基于Fluent流体动力学分析软件对单洞双向隧道火灾烟气特性开展研究,分析了隧道出口700m、1100m、1500m等3种不同位置火灾不同风速条件下烟气蔓延变化规律及导致的火灾临界危险时间变化。结果表明:同样风速条件下,火源位置越靠近洞口,火源上游越安全,火源下游的烟气蔓延速度越快,下游越危险。当通风风速大于1.0m/s时,隧道风速越大,隧道下游火灾早期更安全,但后期火灾危险性增大。 Based on Fluent fluid dynamics analysis software, the smoke characteristics of single-hole bidirectional tunnel were studied. The variation rules of smoke spread under different wind speeds of 700m, 1100m and 1500m at tunnel exit were analyzed and the critical danger time of fire Variety. The results show that, under the same wind speed, the closer the fire source locates to the hole, the safer the upper reaches of the fire, the faster the smoke spread downstream of the fire source and the more dangerous the lower reaches. When the ventilation velocity is more than 1.0m / s, the greater the wind speed of the tunnel, the safer the fire in the lower reaches of the tunnel, but the greater the risk of fire in the later stage.