본 연구는 DME-바이오디젤 혼합연료의 분무 및 연소, 배기 특성을 바이오디젤과 비교한 실험적 연구이며 실험연료는 바이오디젤 (BD100)과 중량 기준으로 DME를 20% 혼합한 DME-바이오디젤 혼합연료 (B-DME20)이다. 거시적 분무 특성을 연구하기 위하여 분무 이미지로부터 분무도달거리, 분무각을 측정하였으며, 연소 및 배기 특성은 단기통 직접 분사식 압축착화 기관을 이용하여 분석하였다. 실험결과 바이오디젤과 DME-바이오디젤 혼합연료는 분사율에서는 큰 차이가 없었지만 혼합연료의 경우에 착화지연기간이 짧고 연소압력이 높았으며soot 배출물이 현저하게 줄어들었다.
The purpose of this study is to investigate experimentally the spray-atomization and combustion-emission characteristics of biodiesel-DME blended fuel. In this study, two types of test fuels pure biodiesel (BD100) and blended fuel (B-DME20) were used, and the spray and combustion characteristics of different fuel compositions were analyzed. DME constitutes 20% and biodiesel constitutes 80% (by mass fraction) of the blended fuel. The overall spray characteristics, spray tip penetration, and cone angle were evaluated using frozen spray images. In addition, the combustion and emission characteristics were analyzed on the basis of the evaluated data for a single-cylinder CI engine with common-rail injection system. It was revealed that the injection profiles of both the test fuels for a given injection pressure showed similar trends. However, the injection profiles of the blended fuel (B-DME20) indicated shorter ignition delay than those of biodiesel.
