Multi-filed coupling numerical simulation of spontaneous combustion in goaf

Coal spontaneous combustion is one of the factors that endangers the produce in coal mine. It is affected by the combined action of seepage and diffusion of gas, chemical reaction of coal and oxygen as well as heat transfer in porous media. Based on this, a series of finite element numerical simulations were conducted to investigate the spontaneous combustion under the effect of different physical field, and the simulation results were compared with the data obtained by in-suit measurement in order to test the accuracy of the simulation data and the feasibility of the simulation model. It is found out that the numerical simulation model acts well in prediction of gas transport and temperature variation, besides it is also discovered that the traditional partition way of the three zone of spontaneous combustion in goaf can not precisely locate the position where spontaneous combustion might occur. In addition, the area behind the entrance of leaked air from working face to the goaf is the place where temperature changes significantly, and it is the most dangerous place that may take place coal fire, so during practical work of coal mining, more attentions should be attached.