CORRELATION OF CONVECTIVE VAPORIZATION ON BANKS OF PLAIN TUBES USING REFRIGERANTS

This article provides a correlation for convective vaporization on ban ks of plain tubes. New data are provided for R-113 and R-123 vaporizat ion 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 ra nge of heat flux. The correlation is based on three data sets: the pre sent data, the R-113 data of Cornwell and Scoones, and that of Jensen and Hsu. The asymptotic model (exponent of 3) provided the best correl ation, having a mean square error of 14.6%. The asymptotic-type correl ation provided better results than the superposition model. A distribu ing 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 Cornwell and Scoones data. More work is required to understand this s ituation. The data were analyzed to interpret whether convection cause s boiling suppression. Assuming that the pool boiling data are correct , it appears that the higher-mass-velocity data of Jensen and Hsu, and of Cornwell and Scoones, may experience suppression.