自然通风条件下隧道火灾动态监测仿真分析

Simulation analysis of tunnel fire dynamic monitoring under natural ventilation condition

为了降低隧道火灾事故影响,如何动态监测隧道火灾的情况是需要解决的关键性问题。通过FDS场模拟软件建立隧道火灾模型,模拟小型货车车厢位于隧道中部着火的隧道火灾情况。分析火源近场的火源功率及隧道顶部温度变化,探测温度场分布动态变化相关性规律。结果表明:火源功率前200 s内处于稳定阶段,1000 s左右达到最大火源功率。隧道顶部温度整体趋势先升后降,热烟气呈现加速状态,温度变化曲线缓步上升。火源近场隧道顶部温度变化曲线与热释放速率曲线趋于一致,可根据隧道顶部温度变化曲线监测近场火源的动态变化。近场4处测点在12 min内处于临界高程和温度之内,此时火灾扑救人员相对安全,灭火可在此范围内采取内攻方式,为消防救援提供一定参考。

In order to reduce the impact of tunnel fire accidents,how to dynamically monitor the situation of tunnel fire is a key issue that needs to be solved.The tunnel fire model was established by FDS field simulation software to simulate the tunnel fire situation when the minivan car was located in the middle of the tunnel and caught fire.The power of the ignition source near the field and the temperature change at the top of the tunnel were analyzed,and the correlation law of the dynamic change of the temperature field distribution was detected.The results show that the ignition power is in the stable stage within 200s,and the maximum ignition power is reached around 1000 s.The overall trend of temperature at the top of the tunnel first rises and then falls,the hot flue gas shows an accelerated state,and the temperature change curve rises slowly.The temperature change curve of the near-field tunnel of the ignition source tends to be consistent with the heat release rate curve,and the dynamic change of the near-field ignition source can be monitored according to the temperature change curve at the top of the tunnel.The near field measurement point is within the critical elevation and temperature within 12min,at which time the fire fighting personnel are relatively safe,and the fire extinguishing can be carried out within this range to provide a certain reference for fire rescue.