隧道内顶棚和侧向机械排烟效果对比

Comparison of smoke exhaust effect between ceiling and lateral mechanical smoke exhaust in tunnel

为了比较顶棚机械排烟和侧向机械排烟在隧道火灾中的排烟效果,采用数值模拟的方法对隧道火灾中两种排烟方式的温度分布、流场分布、排烟量、排热量以及排烟效率进行对比。结果表明,两种排烟方式的流场分布与烟气吸入方式差别较大;侧向机械排烟更容易发生吸穿;顶棚机械排烟的排烟量和排热量更高,排烟效果更好;侧向机械排烟由于更容易发生吸穿,导致大量的空气进入排烟口,其排烟效率始终小于顶棚机械排烟。

In order to compare the smoke exhaust effect of ceiling mechanical smoke exhaust and lateral mechanical smoke exhaust in tunnel fire,the temperature distribution,velocity vector field distribution,smoke output,heat output,and smoke exhaust efficiency of the two smoke exhaust methods in tunnel fire were numerically simulated.The results show that the velocity vector field distribution and the smoke inhalation method of the two smoke exhaust methods are quite different.The ceiling mechanical exhaust has higher smoke exhaust volume and exhaust heat,and the exhaust effect is better;The lateral mechanical smoke exhaust is more likely to occur plug-holing and cause the fresh air drawn directly into the smoke exhaust system,and its smoke exhaust efficiency is always less than that of the ceiling mechanical smoke exhaust.