基于FDS的双洞单向隧道火灾温度变化及烟气扩散分析

On the Fire Temperature Variation and Flue Gas Diffusion in Two-hole One-way Tunnel Based on FDS

为应对隧道火情的发生,避免不必要的人员伤亡和财产损失,分析隧道内温度变化和烟气蔓延特性,选择合适纵向风速和烟气蔓延控制方案具有重要的研究价值。为此,采用PyroSim软件,建立公路隧道模型进行FDS数值模拟。模拟最大热释放功率为20 MW的火灾,在三种不同的纵向通风强度下,观测烟气的逆流长度,确定3.5 m/s为此次模拟的临界风速;在三种不同的纵向风下,依据发生火灾时隧道内温度场变化和烟气的扩散蔓延特点,以及人员的疏散和火灾救援影响;模拟隧道烟气控制方案时,为不让烟气通过横通道蔓延至辅隧道中影响人员疏散,确定合适的主辅隧道的纵向通风强度起着十分重要的作用。

In order to deal with the occurrence of tunnel fire and avoid unnecessary casualties and property losses,it is of great research value to analyze the temperature change and the characteristics of flue gas diffusion in the tunnel,and select the appropriate longitudinal wind speed and flue gas diffusion control scheme.Therefore,PyroSim software is used to establish a highway tunnel model for FDS numerical simulation.The fire with the maximum heat release power of 20 MW was simulated,and the critical wind speed of 3.5 m/s was determined by observing the counter-current length of the flue gas under three different longitudinal ventilation intensity.Under three different longitudinal winds,based on the change of temperature field in the tunnel during fire,the characteristics of flue gas diffusion,and the impact of personnel evacuation and fire rescue,it is very important to determine the proper longitudinal ventilation intensity of the main and auxiliary tunnels in order to prevent the flue gas from spreading to the auxiliary tunnels through the cross passage and affecting the evacuation of personnel in the simulation of tunnel flue gas control scheme.