地下狭长封闭空间烟气填充模式可视化实验研究
Visualizing experiment of smoke filling processes in underground long and narrow enclosed space
摘要:
实验研究结果表明:当模型的形状系数小于2时,烟气形成自上而下的填充方式,烟气界面和水平面平行;当形状系数大于等于2时,烟气形成狭长空间的填充方式,而且形状系数越大,该填充方式越明显。在两种烟气填充方式下,烟气浓度分布特点不同:形状系数小于2时,烟气浓度在同一个水平面内分布相对均匀;形状系数大于等于2时,烟气浓度在同一水平面内分布很不均匀,远离火源处的烟气浓度远高于火源附近区域的烟气浓度。地下狭长、封闭空间的烟气填充方式对人员逃生不利,在制定地下建筑防火排烟逃生预案时应予以充分考虑。
Abstract:
The experiment results show that smoke fills from top down to bottom when the model shape coefficient is less than 2 and the interface of smoke layer is horizontal, and that the long and narrow enclosed space smoke filling mode will be formed when the shape coefficient is equal or greater than 2, and it is more obvious with even larger shape coefficient. The distribution characteristics of smoke density in the two modes are different. When the shape coefficient is less than 2, the distribution of smoke density on the same horizontal plane is relatively uniform, while that is very non uniform when the shape coefficient is equal or greater than 2, the smoke density far away from the fire source is far higher than that near the fire source. The smoke filling mode in a long and narrow enclosed space is unfavorable for human evacuation under fire, so it should be considered fully when the fire evacuation plan was drafted for underground spaces.
Keywords:underground building,enclosed space, visualization, CO concentration, model experiment