Effects of Engine Load and Ternary Mixture on Combustion and Emissions from a Diesel Engine Using Later Injection Timing

Abstract

As a high oxygenated fuel, bioethanol has already obtained more and more widespread attention in diesel engines. The present work aims to study and compare effects of various diesel-bioethanol-biodiesel ternary mixture fuels on combustion and emissions from a four-cylinder diesel engine. A series of engine experiments are conducted on neat diesel fuel (D100), 95% D100 blended with 5% bioethanol and 1% biodiesel by volume (D95E5B1), 90% D100 blended with 10% bioethanol and 1% biodiesel by volume (D90E10B1), and 85% D100 blended with 15% bioethanol and 1% biodiesel by volume (D85E15B1) according to various engine loads (40, 80 and 120 Nm). The experimental results show that the peak value of pressure and heat release rate (HRR) in the cylinder, nitrogen oxides (NOx) and smoke emissions increase with the increase in engine load, but the brake specific fuel consumption (BSFC) decreases. There is no significant variation in cylinder pressure with the addition of ethanol, but HRR is improved and NOx and smoke emissions are effectively controlled. It is exciting that the addition of ethanol can simultaneously reduce NOx and smoke emissions under medium and high load conditions. Specifically, at 120 Nm, ethanol addition simultaneously reduces NOx emissions by 2.08% and smoke opacity by 36.08% on average. Through the results of this study, it is found that the ethanol can improve the combustion of the four-cylinder diesel engine and also effectively control the emissions of NOx and smoke. Therefore, ethanol will play an important role in the future research field of energy saving and emission reduction for diesel engines.