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Unformatted text preview: o Impossible to have a device that interacts with a single reservoir and produces net work out Always must reject heat Efficiency can never be 1.0 must be < 1.0 Reverse Heat Engine o Refrigerator /Air Conditioner o Heat Pump First Law • W in = Q H- Q L Coefficient of Performance • COP Ref = Q L /W in = Q L /(Q H – Q L ) = 1/[(Q H /Q L ) – 1] • COP HP = Q H /W in = Q H /(Q H – Q H ) = 1/[1 – (Q L /Q H )] • COP HP = COP Ref + 1 Clausius – Second Form of the Second Law of Thermodynamics o Impossible to take heat from a lower temperature reservoir and move it to a high temperature reservoir without work input T H Q H Q L T L W net-out Q L } Ref T L Ref/HP W net-in T H Q H } HP...
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This note was uploaded on 04/07/2008 for the course MECH 213 taught by Professor Knisley during the Fall '08 term at Bucknell.
- Fall '08
- Heat Transfer