Combustion analysis of a single cylinder variable compression ratio small size agricultural DI diesel engine run by Nahar biodiesel and its diesel blends

摘要

This study explores the combustion characteristics of a single cylinder four stroke variable compression ratio direct injection diesel engine run by Nahar biodiesel (BD) and its six different blends (B5, B10, B20, B30, B40, and B50). Combustion duration reduced up to B40 and slightly increased for B50 and significantly for B100. Peak cylinder pressure (PCP) increased with BD concentration in the blend. Maximum rate of pressure rise (MROPR), heat release rate, and ignition delay (ID) reduced with an increase in BD share in the blend. At full load, PCP for B100 is obtained as 70.91 bar, whereas for diesel it is 70.04 bar. The MROPR is observed to be 5.67 bar/degrees CA for diesel, whereas 5.31 bar/degrees CA for B100 at full load. Peak heat release rate is observed to be 64.7 J/degrees CA for diesel, whereas it is 54.41 J/degrees CA for B100. ID for the blends reduced by 1-2 degrees CA compared to diesel fuel. Overall, it is recommended to use BD up to B40 blend in a DI diesel engine primarily employed in gen sets and agricultural units.