EGR control in engine equipped with cylinders having dual exhaust valves

摘要

A method and system for controlling recirculated exhaust gas composition and quantity provided to an internal combustion engine, which has one or more separately controllable combustion cylinders, a main exhaust line and an exhaust gas recirculation (EGR) loop. A first exhaust valve is connected to the main exhaust line, and a second exhaust valve is connected to the EGR loop. The operation of the exhaust valves is controlled such that exhaust does not flow through both exhaust valves at the same time. Control of the exhaust valves is coordinated with the main fueling event used to control the exhaust composition exiting each valve for every cylinder on every cycle. During each engine cycle, a post-combustion fuel injection event is also used to add fuel to the exhaust in-cylinder, which flows only through the second (EGR) exhaust valve.

主权项

1. A method of controlling recirculated exhaust gas provided to an internal combustion engine, which has one or more combustion cylinders, a main exhaust line and an exhaust gas recirculation (EGR) loop, comprising:
providing each cylinder with two exhaust valves, each separately controllable; wherein a first exhaust valve is connected to the main exhaust line and a second exhaust valve is connected to the EGR loop; controlling the exhaust valves such that exhaust from each cylinder does not flow through both of its exhaust valves at the same time; providing a post-combustion fuel injection event during each engine cycle; and timing the post-combustion fuel injection event and the operation of the exhaust valves so that exhaust from the post-combustion fuel injection event flows only through the second exhaust valve.