GASEOUS FUEL ENGINE CHARGE DENSITY CONTROL SYSTEM

摘要

A spark ignited gaseous fuel engine including an exhaust gas recirculation system and method for operating a gaseous fuel engine are provided. The exhaust gas recirculation system has an adjustable flow and is operable to supply exhaust gas to at least one engine cylinder. The engine further includes means for determining a value indicative of a charge density of a combustion mixture that includes gaseous fuel, air and exhaust gas supplied to the at least one cylinder, and adjusting a flow quantity through the exhaust gas recirculation system based at least in part on the value. The charge density may permit the controller to set a NOx output rate from the engine via a pre-determined correlation between charge density and NOx output.