Fumiaki Hattori

Analysis of fuel and combustion behavior during cold starting of SI gasoline engine

Abstract In order to reduce hydrocarbon emission from spark ignition engines, it is important not only to improve catalyst conversion efficiency but also to reduce directly engine-out hydrocarbon emissions during cold starting and warming-up processes. This paper quantitatively analyzes the fuel behavior during the cold starting process of a modern production engine. Using a specially designed analytical method, cycle-by-cycle behavior of required fuel amount for stable startability and engine-out hydrocarbon were observed. Further, using a specially designed analytical engine with intake and exhaust values driven by hydraulic control, the fuel amount of intake port and cylinder wall-wetting, burned fuel and engine-out hydrocarbon emissions at the first cycle were measured. The effect of fuel properties and fuel atomization were analyzed and characteristics of engine-out hydrocarbon emissions during this process were observed.