Avoidance of coolant overheating in exhaust-to-coolant heat exchangers

摘要

A method for operating an engine system comprises charging a cylinder of the engine system with exhaust from upstream of an exhaust turbine at a first rate. The method further comprises charging the cylinder with exhaust from downstream of the turbine at a second rate. The exhaust from downstream of the turbine is routed to the cylinder via a low-pressure exhaust-gas recirculation path. The method further comprises increasing the second rate relative to the first rate in response to a coolant-overheating condition.