110kV crosslinked polyethylene insulated low-smoke halogen-free flame-retardant power cable

Abstract

The utility model discloses a 110kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable, which relates to the field of cables and comprises a conductor, a semi-conductive band shielding layer fixedly mounted on the conductor, a conductor shielding layer fixedly mounted on the semi-conductive band shielding layer, an insulating layer fixedly mounted on the conductor shielding layer and an insulating shielding layer fixedly mounted on the insulating layer. And a semi-conductive water-blocking buffer layer is fixedly arranged on the insulation shielding layer. The low-smoke halogen-free high-voltage cable material has excellent mechanical properties, the tensile strength of a finished cable sheath is larger than or equal to 12.5 MPa, the elongation at break is larger than or equal to 300%, and the low-smoke halogen-free high-voltage cable material is good in cracking resistance, high in light transmittance, free of dripping after combustion and more environmentally friendly; the insulation resistance of the sheath is not obviously reduced along with the increase of time, the electrical property of the sheath is relatively stable, and the potential safety hazards of personnel and lines caused by the breakdown of the non-metal sheath of the cable by the induced voltage of the metal aluminum sheath in the operation process of the cable are avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of cables, in particular to a 110kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable. Background Art

[0002] Cables include power cables, control cables, compensation cables, shielded cables, high-temperature cables, computer cables, signal cables, coaxial cables, fire-resistant cables, marine cables, mining cables, aluminum alloy cables, etc. They are all composed of single or multiple strands of wire and an insulation layer, and are used to connect circuits, electrical appliances, etc.

[0003] In the existing technology, the outer sheath of ultra-high voltage cables generally adopts high-electricity PVC or high-electricity PE sheath materials. The PE sheath has certain resistance to low temperatures and chemical solvents, but the PE material is flammable. If it is necessary to use the polyethylene outer sheathed high-voltage cable in tunnels or shafts, corresponding additional flame retardant and fire prevention measures should be taken; the PVC sheath has certain flame retardant properties, but it is toxic when burned and produces a large amount of smoke.

[0004] In the revision of the national standard GB / T11017 "Rated voltage 110kV (Um=126kV) cross-linked polyethylene insulated power cable and its accessories", ST12 low-smoke halogen-free cable material was added. Therefore, it is of great significance to develop a low-smoke halogen-free flame-retardant high-voltage power cable. Utility Model Content

[0005] The purpose of the utility model is to provide a 110kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable to solve the problems raised in the above background technology, such as the PE material is flammable, and if the polyethylene outer sheathed high-voltage cable needs to be used in tunnels or shafts, corresponding additional flame retardant and fireproof measures should be taken; the PVC sheath has certain flame retardant properties, but is toxic when burned and produces a large amount of smoke.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A 110kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable comprises a conductor, a semi-conductive tape shielding layer is fixedly mounted on the conductor, a conductor shielding layer is fixedly mounted on the semi-conductive tape shielding layer, an insulating layer is fixedly mounted on the conductor shielding layer, an insulating layer is fixedly mounted on the insulating layer, a semi-conductive resistive water buffer layer is fixedly mounted on the insulating shielding layer, a metal sheath is fixedly mounted on the semi-conductive resistive water buffer layer, an anti-corrosion layer is fixedly mounted on the metal sheath, a non-metallic sheath is fixedly mounted on the anti-corrosion layer, and an outer conductive layer is fixedly mounted on the non-metallic sheath.

[0008] Preferably, the conductor is a copper conductor with a diameter of 2 mm, the semi-conductive tape shielding layer is a wrapped semi-conductive Tetoron tape, and the thickness of the semi-conductive tape shielding layer is 0.2 to 0.3 mm.

[0009] Preferably, the conductor shielding layer is an extruded ultra-smooth semi-conductive conductor shielding material, and the thickness of the conductor shielding layer is 0.1 to 0.3 mm.

[0010] Preferably, the insulating layer is an extruded cross-linked polyethylene ultra-clean insulating material with a thickness of 0.2 to 0.4 mm, and the insulating shielding layer is an extruded ultra-smooth semi-conductive insulating shielding material with a thickness of 0.3 to 0.5 mm.

[0011] Preferably, the semiconductive water-blocking buffer layer is a wrapped semiconductive water-blocking tape, the thickness of the semiconductive water-blocking buffer layer is 1 mm, and the metal sleeve is a corrugated aluminum metal sleeve, the thickness of the metal sleeve is 1 to 1.5 mm.

[0012] Preferably, the anti-corrosion layer is asphalt, and the thickness of the anti-corrosion layer is 0.5 to 0.9 mm.

[0013] Preferably, the non-metallic sheath is a high electrical insulation grade halogen-free low-smoke flame-retardant sheath, the thickness of the non-metallic sheath is 0.3 to 0.5 mm, the outer conductive layer is graphite, and the thickness of the outer conductive layer is 0.2 to 0.6 mm.

[0014] The beneficial effects of the utility model are:

[0015] This low-smoke halogen-free ultra-high voltage cable material has excellent mechanical properties. The tensile strength of the finished cable sheath is ≥12.5MPa, the elongation at break is ≥300%, and it has good crack resistance, high light transmittance, no dripping after burning, and is more environmentally friendly. The insulation resistance of the sheath will not decrease significantly over time, and the electrical properties of the sheath are relatively stable, avoiding potential safety hazards to personnel and lines caused by the induced voltage of the metal aluminum sheath breaking through the non-metallic sheath of the cable during operation.

[0016] By controlling the volume resistivity, water content of the semi-conductive water buffer zone and the gap between the aluminum sheath trough and the semi-conductive water buffer layer, the potential difference between the cable insulation shielding layer and the metal sheath is avoided, which may cause erosion of the cable buffer layer, insulation shielding layer and metal sheath. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural schematic diagram of a 110kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable of the present invention.

[0018] In the figure: 100, conductor; 200, semi-conductive tape shielding layer; 300, conductor shielding layer; 400, insulation layer; 500, insulation shielding layer; 600, semi-conductive water-repellent buffer layer; 700, metal sheath; 800, anti-corrosion layer; 900, non-metallic sheath; 110, outer conductive layer. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0020] Reference Figure 1 A 110kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable includes a conductor 100, a semi-conductive tape shielding layer 200 is fixedly mounted on the conductor 100, a conductor shielding layer 300 is fixedly mounted on the semi-conductive tape shielding layer 200, an insulating layer 400 is fixedly mounted on the conductor shielding layer 300, an insulating layer 500 is fixedly mounted on the insulating layer 400, a semi-conductive water-repellent buffer layer 600 is fixedly mounted on the insulating shielding layer 500, a metal sheath 700 is fixedly mounted on the semi-conductive water-repellent buffer layer 600, an anti-corrosion layer 800 is fixedly mounted on the metal sheath 700. A non-metallic sheath 900 is fixedly installed on the anti-corrosion layer 800, and an outer conductive layer 110 is fixedly installed on the non-metallic sheath 900. The low-smoke halogen-free high-voltage cable material has excellent mechanical properties. The tensile strength of the finished cable sheath is ≥12.5MPa, the elongation at break is ≥300%, and it has good anti-cracking performance, high light transmittance, no dripping after burning, and is more environmentally friendly; the insulation resistance of the sheath will not decrease significantly with the increase of time, and the electrical properties of the sheath are relatively stable, avoiding the potential safety hazards to personnel and lines caused by the induced voltage of the metal aluminum sheath breaking through the non-metallic sheath of the cable during operation.

[0021] In an optional embodiment: the conductor 100 is a copper conductor, the diameter of the conductor 100 is 2 mm, the semi-conductive tape shielding layer 200 is a wrapped semi-conductive polytetramethylene tape, the thickness of the semi-conductive tape shielding layer 200 is 0.2 to 0.3 mm, the conductor 100 adopts a compressed conductor, a shaped wire conductor or a split conductor, the 20°C DC resistance meets the requirements of GB / T3956-2008, and the semi-conductive tape shielding layer 200 adopts double layers of semi-conductive polytetramethylene tape wrapped in an overlapping manner, and the overlap rate of each layer is ≥50%.

[0022] In an optional embodiment, the conductor shielding layer 300 is an extruded ultra-smooth semi-conductive conductor shielding material with a thickness of 0.1 to 0.3 mm. The insulation layer 400 is an extruded cross-linked polyethylene ultra-clean insulation material with a thickness of 0.2 to 0.4 mm. The insulation shielding layer 500 is an extruded ultra-smooth semi-conductive insulation shielding material with a thickness of 0.3 to 0.5 mm. The conductor shielding layer 300, the insulation layer 400, and the insulation shielding layer 500 are produced using a three-layer co-extrusion chemical cross-linking production line from Mylafil. The new screw design significantly eliminates areas that may produce amber or old glue. This increases production, shortens the residence time of the molten material, and reduces the thermal load of the molten material. The HSC high-stability traction machine is used, and the gears are in direct contact without gaps, regardless of forward or reverse drive, with constant gear tension, truly eliminating cable jitter. The EHT inlet heat treatment system uses cooled nitrogen to cool the first section of the vulcanized pipeline. The cross-linked wire core in hot melt state is cooled and shrinks, which is equivalent to producing a rubber band effect, ensuring the roundness of the cable and the insulation eccentricity ≤5%.

[0023] In an optional embodiment: the semiconducting water-blocking buffer layer 600 is a wrapped semiconducting water-blocking tape, the thickness of the semiconducting water-blocking buffer layer 600 is 1 mm, the metal sleeve 700 is a corrugated aluminum metal sleeve, the thickness of the metal sleeve 700 is 1 to 1.5 mm, the semiconducting water-blocking buffer layer 600 adopts a connected wrapping structure, and the gap rate is 0%-5%; the metal sleeve 700 adopts DC, high-voltage arc ignition metal argon arc welding technology, jaw traction, and the semi-finished product is nitrogen-filled to detect the weld quality.

[0024] In an optional embodiment, the anti-corrosion layer 800 is asphalt, and the thickness of the anti-corrosion layer 800 is 0.5 to 0.9 mm.

[0025] In an optional embodiment, the non-metallic sheath 900 is a high-electrical-insulation-grade, halogen-free, low-smoke, flame-retardant sheath with a thickness of 0.3 to 0.5 mm. The outer conductive layer 110 is graphite with a thickness of 0.2 to 0.6 mm. It should be noted that the non-metallic sheath 900 is extruded using a low-smoke, halogen-free screw with equal spacing and unequal depth. The screw is made of imported 38CrMoALA high-quality alloy steel, which is cut, ground, and then surface-nitrided for high hardness and wear and corrosion resistance. The screw compression ratio is controlled between 1.2 and 2.0. The extrusion temperatures of zone 1, zone 2, zone 3, zone 4, zone 5, zone 6, zone 7, flange, head 1, head 2, head 3, and head 4 are 135°C, 148°C, 150°C, 150°C, 150°C, 150°C, 150°C, 150°C, 150°C, 150°C, and 150°C respectively. The outer conductive layer 110 uses a water-soluble graphite coating machine to evenly and firmly coat the graphite on the non-metallic sheath 900.

[0026] Working principle of this utility model:

[0027] Conductor 100 utilizes compressed, shaped, or segmented conductors, with a 20°C DC resistance meeting the requirements of GB / T3956-2008. Semi-conductive tape shield 200 utilizes double layers of overlapping semi-conductive Tetoron tape, with each layer overlapped at ≥50%. Conductor shield 300, insulation layer 400, and insulation shield 500 are produced using a McLaffer three-layer co-extrusion chemical cross-linking production line. The innovative screw design significantly eliminates areas that could cause amber discoloration or stale rubber. This increases output, shortens melt residence time, and reduces the heat load on the molten material. The HSC high-stability puller ensures direct, gapless gear contact in both forward and reverse drive directions, ensuring constant gear tension and virtually eliminating cable vibration. The EHT inlet heat treatment system utilizes cooled nitrogen to cool the first section of the vulcanized pipe. The cross-linked hot melt core contracts upon cooling, creating a rubber band effect that ensures cable roundness and insulation eccentricity of ≤5%. The semi-conductive water-repellent buffer layer 600 utilizes a continuous wrapping structure with a gap ratio of 0%-5%. The metal sheath 700 utilizes DC, high-voltage arc-ignited metal argon arc welding technology, with jaw-type pulling, and semi-finished products are nitrogen-filled for weld quality inspection. The non-metallic sheath 900 is extruded using equidistant, unequal-depth, low-smoke, halogen-free screws. The screws are made of imported 38CrMoALA high-quality alloy steel, cut and ground, and then surface-nitrided for high hardness, wear resistance, and corrosion resistance. The screw compression ratio is controlled between 1.2 and 2.0. The extrusion temperatures of zone 1, zone 2, zone 3, zone 4, zone 5, zone 6, zone 7, flange, head 1, head 2, head 3, and head 4 are 135°C, 148°C, 150°C, 150°C, 150°C, 150°C, 150°C, 150°C, 150°C, 150°C, and 150°C respectively. The outer conductive layer 110 uses a water-soluble graphite coating machine to evenly and firmly coat the graphite on the non-metallic sheath 900.

[0028] The above are only preferred specific implementation methods of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A 110 kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable, comprising a conductor (100), characterized in that: A semiconductive tape shielding layer (200) is fixedly mounted on the conductor (100), a conductor shielding layer (300) is fixedly mounted on the semiconductive tape shielding layer (200), an insulating layer (400) is fixedly mounted on the conductor shielding layer (300), an insulating shielding layer (500) is fixedly mounted on the insulating layer (400), a semiconductive water-repellent buffer layer (600) is fixedly mounted on the insulating shielding layer (500), a metal sleeve (700) is fixedly mounted on the semiconductive water-repellent buffer layer (600), and the metal sleeve (700) is fixedly mounted on the metal sleeve (700). 00), an anti-corrosion layer (800) is fixedly installed on the anti-corrosion layer (800), a non-metallic sheath (900) is fixedly installed on the non-metallic sheath (900), and an outer conductive layer (110) is fixedly installed on the non-metallic sheath (900); the semi-conductive tape shielding layer 200 adopts a double-layer semi-conductive polytetramethylene tape overlapping wrapping, and the overlap rate of each layer is ≥50%; the semi-conductive water-repellent buffer layer 600 adopts a connected wrapping structure with a gap rate of 0%-5%, the outer conductive layer (110) is graphite, and the thickness of the outer conductive layer (110) is 0.2 to 0.6 mm.

2. The 110kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable according to claim 1, characterized in that: The conductor (100) is a copper conductor, the diameter of the conductor (100) is 2 mm, and the thickness of the semi-conductive tape shielding layer (200) is 0.2 to 0.3 mm.

3. The 110kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable according to claim 1, characterized in that: The conductor shielding layer (300) is an extruded ultra-smooth semi-conductive conductor shielding material, and the thickness of the conductor shielding layer (300) is 0.1 to 0.3 mm.

4. The 110kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable according to claim 1, characterized in that: The insulating layer (400) is an extruded cross-linked polyethylene ultra-clean insulating material, and the thickness of the insulating layer (400) is 0.2 to 0.4 mm. The insulating shielding layer (500) is an extruded ultra-smooth semi-conductive insulating shielding material, and the thickness of the insulating shielding layer (500) is 0.3 to 0.5 mm.

5. The 110kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable according to claim 1, characterized in that: The semiconductive water-blocking buffer layer (600) is a wrapped semiconductive water-blocking buffer tape, the thickness of the semiconductive water-blocking buffer layer (600) is 1 mm, the metal sleeve (700) is a corrugated aluminum metal sleeve, and the thickness of the metal sleeve (700) is 1 to 1.5 mm.

6. The 110 kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable according to claim 1, characterized in that: The anti-corrosion layer (800) is asphalt, and the thickness of the anti-corrosion layer (800) is 0.5 to 0.9 mm.

7. The 110 kV cross-linked polyethylene insulated low-smoke halogen-free flame-retardant power cable according to claim 1, characterized in that: The non-metallic sheath (900) is a high electrical insulation grade halogen-free, low-smoke, flame-retardant sheath, and the thickness of the non-metallic sheath (900) is 0.3 to 0.5 mm.

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