ISSN Online: 2377-424X
ISBN Print: 0-89116-559-2
International Heat Transfer Conference 8
HEAT TRANSFER AND PRESSURE DROP OF BOILING R114 IN A HORIZONTAL TUBE
Résumé
Data on boiling and pressure drop of refrigerant R114 in a horizontal tube under high mass flux and heat flux are reported. Some aspects of non-uniform heat flux around the perimeter of the tube are discussed. Comparisons of some correlations in the forced convective region were made. The effect of vapor mass fraction in the transition from bubbly to annular flow is shown. Boiling pressure drop is reviewed and Martinelli-Nelson's method was expanded for R114. None of the correlations considered can predict well for the whole range of variations of mass flux and heat flux. The relative good prediction-of the homogeneous model suggest that for fluids like refrigerants with very low conductivity, the annular flow pattern may not be fully materialized, instead a mostly dispersed flow is established, with large amount of entrained droplets travelling with almost the same speed as the vapor.