Numerical Simulation On Minimum Inapplicability Of Compaction For Prevention Of Spontaneous Combustion In Coal Stockpile

Coal is a activity porous medium,self-heating carry out automatically and lead to spontaneous combustion in coal stock-pile,this process affect the coal quality seriously,also harm to the environment,severe fires caused heavy casualties and property losses.To preventive the spontaneous combustion in coal stock-pile,study the influence factors on the spontaneous combustion,determine the wind-velocity range of spontaneous combustion under the condition of different stacking parameters,and then provide the reasonable control measures are very necessary.Five two-dimension simulation models have been established by use the software of COMSOLMultiphysics5.0,based on fluid flow in freedom and porous medium,Material migration and transfer in porous medium,porous medium heat transfer.Studied the spontaneous combustion in coal stockpile under the condition of variable wind-velocity and stacking parameters,variable porosity.Identified the law of wind-velocity of spontaneous combustion and the influence factors.Identified the inapplicability range of coals compaction to protect the coal stockpile.Variation of the maximum temperature with wind-velocity is a double-exponential function,Establish the mathematical equation of the smallest,most easily and the largest wind-velocity,that contain the porosity,height of coal stockpile,and the width of top and bottom,Provide the basis for judging the coal spontaneous combustion.Inapplicability range of coals compaction is given,and the range is different because of the different original porosity,establish the mathematical equation of minimum inapplicability wind-velocity,the larger the original porosity the smaller the minimum inapplicability wind-velocity.