Numerical Simulation on Danger Zone for Spontaneous Combustion in Goaf at Fully-Mechanized Caving Face

Most coal mines in China have a tendency to spontaneous combustion, which is outstanding in goaf. To effectively solve the problem, CFD technology is used for flow field in the goaf, and superposed field between volume fraction of oxygen and velocity is adopted as the standard. The influence of air quantity on danger zone for spontaneous combustion and width of oxidation zone is analyzed. The results show that with increasing of air quantity, shape of oxidation zone which is "L" has not changed but moves towards back, however, area of danger zone of spontaneous combustion increases. And width of oxidation zone exhibits an impact of quadric relationship on air quantity.