Extension of Lean Operation and Extinction Limit of Premixed Flame Applying Non-Thermal Plasma

The effects of non-thermal plasma (NTP) on lean-premixed swirl-stabilized flames have been experimentally investigated. The plasma is applied to the flames through the dielectric barrier discharge (DBD) technique. The results show that the streamer applied by the non-thermal plasma extend the lean extinction limit by enhancing flame stability. The non-thermal plasma is also able to significantly decrease CO emission while NOx emission increase slightly due to increased flame temperatures. However, there are an optimal range in equivalence ratio (), i.e. ≤5 ppm for CO emission and ≤15 ppm for NOx at 0.550≤≤0.575, leading to extension of lean operation limits. These results indicate that applying non-thermal plasma on swirled premixed flames ought to be a useful tool for reduction in CO and NOx emissions simultaneously by high streamer.