NUMERICAL STUDY OF NOX EMISSION IN HIGH-TEMPERATURE AIR COMBUSTION

The characteristics of NOx emission in the high-temperature air combus tion technology were investigated numerically. Two kinds of methods we re used. Detailed chemistry and transport properties were used for a t wo-dimensional laminar diffusion flame, and a simplified reaction sche me was used for calculating a turbulent flame in a furnace. Results sh ow that the thermal mechanism dominates NOx emission in high-temperatu re air combustion. If only the preheated air temperature is increased, NOx emission will rise significantly. However, the combination of air preheating and flue gas recirculation not only improves the combustio n efficiency, but also suppresses NOx emission in the combustion proce ss.