Optimal paths for minimizing entropy generation during heat transfer processes with a generalized heat transfer law

An investigation of finite-time heat transfer processes between high- and low-temperature sides with a generalized heat transfer law (q∝[Δ(Tn)]m) is presented in this paper. Optimal heating and cooling strategies for minimizing entropy generation are derived for the fixed initial and final temperatures of the low-temperature side working fluid. Optimal paths are compared with the common strategies of constant heat flux and constant source temperature operation by numerical examples. The condition corresponding to the minimum entropy generation strategy is not only valid for Newton’s [q∝(ΔT)] and linear phenomenological [q∝Δ(T−1)] heat transfer laws but also valid for heat transfer law (q∝[Δ(T−1)]m). The obtained results are general and can provide some theoretical guidelines for the designs and operations of practical heat exchangers.

[1]  Bjarne Andresen,et al.  Convective heat transfer law for an endoreversible engine , 2006 .

[2]  Andreas Fischer,et al.  Optimal Process Paths for Endoreversible Systems , 2003 .

[3]  Jun Li,et al.  Generalized irreversible heat-engine experiencing a complex heat-transfer law , 2008 .

[4]  Fengrui Sun,et al.  Optimal configuration of a class of endoreversible heat engines with linear phenomenological heat transfer law [q∝Δ(T−1)] , 2006 .

[5]  S. Sieniutycz,et al.  Thermodynamic Optimization of Finite-Time Processes , 2000 .

[6]  Jun Li,et al.  Heating load vs. COP characteristic of an endoreversible Carnot heat-pump subjected to the heat-transfer law q ∝ (ΔTn)m , 2008 .

[7]  A. D. Vos,et al.  Efficiency of some heat engines at maximum-power conditions , 1985 .

[8]  Stanislaw Sieniutycz,et al.  Modeling thermal behavior and work flux in finite-rate systems with radiation , 2006 .

[9]  Bjarne Andresen,et al.  Optimal heating and cooling strategies for heat exchanger design , 1992 .

[10]  Fengrui Sun,et al.  Optimal expansion of a heated working fluid for maximum work output with generalized radiative heat transfer law , 2007 .

[11]  Colm O'Sullivan,et al.  Newton’s law of cooling—A critical assessment , 1990 .

[12]  R. Stephen Berry,et al.  Finite-Time Thermodynamics , 2022 .

[13]  Viorel Badescu,et al.  Optimal paths for minimizing lost available work during usual finite-time heat transfer processes , 2004 .

[14]  Viorel Badescu,et al.  Optimal strategies for steady state heat exchanger operation , 2004 .

[15]  Fengrui Sun,et al.  Effect of heat transfer law on the performance of a generalized irreversible Carnot engine , 1999 .

[16]  F. Sun,et al.  Model of real absorption heat pump cycle with a generalized heat transfer law and its performance , 2007 .

[17]  Stanislaw Sieniutycz,et al.  Finite-time thermodynamics and thermoeconomics , 1990 .

[18]  A. D. Vos,et al.  Endoreversible thermodynamics of solar energy conversion , 1992 .

[19]  A. Bejan.  Entropy generation minimization: The new thermodynamics of finite-size devices and finite-time processes , 1996 .

[20]  B. Andresen,et al.  Minimum entropy production and the optimization of heat engines , 1980 .

[21]  Lingen Chen,et al.  Finite Time Thermodynamic Optimization or Entropy Generation Minimization of Energy Systems , 1999 .

[22]  Bjarne Andresen,et al.  Optimal paths for minimizing entropy generation in a common class of finite-time heating and cooling processes , 1992 .

[23]  Bjarne Andresen,et al.  Thermodynamics for Processes in Finite Time , 1984 .

[24]  Fengrui Sun,et al.  Optimal expansion of a heated working fluid with phenomenological heat transfer , 1998 .

[25]  F. Sun,et al.  The influence of heat-transfer law on the endo-reversible Carnot refrigerator , 1996 .