Flame stabilization and emission of a small swiss-roll combustor

Three types of small Swiss-roll combustors, having different depth and different combustion room sizes, were examined. All combustors had channels narrower than the quenching distance at standard state, and flame could not be stabilized without using regenerated heat from the burnt gas. Premixed flame stabilization conditions were studied with equivalence ratio and mean velocity of mixture. The effect of different environments of the heat transfer was also studied. Even though the mean velocity for stable flame had great difference depending on the combustors geometries and shapes, averaged temperature of the combustor was similar and this temperature depended on the equivalence ratio. As the mean velocity increased, temperature of the combustor increased and flames could be stabilized. However, as the temperature increased, flame front moved into the channel upstream of the combustion room. Emission characteristics also depended on the temperature of the combustor. As the size of the combustor became smaller, NO_x decreased and CO increased. Heat regeneration from burnt gas to unburned mixture was important to improve energy efficiency. Heat loss from the combustor was important in stabilizing a flame at the center of the combustor. This is an abstract of a paper presented at the 30th International Symposium on Combustion (Chicago, IL 7/25-30/2004).