地铁隧道火灾烟气湍流反应的数值模拟研究

Numerical Simulation of Smoke Turbulent Reaction in Subway Tunnel Fire

基于PDF湍流非预混燃烧理论,以天津地铁区间隧道作为研究对象,利用FLUENT软件,对隧道纵向通风后火灾烟气的湍流反应进行数值模拟,得到通风后烟气湍流反应的模拟结果,并将模拟结果与天津消防所的火灾实验数据进行比较,验证模拟结果的可靠性.研究结果表明,火灾时隧道氧含量急剧下降,火灾烟气中含有大量CO等不完全燃烧产物,当启动机械通风排烟后,带入隧道的氧气与不完全燃烧产物再次发生氧化反应,烟气的成分及浓度发生相应变化,从而对人的毒性作用也将有所改变.为隧道火灾烟气流动分布规律的进一步研究,有效组织人员疏散提供重要参考.

Based on turbulent non-premixed combustion theory,the smoke turbulent reactions of the tunnel fire on the condition of mechanical ventilation were simulated with FLUENT software.Compared with the experiment taken by Tianjin firehouse,the simulation results were proved to be reliable.The results show that the oxygen content may fall sharply when there is a fire in tunnel.The smoke contains large amounts of CO and other products of incomplete combustion.When starting the mechanical ventilation and smoke extraction,the oxidation reaction will occur again between the oxygen bringing into the tunnel and the incomplete combustion products.Flue gas composition and concentration undergo corresponding change,resulted in low toxicity to human beings.The study provides important inference for further research on smoke flowing distribution rule during subway tunnel fire,and for human evacuation safety.