SYSTEMS AND METHODS FOR EXHAUST CATALYST TEMPERATURE CONTROL

摘要

Methods and systems are provided for exhaust catalyst temperature control by metering exhaust bypass flow from a dedicated EGR cylinder. A continuously variable bypass valve may be adjusted to vary an amount of exhaust directed to an exhaust catalyst from a dedicated EGR cylinder via a bypass passage relative to exhaust recirculated to the engine intake via an EGR passage. At lower catalyst temperatures, more exhaust is metered via the bypass passage to enable catalyst temperature to be maintained above an activation level.

主权项

1. A method for an engine, comprising:
flowing exhaust from a dedicated EGR cylinder to each of an exhaust catalyst via a bypass passage and an engine intake via an EGR passage; and adjusting a relative flow through the passages via a bypass valve, the adjusting responsive to catalyst temperature.