A Study on Swirl Flow and Combustion Characteristics of Air Staged Low NOx Burner

다단 공기 공급 저 NOx 버너의 선회유동 및 연소특성에 관한 실험적 연구 - 다단공기공급에 의한 연소특성(I) -

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, the detailed combustion characteristics 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 of NOx emission. 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 be transferred from the flame via radiation to the chamber heat transfer surfaces, such that the peak flame temperatures are suppressed when the second air is introduced. It is experimentally found out that the total NOx emission level in this type of burner is below 50ppm(3% Ref. O2) at optimum operating conditions.