Low NOx and HC with Direct Fuel Injection and Hydrogen Assisted Jet Ignition

摘要

Hydrogen assiste d jet ignition (HAJI) is an advanced ignition process that allows ignition of ultra lean mixtures inrnan otherwise standard gasoline fuelled engines. The ignition system utilises a spark ignition of a rich hydrogen mixturernto provide turbulent, chemically active jets for reliable ignition of mixtures as lean as λ=5, three times more dilute thanrnthe lean limit with normal spark ignition. Under conditions of gasoline air-fuel ratios greater than λ=1.8 Nox emissionsrncan be maintained at almost zero (0.02 g/kW/h) and in the range λ=2 to 3 thermal efficiency may be increased by 30%rnover stoichiometric operation. Direct cylinder injection of the gasoline is explored as a means of reducing hydrocarbonrnemissions close to zero. The initial results presented here indicate a 50% reduction in hydrocarbons is possible in therncritical range of operation for low Nox and high efficiency.