Exhaust heat recovery and exhaust gas recirculation with common heat exchanger

摘要

An apparatus for a vehicle with an engine is provided that accomplishes exhaust heat recovery and exhaust gas recirculation with a common heat exchanger used for both purposes. The apparatus includes an exhaust system through which exhaust gas is discharged from the engine. A heat exchanger is positioned within the exhaust system. Coolant flow passages are provided in thermal communication with the engine and with the heat exchanger. A bypass valve is operable in a first position to direct the exhaust gas through the heat exchanger to transfer heat to the coolant flow passages in a coolant heating mode, and operable in a second position in which the exhaust gas bypasses the heat exchanger in a bypass mode during which no significant coolant heating occurs via the heat exchanger. A portion of the exhaust gas is recirculated to the engine after cooling via the heat exchanger.