A new model for predicting falling film evaporation heat transfer coefficients

Document Type

Conference Proceeding

Publication Date



Copyright © 2016 by ASME. For falling film evaporation, the most important considerations from a thermal design standpoint are the onset of film dryout and the local heat transfer coefficients in partially and fully wet conditions. Previous methods developed for the prediction of (i) pool boiling heat transfer coefficient (HTCs), (ii) the onset of dryout, and (iii) falling film heat transfer coefficient consist of empirical, tube-specific constants which are quite difficult, if not impossible, to determine, and hence have limited utility. New methods to predict these parameters have been developed in the present study, which eliminate the special constants by incorporating dimensionless parameters that capture the effect of refrigerant properties and macro-level tubegeometry. The predictions of the new model have been found to be better than or comparable to those of the best available existing models.

Publication Title

ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)