Modelling and parametric investigations on spontaneous heating in coal pile

To predict the spontaneous heating of coal pile by computational fluid dynamics (CFD) is very meaningful for preventing the coal pile from self-ignition. A two-dimensional (2-D) numerical model, which could be simply implemented in FLUENT, was developed in this study. The chemical kinetic parameters of low-temperature oxidation of coal, which were expressed by the outer surface area of particles, were well measured in experiments. The coal piles under different conditions were calculated by using the developed model and measured kinetic parameters, in order to make clear the effects of some important factors. The simulation results indicated the evaporation of moisture from coal played a critical role. The pile height, coal type, wind velocity, and heat loss from bottom have significant effects on the process of spontaneous heating of coal pile. According to these effects, in order to increase the heat loss of pile and then effectively inhibit the self-ignition, the low pile height, good ventilation surrounding the pile, and ground material with high thermal conductivity below the pile should be used. The model developed in this model is expected to become a reliable tool to predict the spontaneous heating of coal pile.