摘要
在低湍流风洞实验研究了0～3.95m/s的纵向通风对边长为4cm至9cm的正方形酒精池火燃烧速率的影响,并在实验数据的基础上分析了通风影响酒精池火燃烧速率的机理.实验表明,零风速时酒精池火单位面积燃烧速率基本一致;随着风速的增大,各油池燃烧速率呈单调递增趋势.通风使得酒精油池接收到的热反馈增强是燃烧速率加快的主要原因,其影响远大于对流强制蒸发的作用,且通风影响酒精燃烧速率的趋势主要决定于油池接收的总热反馈量.随着风速的增加,相较于油盘下风侧壁面,燃料表面接收到的热反馈对燃烧速率的影响逐渐占主导.
The effects of a longitudinal air flow ranging in speed from quiescent to 3.95m/s on the burning rate of square ethanol pools ranging in size from 4cm×4cm to 9cm×9cm were studied experimentally in a low-turbulence wind tunnel.Based on the experimental results,the mechanism of how the burning rate is affected by the air flow was discussed.The results show that for all pools tested when the flow speed is quiescent the burning rate of ethanol per unit area was basically constant.And the burning rate increased monotonically with the increase of flow air speed.The main reason for ventilation to speed up the burning rate of ethanol pool fires is that it enhances the heat feedback to the pool,which plays a far more important role than ventilation speeding up the evaporation rate by forced convection.With the increase in air flow speed,the heat feedback to the fuel surface plays an increasingly dominant role in the burning rate than that to the downward side wall of the pool.
关键词
酒精池火
纵向通风
燃烧速率
热反馈
ethanol pool fire
longitudinal air flow
burning rate
heat feedback
