高层建筑火灾时走廊-前室缓冲区效果数值模拟研究

高层建筑火灾时,正压防烟带入的大量新鲜空气被送入着火层并稀释了烟气,降低了机械排烟效率.提出设置高层建筑条形走廊-前室缓冲区的设想,采用双方程κ-ε模型,对设置缓冲区后排烟效果的影响进行了模拟和分析.结果表明:建有前室缓冲区后,前室内烟气的平均质量分数远小于4.6％,前室在较长时间内处于安全状态.从走廊扩散至竖井的烟气分别经过走廊、前室两次降温,温度下降明显,在竖井中容易形成滞止状态,使其向上方其他楼层扩散的趋势降低,对整栋楼内人员疏散而言更为有利.

Numerical simulation of corridor-atria buffer effect in high-rise building fires

In high-rise building fire,a large number of fresh airs will be pressurized into the fire floor when smoke prevention system is used,which dilutes the smoke and reducing the efficiency of mechanical smoke exhaust.The Corridor-atria buffer was put forward to control the smoke which was set between the atria and the corridor.The κ-ε three-dimension turbulence model with two equations were used,and the influences of smoke exhaust effect with Corridor-atria buffer were analyzes by simulation.The simulation results show that： in strip corridor,with setting Corridor-atria buffer,the average mass fraction of smoke in the atria was lower than 4.6%,which make the atria more safety.The smoke had two process of cooling in the effect of air curtain in the corridor and the pressure air in the atria,so the smoke of lower temperture was easy to be stagnant status and the tendency of spreading to other floors was reduced obviously,which make a great benefit to the people evacuation in the whole buidling.