Correlation of Convective Vaporization on Banks of Plain Tubes Using Refrigerants

Abstract

This article provides a correlation for convective vaporization on banks of plain tubes. New data are provided for R-113 and R‐123 vaporization on 16.8‐mm‐O.D. tubes over a wide range of vapor qualities (0.1 to 0.9) with low mass velocities (8 kg / m2 s to 40 kg / m2 s) for a wide range of heat flux. The correlation is based on three data sets: the present data, the R-113 data of Comwell and Scoones, and that of Jensen and Hsu. The asymptotic model (exponent of 3) provided the best correlation, having a mean square error of 14.6%. The asymptotictype correlation provided better results than the superposition model. A disturbing anomaly was noted in the lack of agreement between pool boiling on a single tube and pool boiling on one heated tube in a bundle for the Comwell and Scoones data. More work is required to understand this situation. The data were analyzed to interpret whether convection causes boiling suppression. Assuming that the pool boiling data are correct, it appears that the higher-mass-velocity data of Jensen and Hsu, and of Comwell and Scoones, may experience suppression.