纵向通风隧道内火灾温度场分布规律研究

以狮子洋水下特长隧道为工程背景,利用CFD数值模拟软件FDS 4.01,建立隧道实体物理模型,进行火灾数值模拟分析。研究了列车火灾热释放功率为15 MW、不同坡度、不同纵向通风风速下,该类隧道内拱顶附近和2 m高处温度场的纵向分布规律,以及各工况下拱顶的最高温度,并分析其对隧道结构防火和人员疏散救援的影响。结果表明:随隧道坡度的增大,在同一通风速率下的烟气回流长度逐渐减小,但随着风速的加大,坡度对烟气回流的影响逐渐减弱;随着通风风速的增大,火区附近的温度下降,而沿程温度上升,纵向通风速率越大,拱顶温度越低。

Study on Fire Temperature Field Distribution in Longitudinal Ventilation Tunnel

With the Shiziyang super-long underwater tunnel as the engineering background,FDS4.01 software was used to simulate the fires in this tunnel through a built tunnel physical model before.In the simulations,the longitudinal distribution rules of the smoke temperature below the tunnel vault and 2 m above the road,the maximum smoke temperature and its influences on tunnel structure and safe evacuation were studied in the situation of different gradients,different longitudinal ventilation velocities and a 15-magawatt-power same fire.The results show that,with the increase of the tunnel gradient,the length of the backflow will gradually decrease at the same ventilation rate;but with increase of the ventilation rate,the influence of gradient on the return of smoke will gradually weaken;with the increase of ventilation velocity,the temperature near the fire will drop and the temperature along the tunnel will increase;the bigger the longitudinal ventilation rate,the lower the vault temperature.