Coupled interactive effects of ammonia and hydrogen additions on ethylene diffusion flames: A detailed kinetic study

In order to create effective combustion technologies and fuels with low or no carbon emissions,the research was conducted to assess the coupled interactive effects of NH_(3) and H_(2) additions on ethylene counterflow diffusion flames from a kinetic perspective.The effects of the NH_(3)/H_(2) combination on flame temperatures,major species,key radicals,important intermediate species,representative oxygenated species and NO_xwere examined.The results of the study utilizing fictitious inert NH_(3) and/or H_(2) revealed the chemical effects of the two components.It was found that the NH_(3)/H_(2) coupled effects had a more effective inhibitory effect on soot precursors than the effects of corresponding sum of single NH_(3) or H_(2) addition.The production of soot precursors was promoted by the coupled chemical effects of NH_(3) and H_(2),but the coupled dilution and thermal effects were observed to have a greater impact,resulting in a decrease of the mole fractions of soot precursors.As for the interaction of NH_(3) and H_(2) effects,the presence of H_(2) decreased the chemical effects of NH_(3) on the augmentation of C_(2)H_(2),A1,A2,and CH_(3)CHO mole fractions.The NH_(3) addition alleviated the H_(2) chemical effects on increasing C_(2)H_(2),C_(3)H_(3),A1 and A2 concentrations.Conversely,the NH_(3)chemical effects on C_(3)H_(3),OH and CH_(3)CHO were enhanced when H_(2) was added.The presence of NH_(3) augmented the chemical effects of H_(2) on the growth of OH mole fraction.Moreover,the H_(2) chemical effects hindered the production of NO and NO_(2) in the presence of NH_(3).