Characteristics of coal spontaneous combustion in conical coal bunker based on numerical simulation
Coal bunker self-ignition area has strong concealment and is difficult to extinguish.To clarify the influence of dy-namic stacking and changes in air volume on oxidative spontaneous combustion of coal in a conical coal bunker,a multi-field coupled numerical simulation model is developed using COMSOL software for gas-solid two-phase flow,coal dynamic reten-tion and stacking,and slow calefactive oxidation during coal hopper feeding.The results show that there is a positive correla-tion between the air leakage and the increase in oxygen concentration at the range of 0.2~3.0 m3/h of air volume.The lar-ger the air leakage volume,the more thorough the oxidation of accumulated coal,and the stronger the risk of spontaneous combustion.The increase of accumulated coal thickness and air leakage volume can significantly boost the danger of coal combustion in the coal hopper.There is a clear tendency for spontaneous combustion of the coal accumulated in the coal hopper when the accumulated coal is thicker than 3 m and the air volume is greater than 0.3 m3/h.