Dual-Fuel Spark Ignition (DFSI) combustion fuelled with different alcohols and gasoline for fuel efficiency

This paper investigates an experimental study of Alcohols-gasoline Dual-Fuel Spark Ignition (DFSI) Combustion for knock suppression and high fuel efficiency using a gasoline engine with high compression ratio. Alcohols-gasoline DFSI is organized using a port-fuel-injection (PFI) of high oxygenated, high latent heat and high octane number fuel to suppress knock and a direct injection (DI) of high energy density and high volatility fuel to extend high load. Systematical comparison about the effect of stoichiometric M-G (PFI-Methanol and DI-Gasoline), E-G (PFI-Ethanol and DI-Gasoline), E85W15-G (PFI-15% water and 85% ethanol and DI-Gasoline) and G-G (PFI-Gasoline and DI-Gasoline) DFSI on engine knock suppression was conducted. For each test, the percentage of PFI-Alcohol was varied from 0% to 100%. The effects of these combustion modes on knock-limit extension, fuel economy, and combustion characteristics were investigated. Alcohols-gasoline DFSI is a potential approach of using alternative alcohol fuels in practical gasoline engines with significant improvement in engine efficiency and knock suppression. M-G DFSI exhibits better anti-knock performance and achieves higher fuel efficiency than other combustion modes.