Abstract
Large-eddy simulation （LES） is applied to predict characteristics of NOx formation in two different pulverized coal combustion fields. A laboratory-scale open-type pulverized coal flame generated by a triple stream co-axial swirl burner and a large-scale combustion test furnace with practical complex burners are targeted. The results of the computation on the laboratory-scale burner show that NO formed due to the oxidation reaction of nitrogen from volatile matter of coal rapidly decreases just downstream of the region where the peak value appears due to the reduction reaction. The trend becomes marked with increasing O2 concentration. The results of the large-scale furnace show that the gas temperature and O2 and NO concentrations are qualitatively captured by the present LES. This suggests the usefulness of the LES for predicting the characteristics of NOx formation in coal flames.
