开口位置对楼梯井内烟气运动影响的研究  

Influences of the opening position on the smoke removal in a stairwell

作　　者：许兆宇[1] 李元洲[1] 孙晓乾[1] 许晓元[1] 

机构地区：[1]中国科学技术大学火灾科学国家重点实验室,合肥230027

出　　处：《安全与环境学报》2010年第2期156-161,共6页Journal of Safety and Environment

基　　金：中科院与香港合作项目--香港裘槎基金项目(5-ZH46)

摘　　要：通过在1/3尺寸的高层建筑楼梯井实验台内开展火灾烟气运动试验,对不同开口位置情况下,楼梯井内烟气的竖向温度分布、进出风口速度以及烟气前锋上升时间进行了研究。结果表明,烟气温度沿楼梯井竖直方向衰减较快,并且开口位置对井内的竖向温度分布有较大影响,随着开口高度的减小,其上方楼层的烟气温度降低。开口的存在也会减缓烟气向楼梯井上部蔓延,且开口位置越低,烟气的蔓延速度越慢;反之,升高开口位置,楼梯井上下贯通的竖向结构与外界环境间的对流加强,烟气在楼梯井内的竖向蔓延速度也会加快。The paper has done a series of experiments in a one-third scale model to study the influence of opening position on the smoke dispersing in the stairwell of a building. During the experiments, we kept measuring the smoke temperature distribution along the stairwell, the inflow and outflow velocity at the openings under different opening conditions, and the rising-time of smoke front based on the thermocouple in the staircase was got, which meant that the time at which a thermocouple exhibited a sudden temperature rise was regarded as the time at which the plume front arrived at the height of the thermocouple. The results 9f our research prove that the smoke temperature experienced a rapid decay along the vertical direction and the smoke temperature could be reduced to the ambient temperature in some conditions. Furthermore, the opening height had a significant effect on. the smoke temperature distribution. That is to say, a lower opening can cause a reduction in the smoke temperature at the higher positions. Besides, the opening can also slow down the smoke spreading in the stairwell. Actually, the lower the opening was, the slower smoke would move upward. On the contrary, rising the opening position tends to promote the smoke spreading in the vertical direction obviously, resulting in the increase in the convection between the stair-well and the environment, which means a higher opening position in stairwell may cause greater danger with the other conditions being equal.

关 键 词：安全工程 楼梯井 烟囱效应 竖向温度分布 烟气前锋 

分 类 号：TU834[建筑科学—供热、供燃气、通风及空调工程]