Internal Combustion Engine Having Dedicated Cylinder(s) for Generation of Both EGR and Exhaust Aftertreatment Reformate for Three-Way Catalyst

摘要

An exhaust gas recirculation (EGR) system for an internal combustion engine having dedicated EGR and operating at a net stoichiometric air-fuel ratio. In such engines, one or more cylinders is operable as a dedicated EGR cylinder, such that all of the exhaust produced by the dedicated EGR cylinder(s) may be directed back to the intake manifold. Because the engine's exhaust is net stoichiometric, its exhaust aftertreatment system has a three-way catalyst. An EGR loop is configured to recirculate EGR from the dedicated EGR cylinder(s) to the engine's intake manifold. A diversion line, modulated with a valve, connects the EGR loop to the exhaust aftertreatment system, thereby allowing adjustment of the relative amounts of EGR to be recirculated and to be provided to the exhaust system.

主权项

1. An exhaust gas recirculation (EGR) system for an internal combustion engine having a number of cylinders and having an exhaust aftertreatment system with a three-way catalyst, comprising:
one or more cylinders operable as a dedicated EGR cylinder, such that all of the exhaust produced by the dedicated EGR cylinder(s) may be recirculated to the engine's main (non dedicated) cylinders; an EGR loop for recirculating EGR from the dedicated EGR cylinder(s) to the engine's intake manifold; a diversion line connecting the EGR loop to the exhaust aftertreatment system, thereby operable to deliver EGR as syngas to the three-way catalyst; and a valve on the diversion line for modulating the relative amount of flow of syngas to be recirculated and the amount of flow of syngas to be delivered to the three-way catalyst.