A literature and experimental study was done to create an overview of the behavior of gasoline combusted in a CI-engine. This paper creates a first overview of the work to be done before implementing this Gasoline Compression Ignition concept in a multi-cylinder engine.
According to literature the gasoline blend will have advantages over diesel. First the shorter molecular chain of the gasoline makes it less prone to soot. Second the lower density gives the gasoline a higher nozzle exit speed resulting in better mixing capabilities. Third the lower density and higher volatility lets the spray length decrease. This lowers the chance of wall-impingement, but creates worse mixing conditions looking from a spray point of view. The CO and HC emissions tend to increase relative to operation with diesel fuel, NOx emissions largely depend on the choice of combustion strategy and could be influenced by the nitrogen bound to the EHN molecule that is used as an ignition improver.
Tests on a standard 2.4l 5-cylinder Euro 4 compression ignition engine showed it was fully capable of running on the chosen gasoline blend 95 RON + 5 vol% 2-EHN in every selected load-point. Load-points varied from idle to 10.5 bar BMEP at 1850 RPM. The standard injection strategy was not adjusted for the characteristics of gasoline. Emission measurements showed a decrease in soot and efficiency, and increases in NOx and CO2. At low load points the HC and CO emissions increased, at higher load points the difference was smaller or negligible.