Modelling NOx emissions during staged combustion

Staged combustion has been accepted as an effective way to reduce NOx emission. Based on the comparison of calculated results using Miller and Bowman's (1989, Progr. Energy Combust. Sci. 15, 287) detailed elementary reaction model with experimental data, it is found effective to apply this model in the simulation of NO formation and destruction during staged combustion. Sensitivity analysis shows that C, CH, CH2 and HCCO play an important role in NO destruction and reduction under fuel staging. NO generated in the primary zone can be reduced greatly by staged combustion. Besides the air–fuel ratio in the primary combustion zone, the combustion temperature in the reburning zone and the mass factor of the reburning fuel in the overall fuel, the main factors which affect NO destruction and reduction are the position where reburning is introduced and the types of reburning fuel. It is found that reburning cannot be introduced too close to the primary combustion zone. The reburning fuels that can effectively stimulate NO to HCN are H2 and C2H4. Copyright © 1999 John Wiley & Sons, Ltd.