摘要
为研究集中排烟速率对烟气热分层现象的影响，采用1：20缩尺寸集中排烟隧道模型（22m长），开展2个排烟口对称开启、排烟速率在0．034～0．134m^3／s场景下的模型试验．结果表明：层化曲线随排烟速率变化沿隧道纵向呈复杂的变化趋势，烟气热分层现象具有分段的特点．火源附近层化强度大，且层化曲线不受排烟速率影响；排烟口正下方热分层强度随排烟速率增大迅速减小；排烟口外侧层化曲线随排烟速率增大在隧道底部出现较长的水平直线区段，该段能够反映冷空气层的高度变化．T/Taver=1所在位置高度变化与烟气层临界层高度变化情况具有极大的相似性，可用其来确定烟气层的高度．
To investigate the influence of extraction rates on the thermal stratification between fire smoke and cold air in different places, experiments were conducted by using a 22 m-length tunnel model of central smoke extraction, with the scale of 1 ： 20. Two exhaust vents were symmetrically open. Fire source was set in the middle of the model tunnel. And the smoke extraction rate was within the range of 0.034--0.134 m^3/s. The results show that the stratifica- tion curve along the tunnel varies with extraction rate, which presents a complex tendency. And the smoke stratifica- tion shows a characteristic of structural segmentation. The intensity of thermal stratification grows stronger as it ap- proaches the fire, and the stratification curve is not affected by the extraction rate. The intensity of thermal stratifica- tion under the exhaust vent decreases rapidly with the increase of extraction rate. A horizontal line segment appears on the bottom of the tunnel when the stratification curve outside of the exhaust vent increases with extraction rate. This segment can reflect the height changes of cold air layer. The height change at the location of T/Taver = 1 is similar to that of the critical smoke layer.
出处
《燃烧科学与技术》
EI
CAS
CSCD
北大核心
2015年第4期333-339,共7页
Journal of Combustion Science and Technology
基金
中国博士后科学基金资助项目(2013M540830)
北京市博士后科研活动经费资助项目(2013ZZ-02)
中国科学技术大学火灾科学国家重点实验室开放课题资助项目(HZ2013-KF01)
关键词
集中排烟
排烟速率
热分层
层化曲线
模型试验
central smoke extraction
smoke extraction rate
thermal stratification
stratification curve
model experiment
