A flame retardant insulated cable

Abstract

The utility model discloses a flame-retardant insulated cable, comprising a cable core unit, and an aluminum sheath, an insulating heat insulation layer, an armor layer, and a sheath layer sequentially wrapped around the outer side of the cable core unit; the insulating heat insulation layer comprises a composite heat insulation layer, a first polyimide film layer adhered to one side of the composite heat insulation layer, and a second polyimide film layer adhered to the other side of the composite heat insulation layer. The flame-retardant insulated cable of the utility model has good insulation and flame retardant properties, and has good fire resistance and anti-aging effects, thereby extending its service life.

Description

Technical Field

[0001] The utility model relates to the technical field of cables, in particular to a flame-retardant insulated cable. Background Art

[0002] With the vigorous development of modern industry, the demand for power cable supply has grown rapidly. Transmission cables are called the "arteries and nerves" of the national economy, and the degree of urban cabling has become an important indicator of urban modernization and living environment. In order to meet the demand for electricity and the stability and economy of power transmission, the power grid is constantly developing in the direction of large capacity and high voltage, which will put forward higher requirements on the transmission and reliability of power cables, thereby accelerating the aging of power cables, such as thermal, electrical and mechanical aging.

[0003] Cables are usually rope-like cables twisted together by several or several groups of wires (at least two in each group). Each group of wires is insulated from each other and often twisted around a center. The entire outside is covered with a highly insulating covering layer. Cables have the characteristics of being energized inside and insulated outside. The insulation performance of the insulating material after aging shows a certain degree of deterioration, such as hardening, brittleness, decreased insulation resistance, and even cracking. After aging of the insulating material, the insulation capacity decreases rapidly, and the resistance of the conductor (copper core) increases. According to Joule's law Q=I2Rt, when the current and time remain unchanged, the resistance increases, resulting in increased heat generation and increased temperature, which accelerates the aging of the insulating material. As the degree of aging gradually increases, the insulating material loses its insulating performance and insulation breakdown occurs. After the breakdown, the metal wire core of the cable is connected through direct contact or arc, resulting in a short circuit. The local high temperature formed or the heat accumulated in a short period of time ignites the cable insulation components, and then ignites the entire cable and nearby combustibles, causing a fire. Utility Model Content

[0004] Based on this, the purpose of the utility model is to provide a flame-retardant insulated cable, which has good insulation and flame-retardant properties, good fire resistance and anti-aging effects, and a long service life.

[0005] The purpose of the utility model is achieved through the following technical solutions:

[0006] A flame-retardant insulated cable comprises a cable core unit, and an aluminum sheath, an insulating heat insulation layer, an armor layer, and a sheath layer which are sequentially wrapped around the outer side of the cable core unit; the insulating heat insulation layer comprises a composite heat insulation layer, a first polyimide film layer adhered to one side of the composite heat insulation layer, a second polyimide film layer adhered to the other side of the composite heat insulation layer, and a mica paper layer adhered to the first polyimide film layer on a side away from the composite heat insulation layer.

[0007] Furthermore, the composite heat-insulating layer is a composite layer of silica aerogel and alkali-resistant glass fiber mesh cloth, and the silica aerogel is attached to both sides of the glass fiber cloth layer by molding.

[0008] Furthermore, the cable core unit is composed of two-core, three-core, four-core, five-core or seven-core wire cores; the wire core includes a copper conductor formed by twisting multiple soft copper wires, an inner shielding layer and an inner insulating layer, the inner shielding layer is wrapped around the outside of the copper conductor, and the inner insulating layer is wrapped around the outside of the inner shielding layer.

[0009] Furthermore, the gaps between the wire cores are filled with flame retardant fillers, which are glass fibers or carbon fibers.

[0010] Furthermore, the inner shielding layer is formed by wrapping a single layer of aluminum-plastic composite tape on the outer side of the core in an overlapping manner. The thickness of the aluminum-plastic composite tape is 0.05 to 0.1 mm, and the wrapping overlap ratio is 20 to 30%.

[0011] Furthermore, the inner insulating layer is formed by extruding ceramic silicone rubber on the inner shielding layer.

[0012] Furthermore, the armor layer is formed by longitudinally overlapping steel-plastic composite tapes, and the thickness of the steel-plastic composite tapes is 0.1 to 0.3 mm and the width is 15 to 30 mm.

[0013] Furthermore, the surface of the sheath layer is coated with a waterproof coating.

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

[0015] The cable core unit in the flame-retardant insulated cable of the utility model is provided with an inner shielding layer and an inner insulating layer. The inner insulating layer is made of ceramic silicone rubber and has good high temperature resistance, insulation and flame retardant effects. The gaps between the wire cores are filled with glass fiber or carbon fiber flame retardant filler, which has light weight and low density, and is conducive to reducing the weight of the cable.

[0016] The cable core jacket unit in the utility model flame-retardant insulated cable is provided with an aluminum sheath to protect the cable from mechanical damage and electromagnetic interference; an aerogel + glass fiber cloth composite insulation layer is provided, and insulating polyimide films are adhered to both sides of the composite insulation layer, so that the thermal insulation effect is good; the armor layer can improve the compression resistance of the cable, and ensure that the cable has good tensile bending resistance and high temperature flame retardant performance when subjected to external force; the sheath layer and the waterproof coating improve the wear resistance and waterproofness of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic structural diagram of a flame-retardant insulated cable is provided for one embodiment of the present invention;

[0018] Figure 2A schematic diagram of the cross-sectional structure of an insulating and heat-insulating layer in a flame-retardant insulated cable is provided for one embodiment of the present invention;

[0019] Figure 3 A schematic diagram of the layer structure of the insulating and heat-insulating layer in a flame-retardant insulated cable is provided for one embodiment of the present invention;

[0020] Reference numerals:

[0021] 10-cable core unit; 11-copper conductor; 12-inner shielding layer; 13-inner insulation layer;

[0022] 20-aluminum sheath;

[0023] 30-insulating heat insulation layer; 31-composite heat insulation layer; 311-silicon dioxide aerogel; 312-alkali-resistant glass fiber mesh cloth; 32-first polyimide film layer; 33-second polyimide film layer; 34-mica paper layer;

[0024] 40- armor layer;

[0025] 50-sheath layer;

[0026] 60-Waterproof coating. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] In the description of the present invention, it should be noted that the terms "vertical direction", "upper", "lower", "horizontal" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, or a connection through an intermediate medium, or the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] See also Figures 1 to 3 As shown, an embodiment of the utility model provides a flame retardant insulated cable, including a cable core unit 10 and a jacket unit.

[0031] In this embodiment, the cable core unit 10 is composed of two-core, three-core, four-core, five-core or seven-core wire cores; the wire core includes a copper conductor 11 formed by twisting multiple soft copper wires, an inner shielding layer 12 and an inner insulating layer 13, the inner shielding layer 12 is wrapped around the outside of the copper conductor 11, and the inner insulating layer 13 is wrapped around the outside of the inner shielding layer 12.

[0032] The gaps between the wire cores are filled with flame retardant fillers, which are glass fibers or carbon fibers. Glass fibers and carbon fibers are light in weight and low in density, and are useful as flame retardant fillers to reduce the weight of the cable. In this embodiment, the gaps between the wire cores are filled with carbon fibers.

[0033] The inner shielding layer 12 is made of a single layer of aluminum-plastic composite tape wrapped around the outer side of the wire core, the thickness of the aluminum-plastic composite tape is 0.05-0.1 mm, and the wrapping overlap rate is 20-30%. Specifically, in this embodiment, the thickness of the aluminum-plastic composite tape is 0.1 mm, and the wrapping overlap rate is 30%.

[0034] The inner insulating layer 13 is formed by extruding ceramic silicone rubber on the inner shielding layer 12. The ceramic silicone rubber insulating layer has an insulation resistance of >0.3MΩ and a withstand voltage of ≥1000V / AC after being stored at a high temperature of 400-1100°C for 1 hour, and has good insulation performance.

[0035] In this embodiment, the outer jacket unit includes an aluminum sheath 20 , an insulating and heat-insulating layer 30 , an armor layer 40 , and a sheath layer 50 which are sequentially wrapped around the outer side of the cable core unit 10 .

[0036] In this embodiment, the aluminum sheath 20 serves as the outer sheath of the cable, and is mainly used to protect the cable from damage by the external environment. The aluminum sheath 20 can also provide electromagnetic shielding for the cable, prevent external electromagnetic interference from affecting the cable signal transmission, and ensure the stability and reliability of power transmission.

[0037] In this embodiment, the insulating heat insulation layer 30 includes a composite heat insulation layer 31, a first polyimide film layer 32 adhered to one side of the composite heat insulation layer 31, and a second polyimide film layer 33 adhered to the other side of the composite heat insulation layer 31. A mica paper layer 34 is adhered to the side of the first polyimide film layer 32 away from the composite heat insulation layer 31.

[0038] The composite heat-insulating layer 31 is a composite layer of silica aerogel 311 and alkali-resistant glass fiber mesh cloth 312 , and the silica aerogel 311 is attached to both sides of the glass fiber cloth layer by molding.

[0039] Silica aerogel 311 has ultra-low density and thermal conductivity, and the thermal conductivity can reach 0.013-0.016W / (m·K), which is lower than the thermal conductivity of static air (0.024W / (m·K)) and 2-3 orders of magnitude lower than the corresponding inorganic insulating materials. Glass fiber cloth has good insulation, strong heat resistance, good corrosion resistance, and high mechanical strength. When combined with silica aerogel 311, the mechanical strength of silica aerogel 311 can be improved.

[0040] Mica is resistant to high temperatures, flames, and insulation. Mica has a low thermal conductivity, generally about 0.2W / m·K; Mica also has excellent high temperature resistance, can withstand open flames, and can withstand temperatures of 600-800℃ for a long time.

[0041] Thermosetting polyimide has excellent thermal stability, chemical stability and mechanical properties, and has certain flame retardancy.

[0042] In this embodiment, the armor layer 40 is formed by longitudinally overlapping steel-plastic composite tapes, and the thickness of the steel-plastic composite tapes is 0.1-0.3 mm, and the width is 15-30 mm. The armor layer 40 can improve the compression resistance of the cable, and ensure that the cable has good tensile bending resistance and high temperature flame retardant performance when subjected to external forces. Specifically, in this embodiment, the thickness of the steel-plastic composite tape is 0.2 mm, and the width is 25 mm.

[0043] In this embodiment, the sheath layer 50 is made of thermoplastic polyurethane elastomer material, and the surface of the sheath layer 50 is coated with a waterproof coating 60. The sheath layer 50 and the waterproof coating 60 improve the wear resistance and waterproofness of the cable, and further improve the service life of the cable.

[0044] The above only expresses the preferred technical solution of the utility model, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, and the utility model is also intended to include these modifications and modifications.

Claims

1. A flame retardant insulated cable, characterized in that: It includes a cable core unit, and an aluminum sheath, an insulating layer, an armor layer, and a sheath layer wrapped around the outside of the cable core unit in sequence; the insulating layer includes a composite insulating layer, a first polyimide film layer adhered to one side of the composite insulating layer, and a second polyimide film layer adhered to the other side of the composite insulating layer.

2. The flame-retardant insulated cable according to claim 1, characterized in that: The composite heat-insulating layer is a composite layer of silica aerogel and alkali-resistant glass fiber mesh cloth, and the silica aerogel is attached to both sides of the glass fiber cloth layer by molding.

3. The flame-retardant insulated cable according to claim 1, characterized in that: A mica paper layer is bonded to a side of the first polyimide film layer away from the composite heat insulation layer.

4. The flame-retardant insulated cable according to claim 1, characterized in that: The cable core unit is composed of two-core, three-core, four-core, five-core or seven-core wire cores; the wire core includes a copper conductor formed by twisting multiple soft copper wires, an inner shielding layer and an inner insulating layer, the inner shielding layer is wrapped around the outside of the copper conductor, and the inner insulating layer is wrapped around the outside of the inner shielding layer.

5. The flame-retardant insulated cable according to claim 4, characterized in that: The gaps between the wire cores are filled with flame retardant fillers, which are glass fibers or carbon fibers.

6. The flame-retardant insulated cable according to claim 4, characterized in that: The inner shielding layer is wrapped around the outer side of the core with a single layer of aluminum-plastic composite tape, the thickness of the aluminum-plastic composite tape is 0.05-0.1 mm, and the wrapping overlap rate is 20-30%.

7. The flame-retardant insulated cable according to claim 4, characterized in that: The inner insulating layer is formed by extruding ceramic silicone rubber on the inner shielding layer.

8. The flame-retardant insulated cable according to claim 1, characterized in that: The armor layer is formed by longitudinally overlapping steel-plastic composite tapes, and the thickness of the steel-plastic composite tapes is 0.1-0.3 mm and the width is 15-30 mm.

9. The flame-retardant insulated cable according to claim 1, characterized in that: The surface of the sheath layer is coated with a waterproof coating.

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