The Effects Of Exhaust Gas Re-Circulation And Injection Timing On Combustion Performance And Emissions Of Biodiesel And Its Blends With 2-Methylfuran In A Diesel Engine

Abstract

In this study, the influences of injection timing and exhaust gas re-circulation on combustion and emissions characteristics of biodiesel/2-methylfuran blends are investigated on a modified water-cooled 4-cylinder four-stroke direct injection compression ignition engine. The experimental conditions are, respectively, to adjust injection timing and exhaust gas re-circulation ratio at 0.38 MPa break mean effective pressure with the engine speed at 1800 rpm constantly. With injec-tion timing in advance, the peak cylinder pressure rose while maximum heat re-lease rate first decreased and next slightly raised. Ignition delay and brake spe-cific fuel consumption reduced first and then raised while combustion duration and break thermal efficiency had the opposite trend. The NOx emissions in-creased, and HC emissions first reduced significantly and then slightly increased, while 1,3-butadiene and acetaldehyde emissions presented a reduction tendency. As exhaust gas re-circulation ratio increased gradually, ignition delay as well as combustion duration was prolonged. brake specific fuel consumption increased and break thermal efficiency declined. HC, CO, 1,3-butadiene, and acetaldehyde emissions raised while NOx emissions reduced significantly. Biodiesel could be-have well in a Diesel engine and thus a feasible alternative fuel for diesel. More-over, methylfuran addition into biodiesel could raise break thermal efficiency and the break thermal efficiency of BM20 is higher than BM10. However, both BM10 and BM20 appeared a combustion deterioration when injection timing at 2.5 °CA before top head center.