Improved general correlation for subcooled boiling heat transfer during flow across tubes and tube bundles

The author's earlier published general correlation for subcooled boiling during flow across single tubes was compared with 22 data sets for single tubes and 7 data sets for tube bundles. While the published correlation gave good agreement with all data sets, modifications were made that improve the accuracy slightly and provide an explicit method for determining the subcooling regime. The data include four fluids (water, R-11, R-12, R-113), tube diameters from 1.2 to 26.4 mm, pitch to diameter ratios from 1.2 to 3.0, upstream velocities from 0.001 to 6.9 m/s, subcooling from 0 degrees C to 93 degrees C, Reynolds numbers from 56 to 260000, and boiling numbers from 0.00007 to 0.26. A total of 715 data points were predicted with a mean deviation of 12.5%. No other verified predictive technique was found in literature. Hence, this correlation should be useful in design of heat exchangers.