CN222462431U - A highly flame-retardant and fire-resistant power cable - Google Patents

Abstract

The utility model relates to the technical field of cables and provides a high-flame-retardance fire-resistant power cable which comprises a plurality of cable cores, wherein a filling layer is arranged between the cable cores, a protective layer and a sheath are sequentially arranged outside the filling layer from inside to outside, the cable cores comprise conductors, fire-resistant layers and insulating layers which are sequentially arranged from inside to outside, and the insulating layers comprise irradiation crosslinked polyethylene layers and irradiation crosslinked polyolefin layers which are sequentially arranged from inside to outside.

Description

High flame-retardant fire-resistant power cable

Technical Field

The utility model relates to the technical field of cables, in particular to a high-flame-retardance fire-resistant power cable.

Background

The low-voltage cable is the power cable which is most contacted with activities in daily living, and plays a role in transmitting and distributing power resources, and is vital to activities in daily living. However, unsafe power cables are also one of the routes for fire spread, and the flame retardant and fire-resistant properties of the unsafe power cables are particularly critical.

For the flame-retardant measures for improving the power cable, the flame-retardant measures are realized through flame-retardant materials in the prior art, for example, in the patent document with the publication number of CN116779237A, the cable sequentially comprises a copper core conductor, a flame-retardant layer, an insulating layer, a flame-retardant filling layer, a wrapping tape layer, an oxygen-insulating layer and a sheath from inside to outside, wherein the flame-retardant filling layer is formed by twisting an insulating wire core and a low-smoke halogen-free PP filling rope, the wrapping tape layer is tightly wrapped by overlapping a low-smoke halogen-free flame-retardant ribbon, the oxygen-insulating layer is formed by extrusion drawing of an environment-friendly low-smoke halogen-free flame-retardant material, the sheath is made of a high-flame-retardant low-smoke halogen-free polyolefin compound, however, in practical application, the flame-retardant measures are mainly that the inner layer is made of the high-flame-retardant low-smoke halogen-free polyolefin compound, and the flame-retardant effect of the inner layer still needs to be improved.

Disclosure of utility model

The utility model aims to provide a high-flame-retardance fire-resistant power cable so as to solve the defects in the prior art.

The embodiment of the utility model is realized by the following technical scheme:

The utility model provides a high fire-retardant fire-resistant power cable, includes a plurality of cable cores, is equipped with the filling layer between a plurality of cable cores, is equipped with inoxidizing coating and sheath outside the filling layer from inside to outside in proper order, and the cable core includes conductor, flame retardant coating and the insulating layer that sets gradually from inside to outside, the insulating layer includes irradiation crosslinked polyethylene layer and irradiation crosslinked polyolefin layer that sets gradually from inside to outside.

Optionally, the protective layer sequentially comprises a first wrapping band layer, an oxygen barrier layer and a second wrapping band layer from inside to outside.

Optionally, the first wrapping band layer and the second wrapping band layer are formed by bundling two layers of halogen-free oxygen-isolation bands.

Optionally, the oxygen barrier layer is a B1-grade ceramic halogen-free low-smoke polyolefin.

Optionally, the sheath is a B1 grade halogen-free low smoke polyolefin.

Optionally, the filling layer is an inorganic paper rope.

Optionally, the refractory layer is a double layer mica tape.

Optionally, an armor layer or a metal shielding layer is arranged outside the sheath.

The technical scheme of the utility model has the advantages and beneficial effects that the insulating layer outside the conductor comprises the irradiation crosslinked polyethylene layer and the irradiation crosslinked polyolefin layer which are sequentially arranged from inside to outside, the inner layer has excellent electrical property, mechanical property and temperature resistance level, the outer layer has halogen-free low smoke and flame retardant property, the temperature resistance and flame retardant property inside the cable are greatly improved, the conductor is effectively protected, the safety of the cable in a use place and the continuous power supply time of the cable in case of fire disaster are improved, and emergency measures are conveniently taken for rescue, so that the personal and property safety is ensured.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present utility model and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic structural view of a high flame retardant fire resistant power cable provided by the utility model;

The icons are 1-conductor, 2-fire-resistant layer, 3-irradiation cross-linked polyethylene layer, 4-irradiation cross-linked polyolefin layer, 5-filling layer, 6-first winding band layer, 7-oxygen-isolation layer, 8-second winding band layer and 9-sheath.

Detailed Description

Example 1

Referring to fig. 1, a high flame retardant fire resistant power cable comprises a plurality of cable cores, a filling layer 5 is arranged between the cable cores, a protective layer and a sheath 9 are sequentially arranged outside the filling layer 5 from inside to outside, and the cable cores comprise a conductor 1, a fire resistant layer 2 and an insulating layer which are sequentially arranged from inside to outside.

The conductor 1 is selected from 1 class, 2 class or 5 class conductors 1 conforming to GB/T3956-2008 standard, a T-shaped structure stranding design can be adopted, the compression coefficient of the conductor 1 reaches more than 0.95, and when the copper rod with the resistivity of less than 0.017 omega mm < 2 >/m of the copper conductor 1 is used for processing, the conductor is compared with the compressed round conductor 1 with the same section, and the conductor has small outer diameter, excellent conductivity and smooth and round surface. Taking a 70mm2 three-core 0.6/1kV cable structure as an example, the outer diameter of a T-shaped conductor 1 is 9.3mm, the outer diameter of a finished cable is 32.5mm, the outer diameter of a compressed round conductor 1 is 10.0mm, the outer diameter of the finished cable is 34mm, the outer diameter of the conductor 1 is 7% smaller, the outer diameter of the finished cable is 4.4% smaller, and the materials used for the whole cable can be saved by more than 1%.

In practical application, according to GB/T19666-2019 fire resistance performance, fire resistance performance level and technical requirements (fire supply temperature 950 ℃ to 1000 ℃ for 90min for fire +15min for cooling, test voltage rated voltage, according to GB/T19216.21 test method, circuit integrity satisfies 2A fuse constantly, indicator lamp is not extinguished, smoke toxicity accords with ZA2 level in GB/T20285, smoke density is more than or equal to 80%, corrosion resistance PH value is more than or equal to 4.3, conductivity is less than or equal to 10 mu s/mm), according to GB/T19216 or I EC60331 test method, fire supply temperature and time can respectively or simultaneously satisfy GB/T19666-2019 fire resistance performance table 6 regulation (fire supply temperature 950 ℃ to 1000 ℃ for 90min for cooling, test voltage rated voltage, according to GB/T19216.21 test method, circuit integrity satisfies 2A fuse constantly, indicator lamp is not extinguished), GA 2.2-and fire resistance performance level is more than or equal to 15 mu s/1 mm, and fire resistance performance level is more than or equal to 15 mm, and fire resistance performance level is more than or equal to 15 mm 6 in GB/1/T19216 or 1.

The insulating layer comprises an irradiation crosslinking polyethylene layer 3 and an irradiation crosslinking polyolefin layer 4 which are sequentially arranged from inside to outside, the inner layer has excellent electrical performance, mechanical performance and temperature resistance level, the outer layer has halogen-free low-smoke and flame-retardant characteristics, the temperature resistance and flame retardance of the inside of the cable are greatly improved, the conductor 1 is effectively protected, the safety of a using place of the cable and the continuous power supply time when a fire disaster condition occurs are improved, and emergency measures are conveniently taken for rescue, so that the personal and property safety is guaranteed.

In practical application, the irradiation crosslinked polyethylene layer 3 and the irradiation crosslinked polyolefin layer 4 adopt a double-layer coextrusion technology, are crosslinked by high-energy rays generated by an electron accelerator after extrusion, have good thermal stability of a three-dimensional reticular molecular structure after crosslinking, greatly improve insulation electrical property and mechanical property, meet the insulation property requirements in GB/T12706-2020 and JB/T10491-2022, and simultaneously meet the long-life performance (the long-term maximum working temperature of a conductor 1 is 125 ℃, the test temperature is 180+/-3 ℃, the test time is 168 hours, the retention rate of elongation at break is not less than 50% of the original value of the elongation at break) and the insulation property requirements (the maximum working temperature of the conductor 1 is 150 ℃, the elongation under the load of 200+/-3 ℃ and is not more than 80%, the permanent elongation after cooling is not more than 15%, the change rate of tensile strength after aging is not more than +/-30%, and the elongation at break is not more than +/-30%). The double-layer insulation co-extrusion irradiation crosslinking insulation technology is adopted, so that the normal operation temperature of the cable can be increased to 150 ℃, and the electricity safety, low carbon and environmental protection of the power transmission line are ensured.

The filling layer 5 is an inorganic paper rope, also called an inorganic flame-retardant rope, and has the characteristics of environmental protection and flame retardance.

The inoxidizing coating is from interior to outside including first around band layer 6, separates oxygen layer 7 and second around band layer 8 in proper order, and first around band layer 6 and second around band layer 8 are by two-layer no halogen separates oxygen area and tie up and form, and no halogen separates oxygen area has high fire-retardant, and first around band layer 6 plays the guard action to filling layer 5, increases fire-retardant characteristic and heat dispersion simultaneously. The purpose of the second wrapping band layer 8 is to meet the requirement of d0 in B1 in GB/T31247-2014, prevent the oxygen barrier layer 7 from having precipitate or protruding point caused by gas release at high temperature during combustion, and the wrapping band is favorable for tightly wrapping the sheath 9, thereby avoiding carbonization dropping of the sheath 9.

The oxygen-isolating layer 7 adopts B1-level ceramic halogen-free low-smoke polyolefin, and can form a hard ceramic shell under the condition of flame burning or high temperature, thereby playing a good role in fireproof protection. The oxygen-isolating layer 7 has the advantages that the oxygen index is larger than 40, no precipitate exists under high-temperature combustion, the oxygen-isolating layer is carbonized into a shell, the heat absorption, heat dissipation, flame retardance, no halogen, low smoke and the like are realized, the oxygen-isolating layer can effectively form a double protection layer with the sheath 9, the oxygen can be effectively prevented from being used as a combustion improver to continuously burn a cable, a good flame retardant effect is realized, and meanwhile, the external mechanical property protection can be implemented on the cable insulation wire core, so that the cable is safe and reliable during long-term operation.

The sheath 9 adopts B1-grade halogen-free low-smoke polyolefin, the material has higher crust forming property and better dripping index, and the flame retardant property, the dripping substance/particle grade, the smoke toxicity grade, the corrosiveness grade and the like in the cable combustion process meet the requirements of the combustion property B1 (d 0, T0, a 1) in GB31247-2014, the bundling property A in GB/T19666-2019 and single flame retardant property.

Example two

The first embodiment is further optimized based on the first embodiment, specifically, according to the use requirement, the metal shielding layer can be designed outside the sheath 9 to play a role in resisting electromagnetic interference, or the metal armor layer is designed according to the requirements of laying places, so that the inner structure of the cable core is protected from being damaged by external force, and the functions of tensile resistance and compression resistance are achieved. In other embodiments, the outer sheath 9 may also be made of a low smoke halogen-free flame retardant material with properties of rat and termite resistance according to the high flame retardant B1 level performance in combination with the paving geographical environment, and may also be optimized in combination with properties of water resistance, cold resistance, radiation resistance, aging resistance, etc.

The cable provided by the application can be widely applied to infrastructures, plants, industrial and civil buildings, industrial devices and the like of various industries, and can be used in densely populated places such as high-rise buildings, subways, tunnels, markets, theaters, stations, airports, important distribution lines, building wiring and the like. The product has excellent insulating electrical property and mechanical property under the condition of meeting the halogen-free low-smoke flame retardance, has the service life of more than 70 years, has high temperature resistance level, high flame retardance, energy conservation, environmental protection, fire prevention and service life of not less than 70 years, is synchronous with the 70 years of building property rights, ensures the safety of the cable, does not generate secondary cost caused by cable replacement, has high comprehensive economic benefit, and meets the new building design specification of the living building.

The above is only a preferred embodiment of the present utility model, and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims (7)

1. The high-flame-retardance fire-resistant power cable comprises a plurality of cable cores, wherein a filling layer (5) is arranged between the cable cores, a protective layer and a sheath (9) are sequentially arranged outside the filling layer (5) from inside to outside, the cable cores comprise conductors (1), fire-resistant layers (2) and insulating layers which are sequentially arranged from inside to outside, and the high-flame-retardance fire-resistant power cable is characterized in that the insulating layers comprise an irradiation crosslinked polyethylene layer (3) and an irradiation crosslinked polyolefin layer (4) which are sequentially arranged from inside to outside;

the protective layer sequentially comprises a first wrapping band layer (6), an oxygen isolation layer (7) and a second wrapping band layer (8) from inside to outside.

2. The high flame retardant fire resistant power cable according to claim 1, wherein the first wrapping tape layer (6) and the second wrapping tape layer (8) are each formed by bundling two layers of halogen-free oxygen barrier tape.

3. The high flame retardant fire resistant power cable according to claim 1, wherein the oxygen barrier layer (7) is a B1 grade ceramic halogen free low smoke polyolefin.

4. A high flame retardant fire resistant power cable according to any one of claims 1-3, wherein the sheath (9) is a B1 grade halogen free low smoke polyolefin.

5. A high flame retardant fire resistant power cable according to any one of claims 1-3, wherein the filler layer (5) is an inorganic paper rope.

6. A high flame retardant fire resistant power cable according to any one of claims 1-3, wherein the fire resistant layer (2) is a double layer mica tape.

7. A high flame retardant fire resistant power cable according to any one of claims 1-3, wherein the sheath (9) is externally provided with an armouring layer or a metallic shielding layer.