Korean Journal of Air-Conditioning and Refrigeration Engineering (설비공학논문집)

The Society of Air-Conditioning and Refrigerating Engineers of Korea (대한설비공학회)
권호 표지

The Influence of Variable Thermophysical Properties for Filmwise Condensation of Superheated Vapor on a Vertical Wall

수직 벽에서 과열증기의 막응축에 대한 열물성의 영향

  • 김경훈 (금오공과대학교 기계공학부) ;
  • 성현찬 (금오공과대학교 기계공학과 대학원)
  • Published : 2000.03.01
Download PDF
⟨ Previous Next ⟩

Abstract

A theoretical model for laminar filmwise condensation along an isothermal vertical wall at constant pressure has been formulated on the basis of conservation laws and other fundamental physical principles. The model was applied to the prediction of the influences of variable thermophysical properties of liquid and vapor layers in the filmwise condensation of superheated vapor of Rl2, R134a, R142b and R152a. The dimensionless velocity component method was employed in the transformation of the governing equations and their boundary conditions, and the polynomial method was used for treating variable thermophysical properties of liquid and vapor. Physical quantities, such as the dimensionless thickness of the liquid layer, local heat transfer rate and mean heat transfer coefficient, were investigated for different values of the superheated temperature of the stagnant vapor far from the wall. It was found that the value of mean heat transfer coefficient of R134a was higher than other refrigerants for the change of the superheated temperature.

Keywords

References

  1. Proceedings of the SAREK'99 Annual Summer Conference(Ⅰ) The influence of variable thermophysical properties on laminar film condensation on an isothermal vertical wall Sung, H. C.;Kim, K. H.
  2. Heat and mass transfer Mills, A. F.
  3. Fundamentals of heat and mass transfer Incropera, F. P.;DeWitt, D. P.
  4. Heat transfer Cengel, Y. A.
  5. Hemisphere Liquid-vapor phasechange phenomena : An introduction to the thermophysics of vaporization and condensation processes in heat transfer equipment Carey, V. P.
  6. Int. J. Heat Mass Transfer v.36 no.14 Study on liquid laminar free convection with consideration of variable thermophysical properties Shang, D. Y.;Wang, B. X.;Wang, Y.;Quan, Y.
  7. Int. J. Heat Mass Transfer v.33 no.7 Effect of variable thermophysical properties on laminar free convection of gas Shang, D. Y.;Wang, B. X.
  8. Int. J. Heat Mass Transfer v.34 no.3 Effect of variable thermophysical properties on laminar free convection of polyatomic gas Shang, D. Y.;Wang, B. X.
  9. Int. J. Heat Mass Transfer v.10 Effect of variable physical properties on laminar film condensation of saturated steam on a vertical flat plate Poots, G.;Miles, R. G.
  10. Int. J. Heat Mass Transfer v.9 Condensation heat transfer in the presence of noncondensable, interface resistance, superheating, variable properties, and diffusion Minkowcs, W. J.;Sparrow, E. M.
  11. Int. J. Heat Mass Transfer v.40 no.4 An extended study on steady-state laminar film condensation of a superheated vapour on an isothermal vertical plate Shang, D. Y.;Wang, B. X.
  12. NIST Thermodynamic properties of Refrigerants and Refrigerant Mixtures Database(REFPROP)(Version 6.01) McLinden, M. O.;Klein, S. A.;Lemmon, E. W.;Peskin, A. P.