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Roles of thermal and radical quenching in emissions of wall‐stabilized hydrogen flames

1998; Wiley; Volume: 44; Issue: 9 Linguagem: Inglês

10.1002/aic.690440910

1547-5905

Preeti Aghalayam, Dionisios G. Vlachos,

Atmospheric chemistry and aerosols

Abstract A numerical study of the combustion of H 2 /air mixtures impinging on surfaces has been performed, using detailed chemistry and multicomponent transport, in order to elucidate the roles of surface thermal and chemical quenching in pollutant emissions. For extinguishable fuel/air mixtures, the thermal coupling with the surface has been found to be strong, and surface thermal quenching reduces NO X emissions. However, nonextinguishable mixtures are practically unaffected by changes in surface temperature, except for an increase in NO 2 at low surface temperatures. It is shown that radical wall quenching can affect emissions for all flames, with H being the most important one primarily for NO 2 near the surface, due to the reaction NO 2 + H ↔ NO + OH. A new method to elucidate the dominant paths for NO formation is also presented.