Impact of Cetane Number on Combustion of a Gasoline-Diesel Dual-Fuel Heavy-Duty Multi-Cylinder Engine

Impact of Cetane Number on Combustion of a Gasoline-Diesel Dual-Fuel Heavy-Duty Multi-Cylinder Engine

Type	Report
Author	Andrew Ickes
Author	Thomas Wallner
URL	http://papers.sae.org/2014-01-1309/
Report Type	SAE Technical Paper
Abstract	Dual-fuel combustion using liquid fuels with differing reactivity can achieve low-temperature combustion with moderate peak pressure rise rates, low soot and NOx emissions, and high indicated efficiency. Varying fractions of gasoline-type and diesel-type fuels enable operation across a range of low- and mid-load operating conditions. Expanding the operating range to cover the full operating range of a heavy-duty diesel engine, while maintaining the efficiency and emissions benefits, is a key objective. With dissimilar properties of the two utilized fuels lying at the heart of the dual-fuel concept, a tool for enabling this load range expansion is altering the properties of the two test fuels. Authors on altering the reactivity of the diesel fuel component. Researchers performed tests on a 13L six-cylinder heavy-duty diesel engine modified to run dual-fuel combustion with port gasoline injection to supplement the direct diesel injection. They employed a single diesel injection strategy across a range of operating points. They tested diesel fuels with varying cetane number, including a ULSD certification fuel; a low cetane, low aromatics, high volatility fuel from the Fuels for Advanced Combustion Engines matrix (FACE #1); and a high cetane Fischer-Tropsch diesel fuel.Decreasing diesel fuel cetane number reduces overall mixture reactivity and extends the mixing time prior to onset of combustion, reducing soot emissions and shifting the overall operating window to a higher load range.
Report Number	2014-01-1309