Dimethyl Ether 예혼합 압축 착화 엔진에서 배기 가스 재순환의 영향

Abstract

The combustion and exhaust emission characteristics were investigated in an DME fueled HCCI engine with variable valve timing(VVT). The operation range of HCCI engine was limited by high combustion pressure and noise due to multi-point and spontaneous combustion. To avoid the engine damage and expand the operating range, the combustion phase and start of combustion were controlled by exhaust gas recirculation(EGR) and VVT. EGR rate was varied from 0 to 60 % and intake valve open time was varied from -29 to I CAD ATDC and air excess ratio(A) was varied from 2. I to 3.0. Later auto-ignition timing and longer combustion duration was achieved by adding EGR. However, hydro carbon was increased higher EGR rate and carbon monoxide was increased at higher air excess ratio.