Numerical Simulation Of Coal Spontaneous Combustion Multi-field Coupling

In order to avoid the waste of resources and the damage to people’s life and property incoal mine fire accident caused by coal spontaneous combustion, the research on the laws ofthe coal spontaneous combustion is very necessary to the forecast of coal spontaneouscombustion. Using computer numerical simulation is one of the most important means in thestudy of coal spontaneous combustion rule and influencing factors.Through the simulation of coal spontaneous combustion experiment, the formationmechanism of coalfield fire area, the development process, high temperature point spacetransfer rule can be revealed. The study of coal fire area spontaneous combustion,extinguishing and resurgence characteristics and its influencing factors provides theoreticalbasis for fire prevention measures.Combined with the actual situation of coal spontaneous combustion experiment stationin our school, according to the porous media seepage mechanics and heat mass transfer theory,this article analysis the coupling effect of gas concentration field, leakage of wind flow fieldand temperature field in the process of coal spontaneous combustion, multi-field couplingmodel of coal spontaneous combustion process is studied, the control equation of couplingmodel is viewed as unsteady convection diffusion equation. For the nonstationary twodimensional convection diffusion equations, the high precision compact difference scheme isbuild up, using the Richardson extrapolation method to solve. Combining the characteristicmethod and finite volume method, the characteristics finite volume method is build up tosolve. Combined with the experiment and measured parameters, the boundary and initialconditions are determined, these two methods of numerical simulation are applied into theNingxia Zaoquan mine coal spontaneous combustion process. The occurrence of hot spots inthe spontaneous combustion of coal, development and change process are studied, the simulation results are consistent with the experimental results under the same experimentalconditions. It confirms the correctness of the simulation method and provides the basis for thesubstitute of bench experiments.