狭长通道内火灾烟气毒性成分空间分布的实验

The spatial distribution of toxicant species in fires in a long corridor

利用模拟狭长通道的小型实验台研究了火灾烟气传播过程中毒性成分的空间分布规律.结果发现,烟气成分的分布沿着水平方向呈现不同的特点,在远离火源的位置呈上下两层分布,符合两层区域模型,而在离火源较近位置则递变分布,则须用场模型或者多层区域模型评估.实验表明,烟气毒性成分的浓度峰值随高度的降低呈现明显的阶梯变化,在过渡区段骤升骤降.实验测量到,CO和CO2迁移时浓度峰值在远离火源处仍然保持相当高的浓度甚至高于火源近处的浓度,这与火灾中很多遇难者死于远离火源位置的结果是一致的.

A set of reduced-scale fire tests were conducted in a long corridor structure apparatus to study the characteristic of the spatial distribution of toxicant species in the transport of fire smoke. Results indicate that species concentration distribution varies horizontally：when at a distance from the fire origin they show a 2-layer distribution, suitable for applying 2 layer zone model; and in the vicinity of the fire origin they show a gradual distribution,requiring the field model or multi-layer model for evaluation. It is found that the maximum concentrations of the species change with the decrease of height, rising and dropping drastically in the transition region. The measured CO and CO2 maximums at the remote location are considerably big and some even a little bigger than those at fire vicinity, which is consistent with the phenomenon that most of the fatalities in fires occur far away from the fire origin.