Experimental investigation of the effect of quench air flow on the combustion performance in a RQL combustor

RQL (Rich burn-Quick quench-Lean burn) represents the state-of-the-art technology to reduce NOx emissions in aircraft engines and gas turbines. Quench is paramount for implantation of the whole process. In this paper, an experimental test stand with 3/20 multi-sector combustor was established. The experiments which pay attention to the effect of quench air flow on the combustion performance and emission are conducted. The results show that the flame in RQL combustor is segmented, presenting flameless combustion in rich zone and a pale blue flame in lean zone. Axial temperature distribution is M-type. Two peaks appear at the head and tail of the combustion chamber, and the valley is located in the quench zone. The concentration of CO and NOx decreases rapidly in quench zone because of the injection of quench air. The emissions of CO and NOx in RQL combustor maintains at low level. With the increase of quench air flow, the concentration of NOx in combustor decline gently, the average exhaust temperature depress gradually, and the uniformity coefficient of exhaust temperature increase.