CN212516660U

CN212516660U - Fireproof fire-resistant medium-voltage power cable

Info

Publication number: CN212516660U
Application number: CN202021712050.XU
Authority: CN
Inventors: 芮黎春
Original assignee: Wuxi City Pu Cao Technology Co ltd
Current assignee: Wuxi City Pu Cao Technology Co ltd
Priority date: 2020-08-17
Filing date: 2020-08-17
Publication date: 2021-02-09
Anticipated expiration: 2030-08-17

Abstract

The utility model discloses a fireproof and fire-resistant medium-voltage power cable, which comprises a cable core; the cable comprises a cable core, a packing layer, a cabling belting, a cooling heat insulation layer, a fireproof layer and a sheath layer, wherein the packing layer is arranged on the outer side of the cable core; the cooling heat insulation layer is a structure formed by bonding and wrapping refractory inorganic short fiber filler and refractory or inorganic binder; the fireproof layer is a steel wire woven and graphite inorganic compound extruded structure, and the cable is good in fire resistance and good in flexibility.

Description

Fireproof fire-resistant medium-voltage power cable

Technical Field

The utility model relates to a fire prevention power cable field especially relates to a fire prevention fire-resistant type medium voltage power cable.

Background

The first one is that a mica tape fire-resistant layer is wound on a conductor, and after the insulating layer is burnt, the insulating layer is crust after being sintered by the mica tape to continuously keep the insulating property at high temperature (750-1000 ℃) for 90 minutes, so that after a fire disaster occurs, the insulation can be continuously electrified for more than 90 minutes, and people and property can be conveniently evacuated; the second is to adopt copper core copper sheath magnesium oxide insulated cable, this cable insulation adopts mineral magnesium oxide, when catching fire, the magnesium oxide insulation can not be burnt, the shortcoming of this kind of structure is limited by production technology, can not big length continuous production, small-size cable once can produce one hundred more meters, big specification cable once can only produce tens of meters, the structure of this cable has decided its bending radius big simultaneously, characteristics such as cable flexibility is poor.

The 6-35 kV crosslinked polyethylene insulated medium-voltage fireproof cable (NG-B-BTLY-YJY 23) has the structure determined by the electrical parameters of the cable operating under high voltage, and the structure of the insulated wire core is required to be a conductive wire core-conductor shielding-crosslinked polyethylene insulating-insulating shielding. Therefore, the medium-voltage fireproof cable can not be manufactured in a mode of wrapping fire-resistant mica tapes on a conductor and in a mode of insulating magnesium oxide with a copper core and a copper sheath. In addition, the fireproof cable of majority can adopt two steel band armoring as metal fire blocking layer in the existing market, but through research and the experimental fire blocking layer that adopts two steel band armoring to make middling pressure fire resisting cable of discovery adoption of cooperation, the effect is unstable, two-layer steel band adopts the clearance formula to wind the package, the clearance rate is not more than 50%, can play the effect of keeping off the fire in theory, but in the actual combustion process, discovery inevitable clearance exists between the double-layer steel band, inside flame can follow clearance department and invade the cable, lead to this fire blocking layer to become invalid.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming prior art's shortcoming, providing a novel middling pressure fire prevention power cable that fire resistance and fire proofness are good, pliability is good.

In order to realize the purpose of the utility model, the technical proposal of the utility model is that:

a fire-proof and fire-resistant medium-voltage power cable comprises a cable core; the cable comprises a cable core, a packing layer, a cabling belting, a cooling heat insulation layer, a fireproof layer and a sheath layer, wherein the packing layer is arranged on the outer side of the cable core; the cooling heat insulation layer is a structure formed by bonding and wrapping refractory inorganic short fiber filler and refractory or inorganic binder; the fireproof layer is of a steel wire woven and graphite inorganic compound extruded structure.

Preferably, the filling layer is a dust-free rock wool rope filling layer, the cabling bag belt is a ceramic polyolefin composite belt and a glass fiber belt, and a multimode temperature measuring optical fiber is arranged in the filling layer.

Preferably, a fully-sealed metal fire blocking layer is further arranged between the fireproof layer and the sheath layer, and the fully-sealed metal fire blocking layer is a corrugated aluminum sheath layer.

Preferably, the refractory inorganic short fiber filler is polycrystalline alumina fiber with the alumina content of more than or equal to 95 percent or polycrystalline mullite fiber with the total content of alumina and silica of more than or equal to 99 percent.

Preferably, the sheath layer is a low-smoke halogen-free flame-retardant sheath.

Preferably, the cable core comprises a conductor, and an inner shielding layer, an insulating layer and an insulating shielding layer which are extruded on the outer layer of the conductor.

The utility model has the advantages that:

firstly, the method comprises the following steps: by utilizing a comprehensive structure of wrapping a ceramic polyolefin composite belt and a glass fiber belt, a cooling heat insulation layer, a fireproof layer, a fully-sealed metal fire blocking layer and a sheath layer around a dust-free rock wool rope filling layer, the temperature of 750-1000 ℃ outside a cable can be reduced to 250-350 ℃ when the high temperature is transmitted to the cable core, and meanwhile, oxygen in air can be blocked from invading the cable insulation layer, so that the insulation layer of the insulation core is only softened (crosslinked polyethylene can not be melted), the effect of oxidative decomposition is not generated, and the cable can normally work within a specified time in case of fire; so as to ensure that the cable can meet the fireproof design requirement;

secondly, the method comprises the following steps: filling polycrystalline alumina fiber with alumina content not less than 95% or polycrystalline mullite fiber with alumina and silica content not less than 99%, the material can not become hard and brittle at high temperature, and can still keep good flexibility and elasticity, so that the cable is relatively soft and has good bending property, the cooling heat insulation layer is a structure formed by bonding and wrapping refractory inorganic short fiber filler and a refractory or inorganic binder, can resist the temperature of 1320-1600 ℃ for a long time, the fireproof inorganic short fiber filler is formed by filling a crystalline water-containing compound which can rapidly decompose a large amount of moisture and expand when meeting high temperature in a special high polymer material, the precipitated moisture is attached to the surface of a cable to play a role in isolating air, the volatilized moisture plays a role in cooling, the expansion prevents the air from further contacting the cable, the flame-retardant and heat-insulating role is played, and the fireproof performance of the cable is greatly improved;

thirdly, the method comprises the following steps: compare with traditional medium voltage cable who keeps off fire layer as metal with two steel band armoring, this cable uses the wrinkle aluminium sheath as metal and keeps off fire layer, and the wrinkle aluminium sheath is full seal structure, and inside flame can't invade the cable. In addition, the corrugated aluminum sheath has large surface area and good heat dissipation effect, and can better reduce the heat entering the cable;

fourthly: the fireproof layer is a steel wire woven and graphite inorganic compound extruded structure, the graphite inorganic compound is an expandable graphite inorganic compound material, the fireproof layer begins to expand when heated to a certain temperature, the expansion volume can reach more than 200 times of the initial volume, a very good heat insulation layer is formed, the excellent effects of fire resistance, heat insulation and flame impact prevention can be achieved, and fire and heat diffusion to the center of the cable can be effectively blocked.

Fifth, the method comprises the following steps: multimode temperature measuring optical fibers are added in the cable, and when a fire disaster happens, the temperature rise caused by the fire disaster can trigger an alarm system through the temperature measuring optical fibers, so that the early warning and evacuation efficiency is improved.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

In the figure: 10 is a cable core, 11 is a conductor, 12 is an inner shielding layer, 13 is an insulating layer, 14 is an insulating shielding layer, 20 is a filling layer, 30 is a cabling tape, 40 is a cooling heat-insulating layer, 50 is a fireproof layer, 60 is a fully-sealed metal fire-blocking layer, 70 is a sheath layer, and 80 is a multimode temperature-measuring optical fiber.

Detailed Description

The technical solution in the embodiment of the present invention is clearly and completely described below with reference to the accompanying drawings.

A fire-proof and fire-resistant medium-voltage power cable comprises a cable core 10; the outer side of the cable core 10 is provided with a filling layer 20, the outer side of the filling layer 20 is wrapped with a cabling tape 30, and the outer side of the cabling tape 30 is wrapped with a cooling heat insulation layer 40, a fire-proof layer 50 and a sheath layer 70; the cooling heat-insulating layer 40 is a structure formed by bonding and wrapping refractory inorganic short fiber filler and refractory or inorganic binder; the fireproof layer 50 is of a steel wire woven and graphite inorganic compound extruded structure.

Preferably, the filling layer 20 is a dust-free rock wool rope filling layer, the cabling bag belt 30 is a ceramic polyolefin composite belt and a glass fiber belt, and the filling layer 20 is internally provided with a multimode temperature measuring optical fiber 80.

Preferably, a fully-sealed metal fire barrier layer 60 is further disposed between the fire-proof layer 50 and the sheath layer 70, and the fully-sealed metal fire barrier layer 60 is a corrugated aluminum sheath layer.

Preferably, the sheath layer 70 is a low-smoke halogen-free flame-retardant sheath.

Preferably, the cable core 10 includes a conductor 11, and an inner shield layer 12, an insulating layer 13 and an insulating shield layer 14 which are extruded on an outer layer of the conductor 11.

The described embodiments are only some, but not all embodiments of the invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Claims

1. A fire-proof and fire-resistant medium-voltage power cable, comprising a cable core (10); the method is characterized in that: a filling layer (20) is arranged on the outer side of the cable core (10), a cabling belting (30) is wrapped on the outer side of the filling layer (20), and a cooling heat-insulating layer (40), a fire-proof layer (50) and a sheath layer (70) are wrapped on the outer side of the cabling belting (30); the cooling heat-insulating layer (40) is a structure formed by bonding and wrapping refractory inorganic short fiber filler and a refractory or inorganic binder; the fireproof layer (50) is of a steel wire woven and graphite inorganic compound extruded structure.

2. Fire-resistant medium-voltage power cable according to claim 1, characterized in that: the packing layer (20) is a dust-free rock wool rope packing layer, the cabling bag belt (30) is a ceramic polyolefin composite belt and a glass fiber belt, and multimode temperature measuring optical fibers are arranged in the packing layer (20).

3. Fire-resistant medium-voltage power cable according to claim 1, characterized in that: still set up full-sealed metal between flame retardant coating (50) and restrictive coating (70) and keep off fiery layer (60), full-sealed metal keeps off fiery layer (60) and is wrinkle aluminium restrictive coating.

4. Fire-resistant medium-voltage power cable according to claim 1, characterized in that: the refractory inorganic short fiber filler is polycrystalline alumina fiber with alumina content not less than 95% or polycrystalline mullite fiber with the total content of alumina and silica not less than 99%.

5. Fire-resistant medium-voltage power cable according to claim 1, characterized in that: the sheath layer (70) is a low-smoke halogen-free flame-retardant sheath.

6. Fire-resistant medium-voltage power cable according to claim 1, characterized in that: the cable core (10) comprises a conductor (11), and an inner shielding layer (12), an insulating layer (13) and an insulating shielding layer (14) which are extruded on the outer layer of the conductor (11).