Fundamental Studies on NOx Emission Characteristics in a Dimethyl Ether(DME)/Air Nonpremixed Flame

초록

The NOx emission characteristics of DME in counterflow nonpremixed flames were investigated numerically, and brief experiments were carried out to compare the flame shapes and NOx emissions with those of C3H8 and C2H6. The DME flames were calculated using Kaiser’s mechanism, while the C2H6 flames were calculated using the C3 mechanism. These mechanisms were combined with the modified Miller-Bowman mechanism for the analysis of NOx. Experimental results show that DME flame has the characteristics of partial premixed flame and the flame length becomes very shorter compared with general hydrocarbon fuels and then, the NOx emission of DME is low as much as 60% of C3H8. In the calculated results of counterflow nonpremixed flames, the EINO of DME nonpremixed flame is low as much as 50% of the C2H6 nonpremixed flame. The cause of EINO reduction is attributed mainly to the characteristics of partial premixed flame due to the existence of O atom in DME and partly to the O-C bond in DME, instead of C-C bond in hydrocarbon fuels.