A General Correlation for Heat Transfer During Saturated Boiling with Flow Across Tube Bundles

Abstract

Heat exchangers consisting of bundles of horizontal tubes with boiling on the outer surface of the tubes are widely used in the industry. Examples are refrigerated liquid coolers and kettle reboilers. No well-verified general method for predicting heat transfer during saturated boiling is available in the open literature. Presented here is a dimensionless correlation for predicting heat transfer on individual tubes of a bundle that can be used with predictive models for bundle heat transfer such as that of Brisbane et al. (1980). The new correlation shows good agreement with data for single tubes and tube bundles from many sources covering a wide range of parameters, including seven fluids (water, n-pentane, R-11, R-12, R-113, R-123, and R-134a), reduced pressures from 0.005 to 0.189, mass velocities from 1.3 to 1391 kg/m2s, heat flux from 1 to 1000 kW/m2, tube diameters from 3 to 25.4 mm, and pitch to diameter ratios from 1.17 to 1.5. A total of 690 data points are correlated with a mean deviation of 15.2%. The results of comparisons of the new correlation with test data are presented and discussed.