Emissions and Performance analysis of variable compression ratio engine fuelled with safflower oil methyl ester-diesel blends

Abstract

This paper presents the performance and emission characteristics of safflower oil bio-diesel blends in a 4-stroke single-cylinder water-cooled diesel engine. In this work safflower oil bio diesel is prepared by alkaline transesterification method. All experiments were carried out at constant speed of 1500 rpm and the biodiesel blends were varied for B20 and B40. The engine was equipped with variable compressions ratio (VCR) mechanism. All the blends and pure diesel was checked on the engine at a load of 0kg, 3kg, 6kg and 9kg by varying the compression ratio. The change of compression ratio from 17 to 18 resulted in 6% and 2% increase in brake thermal efficiency in case of blend B20 and B40 respectively. At all load condition, Blend B40 shows minimum fuel consumption as compared from blend B20 and B40. On an average CO2 emissions reduced by 50%, NOX emissions reduced by 45%, HC emissions reduced by 40% and CO emissions reduced marginally when compression ratio was increased from 17 to 18. From this work it has been concluded that blend B20 at compression ratio 17:1 can be used as an alternative fuel for diesel engine without modification.