CN212516661U

CN212516661U - Novel medium-voltage fireproof power cable

Info

Publication number: CN212516661U
Application number: CN202021712063.7U
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 novel medium-voltage fireproof power cable, which comprises a cable core, wherein a heat insulation layer, a cooling heat insulation layer, an isolation layer, a full-sealed metal fire blocking layer and a sheath layer are sequentially arranged outside the cable core; the heat insulation layer comprises a filling layer arranged outside the cable core, and a ceramic polyolefin composite tape and a glass fiber tape wrapping layer wrapped outside the filling layer; the cooling heat insulation layer is a structure formed by bonding and wrapping refractory inorganic short fiber filler and refractory or inorganic binder, and the cable has good fire resistance and good flexibility.

Description

Novel medium-voltage fireproof power cable

Technical Field

The utility model relates to a fire prevention power cable field especially relates to a novel middling pressure fire prevention 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 novel medium-voltage fireproof power cable comprises a cable core, wherein a heat insulation layer, a cooling heat insulation layer, an isolation layer, a fully-sealed metal fire blocking layer and a sheath layer are sequentially arranged on the outer side of the cable core; the heat insulation layer comprises a filling layer arranged outside the cable core, and a ceramic polyolefin composite tape and a glass fiber tape wrapping layer wrapped outside the filling layer; the cooling heat insulation layer is a structure formed by bonding and wrapping refractory inorganic short fiber filler and refractory or inorganic binder.

Preferably, the isolation layer is formed by wrapping a ceramic fireproof and fireproof composite tape.

Preferably, the fully-sealed metal fire barrier layer is a corrugated aluminum sheath layer.

Preferably, the filling layer is a dust-free rock wool rope filling layer, and a multimode temperature measurement optical fiber is further arranged in the filling 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 the comprehensive structure of the heat insulation layer, the cooling heat insulation layer, the isolation layer, the fully-sealed metal fire blocking layer and the sheath layer, the temperature of 750-1000 ℃ outside the cable is transmitted to the cable core and can be reduced to 250-350 ℃, and meanwhile, oxygen in air is blocked and cannot enter the cable insulation layer, so that the insulation layer of the insulation wire core is only softened (crosslinked polyethylene cannot 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: 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 heat insulating layer, 21 is a filling layer, 22 is a wrapping layer, 30 is a cooling heat insulating layer, 40 is an isolating layer, 50 is a full-sealed metal fire blocking layer, 60 is a sheath layer, and 70 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 novel medium-voltage fireproof power cable comprises a cable core 10, wherein a heat insulation layer 20, a cooling heat insulation layer 30, an isolation layer 40, a fully-sealed metal fire blocking layer 50 and a sheath layer 60 are sequentially arranged outside the cable core 10; the heat insulation layer 20 comprises a filling layer 21 arranged on the outer side of the cable core 10, and a ceramic polyolefin composite tape and a glass fiber tape wrapping layer 22 wrapped outside the filling layer 21; the cooling heat-insulating layer 30 is a structure formed by bonding and wrapping refractory inorganic short fiber filler and refractory or inorganic binder.

Preferably, the isolation layer 40 is formed by wrapping a ceramic fireproof and fire-resistant composite tape.

Preferably, the fully-sealed metal fire barrier layer 50 is a corrugated aluminum sheath layer.

Preferably, the filling layer 21 is a dust-free rock wool filling layer, and a multimode temperature measuring optical fiber 70 is further arranged in the filling layer 21.

Preferably, the sheath layer 60 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. The utility model provides a novel medium voltage fire prevention power cable, includes cable core (10), its characterized in that: the outer side of the cable core (10) is sequentially provided with a heat insulation layer (20), a cooling heat insulation layer (30), an isolation layer (40), a fully-sealed metal fire barrier layer (50) and a sheath layer (60); the heat insulation layer (20) comprises a filling layer (21) arranged on the outer side of the cable core (10), and a ceramic polyolefin composite tape and a glass fiber tape winding layer (22) which are wound outside the filling layer (21); the cooling heat insulation layer (30) is a bonding and wrapping structure of refractory inorganic short fiber filler and refractory or inorganic binder.

2. A novel medium voltage fire protection power cable according to claim 1, characterized in that: the isolation layer (40) is formed by wrapping a ceramic fireproof and fireproof composite tape.

3. A novel medium voltage fire protection power cable according to claim 1, characterized in that: the fully-sealed metal fire barrier layer (50) is a corrugated aluminum sheath layer.

4. A novel medium voltage fire protection power cable according to claim 1, characterized in that: the filling layer (21) is a dust-free rock wool rope filling layer, and multimode temperature measuring optical fibers are further arranged in the filling layer (21).

5. A novel medium voltage fire protection 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%.

6. A novel medium voltage fire protection power cable according to claim 1, characterized in that: the sheath layer (60) is a low-smoke halogen-free flame-retardant sheath.

7. A novel medium voltage fire protection 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).