Effect of EGR and injection timing on combustion and emission characteristics of split injection strategy DI-diesel engine fueled with biodiesel

In this study, the effect of injection timing and EGR rate on the combustion and emissions of a Ford Lion V6 split injection strategy direct injection diesel engine has been experimentally investigated by using neat biodiesel produced from soybean oil. The results showed that, with the increasing of EGR rate, the brake specific fuel combustion (BSFC) and soot emission were slightly increased, and nitrogen oxide (NOx) emission was evidently decreased. Under higher EGR rate, the peak pressure was slightly lower, and the peak heat release rate kept almost identical at lower engine load, and was higher at higher engine load. With the main injection timing retarded, BSFC was slightly increased, NOx emission was evidently decreased, and soot emission hardly varied. The second peak pressure was evidently decreased and the heat release rate was slightly increased.

► The paper mainly studied the effect of injection timing and EGR rate on the combustion and emissions of a Ford Lion V6 split injection strategy direct injection diesel engine using neat biodiesel produced from soybean oil.
► Attention was focused on the determination of the main injection timing and EGR rate for biodiesel with the aim to reduce all engine harmful emissions, especially NOx and soot. In the meantime, the influence of main injection timing and EGR rate on the combustion process and BSFC has been studied.
► The main conclusions were that higher EGR rate and retarded main injection timing were effective methods to reduce NOx emission for split injection strategy DI diesel engine fueled with biodiesel without more penalties of soot emission and BSFC.