Influence mechanism of temperature field inside the cable on dynamic process of cable pyrolysis

Cable is used widely in the industrial and public buildings. The hazard assessment of the cable burning is an important consideration fire protection design. In previous studies, the cable was considered as a thermally thin cylinder, which cannot be applied to the large diameter cables used commonly in engineering applications. In this work, fire experiments of individual cables with different diameters were conducted in the cone calorimeter. The increase of cable diameter led to a transition from peak to quasi-steady state mass loss rate during the cable pyrolysis. Based on the one-dimensional numerical model validated with the experimental data, the effect of cable insulation thickness on the heat transfer inside the cable was investigated. The numerical model was able to simulate the transition from peak to quasi steady state burning as a function of cable diameter. The present work provide the influence mechanism of heat transfer inside large diameter cables on the cable pyrolysis and provides a better understanding of cable fire behavior in common engineering applications.