NO x emission characteristics in rich–lean combustion of hydrogen

Abstract

Characteristics of NO x formation in a gas turbine fuelled with hydrogen were analyzed with both an experimental and a numerical approach. This research experimentally investigated NO x reduction effect of rich–lean combustion in a coaxial burner. Hydrogen emits no Prompt NO even in rich mixture conditions, and can be more effective to reduce NO x in the rich–lean combustion system than hydrocarbons. The results show that the rich–lean combustion of hydrogen successfully reduces NO x emission compared with diffusive combustion. In the rich–lean combustion, hydrogen combustion has lower NO x emission compared to methane combustion, especially with larger equivalence ratio of richer side mixture. Calculations of NO x formation in the rich–lean combustion were also done employing the extended Zel’dovich NO formation mechanism.