A STUDY ON THE THERMAL PERFORMANCE AND EMISSIONS OF A VARIABLE COMPRESSION RATIO DIESEL ENGINE FUELLED WITH KARANJA BIODIESEL AND THE OPTIMIZATION OF PARAMETERS BASED ON EXPERIMENTAL DATA

Fossil fuels are the chief contributors to urban air pollution and major source of green house gases and are considered to be the prime cause behind the global climate change. Biofuels are renewable, can supplement fossil fuels, reduce green house gases, and mitigate their adverse effects on the climate resulting from global warming. In the present study, biodiesel produced from karanja oil is evaluated as alternative fuel in a diesel engine. The experiments are conducted on a single-cylinder, four-stroke, direct-injection CI engine and the experimental parameters include the percentage of karanja biodiesel in the blend, engine load, injection pressure, and compression ratio. Comparative measures of brake thermal efficiency, brake-specific fuel consumption, smoke opacity, and HC, CO, and NOX emissions are presented and discussed. Results show that the performance of the engine fuelled with karanja biodiesel and its blends with diesel fuel is generally comparable to that when the engine is fuelled with pure diesel. At higher compression ratios, the engine gives lesser emission and better performance. Genetic algorithm optimization technique was used to optimize the parameters. With respect to maximum efficiency and minimum emissions, the optimum values of load, compression ratio, injection pressure, and blend were 6 kg, 18, 247 bar, and B95, respectively.