An Experimental study on swirl flow and combustion characteristics of 3 staged low NOx burner applied with FGR and FIR

FGR 및 FIR을 적용한 3단 저 NOx 버너의 Swirl유동 및 연소특성에 관한 실험적 연구

The objective of this research is to determine generally applicable design principles for the development of internally staged combustion devices. Utilizing a triple annulus combustor, air staged commercial propane flame configuration are studied. For this triple air staged combustor, the angular momentum weighted by it's swirl number and air distribution ratio was observed to be the critical criteria. An internal recirculation zone which develops on the centerline of the flame immediately downstream of the burner entraps the fuel into a fuel rich eddy. Then sufficient heat must he transferred from the flame via radiation to the chamber heat transfer surfaces, such that when the second air is introduced, peak flame temperatures are suppressed. It is experimentally found out that the total NOx emission level in this type of burner is lower than 0.75g/kg.