Energy and Exergy Based Analysis of A Multi-Fuelled SI Engine

Abstract

In the present work, energy and exergy based analyses of a single cylinder, four-stroke, spark ignition engine fuelled by six di erent fuels namely iso-octane, methane, hydrogen, methanol, ethanol and nbutanol have been carried out. Wiebe function is used to predict realistic burn rates. Since the Wiebe function parameters are generally optimized for conventional fuels, the current study modi es them for di erent alternative fuels using available burning velocity data. Heat losses throughout the cycle have been predicted by appropriate empirical correlations. Detailed equilibrium calculations provided the properties of the mixture inside the cylinder. Analyses are carried out to quantify energy and exegy of the premixed fuel-air mixture inside the engine cylinder at various phases of the cycle and some results obtained from the study are validated against data available in literature. E ect of variation in speed, equivalence ratio on energy and exergy based parameters were studied, and their variation with change in fuel were observed. Results show that about 34 ð€€€ 42% of energy contained in the fuel is converted into useful work and the work quantity is found to increase with engine speed. Exergy destruction associated with exhaust losses are found signi cantly lower than the corresponding energy values for all fuels. The present study highlights the necessity of both energy and exergy analyses for comprehensive analysis of engine performance with alternative fuels.