Combustion Characteristics Study of an SI Engine Operated with DME Blended LPG Fuel

LPG-DME 혼합연료를 사용하는 전기점화 기관의 연소특성 연구

In this study, a spark ignition engine operated with the DME blended LPG fuel was investigated experimentally. Performance, emissions characteristics including hydrocarbon, CO, NOx, and combustion stability of an SI engine fuelled with DME blended LPG fuel were examined at $1200{\sim}5200\;rpm$. Results showed that stable engine operation was possible for a wide range of engine loads within 20% mass content of DME fuel. Also, engine output power within 10% mass content of DME fuel was comparable to that of pure LPG fuel operation. However, engine output power was decreased and break specific fuel consumption (BSFC) was severely increased with the amount of blended fuel as the energy content of DME was much lower than that of LPG. DME blended LPG fuel is expected to be potential for enlarging DME market.

본 연구에서는 DME가 함유된 LPG 연료를 불꽃 점화 기관에서 적용 가능 여부를 실험적으로 살펴보고 있다. LPG와 DME가 함유된 혼합연료로 엔진 구동시 엔진출력, 배출가스 특성, 연소안정성 등의 항목에 대한 실험을 $1200{\sim}5200\;rpm$에서 수행하였다. 결과를 살펴보면 20% 내외의 범위에서 DME를 혼합하는 경우 안정된 연소성능을 얻을 수 있었으며 10%까지는 엔진 출력 저하가 거의 없다. 하지만 혼합율이 증가할수록 DME 연료는 LPG보다 에너지 밀도가 낮으므로 출력이 감소하고 제동연료소비율은 증가하는 현상을 보인다. LPG/DME 혼합연료는 향후 DME 시장을 넓혀 나가는 최선의 방법이 될 것이다.