地铁隧道火灾双点排烟的临界排烟量研究

Investigation on the critical exhaust volumetric flow rate for two point extraction ventilation in subway tunnel fires

基于1∶20的缩尺隧道模型进行一系列试验,研究地铁隧道火灾双点排烟系统下烟气温度分布特性及临界排烟量,并研究火源热释放率和风口长度对临界排烟量的影响。试验发现,临界排烟量随火源热释放率的增大而增大,随风口长度的增大呈现出先减小后增大的趋势,这说明存在一个临界风口长度。

A series of experiments were conducted to investigate the temperature distribution characteristics and critical exhaust volumetric flow rate with two point extraction ventilation based on a 1∶20 reduced scale tunnel model. The effects of heat release rate and vent length onthe critical exhaust volumetric flow rate were studied. The experimental results showed that the critical exhaust volumetric flow rate increased with the increase in HRR, and it decreased first and then increases with the increase of the length of exhaust vent,which indicated that there exists the critical length of exhaust vent.