热老化对阻燃YJV电缆绝缘失效规律与燃烧性能的影响

Effects of Thermal Ageing on Insulation Failure Law and Combustion Performance of Flame Retardant YJV Cable

为评估服役阻燃交联聚乙烯绝缘聚氯乙烯护套(YJV)电缆在火灾中的绝缘失效及燃烧情况,分别采用塑料电缆热辐射试验炉和锥形量热仪,对热老化后阻燃YJV电缆在模拟火灾环境下的绝缘失效规律及燃烧性能进行实验研究。结果表明:阻燃YJV电缆绝缘失效时间和失效温度均随热老化的加剧呈下降趋势,并随老化时间的延长趋于平稳;材料的火灾性能指数先增大后减小,表明电缆老化前期火灾危险性有一定程度的上升。

In order to evaluate the insulation failure and combustion condition of the flame retardant crosslinked polyethylene insulating polyvinyl chloride sheath（YJV） cable in fire, the insulation failure law and combustion performance of the flame retardant YJV cable were studied via thermal radiation test furnace and conical calorimeter after being thermal aged in the simulated fire environment. The results show that both the failure time and the failure temperature of flame retardant YJV cable show a decreasing trend with the aggravation of thermal ageing, and tend to be stable with ageing time. The fire performance index of the materials increases first and then decreases, indicating that the risk of fire rises to a certain extent at the initial stage of cable ageing.