Experimental and empirical analysis of performance, combustion and emission characteristics of diesel engine fueled with pyrolysis waste engine oil under single and split injection strategy

The present investigation studies the effects of single and split injection strategies on a diesel engine fuelled with diesel and microwave pyrolysis oil (MPO). MPO was extracted from waste engine oil (WEO) at 350–380 °C and utilized in a diesel engine after purification. The engine study was conducted using different nozzle opening pressures (NOP: 200 to 500 bar) and fuel injection timings (FIT: 17 to 27 o CA bTDC). Further, this work was extended to investigate the effect of a split injection strategy for MPO at 400 bar NOP under full load. In split injection, different split ratios, start of main injection time, and the start of post-injection time were studied. MPO's brake-specific energy consumption decreased by 7% at 400 bar NOP. NO and soot were 10% and 27% lower than diesel emissions at 400 bar NOP and bTDC 21 o CA FIT, respectively. Split injection strategy improved BTE by 1.4% and reduced NO and soot by 21% and 58% compared to the single injection strategy. The ANN model predicted the experimental results with a higher correlation coefficient (R) in the range of 0.98–0.99. Overall, the study inferred that the split injection strategy reduces exhaust emissions of MPO without affecting engine performance.