Experimental and numerical studies of two-stage ethane-air flames

This paper reports results of experimental and numerical investigations on ethane-air two-stage combustion in a counterflow burner where the fuel stre am, which is partially premixed with air for equivalence ratios from 1.6 to 3.0, flows against a pure air stream. Similar to methane. the two-stage et hane combustion exhibits a green fuel-rich premixed flame and a blue diffus ion flame. Flume structures, including concentration profiles of stable int ermediate species such as C2H4, C2H2 and CH4, are measured by a gas chromat ography and are calculated bq numerical integrations of the conservation eq uations employing an updated elementary chemical-kinetic data base. The imp lications of the results from these experimental measurements and numerical predictions are summarized, the flume chemistry of ethane two-stage combus tion at different degrees of premixing (or equivalence ratio) is discussed, and the relationship between NOx formation and the degree of premixing is established. The present work helps to increase understanding of flame chem istry of hydrocarbon fuels, identify important reactions for pollutant form ation and suggest means to reduce emissions.