technical field, concretely is a kind of flame-retardant environment-friendly crosslinked polyethylene insulation steel-tape armored heavy power cable. BACKGROUND

[0002] In modern society, electricity supports the normal operation of various fields. Stable power supply is crucial. Heavy power cable, as the key carrier of power transmission, its performance is directly related to the reliability and safety of power system. With the acceleration of urbanization and the vigorous development of industry, the demand for electricity is growing rapidly. Large commercial centers, high-rise buildings, factories and other places have an increasing demand for electricity, which requires power cables to have higher current-carrying capacity and better mechanical properties to meet the stable operation of high-power equipment. At the same time, these places are densely populated or valuable equipment, and once a fire breaks out, the consequences are disastrous. Traditional cables have deficiencies in flame retardant performance, and are prone to become a way for fire to spread, causing huge loss of life and property. Therefore, it is urgent to develop power cables with high-efficiency flame-retardant performance.

[0003] The increasing awareness of environmental protection also puts new requirements on cable materials. Traditional cables may release harmful substances during production, use and disposal, causing environmental pollution. Some cable materials contain heavy metals, halogens and other components, which can pollute soil, water and air when incinerated or landfilled. Therefore, developing environmentally friendly cables using non-toxic and biodegradable materials to reduce negative impact on the environment is an inevitable choice for sustainable development of the cable industry. In the process of power transmission, the insulation performance of the cable is crucial. Poor insulation performance can cause problems such as electrical leakage and short circuit, affecting the normal operation of the power system and even causing safety accidents. In addition, cables are subjected to various external forces during installation and use, such as stretching, extrusion, bending, etc. This requires the cable to have sufficient mechanical strength to protect the internal conductor and insulation layer from damage. Steel-tape armored layer can effectively enhance the mechanical properties of the cable and improve its resistance to external damage. At the same time, in order to adapt to different use environments, the outer protective layer of the cable needs to have good weather resistance, wear resistance and anti-static performance, etc.

[0004] The existing heavy power cable is difficult to fully meet the requirements of modern society for power transmission in terms of comprehensive performance. Therefore, the development of a new type of heavy power cable that integrates flame retardant, environmental protection, high-performance insulation and strong mechanical protection has become the key to solving the current power transmission problem. UTILITY MODEL CONTENT

[0005] The utility model discloses a kind of flame-retardant environment-friendly crosslinked polyethylene insulated steel-tape armored heavy power cables, current is transmitted by special specification oxygen-free copper conductor, crosslinked polyethylene insulation layer guarantees electrical isolation and flame retardant, semiconductive shielding layer uniform electric field, polyolefin inner protective layer is added with nano filler to provide protection, two layers of galvanized steel tape armored layer of reverse winding enhance mechanical strength, thermoplastic elastomer outer protective layer with additive resist ultraviolet and static electricity, each layer cooperates to ensure power transmission safety, stability, long-acting.

[0006] To achieve the above object, the utility model provides the following technical scheme:

[0007] A kind of flame-retardant environment-friendly crosslinked polyethylene insulated steel-tape armored heavy power cable, including conductor.The conductor adopts oxygen-free copper material.Oxygen-free copper has the characteristics of high purity, high conductivity, can effectively reduce resistance, reduce the loss in the process of electric energy transmission, improve the conductivity efficiency of cable.And the single filament diameter range of the conductor is 0.3mm to 0.5mm.The diameter range is set by comprehensively considering the load current, flexibility and production cost and other factors of cable.Finer single filament can make cable have better flexibility under the premise of guaranteeing certain load current, facilitate laying and installation;And appropriate upper limit of diameter can ensure that single filament has enough strength, meet the mechanical property requirements of cable.And the stranding pitch ratio of multiple single filaments is between 18 and 22.The stranding pitch ratio refers to the ratio of pitch and outer diameter of stranded wire in stranding process.The ratio range is determined, which helps to make conductor guarantee good flexibility and stability while optimizing electromagnetic performance of cable, reduce signal interference and electric energy loss.The conductor is sequentially provided with insulation layer, inner protective layer, steel-tape armored layer and outer protective layer outward.

[0008] The insulation layer is of crosslinked polyethylene material, and the preparation raw material includes, by weight fraction, crosslinked polyethylene resin 100 parts, flame retardant 30 parts, plasticizer 10 parts, antioxidant 2 parts and coupling agent 1 part.The crosslinked polyethylene resin is used as the main matrix material of insulation layer, and has good electrical insulation performance, heat resistance and mechanical properties.The addition of flame retardant is to improve the flame retardant performance of cable, so that it can effectively inhibit the spread of flame and reduce fire risk when encountering fire and other special conditions.The plasticizer can increase the flexibility and plasticity of the material, improve the processing performance of crosslinked polyethylene resin, and make it more easily formed.The antioxidant prevents the material from aging due to oxidation during long-term use, prolonging the service life of the cable.The coupling agent can enhance the interfacial bonding force between different materials and improve the performance stability of the insulation layer as a whole.

[0009] The flame retardant is a compound of phosphorus-nitrogen intumescent flame retardant and aluminum hydroxide, wherein the mass ratio of phosphorus-nitrogen intumescent flame retardant to aluminum hydroxide is 2:3. The phosphorus-nitrogen intumescent flame retardant can form an expanded carbon layer when heated, which plays a role of heat and oxygen insulation, thereby preventing the spread of fire; the aluminum hydroxide can decompose and absorb heat when heated, thereby reducing the temperature of the material surface, and the released water vapor can also dilute the concentration of combustible gas, and the two compounds can produce a synergistic flame-retardant effect and improve the flame-retardant efficiency. The thickness of the crosslinked polyethylene insulation layer is between 3 mm and 5 mm. This thickness range is determined according to the rated voltage of the cable, the use environment and other factors, and a sufficient insulation layer thickness can ensure that the cable effectively isolates the conductor from the outside electrical connection during normal operation, preventing faults such as electric leakage and short circuit.

[0010] The inner protective layer is made of polyolefin material with a density range of 0.92 g / cm³ to 0.94 g / cm³. The polyolefin material has good chemical corrosion resistance, water resistance and mechanical properties, and can provide reliable protection for the internal structure of the cable. Such a density range can ensure that the material has certain strength and toughness, and also achieve a good balance between quality and cost. Additionally, 3% to 5% by mass of nano-sized inorganic fillers are added, which are a mixture of nano-montmorillonite and nano-titanium dioxide in a mass ratio of 3:2. The addition of nano-sized inorganic fillers can significantly improve the performance of polyolefin materials, such as increasing their strength, hardness, heat resistance and barrier properties. Nano-montmorillonite has a unique layered structure and can form good dispersion in polyolefin materials, enhancing the mechanical properties and barrier properties of the material; nano-titanium dioxide has excellent photocatalytic and ultraviolet absorption properties, which can improve the weather resistance and anti-aging properties of the material. Mixing the two in a specific ratio can produce a synergistic effect.

[0011] The steel strip armor layer is composed of two layers of galvanized steel strips with thicknesses of 0.5 mm and 0.6 mm, respectively, and the winding directions of the two layers of steel strips are opposite, with a winding gap of 0.2 mm. The steel strip armor layer is mainly used to enhance the mechanical strength of the cable and protect the internal structure of the cable from damage caused by external mechanical forces. The use of two layers of galvanized steel strips with different thicknesses can optimize the structural design of the cable while ensuring sufficient mechanical strength. The opposite winding directions of the two layers of steel strips can offset some of the stress caused by external forces, improving the cable's resistance to twisting and stretching. The winding gap of 0.2 mm can ensure the close combination of the steel strips while avoiding mutual extrusion and deformation of the steel strips due to thermal expansion and contraction, which can affect the performance of the cable.

[0012] The outer protective layer is a thermoplastic elastomer material with a Shore hardness of 80. The thermoplastic elastomer material has the advantages of rubber and plastic, and has good elasticity, flexibility, wear resistance and chemical corrosion resistance, and can provide good external protection for the cable. And the outer protective layer is added with an ultraviolet absorber with a mass fraction of 2% to 3% and an antistatic agent with a mass fraction of 1% to 2%. The role of the ultraviolet absorber is to absorb ultraviolet rays in sunlight, prevent the outer protective layer material from aging, discoloration and performance degradation due to ultraviolet radiation; the antistatic agent can reduce the resistance of the material surface, prevent the accumulation of static electricity, avoid the influence of static electricity on the appearance and performance of the cable by adsorbing dust and other impurities, and also reduce the safety hazards caused by static electricity.

[0013] A semiconductive shielding layer is arranged between the insulating layer and the inner protective layer, and the semiconductive shielding layer is made of carbon black filled polyethylene material, the volume resistivity is 1*10²Ω·m to 1*10³Ω·m, and the thickness is 0.5mm. The semiconductive shielding layer can uniform the electric field and prevent the local discharge of the insulating layer caused by the concentration of the electric field, thereby protecting the insulating layer and prolonging the service life of the cable. The carbon black filled polyethylene material has good semiconductive performance, and by controlling the filling amount of carbon black and the formula of the material, the volume resistivity can be controlled in the range of 1*10²Ω·m to 1*10³Ω·m, so that the requirement of the electric field shielding of the cable under different working conditions can be met. The thickness of 0.5mm is determined by comprehensively considering the material cost and the rationality of the overall structure of the cable under the premise of ensuring the effective shielding of the electric field.

[0014] The flame-retardant and environmentally friendly cross-linked polyethylene insulated steel-tape armored heavy-duty power cable works, and the conductor made of oxygen-free copper material, single-wire diameter of 0.3mm to 0.5mm and stranding pitch ratio of 18 to 22 is responsible for transmitting current, which effectively reduces the power loss due to its high purity and low resistance characteristics. The insulating layer outside the conductor is made of cross-linked polyethylene material, and the raw materials are configured in a specific proportion, wherein the flame retardant compound can suppress the flame when encountering fire, and the thickness of the insulating layer of 3mm to 5mm guarantees the electrical isolation. The semiconductive shielding layer between the insulating layer and the inner protective layer is made of carbon black filled polyethylene material, with a volume resistivity of 1*10²Ω·m to 1*10³Ω·m and a thickness of 0.5mm, which can uniform the electric field and prevent local discharge. The inner protective layer is made of polyolefin material added with nanoscale inorganic filler, and the specific density and filler ratio make it have good protection performance. The armored layer is composed of two layers of galvanized steel tapes with thicknesses of 0.5mm and 0.6mm, opposite winding directions and a gap of 0.2mm, which enhances the mechanical strength. The outer protective layer is a thermoplastic elastomer material with a Shore hardness of 80, and is added with an ultraviolet absorber and an antistatic agent, which can resist ultraviolet rays and static electricity. The layers work together to ensure the safety, stability and long-term effectiveness of the cable during power transmission.

[0015] Compared with the prior art, the utility model has the advantages of:

[0016] The insulation layer is made of cross-linked polyethylene material, with the addition of specific proportions of flame retardant, plasticizer, antioxidant and coupling agent. The flame retardant is a compound of phosphorus-nitrogen intumescent flame retardant and aluminum hydroxide. This compound method produces a synergistic flame-retardant effect, which is higher than that of single flame retardant. It can effectively suppress the spread of fire and reduce the risk of fire when a fire occurs. At the same time, the plasticizer improves the flexibility and processing performance of the material, the antioxidant prolongs the service life of the insulation layer, and the coupling agent enhances the interfacial bonding force between materials, so that the comprehensive performance of the insulation layer is significantly improved.

[0017] The inner protective layer is made of polyolefin material, with the addition of 3% to 5% of nano-sized inorganic fillers. Compared with ordinary polyolefin inner protective layer, the strength, hardness, heat resistance and barrier properties of the material are improved after adding nano fillers. The layered structure of nano-montmorillonite and the photocatalytic and ultraviolet absorption properties of nano-titanium dioxide play a synergistic effect, so that the inner protective layer can better protect the internal structure of the cable and resist the erosion of the external environment, improving the overall protection performance of the cable.

[0018] The steel strip armor layer is composed of two layers of galvanized steel strips with thicknesses of 0.5mm and 0.6mm, and the winding directions of the two layers of steel strips are opposite, with a winding gap of 0.2mm. Compared with traditional single steel strip armor or ordinary double-layer steel strip armor, this design not only enhances the mechanical strength of the cable and effectively protects the internal structure from damage by external mechanical forces, but also offsets part of the stress through reverse winding, improving the cable's resistance to twisting and stretching. Reasonable winding gap can ensure the close combination between steel strips and avoid deformation caused by thermal expansion and contraction, ensuring the stability and reliability of the cable under different environmental conditions.

[0019] The outer protective layer is made of thermoplastic elastomer material with a Shore hardness of 80, and contains 2% to 3% of ultraviolet absorber and 1% to 2% of antistatic agent. Compared with ordinary outer protective layer material, thermoplastic elastomer has the advantages of both rubber and plastic, with good elasticity, flexibility, wear resistance and chemical corrosion resistance. The ultraviolet absorber can effectively absorb ultraviolet rays in sunlight, preventing the outer protective layer from aging and prolonging the outdoor service life of the cable; the antistatic agent reduces the surface resistance of the material, preventing the accumulation of static electricity and reducing the safety hazards and effects on the appearance and performance of the cable caused by static electricity.

[0020] The semiconductive shielding layer arranged between the insulation layer and the inner protective layer is made of polyethylene material filled with carbon black, with a volume resistivity of 1*10 2 Ω*m to 1*10 3 Ω*m and a thickness of 0.5 mm. Compared with the conventional cable, the design can more effectively homogenize the electric field and prevent the electric field from concentrating to cause partial discharge of the insulation layer, thereby protecting the insulation layer, greatly prolonging the service life of the cable and improving the safety and stability of the cable operation. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 The utility model relates to a kind of flame-retardant environment-friendly crosslinked polyethylene insulated steel-tape armored heavy power cable

[0022] In the drawing: 1, conductor, 2, insulation layer, 3, inner protective layer, 4, steel-tape armored layer, 5, outer protective layer, 6, semiconductive shielding layer. DETAILED DESCRIPTION

[0023] The technical scheme in the embodiments of the utility model will be described completely in conjunction with the drawings in the embodiments of the utility model.

[0024] As Figure 1 Indicated, a kind of flame-retardant environment-friendly crosslinked polyethylene insulated steel-tape armored heavy power cable, including conductor 1, it is characterized in that, the conductor 1 uses oxygen-free copper material, and the single filament diameter range of the conductor 1 is 0.3 mm to 0.5 mm, and multiple single filaments are stranded pitch ratio between 18 and 22;The conductor 1 is sequentially provided with insulation layer 2, inner protective layer 3, steel-tape armored layer 4 and outer protective layer 5 outward.

[0025] The insulation layer 2 is crosslinked polyethylene material, and its preparation raw material includes, by weight parts: crosslinked polyethylene resin 100 parts, flame retardant 30 parts, plasticizer 10 parts, antioxidant 2 parts, coupling agent 1 part;The flame retardant is the compound of phosphorus-nitrogen system intumescent flame retardant and aluminum hydroxide, and the mass ratio of phosphorus-nitrogen system intumescent flame retardant and aluminum hydroxide is 2:3;The thickness of the crosslinked polyethylene insulation layer is between 3 mm and 5 mm.

[0026] The inner protective layer 3 uses polyolefin material, and its density range is 0.92 g / cm 3 To 0.94 g / cm 3, and add nano inorganic filler with mass fraction of 3% to 5%, the nano inorganic filler is the mixture of nanometer montmorillonite and nanometer titanium dioxide according to mass ratio 3:2.

[0027] The steel-tape armored layer 4 is composed of two layers of galvanized steel strips, and the thickness of the two layers of galvanized steel strips is 0.5 mm and 0.6 mm respectively, and the winding direction of the two layers of steel strips is opposite, and the winding gap is 0.2 mm.

[0028] The outer protective layer 5 is a thermoplastic elastomer material with a Shore hardness of 80, and the outer protective layer is added with an ultraviolet absorber with a mass fraction of 2% to 3% and an antistatic agent with a mass fraction of 1% to 2%.

[0029] The semiconductive shielding layer 6 between the insulating layer 2 and the inner protective layer 3 is made of a carbon black filled polyethylene material with a volume resistivity of 1×10²Ω·m to 1×10³Ω·m and a thickness of 0.5 mm.

[0030] The specific implementation method is as follows: first, high-purity oxygen-free copper is processed into copper wire with a single wire diameter of 0.3 mm to 0.5 mm, and the conductor 1 is twisted to have a pitch diameter ratio of 18 to 22; then, the raw materials such as 100 parts by weight of crosslinked polyethylene resin and 30 parts by weight of flame retardant compounded in a specific ratio are mixed and extruded to form an insulating layer 2 with a thickness of 3 mm to 5 mm on the surface of the conductor 1; the carbon black filled polyethylene material with a volume resistivity of 1×10²Ω·m to 1×10³Ω·m is extruded to form a semiconductive shielding layer 6 with a thickness of 0.5 mm outside the insulating layer 2; the polyolefin material with a density of 0.92 g / cm³ to 0.94 g / cm³ is selected, and the nanoscale inorganic filler is added and mixed to form an inner protective layer 3 by extrusion; then, the galvanized steel strips with thicknesses of 0.5 mm and 0.6 mm are wound in opposite directions with a gap of 0.2 mm outside the inner protective layer 3 to form a steel strip armor layer 4; finally, the thermoplastic elastomer material with a Shore hardness of 80 and added with an ultraviolet absorber and an antistatic agent is extruded to form an outer protective layer 5 outside the steel strip armor layer 4.

Claims

1. A flame-retardant, environmentally friendly, cross-linked polyethylene insulated steel-tape armored heavy power cable comprising a conductor (1), characterized in that, The conductor (1) is made of oxygen-free copper material, the single wire diameter of the conductor (1) ranges from 0.3 mm to 0.5 mm, and the multiple single wire stranded joint diameter ratio ranges from 18 to 22; the conductor (1) is sequentially provided outward with an insulation layer (2), an inner protective layer (3), a steel tape armored layer (4) and an outer protective layer (5).

2. A flame retardant environment-friendly cross-linked polyethylene insulated steel tape armored heavy power cable according to claim 1, characterized in that, The steel tape armored layer (4) is composed of two layers of galvanized steel tapes, the thickness of the two layers of galvanized steel tapes is 0.5 mm and 0.6 mm respectively, the winding directions of the two layers of steel tapes are opposite, and the winding gap is 0.2 mm.

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