Experimental study on combustion characteristics of an indirect injection diesel engine fuelled by biodiesel blends

Abstract

An experimental investigation was conducted to evaluate the performance of an indirect injection (IDI) diesel engine using diesel (D100) and diesel-biodiesel blends (BD25, BD45, BD65) separately. The engine was run in various engine loads at constant engine speed ranging from 1000 to 2400 rpm with an interval 200 rpm. The results showed that the maximum pressure inside a cylinder of D100 is slightly higher than that of BD65 and other biodiesel blends. The biodiesel blends exhibited higher pressure change rate at a moment before peak pressure inside the combustion chamber. It was also clearly observed that the heat release rate of D100 is higher than those of biodiesel blends. This result is consistent with the higher engine power delivered by D100 compared to the biodiesel blends. In related to the combustion period, it was recorded that BD65 started the combustion slightly earlier than that of D100. This resulted in the shorter ignition delay of BD65 compared to D100. On the other hand, from the burnt mass data it was found that the BD65 ended the combustion later than the D100. This means the combustion duration of biodiesel blends are longer than that of diesel fuel which is worse combustion condition.