Waste heat recovery system for an internal combustion engine

摘要

A method and apparatus for recovering and utilizing waste heat from the exhaust and coolant of an internal combustion engine. The waste heat recovery system uses two separate and closed circuits of working fluid with one circuit being heated by the exhaust gases and the other being heated by the engine coolant. In the preferred embodiment, two different working fluids are used and each circuit is designed to operate at temperatures and pressures most efficient for that particular working fluid and the heat available from the exhaust in one case and the coolant in the other case. A heat exchanger is provided between the two circuits for increased efficiency and a heat reservoir of melted salt is built into the exhaust heated circuit to minimize surges in the system and to provide reserve power during high performance demands. In the preferred embodiment, the work produced by the exhaust heated circuit is sequentially added to the power output of the engine and vane expanders rather than turbines are used for a more direct and efficient coupling of the available work from the recovered waste heat to the power output of the engine.