雪峰山公路隧道火灾CO-能见度-温度横向分布

Transverse distributions of CO,visibility and temperature during fire in the Xuefengshan Highway Tunnel

利用FDS4.0仿真隧道在通风失效与火灾通风下不同规模的火灾情况,研究烟气横向分部规律,其中隧道模型通过许多小长方体堆砌建立,网格划分采用多重网格技术(Multiple Meshes)。研究结果表明:(1)CO浓度呈现隧道中线附近低,边墙附近高;能见度呈现隧道中线附近高,边墙附近低;温度的分布不明显;火灾通风下横断面上CO与能见度的梯度均较通风失效下大;由于对流等方面的作用,在火源附近下方会出现一段CO浓度低、能见度高的地段;(2)火灾通风时,建议人员应在有指导情况下向火源上游疏散,没有指导情况下,部分人员向火源下游逃生,应沿着中线进行疏散;火灾失效时,火源上、下游的人员均应沿着隧道中线进行疏散。

FDS4.0 （ Fire Dynamic Simulator） was employed to study the transverse distribution of fire smoke in road tunnel, with several heat release rates （5MW, 20MW and 50MW） and with longitudinal ventilation or no ventilation. The tunnel model grid was formed by using the multiple-mesh technique with small rectangular parallelepipeds. It is found that CO concentration along the centerline is smaller than in the vicinity of the side walls, and visibility is larger along the centerline than in the vicinity of the side walls, while there is no apparent difference in temperature between centerline and the side walls. The gradients of CO and visibility in the transverse direction are larger with ventilation than that under ventilation failure, and due to convection, there are relatively lower CO concentration and larger visibility near the fire. For unidirectional traffic tunnels, personnel should evacuate under guidance, and if no guidance available, people should evacuate along the centerline rather than the walkway.