Twin scroll turbocharger in a variable displacement engine

摘要

Methods and systems are provided for operating an engine with variable displacement engine (VDE) operation coupled to a twin scroll turbocharger. One method comprises directing exhaust from a first outer cylinder and a first inner cylinder of four cylinders to a first scroll of the twin scroll turbocharger, directing exhaust from a second outer cylinder and a second inner cylinder of the four cylinders to a second scroll of the twin scroll turbocharger, and during a first condition, firing all four cylinders with uneven firing.

主权项

1. A method for an engine, comprising:
directing exhaust from a first outer cylinder and a first inner cylinder of four cylinders to a first scroll of a twin scroll turbocharger; directing exhaust from a second outer cylinder and a second inner cylinder of the four cylinders to a second scroll of the twin scroll turbocharger; during a first condition, operating all cylinders with at least one uneven firing; wherein firing events in the first outer cylinder and the first inner cylinder are separated by at least 360 crank angle degrees; wherein firing events in the second outer cylinder and the second inner cylinders are separated by at least 240 crank angle degrees; and wherein operating all cylinders with at least one uneven firing includes firing the second inner cylinder at 120 degrees of crank rotation after the first outer cylinder is fired, firing the first inner cylinder 240 crank angle degrees after firing the second inner cylinder, firing the second outer cylinder 240 crank angle degrees after firing the first inner cylinder, and firing the first outer cylinder 120 crank angle degrees after firing the second outer cylinder, and wherein the first condition includes high engine load conditions.