Experimental evaluation of R22 and R407C evaporative heat transfer coefficients in a vapour compression plant

The mean heat transfer coeAcients of R22 and R407C in the coaxial counterflow evaporator (20 mm ID) of a refrigerating vapour compression plant have been experimentally measured. The experimental conditions under which heat transfer coeAcients were determined reflect a typical working situation for small-scale refrigeration systems. The heat flux ranged from 1.9 to 9.1 kW/m 2 and the mass flux was varied from 30 to 140 kg/m 2 s. The results illustrate that the R22 heat transfer coeAcient is always greater than that of R407C. Furthermore, a comparison carried out between the experimental data and those predicted by means of the most credited literature relationships showed a strongly overprediction for R407C coeAcients. # 2000 Elsevier Science Ltd and IIR. All rights reserved.

[1]  M. Cooper.  SATURATION NUCLEATE POOL BOILING - A SIMPLE CORRELATION , 1984 .

[2]  Adolfo Palombo,et al.  R407C as an alternative to R22 in vapour compression plant : An experimental study , 1997 .

[3]  Kenichi Hashizume,et al.  Flow Pattern and Void Fraction of Refrigerant Two-phase Flow in a Horizontal Pipe , 1983 .

[4]  N. Zuber,et al.  Dynamics of vapor bubbles and boiling heat transfer , 1955 .

[5]  R. Radermacher,et al.  A study of flow boiling heat transfer with refrigerant mixtures , 1989 .

[6]  C. Gabrielii,et al.  Replacement of R22 in tube-and-shell condensers: experiments and simulations , 1997 .

[7]  H. M. Soliman,et al.  On the annular‐to‐wavy flow pattern transition during condensation inside horizontal tubes , 1982 .

[8]  Robert J. Moffat,et al.  Describing the Uncertainties in Experimental Results , 1988 .

[9]  L. E. Scriven.  On the dynamics of phase growth , 1995 .

[10]  A. Dukler,et al.  A model for predicting flow regime transitions in horizontal and near horizontal gas‐liquid flow , 1976 .

[11]  M. Shah.  Chart correlation for saturated boiling heat transfer: Equations and further study , 1982 .

[12]  E. Hihara,et al.  Boiling heat transfer of a ternary refrigerant mixture inside a horizontal smooth tube , 1997 .

[13]  K. Gungor,et al.  Simplified general correlation for saturated flow boiling and comparisons of correlations with data , 1987 .

[14]  S. Kandlikar.  A General Correlation for Saturated Two-Phase Flow Boiling Heat Transfer Inside Horizontal and Vertical Tubes , 1990 .

[15]  K. Gungor,et al.  A general correlation for flow boiling in tubes and annuli , 1986 .

[16]  R. Radermacher,et al.  Prediction of evaporation heat transfer coefficient and pressure drop of refrigerant mixtures , 1993 .

[17]  E. Schlunder.  Heat transfer in nucleate boiling of mixtures , 1983 .

[18]  John R. Thome,et al.  Prediction of the Mixture Effect On Boiling in Vertical Thermosyphon Reboilers , 1989 .

[19]  J. Thome,et al.  Flow Boiling in Horizontal Tubes: Part 3—Development of a New Heat Transfer Model Based on Flow Pattern , 1998 .

[20]  R. Radermacher,et al.  Prediction of evaporation heat transfer coefficient and pressure drop of refrigerant mixtures in horizontal tubes , 1993 .

[21]  J. Thome.  Prediction of binary mixture boiling heat transfer coefficients using only phase equilibrium data , 1983 .

[22]  K. Stephan,et al.  Berechnung des Wärmeübergangs verdampfender binärer Flüssigkeitsgemische , 1969 .

[23]  P. J. Marto,et al.  Nucleate pool boiling of R-114 and R-114-oil mixtures from smooth and enhanced surfaces—I. Single tubes , 1995 .

[24]  J. C. Chen.  Correlation for Boiling Heat Transfer to Saturated Fluids in Convective Flow , 1966 .

[25]  J. Thome.  Boiling of new refrigerants: a state-of-the-art review , 1996 .

[26]  W. Rohsenow,et al.  Handbook of heat transfer applications , 1985 .