The results of orthogonal experiment shows that the effect of the volumetric flow of exhaust gases is the most notable ; the effects of the number of exhaust inlets and the heat released rate of fire source are less notable than the effect of the volumetric flow of exhaust gases on the smoke layer interface ; the effects of the separation of exhaust inlets , the interrelation between the number and the separation of exhaust inlets and the location of exhaust inlets are notable ; but the rest factors " effects are not obvious 实验结果表明：对烟气层高度影响特别显著的是排烟量大小、排烟口数量和火灾负荷大小三个因素；排烟口间距，排烟口数量与间距的交互作用，排烟口位置和大小对烟气层高度的影响也比较明显；而排烟口大小与间距，大小与位置，大小与数量，位置与数量，位置与间距之间的交互作用对烟气层高度的影响不大。
