大尺寸通风管网中障碍物对瓦斯爆炸冲击波传播特性影响的数值模拟

为了研究大尺寸通风管网中的瓦斯爆炸传播规律，采用数值模拟方法，针对具有不同障碍物数量的大尺寸通风管网模型，利用Fluent分析管网中各个监测点的超压变化曲线以及障碍物附近的速度矢量图，分析爆炸冲击波传播规律。研究结果表明:初期瓦斯爆炸后，障碍物的存在改变了通风管网内未燃瓦斯的积聚区域；高温和高压发生耦合作用，在氧气相对充足的进气管道中形成二次爆炸；障碍物与火焰波以及管网自身结构变化等多种因素形成复合作用，改变了通风管网内瓦斯爆炸冲击波的传播路径和叠加区域的位置；无障碍物时高压区域出现在进气管道中，有障碍物时高压区域出现在中部直管与斜管的交汇处附近，且数值相对较大。

Numerical simulation on influence of obstacle on propagation characteristics of shock wave caused by gas explosion in large size ventilation pipe network

At present, the research on the propagation laws of gas explosion mainly focuses on single pipe or simple bifurcated pipe without ventilation. In order to study the propagation laws of gas explosion in the large size ventilation pipe network, through using the method of numerical simulation and aiming at the model of large size ventilation pipe network with different amounts of obstacle, the change curve of overpressure at each monitoring point and the velocity vector diagrams around the obstacle in the pipe network were analyzed by using Fluent, and the propagation laws of explosion shock wave were analyzed. The results showed that after the initial gas explosion, the existence of obstacle changed the accumulation area of unburned gas in the ventilation pipe network. The secondary explosion occurred in the intake pipe with relatively sufficient oxygen due to the coupling effect of high temperature and high pressure. The propagation path of shock wave caused by gas explosion and the location of superimposed area in the ventilation pipe network changed due to the combined effect of multiple factors including the obstacle, flame wave, structural change of pipe network, etc. The high pressure area appeared in the intake pipe when there was no obstacle, while when there was an obstacle, the high pressure area appeared near the intersection of middle straight pipe and inclined pipe, with a relatively large value.