室内火灾中非连续介质着火时间研究

室内发生火灾时,和火源间隔一定距离的可燃物即非连续介质突然发生着火燃烧的现象较为普遍,且具有较强的危害性。从非连续介质着火的原因入手,通过将着火条件进行量化,提出了非连续介质着火时间的确定方法,即:非连续介质着火时间为烟气层和处于着火浓度下限的可燃挥发份接触所需要时间与烟气层温度达到非连续介质自燃点所需要时间的最大者,并通过实验验证了该预测方法和相关计算关系式的有效性,对火灾预防和火灾风险评估具有重要的指导作用。

Study on the Ignition Time of Discrete Objects in Enclosure fires

In enclosure fires, it is often occurred that a local fire first appears in a place, then the combustibles spaced certain distance with the occurred fire that is defined discrete objects will be ignited and begin to burn, and it is of great harmfulness. From the causes for the ignition of discrete objects and by quantifying the ignition conditions, a determination method for the ignition time of discrete objects is proposed, that is the ignition time of discrete objects is the larger one between the needed time that the smoke layer are in contact with the combustible volatiles which is in lower ignition concentration limit and the needed time that the smoke layer temperature arrive at the auto-ignition point of discrete objects. The prediction method and the related calculation formula are proved valid through the experiments and this has important guidance effect for fire prevention and fire risk assessment.