Computational Fluid Dynamics Simulation of Oxygen Distribution in Coal Mine Goaf

摘要

Spontaneous combustion of coal is a global issue that has attracted increasing public attention. Particularly in china, closure of coal workfaces caused by spontaneous combustion has contributed to substantial economic loss. To reduce the occurrence of mine fires, oxygen concentration distribution in goaf which is seriously closed with principle of spontaneous coal combustion needs to be studied. In this paper, a computational fluid dynamics model was developed for oxygen concentration distribution under goaf gas drainage conditions. Then, by using of this model, we simulate the distribution of oxygen in the goaf at the workface in a fully mechanized cave mine. The goaf was treated as an anisotropic medium, and the effects of methane drainage and oxygen consumption on spontaneous combustion were considered. The simulation results matched observational data from a field study, which indicates CFD simulation is suitable for research on the distribution of oxygen in coalmines. The results also indicated that near the workface spontaneous combustion was more likely to take place in the upper part of the goaf than near the bottom, while further from workface the risk of spontaneous combustion was greater in the lower part of the goaf. These conclusions can be used to develop fire-fighting approaches for coalmines.