FLAME SPEED OF HYDROGEN ENRICHED METHANE FUEL AND CHEMICAL KINETIC ANALYSIS OF EMISSIONS


Tuncer O.

ISI BILIMI VE TEKNIGI DERGISI-JOURNAL OF THERMAL SCIENCE AND TECHNOLOGY, cilt.29, sa.2, ss.29-42, 2009 (SCI-Expanded) identifier

Özet

With the proliferation of IGCC technology developement of nececassry technologies for the premixed combustion of syngas have gained importance. Syngas Fuels are obtained via the gasification of coal or bio-mass and have varying proportions of H(2)/CO/H(2)O molecules. present power generation systems have their combustors designed to burn natural gas. Nevertheless. there exists a need to burn hydrogen. main constituent of syngas, in a problem free fashion. Especially high flame speeds of hydrogen within the mixture lead to problems in flame holding and might yield flashback. Within this context, laminar flame speeds of hydrogen enriched methane Mixtures were investigated utilizing detailed chemical kinetics simulations based on GRI 3.0 mechanism. As expected it has been found that hydrogen enrichment increases flame speeds. An empirical corelation was developed to aid in practical computation of flame speeds. Effect of hydrogen enrichment on flame speeds and emissions were investigated. It was found that, increasing pressure reduces flame speeds, while it increases emissions to the contrary. Emissions and flame speeds both increase with increasing hydrogen content. One and zero dimensional simulations were emphasized. In zero dimensional simulations focus was oil the effect of equivalance ratio fluctuations due to thermoacoustic Oscillations Oil lean blowout and emissions. Mixtures With rich hydrogen content were observed to be more immune to equivalance ratio fluctuations. Another observation is that these very fluctuations have ail increasing effect on nitric oxide emissions. It has been found Out that the extended Zeldovich mechanism plays the key role in the production of nitric oxide emissions in hydrogen enriched methane flames.