SYSTEMS AND METHODS FOR CONTROLLING EGR FLOW DURING TRANSIENTS

摘要

Systems, apparatus, and methods are disclosed that include a divided exhaust engine configured to control an EGR fraction in the charge flow to the cylinders in response to an EGR fraction overshoot condition, an exhaust pressure change in the EGR loop, and/or a transient operating condition.

主权项

1. A system comprising:
an internal combustion engine having at least one primary exhaust gas recirculation (EGR) cylinder connected to an EGR passage and a plurality of non-primary EGR cylinders connected to an exhaust passage, wherein the EGR passage is connected to an intake system to provide an EGR flow from the at least one primary EGR cylinder to the intake system, wherein the intake system provides a charge flow to the at least one primary EGR cylinder and the plurality of non-primary EGR cylinders, the charge flow including an EGR fraction corresponding to an expected EGR flow from the at least one primary EGR cylinder; and a controller structured to interpret an EGR fraction deviation condition, and in response to the EGR fraction deviation condition to divert at least a portion of the EGR flow to a secondary location, wherein the secondary location is in at least one of the intake system and the exhaust passage and is lower in pressure than the connection of the EGR passage to the intake system.