巷道火灾时期烟流参数变化规律模拟分析

Simulation analysis of variation law of smoke flow parameters during tunnel being on fire

本文以实际煤矿采区进风系统为原型,按照流体相似原理,建立了矿井巷道火灾模拟实验系统,然后利用GAMBIT软件建立实验巷道的物理模型,采用Hex/Wedge-Cooper方法进行体网格的划分,对初始条件和边界条件进行设定和处理,最后将巷道火灾火源简化为一个固定体积的稳态高温热源,采用FLUENT软件,针对不同的巷道入口初始速度,分别模拟分析火灾巷道烟流温度场、速度场、密度场和压力场的变化规律和分布情况。研究结果表明:火灾发生后,巷道烟流扩散范围逐渐增大,温度逐渐升高,在火区附近温度最高;烟流速度从巷道入口处到出口处逐渐降低,在巷道交叉口处由于存在局部阻力和节流效应,烟流速度会大大降低;烟流密度从巷道入口处到出口处逐渐增大,在通风情况不好的巷道,烟流密度会更大,且巷道顶部烟流密度要小于巷道底部烟流密度;烟流静压总体升高,但在巷道出口处烟流压力最低。

According to the similarity principle,with the ventilation system in mining area of an actual coalmine as prototype,the “simulation experiment system of mine tunnel fire” was established.The physical model of experimental tunnel was built by using GAMBIT software and the body was meshed by using the method of Hex/Wedge-Cooper.The initial and boundary conditions were set and processed.The tunnel fire source was simplified as a steady heat source of fixed volume.The variation law and distribution of temperature field,velocity field,density field and pressure field of smoke flow in fire tunnel were simulated and analyzed respectively with different initial velocity of tunnel entrance.The results show that：after the fire,the smoke flow diffusion range increases,the temperature gradually increases and it is the highest near the fire area;the smoke flow velocity decreases gradually from the inlet to outlet in tunnel,and it greatly reduces at the tunnel intersection due to the presence of local resistance and throttling effect;otherwise,the smoke flow density increases gradually from the inlet to outlet in tunnel,and it becomes greater in tunnel with bad ventilation;the smoke flow density at the top of tunnel is less than at the bottom of tunnel,and the smoke flow pressure is higher overall,but it is the lowest at the outlet of tunnel.