Analysis on Coal Pile Spontaneous Combustion Process and Influence Factors Under Multi Field Coupling

In order to study spontaneous combustion features and ignition law of the coal pile, a multi fields (velocity field, temperature field and oxygen concentrati on field) coupling spontaneous combustion model under the wind power and buoyant power driving was established. The COMSOL Multiphysics software was applied to the numerical simulation analysis on the coal spontaneous combustion process and the influence factors.The study results showed that under the wind velocity of 3.6 m/h, the max temperature point of the spontaneous combustion in the coal pile would be at the middle and low sections of the coal pile.After 65 days, the spontaneous combustion at the location would start finally.With the wind velocity increased, the spontaneous combustion point of the coal pile would downwardly migrated with the wi nd flow in the spontaneous combustion of the coal pile.The natural ignition period would be reduced.The reduction of porosity rate, height and angle could expand the n atural ignition period of the coal pile.