Methods and systems for boost control

摘要

Methods and systems are provided for varying a proportion of compressed air recirculated to a compressor inlet from a location downstream of the compressor and upstream of a charge air cooler and a location downstream of the charge air cooler. A temperature-controlled compressor recirculation flow is used to reduce condensation from EGR being ingested into the compressor. The temperature-controlled compressor recirculation flow is also used to address compressor surge.

主权项

1. A boosted engine method, comprising:
responsive to an indication of compressor surge, adjusting a relative amount of compressed air recirculated to a compressor inlet from a first passage downstream of the compressor and downstream of an intercooler, and a second passage downstream of the compressor and upstream of the intercooler, the adjusting including, as an intake throttle is closed, adjusting the relative amount based on a difference between estimated and desired compressor inlet temperatures.