高层建筑“走廊-前室缓冲区”防火效果的数值分析

摘要

Buffer zone set between aisle and anteroom is proposed to improve the traditional mode of pressurizes mechanic smoke extraction. Fire Dynamic Simulation is used to simulate the model of high-rise fire. Eight models are set and analyzed, in which the smoke temperature distribution and concentration distribution are compared, and the best parameters is worked out. The result shows, when exhaust smoke volume is constant, the velocity of air curtain is as low as possible; when the volume of air curtain is constant, the smoke volume is as low as better. Based on the comparison, it is found that the smoke removal efficiency of mode 4 is the best one, which is about 74. 06%. The evacuating buffer not only can let smoke out timely, but also can guarantee safe personnel evacuation.%在高层建筑火灾研究中,随着前室正压送风研究的深入,发现其存在着一些缺陷.于是提出在走廊段设置“走廊—前室缓冲区”的方式来改善传统正压送风模式.采用Fire DynamicSimulation(FDS)场模拟软件模拟长廊型高层建筑模型.设置8组工况进行分析,比较各种工况下烟气的温度分布,浓度分布,并通过模拟设计出最佳的参数值.结果显示,在一定范围内,当排烟量为定值,空气幕射流速越低且正压送风越高时越好；当空气幕为定值,缓冲区机械排烟口排烟量越低越好.比较发现工况4参数最佳,其机械效率也是最高为74.06％.从而说明前室加压送风,缓冲区防烟空气幕与机械排烟组合的搭配能够较好的体现出“走廊—前室缓冲区”思想,能够更好的便于火灾时人员疏散,并且提供较高的排烟效率,保证走廊内烟气的及时排出.