ENGINE CONTROL FOR CATALYST REGENERATION

摘要

Methods and systems are provided for injecting water during an engine cylinder deactivation event so as to reduce an exhaust catalyst regeneration requirement following the cylinder deactivation. In one example, water is injected at one or more deactivated engine cylinders to reduce oxidation of the exhaust catalyst. Then, during engine cylinder reactivation, a degree of richness of a combustion air-to-fuel ratio may be reduced to decrease fuel penalty to the engine while reducing NOx emission.

主权项

1. An engine method, comprising:
selectively deactivating one or more engine cylinders via deactivatable fuel injectors; and during cylinder deactivation, injecting water at the one or more deactivated engine cylinders to reduce oxygenation of a first exhaust catalyst, wherein injecting water at the one or more deactivated engine cylinders includes port injecting water on a closed intake valve of the one or more deactivated engine cylinders before the intake valve opens.