Numerical and experimental simulation of spontaneous combustion of coal

In this paper, our main aims are to make up for the defects of large-scale coal spontaneous heating tests on trial methods. An unsteady-state numerical model is developed to simulate self-heating in a large-scale coal spontaneous heating reactor with experimental conditions. The self-heating process of coal is reproduced successfully, and the main characteristics of nonlinear heating and windward movement of the fire source are obtained during the whole process. By comparison, the simulated and experimental results of the Tianchi coal samples show a good agreement with the temperature rise features and fire source positions. This confirms the validity of the model. Based on the model, a sensitivity analysis is constructed to investigate the influence of the external environment on coal spontaneous heating. The main contents include (1) heat dissipation surroundings; (2) air quantity; (3) air direction. The simulated conclusions contribute to optimizing the experimental parameters and obtaining the shortest spontaneous combustion period. In addition, the model is found to be of great significance for predicting the fire source temperature and position in practical coal mine conditions.