Research on Relations between Goaf Characteristic of Fully Mechanized Sublevel Caving Mining and Distribution of Oxygen Concentration

By use of the experiment of bundle tube monitoring on site,the characteristics of fully mechanized sublevel caving mining goaf were analyzed and summarized.Based on the principle of computational fluid dynamics and numerical simulation software FLUENT,the oxygen concentration field,i.e.the key delimiting index of oxidation zone and suffocative zone,was simulated for the different characteristics of fully mechanized sublevel caving mining goaf.The simulation results were compared with experimental results. Considering the different characteristics of goaf,the influence of numerical simulation results on division of"Three Zones"(heat dissipation zone,oxidation zone and suffocative zone)of goaf was discussed. Results show that the characteristics of fully mechanized sublevel caving mining goaf play a very important role in concentration distribution of oxygen and must be considered in the numerical simulation process. Numerical simulation,which ignores the characteristics of goaf,is quite different from experimental results. Whether or not the simulation results are accurate depends on understanding of the problem and setting precision of boundary conditions.