地铁车厢汽油火灾的模拟计算与分析

采用数值计算方法,研讨了泼洒燃料总量为5kg汽油的故意纵火情况下产生的火灾功率、烟气的蔓延规律及烟气控制方案。首先理论分析了泼洒液体火灾的液面深度、浸铺面积、单位面积燃料质量损失速率,进而得到了泼洒液体燃料总量与火灾功率的关系。采用多分区区域模型对列车车厢内的烟气温度、厚度进行了计算。分析车厢5kg汽油火灾的烟气危险性中,发现烟气将在30s时下降到危险高度,烟气温度将在30~50s后超过人体的极限,90s后烟气降到车厢地板,150s后车厢会达到轰燃温度。基于数值模拟结果,笔者提出了烟气控制方案。研究成果有助于地铁防灾设计及人员疏散紧急预案的制定。

Simulating Calculation and Analysis of Gasoline Arson Fires in Metro Compartment

An arson fire of 5 kg gasoline is simulated by zone models in the paper so as to obtain the fire power, smoke spreading rule and smoke control methods through numerical calculation. For this purpose, firstly, the surface depth, spill area and mass burning rate of pool fire are theoretically analyzed and the correlation of the total mass of fuel and the resultant fire power is obtained. Then smoke temperature and height in the compartment of the train is calculated based on a multi-cell zone model, It shows that smoke will descend to the dangerous height in 30 s and fall to the floor in 90 s and the temperature of smoke layer will rise up to the limit of hazard temperature to human in 30 - 50 s, and that flashover temperature will be reached in 150 s. Finally smoke control methods are proposed based on the above numerical simulation, which is very useful for the metro design of fire-resistance and the establishment of emergency planning on evacuation.