Open-valve port fuel injection of alcohol in multiple injector engines

摘要

An engine having two or more fuel injectors is disclosed, where at least one of the injectors is used to port fuel inject fuel into the cylinder when the air intake valve is open. The open valve port fuel injector is used to inject a fuel that has alcohol as a constituent and is the same fuel injected by another fuel injector. In other embodiments, the open valve fuel injector is used to inject an anti-knock fuel containing alcohol while a primary fuel, is introduced by another injector. The operation of the open valve fuel injector can be optimized to maximize the vaporization cooling. In other embodiments, the open valve fuel injector may be used in conjunction with direct injection of the primary fuel or the anti-knock fuel. Heavy EGR can be optimally used with the various embodiments.

主权项

1. A spark ignition engine where fuel is directly injected as a liquid and EGR is used; and
where fuel is also port fuel injected; and where the ratio of directly injected fuel to port injected fuel increases with increasing torque; and where the port injected fuel is employed in such a way that the amount of EGR that can be used without encountering a combustion stability limit is increased relative to the amount of EGR that could be used if port fuel injection were not employed.