Abstract
This study focuses on the fundamental characteristics of DME combustion aiming at the development of low-NO_x combustion technology with flue-gas recirculation (FGR). DME has very high potential of applicability of flue-gas recirculation even at the high mixing ratio because of its high burning velocity and low ignition temperature. Combustion tests were conducted with laboratory-scale 11kW combustor, where O_2 concentration and temperature at the combustor inlet was systematically regulated, so that the flue-gas recirculation at various mixing ratios was simulated. The maximum FGR ratio is 86% at the initial air ratio λ=1.5 with preheated diluted air at 600K. The NO_x emission reduced to 13ppm, which is about 10% of that at FGR=0%. The stable combustion sustains even at low oxygen concentration by preheating diluted-air up to near the auto-ignition temperature of DME.
