Experimental Investigation on Combustion Strategy of Light Duty GCI Fueled High Reactivity Gasoline Fuel

Diesel engines are largely used as power units with high fuel efficiency. Conversely, they have an adverse impact on the environment and human health as they emit high NOx and particulate matter emissions. As more stringent regulations for emissions are introduced, low temperature combustion strategy such as Gasoline Compression Ignition evolved and demonstrated the potential to reduce the particulate matter and NOx emissions by operating engines under a Partially Premixed Combustion mode. Therefore, a 0.55 mm single cylinder engine (Gasoline Direct Injection), was tested over range of engine loads with constant speed (1500 rpm) using RON80 without oxygenates. Different operating parameters such as injection, exhaust gas recirculation (EGR) etc. were used to control combustion phasing and mixture stratifications.

At low loads, rebreathing of hot exhaust gas produced low levels of NOx and smoke emissions. It reduced NOx by 60% and smoke levels below 0.20 FSN when it is coupled with low levels of EGR. At medium to high loads, alternative injection strategies were explored to find proper combustion mode with very low NOx of 0.01 g/kwh and smoke of 0.01 FSN emissions while meeting combustion noise targets. Minimum ISFC was measured at 195 g/kwh at 13 bar IMEP.