High-flame-retardant fireproof power cable

Abstract

The utility model relates to the technical field of cables, in particular to a high-flame-retardant fireproof power cable, which comprises a conductor core, a mica tape fireproof layer, a ceramic composite insulating layer, a flame-retardant filling layer, a metal composite shielding layer, a flame-retardant wrapping layer and a flame-retardant sheath layer which are sequentially arranged from inside to outside, and the two layers of mica tapes are bonded through a high-temperature-resistant adhesive. The high-flame-retardancy fireproof power cable has the advantages that the mica tape fireproof layer of the high-flame-retardancy fireproof power cable adopts a double-layer staggered and overlapped wrapping structure, and a high-temperature-resistant adhesive is combined, so that a compact insulation barrier is formed at high temperature, and the erosion of flame to the conductor cores is effectively delayed; meanwhile, the ceramic composite insulating layer is made of a ceramic high polymer material, can be quickly sintered into a hard ceramic body in case of fire, and has a synergistic effect with the mica tape fire-resistant layer to doubly block high temperature and oxygen permeation, so that the cable can still maintain long-time power-on capability under the fire condition, and the fire resistance is far better than that of a common fire-resistant cable.

Description

A high flame-retardant and fire-resistant power cable Technical Field

[0001] This utility model relates to the field of cable technology, and in particular to a high flame-retardant and fire-resistant power cable. Background Technology

[0002] As the core carrier for transmitting electrical energy, power cables play an irreplaceable role in key areas such as energy transmission, rail transportation, and high-rise buildings. Their core structure is typically composed of multiple layers, including conductors, insulation, shielding, and sheathing, and must withstand the multiple challenges of high voltage, high current, and complex environments over long periods. With the development of modern power systems towards high power density and long-distance transmission, the fire resistance and flame retardancy of cables have become critical technical indicators concerning the safety of life and property.

[0003] In existing technologies, mica tape refractory layers are mostly designed as single-layer continuous winding structures. This design exposes significant structural defects under sustained high-temperature conditions. Under prolonged thermal shock, single-layer mica tape refractory layers are prone to internal stress concentration due to the anisotropic coefficient of thermal expansion of the material itself. As the temperature continues to act, cracks propagate along the mica sheet interface, forming penetrating macroscopic cracks, causing the refractory layer to lose its effective isolation from the internal conductors. Summary of the Invention

[0004] The purpose of this invention is to at least solve one of the aforementioned technical defects.

[0005] Therefore, one objective of this utility model is to provide a high flame-retardant and fire-resistant power cable to solve the problems mentioned in the background art and overcome the shortcomings of the existing technology.

[0006] To achieve the above objectives, one embodiment of this utility model provides a high flame-retardant and fire-resistant power cable, comprising, from the inside out, a conductor core, a mica tape fire-resistant layer, a ceramicized composite insulation layer, a flame-retardant filling layer, a metal composite shielding layer, a flame-retardant wrapping layer, and a flame-retardant sheath layer. The mica tape fire-resistant layer adopts a double-layer overlapping wrapping structure, with the two layers of mica tape bonded together by a high-temperature resistant adhesive. The ceramicized composite insulation layer is composed of a ceramicizable polymer material and is coated onto the outer surface of the mica tape fire-resistant layer by an extrusion process. The flame-retardant filling layer adopts an inorganic flame-retardant fiber braided structure and is wrapped onto the ceramicized composite insulation layer by a twisting method. The metal composite shielding layer is composed of a metal foil and a plastic film composite and is wrapped onto the flame-retardant filling layer by a longitudinal wrapping method. The flame-retardant wrapping layer is a fiberglass cloth tape coated with an intumescent flame-retardant coating and is wrapped onto the metal composite shielding layer by an overlapping wrapping method. The flame-retardant sheath layer is made of a low-smoke halogen-free flame-retardant polyolefin material and is wrapped onto the flame-retardant wrapping layer by an extrusion process.

[0007] Preferably, in any of the above schemes, the double-layer mica tape of the mica tape fire-resistant layer adopts an alternating overlapping wrapping method.

[0008] Preferably, the plastic film surface of the metal composite shielding layer has a textured surface to enhance its bonding with adjacent layers.

[0009] Preferably, in any of the above schemes, the fiberglass cloth tape of the flame-retardant wrapping layer adopts a double-layer reverse wrapping structure.

[0010] Preferably, in any of the above embodiments, a hot melt adhesive layer is provided between the flame-retardant sheath layer and the flame-retardant wrapping layer.

[0011] Compared with the prior art, the advantages and beneficial effects of this utility model are as follows:

[0012] 1. The mica tape fire-resistant layer of this high flame-retardant and fire-resistant power cable adopts a double-layer staggered and overlapping wrapping structure, combined with high-temperature resistant adhesive, to form a dense insulation barrier at high temperatures, effectively delaying the erosion of the conductor core by flames; at the same time, the ceramicized composite insulation layer is made of ceramicizable polymer material, which quickly sinters into a hard ceramic body when exposed to fire, working synergistically with the mica tape fire-resistant layer to doubly block high temperature and oxygen penetration, enabling the cable to maintain its power transmission capacity for a long time under fire conditions, and its fire resistance performance far exceeds that of ordinary fire-resistant cables.

[0013] 2. The flame-retardant filler layer adopts an inorganic flame-retardant fiber braided structure, forming a heat-insulating skeleton at high temperatures to inhibit the longitudinal spread of flames along the cable; the textured plastic film of the metal composite shielding layer enhances interlayer adhesion and prevents high-temperature delamination; the intumescent flame-retardant coating of the flame-retardant wrapping layer expands rapidly upon contact with fire, forming a honeycomb-like carbonized layer that isolates heat and oxygen; combined with the low-smoke halogen-free flame-retardant sheath layer, it releases almost no toxic fumes during combustion, ensuring the safety of personnel escape and rescue in fire environments. The synergistic effect of each flame-retardant layer allows the cable to maintain structural integrity under extreme high temperatures and flame impacts, significantly improving its safety performance. Attached Figure Description

[0014] Figure 1 is a cross-sectional structural diagram of this utility model.

[0015] In the diagram: 1-, 2-mica tape fire-resistant layer, 3-ceramic composite insulation layer, 4-flame-retardant filling layer, 5-metal composite shielding layer, 6-flame-retardant wrapping layer, 7-flame-retardant sheath layer. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited thereto.

[0017] As shown in Figure 1, a high flame-retardant and fire-resistant power cable includes, from the inside out, a conductor core 1, a mica tape fire-resistant layer 2, a ceramicized composite insulation layer 3, a flame-retardant filling layer 4, a metal composite shielding layer 5, a flame-retardant wrapping layer 6, and a flame-retardant sheath layer 7. The mica tape fire-resistant layer 2 adopts a double-layer overlapping wrapping structure, with the two layers of mica tape bonded together by a high-temperature resistant adhesive. The ceramicized composite insulation layer 3 is composed of a ceramicizable polymer material and is coated onto the outer surface of the mica tape fire-resistant layer 2 through an extrusion process. The flame-retardant filling layer 4 adopts an inorganic flame-retardant fiber woven structure and is wrapped around the ceramic composite insulation layer 3 by twisting. The metal composite shielding layer 5 is composed of metal foil and plastic film and is wrapped around the flame-retardant filling layer 4 by longitudinal wrapping. The flame-retardant wrapping layer 6 is a fiberglass cloth tape coated with an intumescent flame-retardant coating and is wrapped around the metal composite shielding layer 5 by overlapping wrapping. The flame-retardant sheath layer 7 adopts a low-smoke halogen-free flame-retardant polyolefin material and is wrapped around the flame-retardant wrapping layer 6 by extrusion process.

[0018] As an optional technical solution of this utility model, the double-layer mica tape of the mica tape fire-resistant layer 2 adopts an interlaced wrapping method. The interlaced wrapping method makes the mica tape fire-resistant layer 2 form a denser protective structure, effectively preventing the mica tape from cracking and falling off at high temperatures, and improving the fire resistance and structural stability of the cable.

[0019] As an optional technical solution of this utility model, the plastic film surface of the metal composite shielding layer 5 is provided with concave and convex textures to enhance the bonding force with adjacent layers. The concave and convex textures on the surface of the metal composite shielding layer 5 significantly increase the contact area with adjacent layers, enhance the interlayer bonding force, and avoid delamination caused by material expansion differences under high temperature conditions.

[0020] As an optional technical solution of this utility model, the fiberglass cloth tape of the flame-retardant wrapping layer 6 adopts a double-layer reverse wrapping structure. The flame-retardant wrapping layer 6 with the double-layer reverse wrapping structure forms a cross protective net, which can effectively block the spread of flames and improve the overall mechanical strength and impact resistance of the cable.

[0021] As an optional technical solution of this utility model, a hot melt adhesive layer is provided between the flame-retardant sheath layer 7 and the flame-retardant wrapping layer 6. The hot melt adhesive layer forms a firm connection between the flame-retardant sheath layer 7 and the flame-retardant wrapping layer 6, ensuring that the functional layers of the cable remain tightly bonded under bending, stretching and other working conditions, while having excellent flame-retardant synergistic effect.

[0022] A high flame-retardant and fire-resistant power cable, the working principle of which is as follows:

[0023] 1) The mica tape fire-resistant layer 2 of the flame-retardant and fire-resistant power cable adopts a double-layer staggered and overlapping wrapping structure, combined with high-temperature resistant adhesive, to form a dense insulation barrier at high temperature, effectively delaying the erosion of the conductor core 1 by the flame.

[0024] 2): The ceramicized composite insulation layer 3 is made of ceramicizable polymer material, which is rapidly sintered into a hard ceramic body when exposed to fire. It works in synergy with the mica tape refractory layer 2 to provide double protection against high temperature and oxygen penetration.

[0025] 3): The flame-retardant filler layer 4 adopts an inorganic flame-retardant fiber weaving structure, which forms a heat insulation skeleton at high temperature and inhibits the longitudinal spread of flames along the cable; the textured plastic film of the metal composite shielding layer 5 enhances the interlayer adhesion and prevents high-temperature delamination.

[0026] In summary, this high flame-retardant and fire-resistant power cable adopts a double-layer staggered and overlapping wrapping structure, combined with a high-temperature resistant adhesive, to form a dense insulation barrier at high temperatures, effectively delaying the erosion of the conductor core 1 by flames. Simultaneously, the ceramicized composite insulation layer 3, made of ceramicizable polymer materials, rapidly sintersects into a hard ceramic body upon contact with fire, working synergistically with the mica tape fire-resistant layer 2 to double-block high-temperature and oxygen penetration, enabling the cable to maintain its power-carrying capacity for extended periods under fire conditions. Its fire resistance performance far exceeds that of ordinary fire-resistant cables. The flame-retardant filling layer 4 uses an inorganic flame-retardant fiber braided structure, forming a heat-insulating skeleton at high temperatures and inhibiting the longitudinal spread of flames along the cable. The textured plastic film of the metal composite shielding layer 5 enhances interlayer adhesion and prevents high-temperature delamination. The intumescent flame-retardant coating of the flame-retardant wrapping layer 6 rapidly expands upon contact with fire, forming a honeycomb-like carbonized layer that isolates heat and oxygen. Combined with the low-smoke, halogen-free flame-retardant sheath layer 7, it releases almost no toxic fumes during combustion, ensuring the safety of personnel escape and rescue in fire environments. The synergistic effect of the various flame-retardant layers ensures that the cable maintains its structural integrity under extreme high temperatures and flame impacts, significantly improving its safety performance.

Claims

1. A high flame-retardant and fire-resistant power cable, characterized in that: The structure includes, from the inside out, a conductor core (1), a mica tape fire-resistant layer (2), a ceramicized composite insulation layer (3), a flame-retardant filling layer (4), a metal composite shielding layer (5), a flame-retardant wrapping layer (6), and a flame-retardant sheath layer (7). The mica tape fire-resistant layer (2) adopts a double-layer overlapping wrapping structure, with the two mica tape layers bonded together by a high-temperature resistant adhesive. The ceramicized composite insulation layer (3) is composed of a ceramicizable polymer material and is coated onto the outer surface of the mica tape fire-resistant layer (2) through an extrusion process. The flame-retardant filling layer (4)... 4) An inorganic flame-retardant fiber braided structure is used, which is wrapped around the ceramic composite insulation layer (3) by twisting. The metal composite shielding layer (5) is made of metal foil and plastic film, which is wrapped around the flame-retardant filling layer (4) by longitudinal wrapping. The flame-retardant wrapping layer (6) is a fiberglass cloth tape coated with an intumescent flame-retardant coating, which is wrapped around the metal composite shielding layer (5) by overlapping wrapping. The flame-retardant sheath layer (7) is made of low-smoke halogen-free flame-retardant polyolefin material, which is wrapped around the flame-retardant wrapping layer (6) by extrusion process.

2. The high flame-retardant and fire-resistant power cable according to claim 1, characterized in that: The double-layer mica tape of the mica tape fire-resistant layer (2) adopts an interlaced wrapping method.

3. The high flame-retardant and fire-resistant power cable according to claim 2, characterized in that: The plastic film surface of the metal composite shielding layer (5) has a textured surface to enhance its bonding with adjacent layers.

4. The high flame-retardant and fire-resistant power cable according to claim 3, characterized in that: The fiberglass cloth tape of the flame-retardant wrapping layer (6) adopts a double-layer reverse wrapping structure.

5. A high flame retardant fire resistant power cable according to claim 4, characterised in that: A hot melt adhesive layer is provided between the flame-retardant sheath layer (7) and the flame-retardant wrapping layer (6).

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