Investigation of hydrogen and electrolytic oxy-hydrogen addition to propane flames using planar laser-induced fluorescence

The effect of H2 and electrolytic oxy-hydrogen (EOH) on lean burn (LB) hydrocarbon (propane) flame was investigated using planar OH laser-induced fluorescence (LIF). Analysis of OH species in EOH- and H2-blended flames was conducted under ultralean (Ф = 0.15) burn conditions. A stability map of the flame was obtained for various equivalence ratios (0.1-1) with H2 and EOH addition. The stable region of the flame expanded up to a very low equivalence ratio (0.1) with 40% EOH. The EOH-blended flame had a smaller flame height than the H2-blended flame because of the higher laminar burning speed of the former. The OH concentration in the EOH-blended flame was much higher than that in H2-blended flame under LB conditions. The OH concentration remained high for the EOH-blended flame with decreasing equivalence ratio or increasing Reynolds number. EOH addition thus enhances OH species generation and the laminar burning velocity of lean burn flame.