不同隧道坡度与车厢火灾位置情况下烟气蔓延特性研究

Study on smoke spread characteristics under different tunnel slopes and car fire locations

为研究含坡度隧道不同火源位置情况下车厢火灾烟气蔓延特性,采用CFD数值模拟方法,建立全尺寸地铁隧道与列车数值模型,研究车厢不同火源位置情况下火灾烟气纵向温度分布规律,探讨倾斜隧道车厢火源位置对烟气蔓延的影响。研究结果表明:当火灾烟气蔓延处于纵向通风惯性力与热浮力竞争作用控制阶段时,火源位于车厢上游方向时火灾烟气向车厢方向蔓延距离小于火源位于车厢下游方向情况,且随坡度增大,火源位于车厢上游方向烟气逆流长度不断减小,位于下游方向烟气逆流长度不断增大;当纵向通风风速达到2 m/s时,火源位于车厢上下游方向2种情况下,列车车厢方向均无烟气蔓延(逆流长度为0),此时火灾烟气蔓延将主要由纵向通风控制,隧道坡度无显著影响。

In order to study the characteristics of smoke spread in the car fire with different fire source locations in the tunnel with slope,a full-scale numerical model of subway tunnel and car was established by using the CFD numerical simulation method.The longitudinal temperature distribution of fire smoke in different fire source locations of car was studied,and the influence of fire source location in the car with an inclined tunnel on the smoke spread was discussed.The results showed that when the fire smoke spread was in the competitive control stage of longitudinal ventilation inertia force and thermal buoyancy,the spread distance of fire smoke to the car direction when the fire source was located at the upstream direction of car was less than that when the fire source was located at the downstream direction of car,and with the increase of the slope,the smoke back-layering length decreased when the fire source was located at the upstream of car,while the smoke back-layering length increased when the fire source was located at the downstream of car.When the longitudinal ventilation wind speed reached 2 m/s,there was no smoke spread in the car direction(with back-layering length of 0),no matter the fire source was located at the upstream direction and downstream direction of car.At this time,the fire smoke spread would be mainly controlled by the longitudinal ventilation,and the tunnel slope had no significant influence.