Performance Analysis of Irreversible Combined Refrigeration Cycles Based on Finite Time Thermodynamic Theory

S. Frikha(1*), M. S. Abid(2)

(1) National School of Engineers of Sfax, Department of Mechanical Engineering, Laboratory of Electromechanical Systems, ENIS, LASEM, B.P. W. 3038 sfax, Tunisia
(2) National School of Engineers of Sfax, Department of Mechanical Engineering, Laboratory of Electromechanical Systems, ENIS, LASEM, B.P. W. 3038 sfax, Tunisia
(*) Corresponding author

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This paper provides a performance analysis of combined refrigeration cycles. A theoretical survey based on finite time thermodynamic (FTT) analysis was presented to evaluate the operating performance of two different combined irreversible vapour compression refrigeration cycles: the conventional cascade (CC) and the integrated cascade (IC). The purpose here is to appreciate a new FTT investigation by stage (FTTS) for complicated architecture systems like the IC system that can’t be divided into separate cycles. In this FTTS approach, the system will be divided into n stages where each stage is defined by two consecutive heat exchangers. We began by detailing finite time thermodynamic analyses by cycle (FTTC) and by stage (FTTS) for the CC system. Then FTTS analysis was applied for the IC systems to derive a simple expression for the coefficient of performances (COP). Numerical examples are given to evaluate effects of internal irreversibility and intermediate heat-exchanger temperatures on the coefficient of performance of the CC and IC systems. It was found that at fixed condensing and evaporating temperatures and for same intermediate heat-exchanger temperature ratio, the IC is more efficient than the CC system. The coefficient of performance of the IC system can be more enhanced under the condition of minimum intermediate heat exchanger irreversibilities (less glide between the two counter-flow intermediate heat exchanger)
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Conventional Cascade; Integrated Cascade; Finite Time Thermodynamics; Irreversible Refrigeration Cycle; Coefficient of Performance

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G. Venkatarathnam, S. Srinivasa Murthy, Effect of mixture composition on the formation of pinch points in condensers and evaporators for zeotropic refrigerant mixtures, Int. J. of Refrig., Vol 22, pp. 205-215, 1999.

D. J. Missimer, Refrigerant conversion of Auto-refrigerating Cascade (ARC) systems, Int. J. of Refrig., Vol. 20, n. 3, pp. 201-207, 1997.

S.G. Kim, M.S. Kim, Experiment and simulation on the performance of an autocascade refrigeration system using carbon dioxide as a refrigerant, Int. J. of Refrig., Vol. 25, pp. 1093-1101, 2002.

M.Q. Gong, J.F. Wu, E.G. Luo, Performances of the mixed-gases Joule-Thomson refrigeration cycles for cooling fixed-temperature heat lods, Cryogenics, Vol. 44, pp. 847-857, 2004.

J. chen, A universal model of an irreversible combined Carnot cycle system and its general performance characteristics, J. Phys. A: Math Gen,Vol. 31, pp. 3383-3394, 1998.

Goktun S. and Yavuz H. Performance of irreversible combined cycles for cryogenic refrigeration, Energ. Convers. And Management, Vol. 41, pp. 449-459, 2000.

L. Chen, C. Wu, F. Sun, Effect of heat transfer law on the finite-time exergoeconomic performance of a carnot refrigerator, Exergy Int. J., Vol. 4, p.p. 295-302, 2001.

J. Chen, X. Chen, C. Wu, Ecological optimisation of a multi-stage irreversible combined refrigeration system, Energ. Convers and Management, Vol. 43, pp. 2379-2393, 2002.

S. Bahri, A. Kodal, Thermoeconomic optimization of a two stage combined refrigeration system: a finite-time approach, Int. J. of Refrig., Vol. 25, pp. 872-877, 2002.

A. Kilicarslan, An experimental investigation of different type vapour compression cascade refrigeration system, Applied Thermal Engineering, Vol. 24, pp. 2611-2626, 2004.

T. S. Lee, C.H. Liu, T.W. Chen, Thermodynamic analysis of optimal condensing temperature of cascade-condenser in CO2/NH3 cascade refrigeration systems, Int. J. of Refrig., Vol. 29, pp. 1100-1108, 2006.

S. Bhattacharyya, S. Bose, J. Sarkar, Exergy maximization of cascade refrigeration cycles and its numerical verification for a transcritical CO2-C3H8 system, Int. J. of Refrig., Vol. 30, p.p. 624-634, 2007.

H.M. Getu, P.K. Bansal, Thermodynamic analysis of an R744-R717 cascade refrigeration system, Int. J. of Refrig., Vol. 31, p.p. 45-54, 2008.

A. Bjarne, Comment on “A fallacious argument in the finite time thermodynamic concept of endoreversibility”, J. Appl. Phys. Vol. 90 pp. 6557-6559, 2001.


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