Effect of Recirculation Ratio on the Combustion Characteristics of an Asymmetric Swirling Flameless Combustor using Biogas

This study investigates the influence of recirculation ratio on the combustion characteristics of an asymmetric swirling flameless combustor. The recirculation ratio, defined as the ratio of the total recirculation mass flow rate to the primary air mass flow rate, plays a crucial role in determining the performance and emission characteristics of combustion systems. The asymmetric swirling flameless combustor offers potential advantages in terms of enhanced fuel flexibility, reduced pollutant emissions, and improved combustion stability. Through varying the recirculation ratio, the combustion performance and emission characteristics can be optimized to meet specific requirements. In this research, experimental investigations were conducted to analyse the effect of recirculation ratio on the combustion stability, temperature field and emission of the asymmetric swirling flameless combustion. From the results obtained, it was observed that recirculation ratio has significant effect on the performance of the combustor i.e., as the recirculation ratio increases due to decrease in the exhaust area, more uniform temperature and less emission was observed. At 30mm exhaust diameter and lean condition, average recirculation of 7.21 was obtained with 2ppm NOx emission and 118ppm CO emission along with uniform temperature in the combustion zone.