Abstract
In general, thermal processes can be classified into two categories: heat-work conversion processes and heat transfer processes. Correspondingly, the optimization of thermal processes has to have two different criteria: the well known entropy generation minimization method and the recently proposed entransy dissipation maximization method. This study analyzes the thermal issues in a heat exchanger group, and optimizes the unit arrangements under different constraints based on a suitable optimization criterion. The result indicates that the principle of minimum entropy generation rate is valid for optimizing heat exchangers in a thermodynamic cycle with given boundary temperatures. In contrast, the entransy dissipation maximization is more suitable in heat exchanger optimizations involving only heat transfer processes. Furthermore, the entropy generation rate induced by dumping used streams into ambient surroundings has to be taken into account, except for that originating from the hot and cold-ends of heat exchangers, when using the entropy generation minimization to optimize heat exchangers undergoing a thermodynamic cycle.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Bergles A E. Some perspectives on enhanced heat transfer—2nd-generation heat transfer technology. J Heat Transf-Trans ASME, 1988, 110: 1082–1096
Bergles A E. Heat transfer enhancement—The maturing of second-generation heat transfer technology. Heat Transf Eng, 1997, 18: 47–55
Zimparov V. Energy conservation through heat transfer enhancement techniques. Int J Energy Res, 2002, 26: 675–696
Kreuzer H J. Nonequilibrium Thermodynamics and Its Statistical Foundations. Oxford: Clarendon Press, 1981
Bejan A. The concept of irreversibility in heat exchanger design: Counterflow heat exchangers for gas-to-gas applications. J Heat Transf-Trans ASME, 1977, 99: 374–380
Bejan A. Entropy Generation Minimization. Florida: CRC Press, 1996
Poulikakos D, Bejan A. Fin geometry for minimum entropy generation in forced convection. J Heat Transf-Trans ASME, 1982, 104: 616–623
Grazzini G, Gori F. Entropy parameters for heat exchanger design. Int J Heat Mass Transf, 1988, 31: 2547–2554
Sekulic D P, Campo A, Morales J C. Irreversibility phenomena associated with heat transfer and fluid friction in laminar flows through singly connected ducts. Int J Heat Mass Transf, 1997, 40: 905–914
Sara O N, Yapici S, Yilmaz M, et al. Second law analysis of rectangular channels with square pin-fins. Int Commun Heat Mass Transf, 2001, 28: 617–630
Johannessen E, Nummedal L, Kjelstrup S. Minimizing the entropy production in heat exchange. Int J Heat Mass Transf, 2002, 45: 2649–2654
Balkan F. Comparison of entropy minimization principles in heat exchange and a short-cut principle: EoTD. Int J Energy Res, 2003, 27: 1003–1014
Ko T H. Numerical analysis of entropy generation and optimal Reynolds number for developing laminar forced convection in double-sine ducts with various aspect ratios. Int J Heat Mass Transf, 2006, 49: 718–726
Erek A, Dincer I. An approach to entropy analysis of a latent heat storage module. Int J Therm Sci, 2008, 47: 1077–1085
Hesselgreaves J E. Rationalisation of second law analysis of heat exchangers. Int J Heat Mass Transf, 2000, 43: 4189–4204
Shah R K, Skiepko T. Entropy generation extrema and their relationship with heat exchanger effectiveness—Number of transfer unit behavior for complex flow arrangements. J Heat Transf-Trans ASME, 2004, 126: 994–1002
Guo Z Y, Zhu H Y, Liang X G. Entransy—A physical quantity describing heat transfer ability. Int J Heat Mass Transf, 2007, 50: 2545–2556
Guo Z Y, Cheng X G, Xia Z Z. Least dissipation principle of heat transport potential capacity and its application in heat conduction optimization. Chinese Sci Bull, 2003, 48: 406–410
Xie Z, Chen L, Sun F. Constructal optimization on T-shaped cavity based on entransy dissipation minimization. Chinese Sci Bull, 2009, 54: 4418–4427
Xia S, Chen L, Sun F. Entransy dissipation minimization for liquid-solid phase change processes. Sci China Technol Sci, 2010, 53: 960–968
Chen Q, Ren J, Meng J A. Field synergy equation for turbulent heat transfer and its application. Int J Heat Mass Transf, 2007, 50: 5334–5339
Chen Q, Ren J X. Generalized thermal resistance for convective heat transfer and its relation to entransy dissipation. Chinese Sci Bull, 2008, 53: 3753–3761
Meng J A, Liang X G, Li Z X. Field synergy optimization and enhanced heat transfer by multi-longitudinal vortexes flow in tube. Int J Heat Mass Transf, 2005, 48: 3331–3337
Chen Q, Wang M, Pan N, et al. Optimization principles for convective heat transfer. Energy, 2009, 34: 1199–1206
Wu J, Liang X G. Application of entransy dissipation extremum principle in radiative heat transfer optimization. Sci China Ser E-Technol Sci, 2008, 51: 1306–1314
Guo J, Cheng L, Xu M. Entransy dissipation number and its application to heat exchanger performance evaluation. Chinese Sci Bull, 2009, 54: 2708–2713
Liu X, Meng J, Guo Z Y. Entropy generation extremum and entransy dissipation extremum for heat exchanger optimization. Chinese Sci Bull, 2009, 54: 943–947
Xia S, Chen L, Sun F. Optimization for entransy dissipation minimization in heat exchanger. Chinese Sci Bull, 2009, 54: 3587–3595
Meng J A, Liang X G, Chen Z J, et al. Experimental study on convective heat transfer in alternating elliptical axis tubes. Exp Therm Fluid Sci, 2005, 29: 457–465
Bejan A. Entropy Generation Through Heat and Fluid Flow. New York: Wiley, 1982
Author information
Authors and Affiliations
Corresponding author
Additional information
This article is published with open access at Springerlink.com
Rights and permissions
This article is published under an open access license. Please check the 'Copyright Information' section either on this page or in the PDF for details of this license and what re-use is permitted. If your intended use exceeds what is permitted by the license or if you are unable to locate the licence and re-use information, please contact the Rights and Permissions team.
About this article
Cite this article
Chen, Q., Wu, J., Wang, M. et al. A comparison of optimization theories for energy conservation in heat exchanger groups. Chin. Sci. Bull. 56, 449–454 (2011). https://doi.org/10.1007/s11434-010-4297-7
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11434-010-4297-7