New Performance Bounds for a Finite-Time Carnot Refrigerator

Journal Article · Tue Apr 01 04:00:00 UTC 1997 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.78.3241· OSTI ID:496782

Velasco, S; Roco, J; Medina, A; Hernandez, A ^[1]; Medina, A ^[2]

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1. Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca (Spain)
2. EUITI de Bejar, 37700 Bejar, Salamanca (Spain)

An upper bound for the coefficient of performance (COP) of endoreversible refrigerators which depends only on the ratio {tau}=T{sub c}/T{sub h} between the cold and hot reservoir temperatures has been elusive to date. We address here this long standing problem by analyzing an endoreversible Carnot refrigerator that operates in conditions of maximum per-unit-time COP. Two novel results are obtained: (1) A long sought {tau}-dependent upper bound for the COP of refrigerators. (2) A {tau}-dependent optimum distribution of the heat conductances associated with the coupling between the refrigerant and the heat reservoirs. Moreover, when the method is applied to heat engines, the resulting optimum efficiency is even closer to real efficiencies than the well-known Curzon-Ahlborn result. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 496782
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 17 Vol. 78; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
66 PHYSICS
CARNOT CYCLE
CRYOGENICS
HEAT ENGINES
HEAT TRANSFER
OPTIMIZATION
QUANTUM EFFICIENCY
REFRIGERATORS