PREDICTION OF SELF-IGNITION FIRE PROPAGATION AND COAL LOSS IN AN INCLINED SEAM

The thermo-chemical processes of coal spontaneous combustion in a practical inclined outcrop seam were investigated in order to understand underground mineral self-ignition, fire propagation, and reserves loss. A heat and mass transfer model of porous coal-bearing stratum was employed, combining convection and radiation with transient exothermic source which is coupled with coal oxidation, oxygen supply, and fuel consumption. It is found that spontaneous combustion firstly occurs under lean oxygen condition and fire development controlled by the reaction heat release in the early oxidation process shifts to oxygen restriction after coal self-ignition. The stratum porosity affects significantly the fire propagation. Fire propagation rate slightly increases as the inclined angle decreases. Compared with indirect surface survey, the predicted reverses loss is more reasonable; and thus, the present model could provide a useful reference to loss estimation in coal fire hazards.