高层建筑利用竖井排烟的全尺寸实验研究

通过开展全尺寸实验,对不同竖井高度、火源功率下,室内、补风口、竖井的温度变化,以及补风口、竖井内速度变化进行分析研究。结果表明:竖井内温升随距离竖井底部距离增加呈指数规律衰减,竖井内排烟速度随距离竖井底部距离增加逐渐减小。火源功率一定时,竖井高度增加,烟囱效应增强,控烟效果变好,当竖井高度由2.8 m增加至5.6 m时烟囱效应增加最显著;火源功率增大,烟囱效应也增强,但室内热压力的增大不利于补风口控烟,需适当提高排烟竖井高度或减小补风口面积。

Full-scale experiment study on shaft exhaust smoke of high-rise buildings

Full-scale experiments under different heights of shaft and different fire source powers have been conducted in this work. During the experiments, we analyzed the temperature in room, air inlet and shaft and velocity in the air inlet and vertical shaft. It is indicated that temperature rise of the shaft decreases exponentially with increasing distance from the bottom of the shaft and the velocity in the shaft also decreases with increasing distance from the bottom of the shaft. Furthermore, increasing the height of shaft can enhance the stack effect and can improve the smoke control. The stack effect increases most significantly when the shaft height increases from 2.8 m to 5.6 m. Besides, increasing the fire source power can also improve the stack effect, but the increase of heat pressure in the room is harmful to smoke control of air inlet. So it is necessary to increase the height of shaft or reduce the area of air inlet when the fire source power increases.