城市隧道火灾组合式排烟特性研究

通过1/20小尺寸模型实验对城市隧道火灾组合通风排烟方式下的排烟特性进行了研究.通过对不同纵向风速和不同排烟量下温度和烟气实验结果的分析,表明隧道的顶部排烟量越大,烟气层下降越慢,越有利于隧道内的人员疏散,但是排烟量的增大对降低隧道顶部温度效果不大.根据实验结果可知,对于组合通风方式下的隧道火灾,应先打开顶部排烟口进行排烟,然后开启火源上游风机进行纵向通风,纵向通风风速应控制在临界风速左右.

Study of smoke exhaust of combined ventilation system in urban tunnel fires

Experiments are carried out to study the smoke control of combined ventilation system in a 1/20 scale model tunnel.Based on the analysis of the temperature and smoke height under different ventilation conditions,it is concluded that the higher the smoke exhaust volume,the lesser the smoke descends; but the temperature in the ceiling does not drop much as the exhaust volume increase.According to the experiment,when a fire breaks out in a tunnel with combined ventilation system,it is best to open the ceiling exhaust first; and then to control the longitudinal velocity to be critical velocity.