Effect of Ethanol-Coconut Oil Methyl Ester on the Performance, Emission and Combustion Characteristics of a High-Pressure Common-Rail DI Engine

摘要

The effects of using ethanol as additive to biodiesel-diesel blends on engine performance, emissions and combustion characteristics was investigated on a four-cylinder, turbocharged and high-pressure common-rail direct injection diesel engine. Three test fuels have been compared: baseline diesel, coconut oil methyl ester (CME) with 20% of biodiesel by volume (B20) and 5% of ethanol and 20% of CME by volume (B20E5). The tests were performed in steady state conditions at 2000 rpm with 25%, 50% and 75% load setting conditions. The results indicate that higher brake specific fuel consumption and brake thermal efficiency is observed when operating with B20 and B20E5 blend. B20E5 blend shows reduction in smoke opacity, CO and NO_x emissions compared to baseline diesel fuel. In terms of combustion characteristics, B20E5 shows slightly higher in both of the peak pressure and peak of HRR at low engine load.