Simulation investigation of the effect of various exhaust gas recirculation temperatures and amounts on the exergy terms in a direct injection diesel engine fueled by diesel/biodiesel

摘要

Recently, applying biodiesel as an alternative fuel to improve the combustion stability in combination with implementing exhaust gas recirculation (EGR) to bring in-cylinder temperature under control has come under focus. Exergy analysis deals with the energy lost because of the irreversibilities and heat transfer across the combustion chamber. The present study investigates the effect of the various EGR amounts and temperatures on diesel/biodiesel combustion in a turbocharged direct injection diesel engine from the exergy analysis standpoint. The employed biodiesel percentages are considered at two levels, 0 and 20% (i.e., BO and B20). The rates of EGR amount are 0, 5, 10, 13, and 20%, which are inducted into the combustion chamber at various temperatures of 370, 395, 575, 735, and 825 K. The results revealed that the higher EGR implementation at higher temperature had reduced the accumulative (acc) work and fuel burn exergies as well as irreversibility. In contrast, the total fuel and acc heat loss exergies are increased. The maximum and minimum ace exergy losses are detected for B0-EGR20-835 K and B0-EGR5-370 K, respectively.