Theoretical Route toward the Estimation of Second Law Potential of an Emulsified Palm Biodiesel Run Diesel Engine

The application of biodiesel as an alternative to diesel is well recognized. However, having a lesser calorific value than diesel, it results in a lower power and efficiency. This can suitably be improved by emulsifying biodiesel with water. However, the properties of biodiesel emulsions are not similar to that of diesel. Hence, the energy and availability distribution of a biodiesel emulsion-run engine will not be identical to that of a diesel-run engine at standard diesel settings. To enlighten this ambiguous fact of literature, an energy-exergy analysis has been performed for a water-in-biodiesel emulsion run diesel engine for a set of compression ratios (CRs) and injection timings (ITs) at full engine load. The biodiesel considered for the study is palm oil methyl ester (POME). The parameters analyzed are the energy and exergy potential of fuel input, shaft work, cooling water, exhaust gas, and exergy destruction. Side by side, the effects of the variation of CR and IT on peak pressure, peak heat release rate, brake thermal efficiency, exergy efficiency, exhaust gas temperature, and entropy generation rate are also discussed. (C) 2014 American Society of Civil Engineers.