大空间建筑不同排烟系统作用下的烟气控制效果研究

利用FDS(Fire Dynamics Simulator)分别对自然排烟和机械排烟作用下的中庭火灾烟气控制效果进行了数值模拟研究,自然排烟口的面积分别为中庭地面面积的5.6%、11.3%和22.5%,机械排烟量分别为43182m3/h和102000m3/h,同时改变机械排烟口的位置。通过对比各工况下的竖向温度分布、中庭内温度场、烟气层界面高度来判断不同工况下的排烟效果,并计算得到了相应排烟效率来判断各排烟模式下的排烟有效性。结果显示,中庭内的温度和排烟效率都随排烟量的增大而减小,自然排烟的排烟效率最低,仅为17.9%~21.3%,机械排烟量43182m3/h时的排烟效率最高,可达45%左右。

Research on the effect of different smoke controlling methods in large space

The effect of different smoke controlling methods, including the mechanical smoke exhaust and natural smoke exhaust, adopted in large space fire was studied by numerical simulation using FDS (Fire Dynamics Simulator). The areas of openings account for 5.6%, 11.3% and 22.5% of the large space area, respectively. The mechanical exhaust rates were set as 43,182m3/h and 102,000m3/h, respectively, and the positions of smoke vent also differed for each exhaust rate. The vertical temperature distribution, the temperature field in the large space and the location of smoke layer height for all the cases were compared with each other and the smoke exhaust efficiency was also calculated. The results showed that the temperature in the large space and the smoke exhaust efficiency decreased with exhaust rate. The natural smoke exhaust had the lowest efficiency of 17.9%~21.3%, while the mechanical smoke exhaust with rate of 43,182m3/h had the highest efficiency of about 45%.