Flame-retardant and fire-resistant direct current power cable applied to rail transit and production system and method

Abstract

The invention discloses a flame-retardant and fire-resistant direct current power cable applied to rail transit and a production system and method. The cable comprises a stranded conductor, a fire-resistant insulation layer, a flame-retardant insulation layer, a water-blocking layer, a flame-retardant and fire-resistant waterproof isolation layer, an armor layer and a flame-retardant outer protective layer. The flame-retardant and fire-resistant waterproof isolation layer comprises an inner longitudinal package aluminum-plastic composite belt, and an outer flame-retardant and fire-resistant polyolefin cover. The longitudinal package aluminum-plastic composite belt and the flame-retardant and fire-resistant polyolefin cover are spliced and combined into a composite integral structure. The stranded conductor is formed by stranding annealed copper wires into a regular stranded conductor or soft conductor of 50mm<2> to 400mm<2>. The fire-resistant insulation layer is formed by wrapping double-layer ceramic fireproof and fire-resistant silicone rubber composite tapes on a wrapping device in an overlapped manner. An ultraviolet light irradiation crosslinking halogen-free low smoke flame-retardant polyolefin insulation material is extruded on an insulation extrusion crosslinking production device to form a coating structure. The cable provided by the invention has the advantages of high flame-retardant and fire-resistant ability, good insulation performance, great fire resistance and high cable production efficiency.

Description

Technical field [0001] The invention relates to a direct current power cable used in a direct current traction power supply system for urban rail transit, in particular to a flame-retardant and fire-resistant direct current power cable for rail transit and a manufacturing system and method. Background technique [0002] The rapid development of urban rail transit has greatly eased urban traffic congestion, and at the same time put forward higher requirements for the safety and reliability of urban rail transit operations. Urban rail transit DC traction power supply system is an important part of urban rail transit. It provides reliable power and electric energy for the safe and stable operation of urban rail transit. As a transmission channel for traction power, DC power cables directly affect the safety and reliability of subway vehicles and even the entire system. In addition, DC power cables are mostly used in densely populated underground places. Once they are unable to work...

AI Technical Summary

Problems solved by technology

Its defect is that when a fire occurs, although the sheath of the cable can delay the burning and spreading speed of the entire cable, when the fire continues to burn, it will break through the sheath and ignite the insulation, causing the cable to short circuit and fail to work.

(2) The refractory layer of traditional fire-resistant cables is generally wrapped with high-priced refractory mica tape. The wrapping speed is slow, and the mica powder is easy to fall off during the wrapping process, which affects the fire-resistant effect; Brittle, easy to fall off when encountering vibration and spraying, poor fire resistance effect, it is difficult to ensure that the power line can still be safe and smooth in the event of a fire

(3) The refractory layer of some fire-resistant power cables is made of ceramic fire-resistant and refractory silicone rubber. The processing technology is: vulcanization→extrusion→vulcanization. The extrusion process requires a special silicone rubber wire and cable extruder to complete. Vulcanization also requires special vulcanization equipment, such as: hot air vulcanization furnace, microwave vulcanization oven, etc. The processing technology of the refractory layer is complex and the production efficiency is low

(4) The fire-resistant cable structure of the prior art is only designed with one layer of refractory layer, which is coated on the outside of the conductor. Although the structure is simple and the proces

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