Advertisement

KSME International Journal

, Volume 18, Issue 3, pp 513–525 | Cite as

An experimental investigation of heat transfer in forced convective boiling of R134a, R123 and R134a/R123 in a horizontal tube

  • Tae Woo Lim
  • Jun Hyo Kim
Article

Abstract

This paper reports an experimental study on flow boiling of pure refrigerants R134a and R123 and their mixtures in a uniformly heated horizontal tube. The flow pattern was observed through tubular sight glasses with an internal diameter of 10 mm located at the inlet and outlet of the test section. Tests were run at a pressure of 0.6 MPa in the heat flux ranges of 5–50 kW/m2, vapor quality 0–100 percent and mass velocity of 150–600 kg/m2s. Both in the nucleate boiling-dominant region at low quality and in the two-phase convective evaporation region at higher quality where nucleation is supposed to be fully suppressed, the heat transfer coefficient for the mixture was lower than that for an equivalent pure component with the same physical properties as the mixture. The reduction of the heat transfer coefficient in mixture is explained by such mechanisms as mass transfer resistance and non-linear variation in physical properties etc. In this study, the contribution of convective evaporation, which is obtained for pure refrigerants under the suppression of nucleate boiling, is multiplied by the composition factor by Singal et al. (1984). On the basis of Chen’s superposition model, a new correlation is presented for heat transfer coefficients of mixture.

Key Words

Convective Boiling Flow Pattern Heat Transfer Horizontal Tube Mixture 

Nomenclature

a

Thermal diffusivity (m2/s)

Bo

Boiling number (=q/Ghfg)

Co

Convection number ( = (ρυι)0.5( (1-β/β0.8)

Cp

Specific heat (J/kgk)

D

Tube Diameter (m)

g

Gravitational acceleration (m/s2)

h

Specific enthalpy (J/kg)

hfg

Latent heat of vaporization (J/kg)

Fr

Froude number

G

Mass velocity (kg/m2s)

k

Thermal conductivity (W/mK)

P

Pressure (Pa)

q

Heat flux (W/m2)

Re

Reynolds number

T

Temperature (K)

X

Mole fraction in liquid

Xtt

Martinelli parameter

Y

Mole fraction in vapor

z

Axial distance (m)

Greek Letters

α

Heat transfer coefficient (W/m2K)

β

Vapor quality

θ

Contact angle (=35°)

ΔTbp

Boiling point range (K)

ΔTid

Ideal wall superheat (K)

ρ

Density (kg/m3)

σ

Surface tension (N/m)

μ

Viscosity (Pa · s)

ν

Kinematic viscosity (m2/s)

Subscripts

c

Critical

in

Inlet of the heat transfer section

l

Liquid

nb

Nucleate boiling

s

Saturation

v

Vapor

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bennett, D. L. and Chen, J. C., 1980, “Forced Convective Boiling in Vertical Tubes for Saturated Pure Components and Binary Mixtures,”AIChE J, Vol. 26, pp. 451–461.CrossRefGoogle Scholar
  2. Chen, J. C., 1966, “Correlation for Boiling Heat Transfer to Saturated Fluids in Convective Flow,”I.E.C. Proc. Dev. Vol. 5, pp. 322–329.CrossRefGoogle Scholar
  3. Dittus, F. W. and Boelter, 1930, L.M.K.,Univ. Calif. Publs. Engng. Vol. 2, p. 443.Google Scholar
  4. Fujita, Y. and Tsutsui, M., 1994, “Heat Transfer in Nucleate Pool Boiling of Binary Mixtures,”Int. J. Heat and Mass Transfer Vol. 37, pp. 291–302.CrossRefGoogle Scholar
  5. Gungor, K. E. and Winterton, R. H. S., 1986, “A General Correlation for Flow Boiling in Tubes and Annuli,”Int. J. Heat and Mass Transfer Vol. 29, pp. 351–358.MATHCrossRefGoogle Scholar
  6. Gungor, K. E. and Winterton, R. H. S., 1987, “Simplified General Correlation for Saturated Flow Boiling and Comparison of Correlations with Data,”Chem. Eng. Res. Des Vol. 65, pp. 148–156.Google Scholar
  7. Jung, D. S., McLinden, M., Radermacher, R. and Didion, D.. 1989, “A Study of Flow Boiling Heat Transfer with Refrigerant Mixture,”Int. J. Heat and Mass Transfer Vol. 32, pp. 1751–1764.CrossRefGoogle Scholar
  8. Jung, D. S. and Radermacher, R., 1989, “Horizontal Flow Boiling Heat Transfer Experiments with a Mixture of R22/R114,”Int. J. Heat and Mass Transfer Vol. 32, pp. 131–145.CrossRefGoogle Scholar
  9. Kandlikar, S. G., 1990, “A General Correlation for Saturated Two-phase Flow Boiling Heat Transfer inside Horizontal and Vertical Tubes,”J. Heat Transfer Vol. 112, pp. 219–228.CrossRefGoogle Scholar
  10. Kandlikar, S. G., 1991, “Correlation Flow Boiling Heat Transfer Data in Binary Systems, HTD-Phase Change Heat Transfer,”ASME, Vol. 159, pp. 163–170.Google Scholar
  11. Kattan, N., Thome, J. R. and Favrat, D., 1995, “R-502 and Two Near-Azeotropic Alternatives, Part II: Tw-Phase Flow Patterns,”ASHRAE Trans. Vol. 101, pp. 509–519.Google Scholar
  12. Klimenko, V. V., 1988, “A Generalized Correlation for Two-Phase Forced Flow Heat Transfer,”Int. J. Heat and Mass Transfer, Vol. 31, pp. 541–552.CrossRefGoogle Scholar
  13. Kutateladze, S. S., 1961, “Boiling Heat Transfer, ”Int. J. Heat Mass Transfer Vol. 4, pp. 31–45.CrossRefGoogle Scholar
  14. Lavin, G. and Young, E. H., 1965, “Heat Transfer to Evaporating Refrigerants in Two-Phase Flow,”AIChE J Vol. 11, pp. 1124–1132.CrossRefGoogle Scholar
  15. Lim, T. W. and Han, K. I., 2003a, “A study on Forced Convective Boiling Heat Transfer of Non-Azeotropic Refrigerant Mixture R134a/ R123 Inside Horizontal Smooth Tube,”Trans of KSME B Vol. 27, No. 3, pp. 381–388.Google Scholar
  16. Lim, T. W. and Kim, J. H., 2003b, “A study on Two-Phase Flow Pattern of Pure Refrigerants R134a and R123 and Zeotropic Mixture R134a/ R123 in Horizontal Tube,”Trans of KSME B, Vol. 27, No. 8, pp. 1033–1041.Google Scholar
  17. Liu, Z. and Winterton, R. H. S., 1988, “Wet Wall Flow Boiling Correlation with Explicit Nucleate Boiling Term, in Multi-Phase Transport and Particulate Phenomena,” (Veziroglu, T. N., ed.), Hemisphere, Washington, DC, Vol. 1, pp. 419–432.Google Scholar
  18. Mishra, M. P., Sharma, C. P. and Varma, H. K., 1979, “Heat Transfer Coefficients During Forced Convection Evaporation of RI2 and R22 Mixtures in Annular Flow Regime,”Proc. XVth Int Cong Refrig, Venice, pp. 23–29.Google Scholar
  19. Murata, K. and Hashizume, K., 1993, “Forced Convective Boiling of Nonazeotropic Refrigerant Mixtures Inside Tubes,”J. Heat Transfer, Vol. 115, pp. 680–689.CrossRefGoogle Scholar
  20. Nishiumi, H. and Saito, S., 1977, “Correlation of the Binary Interaction Parameter of the Modified Generalized BWR Equation of State,”J. Chem. Eng. Japan Vol. 10, pp. 176–180.CrossRefGoogle Scholar
  21. Shah, M. M., 1976, “A New Correlation for Heat Transfer during Boiling Flow Through Pipes,”ASHRAE Trans. Vol. 82, pp. 66–86.Google Scholar
  22. Shah, M. M., 1982, “Chart Correlation for Saturated boiling Heat Transfer: Equation and Further Study,”ASHRAE Trans. Vol. 88, pp. 185–196.Google Scholar
  23. Singal, L. C., Sharma, C. P. and Varma, H. K., 1984, “Heat Transfer Correlations for the Forced Convection Boiling of R12-R13 Mixtures,”Int. J. of Refrigeration Vol. 7, pp. 278–284.CrossRefGoogle Scholar
  24. Stephan, K. and Abdelsalam, M., 1980, Heat Transfer Correlation for Natural Convection Boiling,Int. J. Heat and Mass Transfer Vol. 23, pp. 73–87.CrossRefGoogle Scholar
  25. Thome, J. R., 1983, “Prediction of Binary Mixture Boiling Heat Transfer Coefficients Using Only Phase Equilibrium Data,”Int. J. Heat and Mass Transfer Vol. 26, pp. 965–974.MATHCrossRefGoogle Scholar
  26. Wattelet, J. P., Chato, J. C., Souza, A. L. and Christoffersen, B. R., 1992, “Evaporation Characteristics of R12, R134a and MP-39 at Low Fluxes,”ASHRAE Trans. Vol. 100, pp. 185–196.Google Scholar
  27. Webb, R. L. and Gupte N. S., 1992, “A Critical Review of Correlations for Convective Vaporization in Tubes and Tube Banks,”Heat Transfer Engineering Vol. 13, pp. 58–81.CrossRefGoogle Scholar

Copyright information

© The Korean Society of Mechanical Engineers (KSME) 2004

Authors and Affiliations

  1. 1.School of Mechanical EngineeringPukyong National UniversityBusanKorea
  2. 2.Division of Marine EngineeringMokpo National Maritime UniversityMokpoKorea

Personalised recommendations