A general method for calculation of flow boiling and flow condensation heat transfer coefficients in minichannels

Abstract

Flow boiling and flow condensation are often regarded as two opposite or symmetrical phenomena, however their description with a single correlation has yet to be suggested. In the case of flow boiling in minichannels there is mostly encountered the annular flow structure, where bubble generation is not present. Similar picture holds for inside tube condensation, where annular flow structure predominates. In such case the heat transfer coefficient is primarily dependent on the convective mechanism. In the paper a method developed earlier by D. Mikielewicz et al. (2007) is applied to calculations of heat transfer coefficient for inside tube condensation. Satisfactory consistency with well established correlations for condensation has been found.