Abstract
A large-eddy simulation (LES) is performed to predict characteristics of NOx formation in pulverized coal combustion field. 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 to apply the LES to investigate the NOx formation. Results of the computation on the lab-scale burner show that NO is rapidly formed due to the oxidation reaction of nitrogen from volatile matter of coal and NO 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. Results of the large-scale furnace show that the gas temperature, O2 and NO concentrations are precisely captured by the present LES. Present study shows the usefulness of the LES for predicting the characteristics of NOx formation in coal flames.
