孔隙率和风速对煤矸石山自燃的影响

Effect of porosity and wind speed on spontaneous combustion of coal gangue hill

煤矸石山一般以顺沟排放和自然堆积为主,长期堆积会导致其自燃。为减小煤矸石山自燃的风险,采用Fluent软件探究孔隙率和外界风速对矸石山内部温度场分布的影响。数值模拟表明,煤矸石山自燃的孔隙率范围为0.20~0.40;孔隙率为0.20时,对应的风速是0.5 m/s,高温危险区域与斜坡面垂直距离为4.0 m;孔隙率为0.35时,对应的风速是0.01~1.8 m/s,高温危险区域与斜坡面垂直距离为2.8~7.5 m;孔隙率不变时,风速的提高会导致矸石山高温区与斜坡面的垂直距离增大;风速不变时,孔隙率的提高会导致矸石山高温区温度先升高,后降低。

Coal gangue hill is mainly discharged along the ditch and natural accumulation,long-term accumulation will lead to its spontaneous combustion.In order to reduce the risk of spontaneous combustion of coal gangue hill,Fluent software was used to explore the effects of porosity and external wind speed on the temperature field distribution inside the gangue hill.The numerical simulation shows that the porosity range of spontaneous combustion of coal gangue hill is 0.20~0.40.When porosity is 0.20,the corresponding wind speed is 0.5 m/s,and the vertical distance between high temperature danger zone and slope surface is 4.0 m.When the porosity is 0.35,the corresponding wind speed is 0.01~1.8 m/s,and the vertical distance between the high temperature danger zone and the slope surface is 2.8~7.5 m.When porosity is constant,the vertical distance between high temperature area of coal gangue hill and slope surface increases with the increase of wind speed;When the wind speed is constant,the increase of the porosity will cause the temperature in the high temperature area of the coal gangue hill to increase first and then decrease.