A semi-empirical model to predict the evaporation heat transfer of pure refrigerants and refrigerant mixtures flowing inside microfin tubes has been presented. The heat transfer coefficient correlation developed in the new model takes into account the nucleate boiling component and the forced convention component. The model was validated using a set of around 380 experimental data points compiled from published literature. Comparison shows that the model is capable of predicting evaporation heat transfer coefficients for different refrigerants and refrigerant mixtures within 10-25 per cent mean absolute deviation for the data sets.
ChamraL. M.WebbR. L.RandlettM. R.Advanced microfin tubes for evaporation. Int. J. Heat Mass Trans., 1996, 39(9), 1827–1838.
2.
CavalliniA.Del ColD.DorettiL.LongoG. A.RossettoL.Refrigerant vaporization inside enhanced tubes: A heat transfer model. Heat Technol., 1999, 17(2), 29–36.
3.
BogartJ.ThorsP.In-tube evaporation of HCFC-22 with enhanced tubes. J. Enhanc. Heat Transf., 1994, 1(4), 365–377.
4.
BogartJ.ThorsP.In-tube evaporation of R-22 and three of its alternatives in a 15.88mm internally enhanced tubes. J. Enhanc. Heat Transf., 1999, 6, 317–326.
5.
EckelsS. J.PateM. B.Evaporation and condensation of HFC-134a and CFC-12 in a smooth tube and a microfin tube. ASHRAE Trans., 1991, 97(2), 71–81.
6.
EckelsS. J.DoerrT. M.PateM. B.In-tube heat transfer and pressure drop of R-134a and ester lubricant mixtures in a smooth tube and a microfin tube: Part I - evaporation. ASHRAE Trans., 1994, 100(2), 265–282.
7.
EckelsS. J.DoerrT. M.PateM. B.Heat transfer coefficients and pressure drops for R-134a and an ester lubricant mixture in a smooth tube and a micro-fin tube. ASHRAE Trans., 1998a, 104(1a), 366–375.
8.
EckelsS. J.DoerrT. M.PateM. B.A Comparison of the heat transfer and pressure drop performance of R134a-lubricant mixtures in different diameter smooth tubes and micro-fin tubes. ASHRAE Trans., 1998b, 104(1a), 376–386.
9.
Hitachi Cable, Ltd.Effect on performance of expanding the Thermofin-EX and Thermofin-HEX, tube; Hitachi Cable, Ltd, Technical Data 14–958, 1987, pp. 14–958.
10.
KidoO.TaniguchiM.TairaT.UeharaH.Evaporation heat transfer of HCFC22 inside an internally grooved horizontal tube. ASME/JSME Therm. Eng. Conf., 1995, 2, 323–330.
11.
KuoC. S.WangC. C.ChengW.Y.LuD.C.Evaporation of R-22 in a 7-mm microfin tube. ASHRAE Trans., 1995, 101(1), 1055–1061.
12.
KuoC. S.WangC. C.Horizontal flow boiling of R22 and R407C in a 9.52mm micro-fin tube. Appl. Therm. Eng., 1996, 16(8), 719–731.
13.
MurataK.HashizumeK.An investigation on forced convection boiling of nonazeotropic refrigerant mixtures. Heat Transf. Jpn. Res., 1990, 19(2), 95–109.
14.
MuzzioA.NiroA.ArosioS.Heat transfer and pressure drop during evaporation and condensation of R22 inside 9.52-mm O.D. microfin tubes of different geometries. Enhanc. Heat Transf., 1998, 5(1), 39–52.
15.
SchlagerL. M.The effect of oil on heat transfer and pressure drop during evaporation and condensation of refrigerant inside augmented tubes. PhD Dissertation, Iowa State University, Ames, Iowa, 1988.
16.
ShinoharaY.TobeM.Development of an improved ‘Thermofin Tube’. Hitachi Cable Rev., 1985, 4, 47–50.
CuiS.TanY.LuY.Heat transfer and flow resistance of R-502 flow boiling inside horizontal ISF tubes. In Multiphase flow and heat transfer: Second international symposium, (Eds. ChenX.-J.VezirogluT. N.TienC. L.), 1992, vol. 1, pp. 662–670. (Hemisphere Publishing Corp.).
19.
EbisuT.TorikoshiK.Experimental study on evaporation and condensation heat transfer enhancement for R-407c using Herringbone heat transfer tube. ASHRAE Trans., 1998, 104(2), 1044–1052.
SteinerD.Heat transfer to boiling saturated liquid (VDI Warme Atlas:VDIVerlagDusseldorf), 1993, chapter Hbb, pp. 551–556.
22.
DittusF. W.BoelterL. M. K.Heat transfer in automobile radiators of the tubular type. University of California Publications of Engineering USA, 1930, vol. 2, pp. 443–461.
23.
HoriM.ShinoharaY.Internal heat transfer characteristics of small-diameter thermofin tubes. Hitachi Cable Rev., 1991, 10, 85–90.
24.
WebbR. L.Enhancement of film condensation. Int. Commun. Heat Mass Transf., 1988, 15(4), 475–507.
25.
KimuraI.ItoM.Evaporating heat transfer in horizontal internal spiral-grooved tubes in the region of low flow rates. Bull. JSME, 1981, 24(195), 1602–1607.
26.
ThomeJ. R.Boiling of new refrigerants: A state-of-theart review. Int. J. Refrig., 1996, 19(7), 435–457.
27.
MontgomeryD. C.PeckE. A.Introduction to linear regression analysis. 2nd edition, 1992 (John Wiley and Sons, New York).
