Single zone combustion modeling of biodiesel from wastes in diesel engine
Résumé
Increasing interest in diesel engine technology and the continuous demand of finding alternate fuels and reducing emissions has motivated over the years for the development of numerical models, to provide qualitatively predictive tools for the designers. Among the alternative fuels, biodiesel is considered suitable and the most promising fuel for diesel engine. The properties of biodiesel from waste oils are found similar to that of diesel. In this present work, a unique single zone combustion model for diesel fuel and biodiesel was implemented to predict the cylinder pressure for the better understanding of combustion characteristics of different fuels tested in a diesel engine and also to predict the combustion and performance characteristics of the same engine running on different fuels. The single zone model coupled with a triple-Wiebe function was performed to simulate heat release between the period of IVC (inlet valve close) and EVO (exhaust valve open). This model also includes the submodels of intake and exhaust gases through the valves, ignition delay, burned fuel during the cycle and heat losses through walls to simulate all phases of combustion. The model calibration was performed using data from experiments on diesel fuel and biodiesel from waste cooking oil. Later the same model was used to simulate the combustion and the cylinder pressure of engine running on biodiesel derived from animal fat residues. Finally, cylinder pressure traces predicted by using single-zone model are compared to experimental pressure traces obtained from a diesel engine fuelled with diesel fuel and biodiesel. (C) 2012 Elsevier Ltd. All rights reserved.