Esquivel, Jason (2008-12). Performance Characterization of a Medium-Duty Diesel Engine with Bio-Diesel and Petroleum Diesel Fuels. Master's Thesis.
In the wake of global warming and fossil fuel depletion, renewed attention has been paid to shifting away from the use of petroleum based fuels. The world?s energy demand is commencing its dependency on alternative fuels. Such alternative fuels in use today consist of bio-alcohols (such as ethanol), hydrogen, biomass, and natural oil/fat derived fuels. However, in this study, the focus will be on the alternative fuel derived from natural oils and fats, namely biodiesel. The following study characterizes the performance of a medium-duty diesel engine fuelled with biodiesel and conventional diesel. The objective is accomplished by taking measurements of manifold pressure and temperature, fuel flow, air flow, and torque. The study first characterizes a John Deere 4.5 liter 4 cylinder direct injection engine with exhaust gas recirculation (EGR), common rail fuel injection, and variable turbo-charging with conventional petroleum diesel to set a reference for comparison. The study then proceeds to characterize the differences in engine performance as a result of using biodiesel relative to conventional diesel. The results show that torque decreases with the use of biodiesel by about 10%. The evaluation of engine performance parameters shows that torque is decreased because of the lower heating value of biodiesel compared to conventional diesel. The insignificant difference between the other performance parameters shows that the ECM demands the same performance of the engine regardless of the fuel being combusted by the engine.