Particulate emissions and engine performance of a gasoline direct injection engine fueled with ethanol blends at high pressure fuel injection

Abstract

In this study, effects of gasoline and ethanol blended fuel and high pressure fuel injection on particulate emission and engine performance of a gasoline direct injection engine are investigated. Experiments were conducted using a 398 cc single-cylinder engine. The fuel injection system was configured to pressurize the fuel using an air compression pump driven. The gaseous emission was measured by an emission bench and a particulate matter number is counted by PPS-M device. Experiments were carried out under the condition that the maximum injection pressure was 50 MPa and the intake flow rate was constant with various injection conditions. Gasoline and ethanol blended fuel was used as supply fuel and blending ratio is varied from 10% to 50% by volume. All experiments were conducted at constant engine speed and stoichiometric air-fuel ratio. The total heat release increased with the increase of the ethanol proportion when the intake flow rate and the equivalence ratio were fixed at the injection pressure of 50 MPa. In the region where the wall wetting occurred, the ethanol blended fuel had a maximum PN reduction effect of 88% compared to the gasoline. Addition of ethanol to the gasoline led to rapid decrease of the wall wetting with increasing injection pressure, and addition of 30% ethanol to gasoline over 10MPa injection pressure make lower PN emission to gasoline level with 50MPa injection pressure.