Medium-voltage fire-proof cable

Abstract

The invention relates to a medium-voltage power transmission fire-resistant cable, which is characterized in that the outer fire-resistant layer of the medium-voltage cable core is made of fire-resistant inorganic fiber heat insulation layer on the inner side, and the outer side is a soft thermosetting elastomer for normal use. The composite fire-resistant and heat-insulating layer of the heat layer, the thermosetting elastomer, is composed of 30-50wt% silicon-based elastic material, 40-60wt% inorganic filler, 5-15wt% medium and low temperature frit, 4-10wt% vulcanizing agent, It is made by mixing extrusion molding and vulcanization. The composite fire-resistant and heat-insulating layer is a relatively soft sheath material when it is not exposed to flames, which can ensure good bending performance of the refractory structure in normal conditions, and quickly transforms into a shell-and-tube refractory and heat-insulating structure when it encounters fire or high temperature. In the fire-fighting environment, it can still maintain a certain period of time without being damaged, effectively preventing damage to the inner insulation caused by flames or high temperatures. When the flame temperature of the outer layer is 850°C, the temperature of the inner insulation surface is lower than 180°C. This fire-resistant and heat-insulating structure can be applied according to conventional cable production methods, and the production efficiency is extremely high.

Description

technical field [0001] The invention relates to a medium-voltage fire-resistant cable, in particular to a medium-voltage fire-resistant cable with a soft fire-resistant structure in normal use and a hard-shell fire-resistant and heat-insulating structure in case of fire. Background technique [0002] For extra-large high-rise buildings, if 0.6 / 1kV low-voltage power distribution is used as usual, the amount of cables used and the workload of laying and installation will increase by tens of times compared with ordinary buildings, and the space for laying cables will increase by several times. Can, and too many and too large cables in the building will also have an adverse effect on safe use. Therefore, super-large high-rise buildings began to use medium voltage (6-35kV) power supply. As a fire-resistant cable, the low-voltage cable structure does not need to add an insulating shielding layer, so the fire-resistant insulating layer can be directly applied to the conductor, and...

AI Technical Summary

Problems solved by technology

The disadvantages of this cable: First, the fire-resistant structure is still a hard-structure fire-resistant cable, and second, the fire-resistant structure is still only suitable for low-voltage cables, and it is difficult to directly apply to medium-voltage cables

[0015] Therefore, so far, there has not been a medium-voltage fire-resistant cable that is fire-resistant under normal use conditions and has a soft structure, and can maintain normal power supply under dynamic conditions for a certain period of time after fire.

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