바이오에탄올 적용 스파크 점화엔진의 운전조건에 따른 배출가스 특성

Abstract

Bioethanol has been applied to spark ignition engine as an alternative fuel to gasoline since it is renewable bio-based and oxygenated fuel. It can provide the potential to reduce the harmful exhaust emissions such as HC, NOx, CO, CO2 and particulate matters. It can also improve the power and thermal efficiency due to its higher octane number and heat of vaporization. In order to apply bioethanol as a fuel in a gasoline engine, it is necessary to clearly grasp exhaust gas emission characteristics near the stoichiometric air-fuel ratio in order to sufficiently secure the conversion efficiency of the catalytic converter while changing the air-fuel ratio and ignition timing under partial load conditions. It was found that the peak NOx emissions occurred at near stoichiometry due to oxygen contained in bioethanol and lower than gasoline. HC, CO and CO2 were also emitted lower than gasoline due to contained oxygen and highert H/C ratio.