A Simple Correlation for Horizontal Microfin Tube Convective Boiling

Abstract

This paper presents a simple correlation containing nine dimensionless parameters to predict the local convective boiling heat transfer within a microfin tube that was developed from a dataset that included a wide range of refrigerants, flow conditions, and hydraulic diameters. Flow boiling measurements from 36 studies were gathered to produce a dataset containing 29 refrigerants and 15 different hydraulic diameters ranging from 1.8 mm to 6.7 mm. The database was adjusted so that the definition of the Nusselt number, the Reynolds number, the heat flux, and heat transfer coefficient were all defined in the same way for each study. In addition, values for the most recent fluid properties were used for the calculation of dimensionless parameters that were used in the new correlation. The new correlation for microfin convective boiling predicted the measurements from the database to within ±10.3% for pure-refrigerants and azeotropic mixtures and ±12.3% for zeotropic mixtures.