外文翻译冷凝器和蒸发器热力设计 制定和应用.docxVIP

附录B：参考英文文献及译文Thermodynamic design of condensers and evaporators:Formulation andapplicationsChristian J.L. Hermesa b s t r a c t This paper assesses the therm-hydraulic design approach introduced in a previous publication (Hermes, 2012) for condensers and evaporators aimed at minimum entropy generation. An algebraic model which expresses the dimensionless rate of entropy generation as a function of the number of transfer units, the ?uid properties, the thermal-hydrauliccharacteristics, and the operating conditions is derived. Case studies are carried out with different heat exchanger con?gurgitations for small-capacity refrigeration applications. The theoretical analysis led to the conclusion that a high effectiveness heat exchanger does not necessarily provide the best thermal-hydraulic design for condenser and evaporator coils, when the rates of entropy generation due to heat transfer and ?uid friction are of the sameorder of magnitude. The analysis also indicated that a high aspect ratio heat exchanger produces a lower amount of entropy than a low aspect ratio one.Conception thermodynamiccondenser et desse ′evaporate: formulation et applications.Keywords: floating head;heat exchanger;design;industry1. IntroductionCondensers and evaporators are heat exchangers with fairly uniformwall temperature employed in a wide range of HVACR products, spanning from household to industrial applications. In general, they are designed aiming at accomplishing a certain heat transfer duty at the penalty of pumping power.There are two well-established methods available for the thermal heat exchanger design, the log-mean temperature difference (LMTD) and the effectiveness/number of transfer units (ε-NTU) approach (Kakac? and Liu, 2002; Shah andSiliculose, 2003). The second has been preferred to the former for the sake of compact heat exchanger design as the effectiveness (ε), de?ned as the ratio between the actual heattransfer rate and the maximum amount that can be transferred, provi