EXPERIMENTAL INVESTIGATION OF B20 COMBUSTION AND EMISSIONS UNDER VARIOUS INTAKE CONDITIONS FOR LOW-TEMPERATURE COMBUSTION

Abstract

Recently, biodiesel has emerged as an alternative fuel for achieving low-temperature combustion (LTC). Several articles in the literature have showed that oxygenated biofuels, including biodiesel, can improve combustion stabilityunder high exhaust gas recirculation (EGR) operation, which is considered to be necessary for the removal of nitric oxides(NOx). The objective of this study was to investigate the performance and emissions of 20% biodiesel blended diesel fuel(B20) at various intake pressures and oxygen concentration levels to characterize the fuel for LTC application. Theexperimental investigation of B20 was carried out using a single-cylinder engine (SCE) at 1400 rpm and 50% load condition. A set of critical flow orifices with synthetic EGR was employed to simulate various intake pressures and EGR levels. Thebehavior of the B20 was first characterized under various intake conditions. The results showed that with high oxygen intake,B20 exhibited combustion and emission levels that were very similar to conventional diesel. However, B20 reducedcombustion deterioration while exhibiting lower carbon monoxide (CO) and hydrocarbon (HC) emissions than diesel underlow oxygen intake conditions.