大坡度倾斜巷道火灾烟气温度分布特征研究

Study on fire-induced smoke temperature distribution characteristics in largely inclined roadway

为研究矿井大坡度纵向通风倾斜巷道发生火灾时烟气蔓延特征,采用Pyrosim数值模拟方法,分析坡度为5~30°的巷道火灾顶棚烟气最高温度和纵向衰减特性;提出坡度修正系数,构建一种适合坡度大于10°的巷道顶棚烟气最高温度预测模型。研究表明:随着巷道坡度增大,顶棚烟气最高温度下降,但烟气层垂直方向温升梯度减小,高温烟气充满近火源巷道。火源下风侧顶棚烟气温度衰减服从双指数函数和分布特征;大坡度巷道火源下风侧纵向温度可以分成2个区域,当无量纲纵向距离x/H小于5时,随着巷道坡度的增大,烟气温度随距离增加而降低;x/H大于5时,坡度大于10°时,坡度越大,烟气温度越高;坡度在10°以内,坡度越大,温度越低。

In order to study fire smoke distribution features in inclined mine roadway with longitudinal ventilation,maximum temperature and longitudinal attenuation characteristics beneath ceiling in a roadway with slope ranging from 5°to 30°were analyzed through Pyrosim numerical simulation method.Then,slope correction coefficients were put forward,and a new prediction model of maximum smoke temperature beneath ceiling with slope greater than 10°was established.The results show that with increase of roadway slope,maximum smoke temperature decreases,but temperature rising gradient in vertical direction decreases,and roadway near fire source is filled with hot smoke.Temperature attenuation characteristics along downwind ceiling of fire source can be correlated well by sum of two exponential functions.Longitudinal smoke temperature distribution downstream fire source with large roadway slopes can be divided into two regions.When dimensionless longitudinal distance x/H is smaller than 5,smoke temperature decreases along with increase of distance as slope increases.In case of x/H greater than 5,the greater roadway slope is,the higher smoke temperature is when slope is larger than 10°,however as it is within 10°,the greater it is,the lower temperature will be.