The effect of methanol/diesel fuel blends with co-solvent on diesel engine combustion based on experiment and exergy analysis

In this paper, the influences of methanol/n-butanol/biodiesel/diesel blend fuels on turbocharged diesel engines' performance were systematically examined. Exhaust gas recirculation (EGR) and injection module calibration have been conducted to optimize blended fuel emission characteristics and combustion. Further, methanol/diesel/n-butanol alternative blends were modeled numerically to analyze their energy balance and exergy. According to the results, compared to diesel at a constant speed and medium and high loads, the cylinder peak pressure was higher, the ignition delay period was longer, and the effective fuel consumption rate and brake thermal efficiency (BTE) increased. Multi-blend fuel reduced soot emission by more than 30% while increasing NOx emission slightly. Moreover, EGR and delayed main injection timing can significantly reduce NOx emissions. For this supercharged diesel engine experiment, M10Bu10, -3°CA ATDC, and 15% EGR rate were selected as the optimal solution. The exergy analysis revealed that the indicated thermal efficiency and the blending efficiency of diesel fuel with alcohol fuel improved, as did the irreversible loss, as the percentage of alcohol fuel blending increased (0%–15%). Increasing the load on a diesel engine can improve thermal and wiring efficiency.