Experimental Investigation on Laminar Flame Speeds of Premixed CH_4/O_2/CO_2 Mixture

The laminar flame speeds of CH4/ O2/ CO2mixtures in atmospheric conditions were measured using Bunsen method. The whole surface area methodology based on the images of flame was performed to obtain the laminar flame speeds of the Bunsen burner. The effect factors on laminar flame velocities of CH4/ O2/ CO2mixtures were discussed,including equivalence ratios( 0. 8 ~1. 2),oxygen concentrations( 25% ~ 35%) and dilutions( N2,CO2). Results showed that the laminar flame speeds of the premixed oxy-methane mixture reached a maximum at the stoichiometric ratio of 1 while gradually lowered on either side. The laminar flame speeds increased with the increase of the O2concentration and there was a quadratic function relationship between the flame velocities and the concentration of the O2. Compared with N2,the high concentration of CO2decreased the flame speeds and the measured flame speeds using CO2as the oxidizer was about onefifth of that using N2 as the oxidizer.