Exergy Analysis of a Four Stroke Spark-Ignition Engine Using Different Fuels

Abstract

The present thesis reports the exergestic analysis of a four stroke spark ignition internal combustion engine fuelled by four fuels namely octane, methane, hydrogen and methanol. A thermodynamic model has been developed and simulation is done using FORTRAN 95 programming language. The model includes finite heat release, convective heat loss from engine cylinder, frictional loss and temperature dependant thermodynamic properties. Thermodynamic state and composition of gases inside the cylinder during thermodynamic cycle are calculated. Different performance parameters are estimated. The change in exergy through key processes of ideal thermodynamic cycle is calculated. Analysis of the results show that around 10 to 15% of the fuel exergy is destroyed during combustion & 25 to 35% is left unused at the end of the expansion stroke which is exhausted to the atmosphere.