热老化对XLPE绝缘核级电缆火灾绝缘失效影响研究

Experimental Study of Thermal Ageing Effect on Insulation Failure of XLPE Nuclear Grade Cable

为评估服役核级电缆在火灾中绝缘失效情况,对加速热老化后的XLPE绝缘核级电缆在模拟火灾环境下的绝缘失效参数展开试验研究,结合加速热老化与实际老化年限关系,分析老化影响规律在工程中的应用方法。结果表明,电缆绝缘失效线芯温度和绝缘失效时间随着加速热老化时间的增长呈线性下降趋势。基于电缆绝缘材料断裂伸长率保留率,可以有效估算电缆试样老化寿命和一定服役年限电缆的绝缘失效参数。

Application methods of the insulation failure laws of nuclear grade cable in engineering were also analyzed by combining the relation between accelerated thermal aging and physical life of nuclear grade cable. Results indicate that the insulation failure temperature of wire core and time of insulation failure decreased linearly with the time increase of thermal aging. The physical life of nuclear grade cable and insulation failure parameters could be estimated, on the basis of elongation at break.