Daiqing Zhao

A numerical study on NOx reduction by steam addition in counterflow diffusion flame using detailed chemical kinetics

Publisher Summary This chapter proposes the counterflow diffusion flame calculations of methane air flame employed to elucidate the NOx reduction mechanism by steam addition. The formation of NO is governed by the prompt NO mechanism in the methane–air counterflow diffusion flame, which has a comparatively high strain rate. The production rate of thermal NO via the elementary reaction is very small. The production rates of NO decrease according to an increase in the amount of steam addition, and they become extremely small when steam is added to the airside. Moreover, the mass production rates of HCN and CH become as small as that of NO. Therefore, the decreases in the flame temperature and in the concentrations of HCN and N related to prompt NO formation play an important role in the reduction mechanism of NOx by steam addition.