Study on Numerical Simulation Model of Spatio-Temporal Evolution in Dynamic Gob Areas

Researching on the spontaneous combustion of coal in gob areas (i.e. areas in which residual coal is deposited) by using computer simulation is one of the main method, which can provide theoretical basis for preventing fire in coal mine, and the spatial-temporal evolution model is one of the key point. Based on double-coordinate system and low-temperature oxidation kinetics, a dynamic model of gob's spatio-temporal evolution was established. The model mainly including a spatial characteristics of chemical reactions and a spatial characteristics of physical structure of gob, through establishing the coal oxidation kinetics at low temperature and the spatio-temporal evolution function of porosity. Then, the User-Defined Functions in FLUENT were used to simulate the spatio-temporal evolution model of gob, and the model was validated by similarity simulation experiment and applied to research on the influence of working face advancement on the migration speed of the highest-temperature point, which show that research model was effective, and it will be effective method to study on the spatio-temporal evolution of spontaneous combustion in gob areas.