Control Strategy to Better Usage Of Gaseous Fuel in an Engine

摘要

A method and system for operating a fuelling system in a vehicle which has an engine capable of burning gaseous fuel supplied from at least a first and second source to a direct fuel injector of the engine; the first source has a higher source pressure than the second source, the method comprises supplying gaseous fuel to the direct injector from at least the first source during a first engine demand; and supplying gaseous fuel to the direct injector from at least the second source during a second engine demand less than said first engine demand. Preferably the injector is a piezoelectric type injector. Additionally a pressure regulator may be used to regulate fuel pressure in a fuel rail pressure system to a desired range. Also injection timing may be adjusted based on EGO sensor during fuel demand.