Publication de 18 numéros par an
ISSN Imprimer: 1064-2285
ISSN En ligne: 2162-6561
Indexed in
HEAT TRANSFER AND PRESSURE DROP DURING CONDENSATION OF R-410A IN ALUMINUM EXTRUDED ENHANCED TUBES
RÉSUMÉ
The literature shows that axial microfin tubes and spoke tubes are promising means for enhancing condensation of refrigerants in them. However, studies are lacking, and those available are generally limited to high mass fluxes. In this study, condensation heat transfer and pressure drop tests were performed on four tubes−smooth, helical microfin, axial microfin, spoke−having 7.0-mm outer diameter for the mass flux from 50 to 250 kg/m2·s using R-410A. During the test, the heat flux and the saturation temperature were maintained at 3.0 kW/m2 and 46°C. At low mass fluxes, helical microfin tube yields the best heat conductance (hiAi) enhancement. Above 150 kg/m2s, however, the best enhancement is obtained from the axial microfin tube. The spoke tube yields approximately an intermediate heat conductance enhancement. Possible reasoning is provided based on the flow pattern in each tube. As for the pressure drop, the spoke tube shows significantly higher pressure drop than other tubes. In addition, the pressure drops of the axial microfin tube are higher than those of the helical microfin tube. Possible explanations are provided considering the effect of hydraulic diameter on pressure drop.
-
Cavallini, A., Del Col, D., Mancin, S., and Rossetto, L., Condensation of Pure and Near-Azeotropic Refrigerants in Microfin Tubes: A New Computational Procedure, Int. J. Refrig., vol. 32, pp. 162-174, 2009.
-
Chiang, R., Heat Transfer and Pressure Drop during Evaporation and Condensation of Refrigerant-22 in 7.5 mm and 10 mm Diameter Axial and Helical Grooved Tubes, AIChE Heat Transf. Symp. Ser., vol. 89, no. 295, pp. 205-210, 1993.
-
Doretti, L., Zilio, C., Mancin, S., and Cavallini, A., Condensation Flow Patterns inside Plain and Microfin Tubes: A Review, Int. J. Refrig., vol. 36, pp. 567-587, 2013.
-
Graham, D., Chato, J.C., and Newell, T.A., Heat Transfer and Pressure Drop during Condensation of Refrigerant 134a in an Axially Grooved Tube, Int. J. Heat Mass Transf., vol. 42, pp. 1935-1944, 1999.
-
Kim, N.-H., Condensation Heat Transfer and Pressure Drop of R-410A in Flat Aluminum Multi-Port Tubes, Heat Mass Transf., vol. 54, pp. 523-535, 2018.
-
Kline, S.J. and McClintock, F.A., The Description of Uncertainties in Single Sample Experiments, Mech. Eng., vol. 75, pp. 3-9, 1953.
-
Laohalertdecha, S., Dalkilic, A.S., and Wongwises, S., A Review on Heat Transfer Performance and Pressure Drop Characteristics of Various Enhanced Tubes, Int. J. Air-Cond. Refrig., vol. 20, 1230003, 2012.
-
Muller-Steinhagen, H. and Heck, K., A Simple Friction Pressure Drop Correlation for Two-Phase Flow in Pipes, Chem. Eng. Process., vol. 20, pp. 297-308, 1986.
-
Shah, M.M., An Improved and Extended General Correlation for Heat Transfer during Condensation in Plain Tubes, Int. J. HVAC&R Res., vol. 15, no. 5, pp. 889-913, 2009.
-
Shinohara, Y. and Tobe, M., Development of an Improved Thermofin Tube, Hitachi Cable Rev., vol. 4, pp. 47-50, 1985.
-
Webb, R.L. and Kim, N.-H., Principles of Enhanced Heat Transfer, 2nd Ed., Abingdon-on-Thames, UK: Taylor and Francis, 2005.
-
Wilson, E.E., A Basis for Rational Design of Heat Transfer Apparatus, Trans. ASME, vol. 37, pp. 47-70, 1915.
-
Xiao, J. and Hrnjak, P., A New Flow Regime Map and Void Fraction Model Based on the Flow Characterization of Condensation, Int. J. Heat Mass Transf.., vol. 108, pp. 443-452, 2017.
-
Yang, C.Y. and Webb, R.L., Condensation of R-12 in Small Hydraulic Diameter Extruded Aluminum Tubes with and without Micro-Fins, Int. J. Heat Mass Transf, vol. 39, no. 4, pp. 791-800, 1996.
-
Zhang, G.M., Wu, Z., Wang, X., and Li, W., Convective Condensation of R-410A in Microfin Tubes, J. Enhanced Heat Transf., vol. 19, pp. 515-525, 2015.