Prediction of Local Bundle Boiling Heat Transfer Coefficients: Pure Refrigerant Boiling on Plain, Low Fin and Turbo-BII HP Tube Bundles
New correlations predicting the local boiling heat transfer coefficients for vertical flow over a tube bundle have been developed. These correlations were developed for three different classes of tubes: smooth, low-finned, and Turbo-BII HP. These correlations are based on experiments with refrigerants R-134a, R-507A, and R-410A, at a saturation temperature of 4.4°C (40°F). Each one accounts for the local flow structure and/or local geometry particular to each tube. Each one also uses a void fraction model designed specifically for vertical two-phase flow in a tube bundle as an integral part of the correlation. The correlations have been compared to recent local bundle boiling data and show good agreement to within ± 20%.