CALCULATION METHOD IN PRESSURIZATION SMOKE CONTROL SYSTEM IN CASE OF BUILDING FIRE

通过模型试验，研究了建筑火灾中顶板下烟幕锋面运动的基本机理。实验结果表明，在45度角下，烟幕锋面速度随角度的增大而增大，45度以上，烟幕锋面的运动速度基本相同。建立了倾斜天花板的简单密度模型。将该模型的预测结果与实验结果进行了比较，结果表明该模型在45度角以下是成功的。建立了角度较大的混合模型，结果表明该模型在角度小于60度的情况下是成功的，这对考虑当前高层建筑的排烟控制问题具有重要的意义。但对整个建筑火灾时的防排烟系统的研究还不够充分。为保障消防人员的安全，本研究提出了舞台火灾充分发展时增压防排烟系统送风量的简易计算方法。考虑了烟囱效应和室外风速的影响，并考虑了防止烟尘流入竖井的条件。同时构造了计算方法，对简单计算方法进行了比较。结果表明，这种简单的计算方法能有效地计算出阶段火灾充分发展时的送风量。

The basic mechanism of smoke front movement under ceiling in building fire is investigated by the model experiments. As a result of this experiments, under 45 degree of angle the velocity of smoke front increases with increasing angle and over 45 degree the smoke front moves with evenly same speed. The simple density model is constructed to the inclined ceiling. It is shown that this model is successful for less than 45 degree of angle by comparison predicted results of this model with experiments. The Hybrid model is constructed for larger degree of angle, it is shown that the model successful for less than 60 degree of angle.It is important to consider the problem of smoke control system in recent high-rise buildings. But the research of smoke control system of whole building in case of fire is insufficient. In this research the simple calculation method of supply air rates in pressurization smoke control system in case of fully developed stage fire is proposed to secure the place for firemen. The effects of the stack effect and the outdoor wind velocity are considered and the condition to prevent smoke inflow to shaft is considered. Simultaneously the computational calculation method is constructed to compare the simple calculation method. As results the simple calculation method is efficient to calculate supply air rates in case of fully developed stage fire.