Investigation of EGR rate and biodiesel fuel effects on the combustion parameters, soot and NOx emission of a compression ignition

In this study, the effects of EGR on the combustion behavior, and and soot emissions of a diesel engine fueled by biodiesel is investigated. To do so, a compression ignition engine, diesel fuel, biodiesel fuel blend (B20) obtained from waste cooking oil, three EGR rates (0, 10 and 20%) and 7, 14 and 21Nm engine loads are used. The results show that the addition of biodiesel to diesel fuel increases the cylinder pressure and the maximum increase is 1.97%. In addition, the cylinder pressure increases with increasing EGR rate. Also, the ignition delay of B20 is lower than diesel and the maximum decrease of the ignition delay is 7.3%. The in-cylinder temperature is decreased with increasing EGR rate and ultimately, it can be stated that the maximum heat release rate increases with increasing EGR rate. The emissions decrease with increasing EGR rate for both types of fuels.