Investigation of the effects of using alternative fuel mixtures on engine performance and combustion characteristics in a diesel engine, part A: Under different intake air conditions

Given the limited availability of fossil fuels in certain regions and the resulting energy security risks, research into alternative energy sources to prevent global warming and environmental pollution is intensifying. This study investigated the effects of intake air pressure (IAP) (25% and 50%) and IAP and intake air temperature (IAT) (25% pressure+25% temperature, 50% pressure+50% temperature) on engine performance and combustion parameters in a single-cylinder, four-stroke, common rail fuel-injected, supercharged diesel engine, at constant engine speed (1750 rpm) and pedal position (50%), using three different fuel types (D100, F15H3, and F30H6). The highest brake thermal efficiency (BTE) was found to be 26.19% with F30H6 fuel and a 50% increase in IAP, while the lowest brake specific fuel consumption (BSFC) was measured at 315.4 g/kWh with a 50% increase in IAP and temperature. Increasing the IAP by 50% generally increased the maximum cylinder pressure (CP). Furthermore, compared to the D100, a general upward trend in maximum heat release rate (HRR) was observed when using blended fuels. Overall, compared to D100, blended fuels reduced exhaust gas temperature (EGT) but increased combustion noise. When using blended fuels, the combustion time and time to reach CAD50 (the point where 50% of injected fuel burned) were shortened, while the ignition delay increased. For the D100, the shortest combustion time of 41.3 °CA was achieved by increasing the IAP by 50%.