An experimental study on the combustion characteristics of YJV and YC cables in urban utility tunnels
Mengzhen Liu, Ruhong Zhou, Jian Li, Yuan Chen, Shengzhong Zhao, Tiantian Xu, Fei Wang, Zhaoyi Zhuang
Abstract
Cable fires in utility tunnels can lead to severe economic losses and potentially cause citywide paralysis. Therefore, a comprehensive study on cable combustion characteristics under thermal stress holds paramount importance both theoretically and practically. In this study, two types of cables (YJV and YC cables) commonly used in urban utility tunnels were selected as the subjects for investigation. Cone calorimeter was used to examine the influence of heat fluxes, quantities of copper cores, and cross-sectional areas of copper cores on the combustion characteristics of cables. The results show that the combustion process can be broadly categorized into six distinct stages, i.e., Ignition, Sheath fire, Slow spread, Rapid spread, Fully development and Decay. In comparison, YJV cables are more susceptible to carbonization layer shedding during the combustion process. In addition, the time to ignition (TTI), mass loss rate (MLR), and heat release rate (HRR) were analyzed and discussed in detail. This study can provide valuable insights into understanding the combustion behavior of power cables and offers practical guidance for enhancing fire safety in power compartment of urban utility tunnel.