SPONTANEOUS COMBUSTION OF CHAR STOCKPILES

A transient one-dimensional spontaneous heating model has been formula ted to describe the spontaneous heating process at relatively low temp eratures. The model consists of three differential equations describin g the temperature, oxygen, and moisture concentration in a char pile. These equations have been solved numerically by a finite difference te chnique, and the influence of the initial char temperature, char react ivity, particle size, and moisture content on the process of spontaneo us heating have been examined. Sensitivities are presented for the mos t important factors affecting the self-heating of coal, including a co mparison of coal pile characteristics with and without moisture adsorp tion, desorption, and migration. This model was also validated against data from large-scale spontaneous heating tests.