Abstract
Examples of heat transfer and heat-work conversion are optimized with entropy generation and entransy loss, respectively based on the generalized heat transfer law in this paper. The applicability of entropy generation and entransy loss evaluation in these optimization problems is analyzed and discussed. The results show that the entransy loss rate reduces to the entransy dissipation rate in heat transfer processes, and that the entransy loss evaluation is effective for heat transfer optimization. However, the maximum heat transfer rate does not correspond to the minimum entropy generation rate with prescribed heat transfer temperature difference, which indicates that the entropy generation minimization is not always appropriate to heat transfer optimization. For heat-work conversion processes, the maximum entransy loss rate and the minimum entropy generation rate both correspond to the maximum output power, and they are both appropriate to the optimization of the heat-work conversion processes discussed in this paper.
Similar content being viewed by others
References
Yuan F, Chen Q. Two energy conservation principles in convective heat transfer optimization. Energy, 2011, 36: 5476–5485
Bejan A. General criterion for rating heat-exchanger performance. Int J Heat Mass Transfer, 1978, 21: 655–658
Bejan A. Advanced Engineering Thermodynamics. 2nd ed. New York: John Wiley & Sons, 1997
Klein S A, Reindl D T. The relationship of optimum heat exchanger allocation and minimum entropy generation rate for refrigeration cycles. J Energy Res Tech Trans ASME, 1998, 120: 172–178
Grazzini G, Gori F. Entropy parameters for heat exchanger design. Int J Heat Mass Transfer, 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 Transfer, 1997, 40: 905–914
Johannessen E, Nummedal L, Kjelstrup S. Minimizing the entropy production in heat exchange. Int J Heat Mass Transfer, 2002, 45: 2649–2654
Myat A, Thu K, Kim Y D. A second law analysis and entropy generation minimization of an absorption chiller. Appl Therm Eng, 2011, 31: 2405–2413
Mistry K H, Lienhard J H, Zubair S M. Effect of entropy generation on the performance of humidification-dehumidification desalination cycles. Int J Therm Sci, 2010, 49: 1837–1847
Chen Q, Wu J, Wang M R, et al. A comparison of optimization theories for energy conservation in heat exchanger groups. Chin Sci Bull, 2011, 56: 449–454
Maheshwar G, Chaudhary S, Somani S K. Performance analysis of endoreversible combined Carnot cycles based on new maximum efficient power (MEP) approach. Int J Low Carbon Tech, 2010, 5: 1–6
Adavbiele A S. Optimization of thermofluid systems with second law. Int J Eng Research Africa, 2010, 1: 67–80
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 Transfer Tran ASME, 2004, 126: 994–1002
Guo Z Y, Liang X G, Zhu H Y. Entransy-A physical quantity describing heat transfer ability (in Chinese). Prog Nat Sci, 2006, 16: 1288–1296
Guo Z Y, Zhu H Y, Liang X G. Entransy-A physical quantity describing heat transfer ability. Int J Heat Mass Transfer, 2007, 50: 2545–2556
Xie Z H, Chen L G, Sun F R. Constructal optimization for geometry of cavity by taking entransy dissipation minimization as objective. Sci China Ser E-Tech Sci, 2009, 52: 3413–3504
Wei S H, Chen L G, Sun F R. “Volume-Point” heat conduction constructal optimization with entransy dissipation minimization objective based on rectangular element. Sci China Ser E-Tech Sci, 2008, 51: 1283–1295
Wei S, Chen L, Sun F. Constructal optimization of discrete and continuous variable cross-section conducting path based on entransy dissipation rate minimization. Sci China Tech Sci, 2010, 53: 1666–1677
Xiao Q H, Chen L G, Sun F R. Constructal entransy dissipation rate minimization for heat conduction based on a tapered element. Chin Sci Bull, 2011, 56: 2400–2410
Chen L, Wei S, Sun F. Constructal entransy dissipation rate minimization of a disc. Int J Heat Mass Transfer, 2011, 54: 210–216
Wei S, Chen L, Sun F. Constructal entransy dissipation rate minimization of round tube heat exchanger cross-section. Int J Therm Sci, 2011, 50: 1285–1292
Xiao Q H, Chen L G, Sun F R. Constructal entransy dissipation rate minimization for “disc-to-point” heat conduction. Chin Sci Bull, 2011, 56: 102–112
Chen Q, Ren J, Meng J A. Field synergy equation for turbulent heat transfer and its application. Int J Heat Mass Transfer, 2007, 50: 5334–5339
Liu W, Liu Z, Jia H, et al. Entransy expression of the second law of thermodynamics and its application to optimization in heat transfer process. Int J Heat Mass Transfer, 2011, 54: 3049–3059
Wu J, Liang X G. Application of entransy dissipation extremum principle in radiative heat transfer optimization. Sci China Ser E-Tech Sci, 2008, 51: 1306–1314
Cheng X T, Liang X G. Entransy flux of thermal radiation and its application to enclosures with opaque surfaces. Int J Heat Mass Transfer, 2011, 54: 269–278
Guo Z Y, Liu X B, Tao W Q, et al. Effectiveness-thermal resistance method for heat exchanger design and analysis. Int J Heat Mass Transfer, 2010, 53: 2877–2884
Qian X D, Li Z X. Analysis of entransy dissipation in heat exchangers. Int J Therm Sci, 2011, 50: 608–614
Xu M T, Cheng L, Guo J F. An application of entransy dissipation theory to heat exchanger design (in Chinese). J Eng Thermophys, 2009, 30: 2090–2092
Xia S J, Chen L G, Sun F R. Optimization for entransy dissipation minimization in heat exchanger. Chin Sci Bull, 2009, 54: 3572–3578
Cheng X T, Zhang Q Z, Liang X G. Analyses of entransy dissipation, entropy generation and entransy-dissipation-based thermal resistance on heat exchanger optimization. Appl Therm Eng, 2012, 38: 31–39
Cheng X T, Liang X G. Computation of effectiveness of two-stream heat exchanger networks based on concepts of entropy generation, entransy dissipation and entransy-dissipation-based thermal resistance. Energy Convers Manage, 2012, 58: 163–170
Xu M T. The thermodynamic basis of entransy and entransy dissipation. Energy, 2011, 36: 4272–4277
Sahin A Z. The inherent optimality in steady conduction of heat. Int J Phys Sci, 2011, 6: 7828–7837
Sahin A Z. The natural optimality in heat and fluid flow phenomena. Int J Exergy, 2011, 9: 346–354
Liu X B. Entransy Analysis of Thermal Performance for Heat Exchangers and Cooling Channel Networks (in Chinese). Dissertation of Doctoral Degree. Beijing: Tsinghua University, 2009
Wu J. Potential Energy (Entransy) in Thermal Science and Its Application (in Chinese). Dissertation of Doctoral Degree. Beijing: Tsinghua University, 2009
Xia S J, Chen L G, Sun F R. Optimization for minimizing entropy generation during heat transfer processes with heat transfer law q √ (Δ(T n))m (in Chinese). J Therm Sci Tech, 2008, 7: 226–230
Chen L, Li J, Sun F. Generalized irreversible heat engine experiencing a complex heat transfer law. Appl Energy, 2008, 85: 52–60
Chen L, Xia S, Sun F. Optimal paths for minimizing entropy generation during heat transfer processes with a generalized heat transfer law. J Appl Phys, 2009, 105: 44907
Xia S, Chen L, Sun F. Optimal paths for minimizing lost available work during heat transfer processes with complex heat transfer law. Brazilian J Phys, 2009, 39: 98–105
Chen L, Sun F, Wu C. Optimal expansion of a heated working fluid with phenomenological heat transfer. Energy Convers Manage, 1998, 39: 149–156
Osullivan C T. Newton’s law of cooling-A critical assessment. American J Phys, 1990, 58: 956–960
Angulo-Brown F, Paez-Hernandez R. Endoreversible thermal cycle with a nonlinear heat transfer law. J Appl Phys, 1993, 74: 2216–2219
Huleihil M, Andresen B. Convective heat transfer law for an endoreversible engine. J Appl Phys, 2006, 100: 014911
Song H, Chen L, Sun F. Optimal expansion of a heated working fluid for maximum work output with generalized radiative heat transfer law. J Appl Phys, 2007, 102: 094901
Cheng X T, Liang X G, Guo Z Y. Entransy decrease principle of heat transfer in an isolated system. Chin Sci Bull, 2011, 56: 847–854
Andresen B, Berry R S, Nitzan A, et al. Thermodynamics in finite time I: the step Carnot cycle. Phys Review A, 1977, 15: 2086–2093
Salamon P, Andresen B, Berry R S. Thermodynamics in finite time II: potentials for finite time processes. Phys Review A, 1977, 15: 2094–2101
Berry R S, Salamon P, Heal G. On a relation between economic and thermodynamic optima. Res Energy, 1978, 1: 125–137
Chen L G, Sun F R. Finite time thermodynamic theory and applications: state of the arts. Prog phys, 1998, 18: 395v422
Curzon F L, Ahlborn B. Efficiency of a Carnot engine at maximum power output. American J Phys, 1975, 43: 22–24
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Cheng, X., Wang, W. & Liang, X. Optimization of heat transfer and heat-work conversion based on generalized heat transfer law. Sci. China Technol. Sci. 55, 2847–2855 (2012). https://doi.org/10.1007/s11431-012-4915-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11431-012-4915-5