Flame-retardant fireproof medium-voltage cable

Abstract

The utility model relates to the technical field of cables, in particular to a flame-retardant and fire-resistant medium-voltage cable which comprises a plurality of core wires, a wrapping layer, an oxygen barrier layer, an armor layer and a sheath layer, the wrapping layer, the oxygen barrier layer, the armor layer and the sheath layer sequentially wrap the peripheries of the plurality of core wires, and filling ropes are filled among the plurality of core wires. Each core wire comprises a conductor, an insulating layer, a buffer layer and a metal shielding layer, wherein the insulating layer, the buffer layer and the metal shielding layer sequentially wrap the conductor. The buffer layer enables the whole insulating core wire to play a role in protecting the insulating layer when the metal shielding layer is lapped on the whole insulating core wire. An electromagnetic field caused when the cable is powered on is shielded in the core wire through the metal shielding layer, so that electromagnetic interference generated to the outside is reduced. The oxygen barrier layer can prevent flames from damaging the inner structure of the cable core and can reduce volatilization of combustible gas in the cable core, and the armor layer can ensure the characteristics of shock resistance, tensile resistance, pressure resistance, biological prevention and the like of the cable, so that the cable has the advantages of flame retardance, fire resistance, durability, reliability, long service life and the like, and meets the use performance requirements of the medium-voltage cable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cables, in particular to a flame-retardant and fire-resistant medium-voltage cable. BACKGROUND

[0002] Flame-retardant and fire-resistant cables have been used in more and more occasions. With the increasing use year by year, the safety performance of the cable during operation, energy saving and consumption reduction, and the service life of the cable are also concerned. In particular, in the cable-intensive laying place, the temperature released by the cable during operation can cause the cable insulation material to accelerate aging, the service life of the cable is low, and fire is prone to occur. At the same time, the traditional medium-voltage cable has a large amount of partial discharge, which can also accelerate the aging of the cable insulation, the service life of the cable is low, and these factors put forward higher requirements on the halogen-free low-smoke flame-retardant performance of the medium-voltage cable. CONTENT OF THE INVENTION

[0003] In order to solve the above technical problems, the present application provides a flame-retardant and fire-resistant medium-voltage cable, which comprises a plurality of core wires, a wrapping layer, an oxygen barrier layer, an armor layer and a sheath layer which are sequentially wrapped outside the plurality of core wires, and a filling rope filled between the plurality of core wires, wherein the core wire comprises a conductor, an insulation layer, a buffer layer and a metal shielding layer which are sequentially wrapped around the conductor.

[0004] Preferably, the insulation layer comprises a first shielding layer, an insulation wrapping layer and a second shielding layer.

[0005] Preferably, the buffer layer is wrapped by a semi-conductive nylon belt.

[0006] Preferably, the metal shielding layer is wrapped by a copper belt.

[0007] Preferably, the filling rope is a halogen-free, smoke-free and alkali-free glass fiber rope.

[0008] Preferably, the wrapping layer is wrapped by a halogen-free, smoke-free and alkali-free glass fiber belt, and the wrapping overlap coverage rate is greater than 20%.

[0009] Preferably, the oxygen barrier layer is extruded by a ceramicized polyolefin fire-resistant material.

[0010] Preferably, the armor layer is wrapped by a galvanized steel belt.

[0011] From the above, the application can obtain the following beneficial effects: the filling rope is filled between the plurality of core wires, the core wire comprises a conductor, an insulating layer, a buffer layer and a metal shielding layer which are sequentially wrapped on the conductor. The buffer layer protects the insulating layer when the metal shielding layer is wrapped around the insulating core wire. The electromagnetic field caused by the energization of the cable is shielded in the core wire by the metal shielding layer to reduce the electromagnetic interference generated to the outside, and also limits the influence of the external electromagnetic field on the inside. The oxygen barrier layer forms a dense oxygen barrier layer under the condition of flame burning, which can prevent the flame from damaging the internal structure of the cable core, and also can reduce the volatilization of the combustible gas in the cable core, thereby reducing the corresponding burning temperature. The armor layer can ensure the shock resistance, tensile resistance, compression resistance, biological resistance and other properties of the cable, so that the cable has the advantages of flame-retardant fire-resistant, durable and reliable, long service life and the like, and meets the performance requirements of the medium voltage cable. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application or the prior art. Obviously, the drawings in the following description are only part of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0013] Fig. 1 The structure diagram of the flame-retardant fire-resistant medium voltage cable of the embodiment of the present application;

[0014] Fig. 2 The core wire schematic diagram of the flame-retardant fire-resistant medium voltage cable of the embodiment of the present application. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0016] EMBODIMENT

[0017] In order to solve the above technical problems, the embodiment provides a flame-retardant fire-resistant medium voltage cable, which comprises Figs. 1-2As shown, including several core wires 10, the wrapping layer 20, oxygen barrier layer 30, armor layer 40 and sheath layer 50 are sequentially wrapped outside the several core wires 10, and the filling rope 60 is filled between the several core wires 10. The core wire 10 includes a conductor 11, an insulating layer 12, a buffer layer 13 and a metal shielding layer 14 which are sequentially wrapped on the conductor 11. The buffer layer 13 protects the insulating layer when the entire insulated core wire 10 is wrapped around the metal shielding layer 14. The electromagnetic field caused by the energization of the cable is shielded in the core wire 10 by the metal shielding layer 14 to reduce the electromagnetic interference generated to the outside, and also limits the influence of the external electromagnetic field on the inside. The metal shielding layer 14 has the characteristics of homogenizing the electric field, preventing axial discharge, lightning protection, etc. The oxygen barrier layer 30 forms a dense oxygen barrier layer under the condition of flame burning, which can prevent the flame from damaging the internal structure of the cable core, and also can reduce the volatilization of the combustible gas in the cable core, thereby reducing the corresponding combustion temperature. The armor layer 40 can ensure the shock resistance, tensile resistance, compression resistance, biological resistance and other properties of the cable, so that the cable has the advantages of flame retardant, fire resistance, durability, reliability and long service life, and meets the performance requirements of medium voltage cables.

[0018] Specifically, the insulating layer 12 includes a first shielding layer 121, an insulating wrapping layer 122 and a second shielding layer 123. In some embodiments, the insulating wrapping layer 122 is made of pp extrusion molding, and the insulating layer 12 has a three-layer structure to make the cable have the characteristics of wear resistance, corrosion resistance and long service life.

[0019] In the above scheme, the buffer layer 13 is wrapped by a semi-conductive nylon belt. The semi-conductive nylon belt is wrapped for two layers, and when the metal shielding layer 14 is wrapped, the buffer layer 13 protects the insulating layer 12.

[0020] Further, the metal shielding layer 14 is wrapped by a copper belt. The electromagnetic field caused by the energization of the cable is shielded in the insulated wire core by the metal shielding layer 14 to reduce the electromagnetic interference generated to the outside, and also limits the influence of the external electromagnetic field on the inside. The metal shielding layer 14 has the characteristics of homogenizing the electric field, preventing axial discharge, lightning protection, etc.

[0021] Further, the filling rope 60 is a halogen-free, smoke-free and alkali-free glass fiber rope. Under the condition of flame burning, the air content in the cable core is reduced, and the corresponding combustion temperature is reduced.

[0022] Further, the wrapping layer 20 is wrapped by a halogen-free, smoke-free and alkali-free glass fiber belt, and the wrapping overlap coverage rate is greater than 20%. The cable inside is tightly rounded to ensure the integrity under the condition of flame burning, and is not powdery.

[0023] The oxygen barrier layer 30 is formed by extrusion of ceramicized polyolefin fireproof material. Under the condition of flame combustion, a dense oxygen barrier layer is formed, which can prevent the flame from damaging the internal structure of the cable core and ensure the integrity of the cable core, and can also reduce the volatilization of combustible gas inside the cable core, thereby reducing the corresponding combustion temperature.

[0024] The armored layer 40 is formed by winding a galvanized steel belt. A high-strength galvanized steel belt is used, and a gap type double steel belt winding method is used, and the winding gap of the steel belt is not greater than 50% of the width of the steel belt, which ensures the shock resistance, tensile resistance, compression resistance, and biological resistance of the cable.

[0025] The sheath layer 50 is made of halogen-free low-smoke flame-retardant polyolefin sheath material that meets the standards of oxygen index, smoke density, and shell formation and complies with the EU ROHS directive. There is no obvious combustion dripping during the flame combustion process, and the B1 level of use performance target is achieved.

[0026] In some embodiments, the conductor 11 can also have a special-shaped conductor structure, the single-wire contact area of the conductor 11 is large, and the eddy current loss is small. Under the same laying conditions, the outer diameter of the special-shaped conductor structure is smaller than that of the traditional twisted conductor, the overall cable outer diameter is smaller, the cable spacing is larger, the heat dissipation is good, the current-carrying capacity is improved, the conductor has no burr, the gap between single wires is small, the partial discharge is low, the cable operation failure rate is low, and the cable service life is improved.

[0027] In summary, the scheme of the present application is provided by the wrapping layer, the oxygen barrier layer, the armored layer and the sheath layer which are sequentially wrapped outside the plurality of core wires, and the filling rope is filled between the plurality of core wires. The core wire includes a conductor, an insulation layer, a buffer layer and a metal shielding layer which are sequentially wrapped on the conductor. The buffer layer protects the insulation layer when the metal shielding layer is wrapped around the entire insulated core wire. The electromagnetic field caused by the cable when it is energized is shielded in the core wire to reduce the electromagnetic interference to the outside, and also limits the influence of the external electromagnetic field on the inside. The oxygen barrier layer forms a dense oxygen barrier layer under the condition of flame combustion, which can prevent the flame from damaging the internal structure of the cable core, and can also reduce the volatilization of combustible gas inside the cable core, thereby reducing the corresponding combustion temperature. The armored layer can ensure the shock resistance, tensile resistance, compression resistance, biological resistance and other characteristics of the cable, so that the cable has the advantages of flame-retardant fire resistance, durability and reliability, long service life, and meets the performance requirements of medium-voltage cables.

[0028] The above-described embodiments do not constitute a limitation on the protection scope of the technical solution. Any modifications, equivalent replacements and improvements made within the spirit and principles of the above-described embodiments shall be included in the protection scope of the technical solution.

Claims

1. A fire-retardant, fire-resistant medium voltage cable, characterized in that: The cable comprises a plurality of core wires (10), a wrapping layer (20), an oxygen barrier layer (30), an armor layer (40) and a sheath layer (50) which are sequentially wrapped around the plurality of core wires (10), and a filling rope (60) filled between the plurality of core wires (10), wherein the core wire (10) comprises a conductor (11), an insulating layer (12), a buffer layer (13) and a metal shielding layer (14) which are sequentially wrapped around the conductor (11); the buffer layer (13) is formed by wrapping two layers of semi-conductive nylon belts, the armor layer (40) is formed by wrapping a galvanized steel belt, the filling rope (60) is a halogen-free, smoke-free and alkali-free glass fiber rope, the wrapping layer (20) is formed by wrapping a halogen-free, smoke-free and alkali-free glass fiber belt, and the wrapping overlap coverage rate is greater than 20%.

2. A flame and fire retardant medium voltage cable according to claim 1, characterized in that: The insulating layer (12) comprises a first shielding layer (121), an insulating wrapping layer (122) and a second shielding layer (123).

3. The fire-retardant, fire-resistant medium voltage cable of claim 1, wherein: The metal shielding layer (14) is formed by wrapping a copper belt.

4. The fire-retardant, fire-resistant medium voltage cable of claim 1, wherein: The oxygen barrier layer (30) is formed by extruding a ceramicized polyolefin fire-resistant material.

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