不同堆放条件下煤堆压实最低不适用风速研究

Study on the Minimum Inapplicable Wind Velocity of Coal Stockpile Compaction under Different Conditions of Stacking

为提高煤堆压实防治自燃可行性的预判能力,基于煤堆自燃理论,使用COMSOL Multiphysics 5.0数值仿真软件,建立煤堆自燃模型,对5个不同堆放规格尺寸煤堆进行压实后温度变化和自然发火期变化进行了分析,从以上两个角度研究了煤堆最低不适用压实风速,建立了与煤堆孔隙率相关的最低不适用压实的风速方程。结果表明,煤堆压实防治自燃存在不同的最低不适用风速,从温度变化角度考虑的最低不适用压实风速小于从自然发火期角度考虑时的最低风速,从安全角度考虑取二者较小值作为判断标准,煤堆压实最低不适用风速与煤堆堆放参数相关性不强,受原孔隙率影响较为显著,最低不适用压实风速与孔隙率之间具有幂函数关系。

In order to enhance the pre-judgment ability of feasibility of compaction for prevention of spontaneous combustion in coal stockpiles,the simulation model of spontaneous combustion in coal stockpile has been established by using the software of COMSOLMultiphysics5. 0. Numerical simulations for 5 different stack dimensions of coal stockpile were carried out,and the changes of temperature and time of spontaneous combustion after compacting were studied and the applicability of compaction in coal stockpile were analyzed. The minimum impropriety wind-velocity equation of coal stockpile compaction was established with the consideration of porosity. The results show that,there are different minimum impropriety wind velocities for the compaction of coal stockpile. The minimum impropriety wind-velocity from the perspective of changes in temperature is lesser than that from the perspective of changes in time of spontaneous combustion. Set the smaller value as the judgment standard,there is a weak correlation with the stack dimensions and the minimum impropriety wind-velocity,but it is significantly affected by the original porosity. The relationship between the minimum impropriety wind-velocity of compaction and the original porosity of coal stockpile exhibits a power function correlation.