多窗口羽流火焰高度计算公式及其影响因素

The Practical Formulas and Influence Factors for the Height of the Windows Plume Flame

目的研究高层建筑纵向相邻多窗口羽流火焰的融合机制,引入危险温度T、T1及T2,分析危险温度高度与各影响因素之间的变化规律.方法采用软件PyroSim对不同窗口尺寸、火灾荷载密度以及纵向窗口数量等因素影响下的火灾建筑模型进行数值模拟,并根据模拟所得数据绘制窗口温度时间历程曲线与纵向温度分布等温线.结果纵向相邻多窗口羽流火焰出现了融合现象;危险温度T1和T2所处高度在纵向相邻两窗口比单窗口提升了2. 1～4. 0 m,纵向相邻三窗口比纵向相邻两窗口提升了0. 05～0. 8 m.结论纵向相邻两窗口羽流火焰的危险温度T1和T2所处高度与纵向相邻三窗口相似,对于同类型的高层建筑外部火蔓延的防控,考虑纵向相邻两窗口的危险温度分布即可满足要求.

The purpose of this paper is to study the fusion mechanism of vertically adjacent multiwindowplume flame in high-rise buildings. First,the dangerous temperatures of the plume flame T,T1 and T2are introduced in this paper. Second,the changing rules of the dangerous temperatures and the influencing factors are analyzed. The software PyroSim was used to study the numerical simulation of the fire building models under the different conditions such as the windowsize,fire load density and the number of vertical windows and other factors. Based on the data from simulation,we drewcurves of changing temperatures and the vertical temperature isotherms. The result shows the fusion phenomenon of the vertical adjacent multi-windowplume flame. The height of dangerous temperature T1 and T2in the vertical two windows is increased by 2. 1 ~ 4. 0 m compared with the single window. The height of dangerous temperature T1 and T2in the vertical three windows is increased by 0. 05 ~ 0. 8 m compared with the two windows. The height of the danger-ous temperatures T1,T2 in the vertical two windows are similar to the three windows. For the prevention and control of the fire spreading outside the high-rise buildings of the same type,the dangerous temperature distribution of two adjacent windows in the vertical direction can be met. Based on the simulation research and previous research,applicable formulas of dangerous temperatures T1 and T2are obtained. The concept of safety factors is introduced and the range of its value is determined.