Characterizing ammonia and nitric oxide interaction with outwardly propagating spherical flame method

Abstract

With the growing attention on ammonia (NH3) combustion, understanding NH3 and nitric oxide (NO) interaction at temperatures higher than DeNOx temperature region or even flame temperature becomes a new research need. In this work, the outwardly propagation spherical flame method was used to investigate the laminar flame propagation of NH3/NO/N2 mixtures and constrain the uncertainties of the specific kinetics. The present experiments were conducted at initial pressure of 1 atm, temperature of 298 K and equivalence ratios from 1.1 to 1.9. A kinetic model of NH3/NO combustion was updated from our previous work. Compared with several previous models, the present model can reasonably reproduce the laminar burning velocity data measured in this work and speciation data in literature. Based on model analyses, the interaction of NH3 and NO was thoroughly investigated. As both the oxidizer and a carrier of nitrogen element, NO frequently reacts with different decomposition products of NH3 including NH2, NH and NNH, and converts nitrogen element to the final product N2. It is found that the laminar burning velocity experiment of NH3/NO/N2 mixtures using the outwardly propagating spherical flame method can provide highly sensitive validation targets for the kinetics in NH3 and NO interaction.