Experimental investigations on efficiency and instability of combustion process in a diesel engine fueled with ternary blends of hydrogen peroxide additive/biodiesel/diesel

The current study intends to assess the impact of incorporating an oxygenated fuel additive (hydrogen peroxide (H₂O₂)) into a biodiesel/diesel fuel mix on diesel engine combustion efficiency and instability. The combustion, performance, and emission properties were evaluated using advanced test equipment to offer a full study. The combustion instabilities in terms of cyclic fluctuations were investigated to discover any unusual behavior when H₂O₂ was added to biodiesel/diesel fuel mixtures. Statistical and continuous wavelet transformations were used to investigate the cyclic fluctuations in peak cylinder pressure and indicated mean effective pressure (IMEP). Diesel, B20 (20%/80% of biodiesel/diesel fuel), B20H5 (20%/5%/75% of biodiesel/H₂O₂/diesel fuel), and B20H10 (20%/10%/70% of biodiesel/H₂O₂/diesel fuel) were tested in the study. Experiment results indicated that B20H10 produced the best results. In comparison to B20, B20H10 improved BTE by 6.56% and HRR by 8.5%, while decreasing BSFC by 7.98%, CO and HC emissions by 26.5%, and 6.67%, respectively. Furthermore, the peak pressure and IMEP cyclic changes were also well within permissible ranges. However, it was shown that adding H₂O₂ to B20 increased NOx emissions. The cyclic variations in the cylinder peak pressure and indicated mean effective pressure were analyzed using statistical methods and continuous wavelet transformation. No abnormality was detected in cyclic variation, thus ruling out any unsafe behavior in introducing test fuel additive to biodiesel blends. In principle, introducing H₂O₂ into a biodiesel/diesel fuel mix helped improve the engine performance and emissions while having no negative effects on engine life.