Patent ID: 7832204

Claim:
An engine system for a vehicle, comprising: an engine producing exhaust gases; an exhaust passage for transporting the exhaust gases to a surrounding environment; and a plurality of heat pipes for transferring heat energy between a boiler end and a condenser end of each heat pipe without a mechanical pump, heat being transferred via evaporation of a working fluid of each heat pipe at the boiler end and condensation of the working fluid at the condenser end, the plurality of heat pipes comprising: a first heat pipe having a first end in thermal contact with the exhaust passage and a second end in thermal contact with a first fluid of the engine system, and a second heat pipe having a first end in thermal contact with the exhaust passage and a second end in thermal contact with a second fluid of the engine system, the first heat pipe being configured to provide increased heat transfer between the exhaust passage and the first fluid during at least a first temperature condition and the second heat pipe being configured to provide increased heat transfer between the second fluid and the exhaust passage during at least a second temperature condition different than the first temperature condition, wherein the first temperature condition is during a warm-up operation of the engine and the second temperature condition is during an operation where combustion is discontinued in at least one cylinder of the engine.