Effects of CO addition on the characteristics of laminar premixed CH4/air opposed-jet flames

Combustion characteristics of premixed propane flame with added H 2 and CO on a V-shaped impinging burner

“…The flame front was forced to become balanced further downstream at which the flow velocity was smaller. The premixed mixture that had not reacted collided with other parts near the exit; this impinging effect slowed the adjacent flow through a drag force, causing two faint flame fronts on both sides of this section, similar to the observation in the combustion of the opposed flame [19,42,43]. Fig.…”

“…That the flammability limit of the H 2 / C 3 H 8 /air flames was wider than that of CO/C 3 H 8 /air flames resulted from the improved ignitability, because of the small ignition energy of hydrogen, enhanced burning velocity [19,36,37], and increased resistance to strain [38]. [19,42,43]. For the effects of H 2 and CO on the flame, the varied chemical kinetics of propane in generating more rapid oxidation and decomposition to produce H atoms might also play an important role [44].…”

“…The effect of added hydrocarbon on the chemical kinetics of the CO flame was investigated [22]. Wu et al [19] showed that the effect of added CO on the burning velocity of stoichiometric flames is dominated by some chemical kinetic steps.…”

Numerical study on laminar flame speed of natural gas-carbon monoxide-air mixtures

“…The GRI mechanism, which was developed for natural gas combustion, has been successfully validated over a wide range of conditions. The mechanism was also used for natural gas-hydrogen-air mixtures [8], hydrogen-carbon monoxide-air mixtures 2) , methane-carbon monoxide-air mixtures [4], and wood syngas [6] with reasonable success. It consists of 325 elementary chemical reactions with associated rate coefficient expressions and thermochemical parameters for the 53 species.…”

“…Results show that the addition of small amounts of H 2 and CH 4 results in the increase of the laminar flame speeds and extinction strains since the added H radicals lead to increased branching and accelerate the rate of the carbon monoxide oxidation reaction. Wu et al [4] studied the effects of CO addition on the characteristics of premixed CH 4 -air opposed-jet flames. They found that the effect of CO addition on the laminar burning velocity of the stoichiometric CH 4 -CO-air flames is most likely dominated by the chemical effect of the transition of dominant reaction steps.…”