基于CFD的公路隧道火灾烟气分布规律研究  

Numerical research on fire smoke distribution in highway tunnels

作　　者：丁翠 DING Cui(School of Safety Engineering,China University of Labor Relations,Beijing 100048,China)

机构地区：[1]中国劳动关系学院安全工程学院,北京100048

出　　处：《工业安全与环保》2022年第9期5-8,44,共5页Industrial Safety and Environmental Protection

基　　金：中央高校基本业务费专项资金项目(22ZYJS013)。

摘　　要：采用CFD数值模拟方法,建立隧道火灾模型,研究不同纵向通风风速和火源功率对隧道内火灾临界风速和烟气分布的影响。结果表明:烟流滚退距离受火源功率和通风风速影响,5、30、50 MW火源功率的临界风速分别为2.0、2.2、2.2 m/s;同一火源功率下,拱顶最高温度随着通风风速的增大,呈现出指数函数的下降趋势;同一通风风速下,拱顶最高温度随着火源功率的增大呈现正向线性关系,并且随着通风风速的增大,拱顶最高温度随功率增大的速度逐渐降低;不同火源功率及不同通风风速下,火源上风侧CO浓度均低于安全浓度(体积分数0.002 4%),火源下风侧远高于安全浓度。故若隧道发生火灾,应启动排烟风机并使隧道内的风速高于2.0 m/s,且在火源上风侧开展救援及逃生。The CFD numerical simulation method was used to establish a tunnel fire model to study the effects of different longitudinal ventilation wind speeds and fire source power on the critical wind speed and smoke distribution of fire in the tunnel.The results showed that the backflow distance of smoke was affected by fire power and velocity. The critical velocities of 5 MW,30 MW and 50 MW were 2.0 m/s,2.2 m/s and 2.2 m/s respectively;The maximum temperature of ceiling smoke showed a downward trend of exponential function with the increase of velocity under the same fire source power;The maximum temperature of ceiling smoke presented a positive linear relationship with the increase of fire power under the same velocity and the growth rate decreased with the increase of velocity;The CO concentration on upwind side of the fire was lower than 0.002 4% but much higher than 0.002 4% on the downwind side of the fire under different fire powers and different velocities. Therefore,when fire happens in tunnels,the smoke exhaust fan should be started and the velocity in the tunnel should be higher than 2.0 m/s,and the rescue and escape should be carried out on the upwind side of the fire.

关 键 词：隧道火灾 临界风速 烟气分布 烟流滚退 数值模拟 

分 类 号：U458[建筑科学—桥梁与隧道工程]