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Roles of thermal and radical quenching in emissions of wall‐stabilized hydrogen flames
Author(s) -
Aghalayam P.,
Vlachos D. G.
Publication year - 1998
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690440910
Subject(s) - quenching (fluorescence) , combustion , thermal , hydrogen , chemistry , coupling (piping) , surface (topology) , pollutant , photochemistry , chemical physics , thermodynamics , chemical engineering , materials science , composite material , organic chemistry , optics , geometry , mathematics , fluorescence , engineering , physics
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.