受限开口小房间内火灾受水雾作用的数值模拟

Numerical Simulation on the Suppression of Fire by Water Mist in a Cabin with Confined Opening

为了掌握水雾在受限制开口房间内对火灾的作用情况,利用数值模拟方法对有限宽度开口小房间内的水雾粒径范围为200~1 400μm时对液体火灾的作用进行数值计算分析,比较房间内的流场影响,房间如果开口过大则水雾起不到灭火作用,若开口较小使火灾转变为通风控制燃烧时,水雾的灭火效能随着水雾平均粒径增大而降低,水雾粒径为200μm可以起到有效的灭火作用,而且开缝宽度较小时的灭火速度更快;对于粒径大于400μm的水雾来说,灭火效能并非是随着房间门打开宽度的减小而增大,同样的水雾在开口宽度为0.15 m时对火灾的抑制作用效果较门开口宽度为0.25 m时差;靠近门开口中下部分的附近区域是易发生回燃的危险区域。

To study the influence of the water mist on the fire in a confined opening compartment,some researches are carried out about the effect of the diameter between 200- 1,400 μm of the water mist on the liquid fire. By numerical simulations,it is found that when the opening is large enough,water mist has no effect on the fire; when the opening is so small that the fire became wind-controlled,the efficiency of water mist becomes strong with the averaged diameter of water mist enlarged. And the diameter with 200 μm can extinguish fire effectively when the opening reduced. But when the diameter is larger than 400 μm,the efficiency is not increased with opening width less. With the same sized water mist,the effect of extinguishing fire with the opening width 0. 15 m becomes less than that with the opening width 0. 25 m. The region near the bottom of the door opening was easier to burn again.