Second Law analysis of an EGR implemented SI engine running onalternative fuels

The first‐law analysis is a proper method to predict engine performance and influence of its various operativeparameters. On the other hand, it is known that the first‐law analysis is unable to give the best observation toengineer about engine performance alone. To analyze the value of engine efficiency that it needs to evaluate theperformance associated with various processes, the second‐law analysis must be applied. In this study the effectof exhaust gas recirculation (EGR) on the terms of second law of thermodynamics under the various EGRpercentages in a four cylinder natural aspirated spark ignition engine running with alternative fuels such ashydrogen, ethanol, methanol, methane and propane in comparison with gasoline as a conventional fuel havebeen studied. The analysis is done by using the results of a three dimensional CFD code. The results show a goodagreement with the experimental data. The results show that although applying EGR could decrease harmfulemissions of engine, but due to substantial fall in flame speed, it has unbecoming effects on combustiontemperature and consequently on irreversibility’s and second law efficiency.

Keywords:

Second Law Analyses , Alternative Fuels , SI Engine , EGR