Investigation on the adjusting compression ratio and injection timing for a DI diesel engine fueled with policy-recommended B20 fuel

Abstract

AbstractIn this investigation, Jatropha methyl ester (JME) [JME 20% (volume) + diesel 80% (volume)] was used to adjust the engine’s compression ratio (CR 16, 17, 17.5, and 18) and fuel injection (IT) in the range of 21–25 deg. crank angle (CA) in steps of 2 deg. before top dead center (BTDC), to identify emission profiles of the engine, where the standard CR and IT were 17.5 and 23 deg. CA BTDC. The results reveal that the CO and UHC were obtained to be as low as 0.03% vol at 75% load, CR18, and IT25, and 5 ppm at full load, CR18, and IT25 respectively. The NOx emission rallied from as low as 47 ppm at no load to as high as 1179 ppm at full load, IT of 25, and CR of 18. Whereas the NOx for diesel was 1108 ppm at full load with standard engine operation. The smoke was about 22.1% with CR18 and IT25 for JME20. However, at standard CR and IT for JME20, the smoke was 34.6%. Elevated CR of 18 and advanced IT of 25 are superior to other conditions, hence it is recommended for JME20-powered engines.