A comparison of the thermal and emission characteristics of co and counter swirl inverse diffusion flames

In this work the influence of co-swirl and counter-swirl burners on the inverse diffusion flame (IDF) characteristics has been studied using liquefied petroleum gas (LPG). The flame shape of the co and counter IDFs were compared. The momentum exchange between the air and fuel jets for swirled IDF burners effects on the produced flame length and stability. The analysis of the results showed that the co-swirling IDF is shorter and more stable than the counter swirling one. The influence of the air jet Reynolds number (Re) consequently the primary equivalence ratio (Φ) on the flame centerline temperature and exhaust gas emissions were examined. The results showed that for the co swirling IDF the centerline temperature profile is higher than the centerline temperature profile of the counter swirl IDF for all values of Φ used in this study. The CO and NOx emissions comparison were made for the two swirled burners. It was found that Re and swirl directions are two key factors for reducing CO emissions. This study indicates that the CO emission is decreased by using co-swirl IDF.