A small-scaled fire shaft bench was established and experiments were conducted to investigate the rise time of the plume in a two-end-open shaft and bottom-end-closed shaft. The rise time of the smoke plume fronts was considered as the moment when the temperature of a thermocouple became 15℃ in this paper. Semi-empirical e-quations, respectively t =8. 96Q-5/4z1/2 axid t = 15. 46Q-3/4z4/3. , for the rise time of the plume in a two-end-open shaft and bottom-end-closed shaft were obtained. It was proven that the smoke plume front spread in an open shaft is faster than in a bottom-end-closed shaft under the same fire and shaft dimensions. These results can be a reference for safety engineering design.%为得到竖井火灾中羽流前锋上升时间,搭建了小尺寸竖井火灾试验台,测量了两端开放竖井火灾和底部封闭竖井火灾中温度分布.当热电偶温升达到15℃时,确定为烟气羽流前锋到达该处,在此条件下,得到了两端开放竖井与底部封闭竖井中羽流前锋上升时间半经验公式,分别为t=8.96(Q)-5/4z1/2和t=15.46(Q) -3/4z4/3.在相同火源及竖井尺寸条件下,开放竖井中羽流前锋上升速度远高于底部封闭竖井中羽流前锋上升速度.试验结果可为安全工程设计提供参考.
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