The effect of fuel type and engine speed on the exergy of a CI engine

In order to measure the quality of energy, a concept known as “exergy" is defined. In this study, the exergy of a diesel engine using different blends of diesel and biodiesel fuels (B0, B20, B40 and B100) were investigated. In addition, the effect of speeds of 1200, 1600 and 2000 rpm on analysis of the second law of thermodynamics with various fuels were studied. The parameters evaluated in this study include exergy through work and heat transfer, irreversibility, total exergy, the thermomechanical exergy, and burnt fuel exergy. The results showed that exergy parameters for different blends of diesel and biodiesel fuels increased by the end of combustion stroke and then decreased at the beginning of expansion stroke. Total exergy of B0 increased by 3.3, 7 and 16.7% respectively, as compared to B20¡ B40 and B100. The maximum efficiency of the second law of thermodynamics were attained at 2000 rpm as 44.5, 46.38, 47.89 and 48.5% for B0, B20, B40 and B100, respectively.