EGR FLOW METERING SYSTEMS AND METHODS

摘要

Methods and systems for metering at least one EGR valve to a position determined to pass a desired EGR flow for a given set of engine characteristics. The methods include determining the EGR valve position based on pipe flow characteristics, or determining the EGR valve position based on pipe flow characteristics when differential pressure across the EGR valve is less than a pressure threshold.

主权项

1. A method of setting at least one exhaust gas recirculation (EGR) valve position for mixing EGR with intake air in an engine system comprising an engine, an EGR system including EGR piping, and at least one EGR valve and an air intake system including air intake piping, the method comprising:
determining by a controller operating characteristics of the engine system; determining by the controller a desired EGR flow ratio based on the operating characteristics of the engine system; determining by the controller at least one EGR flow loss factor corresponding to the desired EGR flow ratio based on a relationship between the desired EGR flow and a pipe flow characteristic ratio; determining by the controller an EGR valve position using the at least one EGR flow loss factor; and configuring by the controller the EGR valve position to the determined EGR valve position, wherein the desired EGR flow ratio comprises the relationship of a flow rate of air to a flow rate of EGR, and the pipe flow characteristic ratio comprises a ratio of an EGR system characteristic to an air intake system characteristic.