Numerical simulation on spontaneous combustion of residual coal with complicated contacts

In order to solve the problem of preventing spontaneous combustion of residual coal in the goaf of a fully mechanized top-coal caving face with complicated connections and contacts,a numerical simulation method was applied to model the spontaneous combustion characteristics of residual coal in the goaf of a fully mechanized top-coal caving face.A mathematical model of the spontaneous combustion of residual coal at a fully mechanized top-coal caving face was developed.Using the model developed,the spontaneous combustion characteristics of residual coal with complicated contacts were simulated.The spontaneous combustion of residual coal occurs in two locations when oxygen concentration is high in goaf.The spontaneous combustion of residual coal occurs in one location when the mine gas and the consumption of oxygen are conditioned.When both nitrogen injection and negative catalyzer are used together,the spontaneous combustion of residual coal can be prevented.The spontaneous combustion period of residual coal is positively proportional to the advance rate of working face and is inversely proportional to the ventilation air quantity of working face and the oxidation rate of residual coal.This paper provides a good reference for preventing the spontaneous combustion of residual coal in the goaf of a fully mechanized top-coal caving mining face.