CN211555553U - Economical and applicable medium-voltage fire-resistant power cable - Google Patents

Abstract

The utility model discloses an economical and applicable medium-voltage fire-resistant power cable, which comprises a cable inner core and a cable outer layer wrapped outside the cable inner core; the cable inner core comprises a plurality of insulating wire cores, soft flame-retardant filling manufactured by adopting a nanotechnology is arranged between the cable inner core and the cable outer layer, and the cable outer layer sequentially comprises a first oxygen isolation layer, a second flame-retardant layer, a third armor layer and an outer sheath from inside to outside. The fire-resistant grade of the scheme is the highest NH-IA standard, the fire-receiving temperature is 950-1000 ℃, the fire supply time is 90min, the cable can reach the fire-delay height, the fire-delay height is less than 0.3m, the self-extinguishing time is less than or equal to 5s, the comprehensive manufacturing cost of the product is reduced by 50% compared with the common medium-voltage fire-resistant power, the fire-resistant cable is economical and applicable, environment and safety cleaning fire prevention and control are facilitated, the popularization and application of the medium-voltage fire-resistant cable in a large range are facilitated, the fire-resistant, spraying-resistant and shock-resistant performance is good, the use requirement of a place with a.

Description

Economical and applicable medium-voltage fire-resistant power cable

Technical Field

The utility model relates to a fire-resistant power cable of middling pressure relates to a fire-resistant power cable of economy suitable type middling pressure particularly.

Background

In recent years, high-rise buildings and super high-rise buildings are built continuously in China, and the fire protection design specifications for high-rise civil buildings, the electrical design specifications for civil buildings and other national standard regulations are as follows: the fire-proof protection system is laid and protected from the building house to the medium-voltage power distribution cabinet and from the medium-voltage power distribution cabinet to the power transformer according to the fire-proof requirement. Meanwhile, the power transmission and distribution lines for primary load power utilization places such as important transportation hubs, important communication hubs, large-scale gymnasiums, public places of international activities, important power loads, hotels in high-rise buildings and super high-rise buildings, office buildings and the like all have fireproof performance.

The appearance of the medium-voltage fire-resistant cable just fills the blank. At present, the commonly adopted cable structure of medium-voltage fire-resistant cable products is as follows: the composite structure consisting of the high-oxygen-index low-smoke halogen-free polyolefin inner oxygen-insulating layer material, the ceramic fireproof fire-resistant composite tape wrapping layer, the high-oxygen-index low-smoke halogen-free polyolefin outer oxygen-insulating layer material and the ceramic low-smoke halogen-free polyolefin fire-resistant material isolation layer is arranged outside the insulated wire core, so that the purposes of flame retardance and fire resistance are achieved.

However, such medium voltage fire resistant cables have the following problems:

1. the product manufacturing process is complex, the product needs to be processed and molded through a plurality of procedures, the production efficiency of the product is low, the manufacturing cost is high, the comprehensive manufacturing cost of the finished cable is about 1.5-1.7 times of that of the common cable, and the popularization and the application of the product are seriously influenced.

2. The cable has poor bending property and strong rigidity, and the laying and installation of the cable are influenced.

3. The finished product has low percent of pass and does not have the properties of fire resistance, water spray resistance, fire resistance and mechanical impact resistance.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome the problem that exists among the prior art, provide an economy and be suitable for type middling pressure fire-resistant power cable to solve a great deal of problem among the prior art.

In order to achieve the above purpose, the technical solution of the present invention is as follows:

an economical and applicable medium-voltage fire-resistant power cable comprises a cable inner core and a cable outer layer wrapping the cable inner core; the cable is characterized in that the cable inner core comprises a plurality of insulating wire cores, soft flame-retardant filling manufactured by adopting a nanotechnology is arranged between the cable inner core and the cable outer layer, and the cable outer layer sequentially comprises a first oxygen isolation layer, a second flame-retardant layer, a third armor layer and an outer sheath from inside to outside.

In a preferred embodiment of the present invention, the first oxygen-isolating layer is extruded by high-oxygen-index low-smoke halogen-free polyolefin, and the second flame-retardant layer is made of metal hydrate.

In a preferred embodiment of the present invention, the armor is a steel tape interlocking armor.

In a preferred embodiment of the present invention, the outer sheath is extruded with a halogen-free low-smoke flame-retardant polyolefin material with a high oxygen index.

The utility model discloses a fire-resistant rank is the highest NH-IA standard, and the temperature of being fired is 950 ℃ -1000 ℃, and the time of supplying fire is 90min, and the cable can reach to delay to burn highly and delay to fire highly and highly to be less than or equal to 0.5m, and the time of putting out certainly is less than or equal to 10s, belongs to the economy and is suitable for the type, is favorable to the clean fire prevention and cure of environment and safety, has good fire-resistant water-fast shock resistance that sprays.

The utility model discloses a fire-retardant packing of soft type, first oxygen layer, second flame retardant coating, third armor separate, its material economy is suitable for. The problems of complex manufacturing process, high product manufacturing cost, poor fire resistance, poor bending property, mechanical impact of non-fire-resistant spraying and the like of the medium-pressure fire-resistant layer are fundamentally solved.

The features of the present invention will be apparent from the accompanying drawings and from the detailed description of the preferred embodiments which follows.

Drawings

Fig. 1 is a schematic diagram of a cable profile structure according to the present invention.

Detailed Description

In order to make the technical means, creation features, achievement purposes and functions of the present invention easy to understand, the present invention will be further described with reference to the following embodiments.

As shown in fig. 1, an economical medium-voltage fire-resistant cable includes a cable core and a cable outer layer wrapped around the cable core.

The cable inner core includes three insulation core 1, and insulation core 1 twists together. A soft flame-retardant filler 2 manufactured by adopting a nanotechnology is arranged between the inner core of the cable and the outer layer of the cable, and the outer layer of the cable sequentially comprises a first oxygen-insulating layer 3, a second flame-retardant layer 4, a third armor layer 5 and a sheath 6 from inside to outside.

The first oxygen layer that separates adopts the crowded package of high oxygen index low smoke and zero halogen polyolefin, separates to fill a large amount of aluminium hydroxide and magnesium hydrate in the oxygen layer material, meets high temperature and begins to decompose when taking place the conflagration, releases the evaporation of water and absorbs the heat, and the cooling, the carbide that the oxide that generates and burning formed combines to form hard casing, not only protects cable run not receive external force and harms, has still cut off oxygen and thermal invasion, has played the effect of isolation.

The second composite fire-resistant layer 4 is composed of inorganic mineral metal hydrate comprising 70% of aluminum hydroxide, 25% of sodium silicate and 5% of coagulant; the material cost is only 1/10 of ceramic material, the inorganic mineral metal hydrate forms a porous net-shaped skeleton structure, the structure has the functions of heat insulation and fire source isolation, the formed porous structure can be adsorbed in smoke in the combustion process, the heat conductivity coefficient of the aluminum hydroxide metal hydrate inorganic mineral heat-dissipation fireproof layer is large under the normal working condition and is about 15-30 times larger than that of glass fiber or PP rope, so that the cable has good heat dissipation, the steady-state current-carrying capacity below 90 ℃ is about 15% larger than that of the common model with the same specification, and the cable is economical and applicable.

The armor layer 5 is a steel belt interlocking armor layer, not only can effectively prevent flame from spreading, but also has good bending property.

The flexible flame-retardant composite material comprises a flexible flame-retardant filling layer, a first composite flame-retardant layer, a second composite flame-retardant layer and an armor layer, wherein the materials are manufactured by adopting a nanotechnology. Fundamentally solves the problems of moisture absorption and corrosion of the oxygen-isolating layer, poor bending property, fire fighting spray intolerance and the like.

The sheath 6 is a halogen-free low-smoke flame-retardant polyolefin material with a high oxygen index, has good flame-retardant and fire-resistant characteristics, does not generate toxic gas under fire conditions, and meets the requirements of relevant national standards on technical indexes such as pH value, heavy metal content, smoke density and light transmittance.

The technical indexes of the cable are as follows

Current carrying capacity (in air, 40 ℃): 285A.

Conductor resistance (20 ℃) is 0.183 omega/km.

In the high-voltage test, the 31kV/5min cable is not broken down.

Partial discharge capacity (16 kV): less than or equal to 3 pC.

Fire resistance test:

during the period of supplying fire and supplying fire for 90min and cooling for 15min by the double-blast lamps with the flame temperature of not less than 950 ℃, 15kV is applied to the sample, and the sample is not punctured.

Within 1h of test result, 31kV is applied to the sample for 15min, and the sample is not broken down.

Cable structure data

A. Conductor structure (number/filament diameter mm): 19/2.61; diameter of the conductor: 11.2 mm.

B. Thickness of the conductor shielding layer: 0.8 mm.

C. Thickness of the insulating layer: 5.0 mm.

D. Thickness of the insulating shielding layer: 0.8 mm.

E. Thickness of the metal shielding layer: 0.15 mm.

F, the outer diameter of a wire core: 24.7 mm.

G. Flexible fill approximate diameter: 12.0 mm.

H. Thickness of the oxygen barrier layer: 2.8 mm.

I. Thickness of the refractory layer: 5.0 mm.

J. Thickness of the armor layer: 1.2 mm.

K. The thickness of the outer sheath: 3.5 mm.

L. cable calculated outer diameter: 79.6 mm.

The utility model discloses a fire-resistant rank is the highest NH-IA standard, it is 950 ℃ -1000 ℃ to receive the fire temperature, the time of supplying fire is 90min, the cable can reach and delay burning height <0.3m, from putting out the time and being less than or equal to 5s, the more ordinary middling pressure fire-resistant electric power of the comprehensive manufacturing cost of product reduces 50%, economy is suitable for, be favorable to environment and safe clean fire prevention and cure, be favorable to the popularization and application on a large scale of middling pressure fire-resistant cable, have good fire-resistant shock resistance that sprays, lay the use needs in the less place in space, and is rational in infrastructure, and novel in design.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that the principles of the present invention may be applied to any other embodiment without departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (5)

1. An economical and applicable medium-voltage fire-resistant power cable comprises a cable inner core and a cable outer layer wrapping the cable inner core; the cable is characterized in that the cable inner core comprises a plurality of insulating wire cores, a nano soft type flame-retardant filling layer is arranged between the cable inner core and the cable outer layer, and the cable outer layer sequentially comprises a first oxygen isolation layer, a second flame-retardant layer, a third armor layer and an outer sheath from inside to outside.

2. The economical and applicable medium-voltage fire-resistant power cable according to claim 1, wherein the first oxygen barrier layer is formed by extruding and wrapping high-oxygen-index low-smoke halogen-free polyolefin.

3. An economically viable medium voltage fire resistant power cable according to claim 1 wherein the third armouring layer is a steel tape interlocking armouring layer.

4. The economical and applicable medium-voltage fire-resistant power cable according to claim 1, wherein the outer sheath is formed by extruding and wrapping a halogen-free low-smoke flame-retardant polyolefin material with a high oxygen index.

5. An economical and applicable medium voltage fire-resistant power cable according to claim 1, characterized in that the cable core comprises three insulated wire cores, which are twisted together.

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