Patent ID: 9200599
Filing Date: 2015-12-01
Classification: F02M,Y02T

Abstract:
1. A method of using exhaust gas recirculation (EGR) to improve combustion efficiency of an internal combustion engine having a number of cylinders, comprising: operating one or more of the cylinders as dedicated EGR cylinder(s), such that all exhaust from the dedicated EGR cylinders) is recirculated as dedicated EGR, and thereby operating the remaining cylinders as main cylinders; operating the dedicated EGR cylinder(s) at a different air-fuel ratio than the main cylinders; providing a dedicated EGR loop for delivering the dedicated EGR to all cylinders; providing a low pressure EGR loop for delivering recirculated low pressure loop EGR from the main cylinders back to the main cylinders; operating the main cylinders to receive a mixture of fresh air and dedicated EGR gas, or to receive a mixture of fresh air, dedicated EGR gas and low pressure loop EGR gas; providing each main cylinder with two intake ports, such that each main cylinder may receive a mixture of fresh air and dedicated EGR through one intake port and a mixture of fresh air and low pressure EGR through the other intake port; determining a desired EGR rate; based on the desired EGR rate, providing EGR to all cylinders only from the dedicated EGR loop or also providing additional EGR to at least the main cylinders from the low pressure EGR loop.