Gasoline Compression Ignition Operation of a Heavy-Duty Engine at High Load

Engine experiments were carried out on a heavy-duty single-cylinder engine to investigate the effects of Gasoline Compression Ignition on emissions and performance of a heavy-duty engine operating at a high load condition. Comparisons between gasoline fueled operation and diesel fueled operation are presented using a single, near top dead center injection. Although the fuel’s cetane numbers are very different, the combustion characteristics of the two fuels at high load are similar, with the gasoline-fueled case showing less than two crank angle degree longer ignition delay. Gasoline operation showed lower soot production at similar levels of NO_x, initiating study of the impact of exhaust gas recirculation which spanned a range of NO_x levels covering the range from minimal urea dosing to high urea dosing. A conventional soot-NO_x tradeoff was found to exist with gasoline as exists with diesel. For the gasoline-fueled cases, the impact of premixed fuel was investigated and the tradeoffs between particulate matter (soot) and peak pressure rise rate is discussed. As the amount of premixed fuel is increased, the trend of increasing peak pressure rise rate and decreasing soot is seen.