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 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.
