Experimental Investigation of Plasma Discharge Effect on Swirl Flames at a Scaled Siemens Dry Low Emission Burner

Abstract

The effect of a Rotating Gliding Arc (RGA) plasma discharge on the flame in a scaled Siemens Dry Low Emission (DLE), SGT-750, burner was experimentally investigated under atmospheric combustion conditions. The central pilot section of the burner, named RPL (rich pilot lean), was redesigned with an integrated high voltage electrode to generate an RGA. The exhaust gas was sampled and analysed in terms of CO and NOx emissions, and the CO emission data show that the RGA extends the lean blow-out limit (LBO). High-speed OH chemiluminescence imaging was employed to understand the transient behaviour of the flame in both conditions with and without RGA and also to study the process of flame re-stabilization by the assistance of the RGA. A flame kernel, initiated around the RGA channel, was observed to play an important role in the re-stabilizing process of the flame. Although the NOx emission for the flame with RGA was found to be higher than that without RGA, it was still less than what previous data show for operating conditions with the RPL flame.