Mathematical investigation of syngas fired burner with various configurations in the BERL combustor

Abstract

This paper discusses the effect of burning syngas in a configuration similar to that of the BERL (Burner Engineering Research Laboratory) 300 KW swirl-stabilized combustor which has previously been used with methane as a fuel. Due to the axisymmetric configuration, only 15° from the burner angle is studied with periodic boundary. The model adopts RANS (Reynolds Averaged Navier–Stokes) technique including a realizable k-ε turbulent scheme. The non-premixed combustion model used is based on applying flamelet concept. The study shows that the structure of the flame is affected with changing the burner quarl angle and the inlet air swirl number. The detailed parametric study of this synthetic fuel in the BERL paradigm relates easily to the accumulated experimental and numerical studies available in this configuration and then acquiring add noval value to the present work. The study also shows the presence of different recirculation zones, one of which is central recirculation zone and an external recirculation zone. When increasing quarl angle, the central recirculation zone is shifted outward and the turbulent interaction between the central fuel jet and the recirculation zone induces small vortices between these two flow patterns. On the other hand, the effect of flue gas recirculation and air staging into the burner on the reduction of NOx formation is discussed. The flue gas data show that FGR reduces NOx emissions significantly while having no influence on flame stability, total combustion efficiency, or CO emissions. Changes in fuel composition are also taken into account. The results reveal that when the hydrogen blending in the fuel increases, the temperature rises.