铁路隧道火灾中烟气逆流层长度的研究

以狮子洋隧道为工程背景,对不同火源热释放速率、不同通风风速、不同坡度及不同断面当量直径情况下的火灾进行了数值模拟。分析了隧道烟气逆流层长度的变化规律,并对模拟数据进行了拟合。结果表明,隧道烟气逆流层长度与通风风速、火源热释放速率、隧道断面当量直径的自然对数值拟合均符合直线关系,呈递增或递减变化;坡度对烟气逆流层长度的影响随通风风速的增大而减弱。在分析烟气逆流层长度变化规律的基础上,建立了烟气逆流层长度与火源热释放速率、通风风速及断面当量直径的关系式,通过对数据拟合获得了烟气逆流层长度公式,该公式推导合理,并有所创新。

Study on Backflow Distance of Smoke under the Fire Situation in Railway Tunnel

Taking Shiziyang tunnel as the background,the numerical simulation of fire was carried out under the conditions of different fire sources power,different ventilation velocities,different slopes and different equivalent diameters.The change law of backflow distance of smoke in the tunnel was analyzed,and the data of simulation was fitted.The result indicated that there are line relationships between backflow distance of smoke and natural logarithm of ventilation velocity,fire source power and tunnel equivalent diameter,increasing or decreasing.The impact of slope on backflow distance of smoke weakened with the increase of ventilation velocity.And then,relational expression between backflow distance of smoke and fire source power,ventilation velocity,and equivalent diameter was proposed based on analysis of change laws of backflow distances of smoke,and backflow distance formula was built up through data fitting.The formulas' rationality and advantage were analyzed.