正压送风位置和风量对高层建筑火灾烟气控制的影响

正压送风控烟是高层建筑烟气控制的重要手段,目前消防队伍普遍配备移动排烟装备,但这类装备在高层建筑的应用尚未普及,有必要开展高层建筑正压送风控烟技战术的研究。本研究在1/4缩尺寸高层建筑正压送风控烟实验研究的基础上,进一步开展了数值模拟研究,重点关注正压送风位置和送风风量对高层建筑竖井烟气控制效果的影响。研究结果表明,从高层建筑火灾中着火层下部进行正压送风比上部更具优势,在着火层上方楼层送风时,由于烟囱效应的影响,需要更大的送风风量才能有效控制烟气,且当正压送风强度不足时,还会造成竖井内温度的显著上升,从而威胁到建筑内部人员的安全,着火层下方正压送风的最佳位置应根据通风情况综合确定。

Effect of position and supplying volume of positive pressure ventilation on smoke control in high-rise building fire

Positive pressure ventilation (PPV) is an important means to control smoke in high-rise buildings, at present, the fire brigade is generally equipped with mobile smoke extraction equipment. However, the application of this kind of equipment in high-rise buildings has not yet been widely used. It is necessary to develop smoke control tactics of positive pressure ventilation in high-rise buildings. This study was based on the experimental study on smoke control under positive pressure ventilation in 1/4 scaled high-rise buildings, CFD numerical simulation was conducted. The present simulation-based study described in this research is mainly focused on the influence of position and air supply rate of positive pressure ventilation on smoke control in vertical shaft in high-rise buildings. The results have shown that the PPV is placed under the fire floor is more advantageous than that above the fire floor, applying PPV above the fire floor, more PPV supply rate is needed to control smoke due to stack effect in vertical shaft. When the supply rate of positive pressure ventilation is insufficient, the temperature in the shaft will also rise significantly, the lives of any victims trapped in the building under the ?re floor will be injured. The optimal position of positive pressure ventilation under the fire layer should be determined comprehensively based on the ventilation condition.