凝并作用下火灾烟颗粒粒径分布及变化  

Fire Smoke Particle Size Distribution Evolution Under Brownian Coagulation

作　　者：马绥华[1] 张永明[1] 方俊[1] 祝玉泉[1] 蒋亚龙[1] 王进军[1] 袁宏永[2] 

机构地区：[1]中国科学技术大学火灾科学国家重点实验室,合肥230027 [2]清华大学公共安全研究中心,北京100084

出　　处：《燃烧科学与技术》2007年第2期147-151,共5页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(50476023)

摘　　要：预测火灾烟颗粒粒径分布特征参数的动态变化可实现探测系统对环境参数响应的动态模拟.顶棚烟气输运中,烟颗粒的布朗凝并是改变粒径分布的主要过程,应用矩方法求解布朗凝并作用下对数正态颗粒粒径分布的烟颗粒非线性凝并方程,得到随燃烧变化的凝并速率下粒径分布特征参数随时间的计算结果.正庚烷试验火烟颗粒分布的计算预测值与实验测量值相近,结果表明,在烟雾浓度快速上升阶段,烟颗粒凝并造成颗粒浓度损失不明显,几何平均粒径变化很小,而燃烧基本结束后,烟颗粒数密度衰减很快.It is needed to predict evolution of smoke particle size distribution characteristics for simulating response of smoke detection system. At the ceilling smoke transport, Brownian coagulation is the dominant dynamic process for broadening the smoke particle size distribution. The experimental results of standard test fires indicate that the fire smoke particle size distribution fits to lognormal distribution. Applying moment method to solve the non-linear coagulation equation of fractal smoke aggregation with a log-normal size distribution,and combining fire dynamic simulator （FDS）, can caculated the change of smoke particle distribution characteristics with various coagulation rates. In the simulation of smoke aggregation distribution of heptane test fire （TFS） at standard test room, coagulation effect on the smoke particle number concentration loss and the geometric mean particle size increment is not obvious during the smoke concentration rising. But after the fire burns out, the particle number concentration decays sharply.

关 键 词：火灾烟颗粒 粒径分布 凝并 火灾动力学模拟 数值预测 

分 类 号：X928.7[环境科学与工程—安全科学]