Heat transfer characteristics of boiling phenomenon in flooded refrigerant evaporators

This paper presents an overview of the heat transfer characteristics of shell and tube flooded evaporators and boiling on the outside of tubes and tube bundles. In the process over 80 papers are reviewed where the boiling on the outside of horizontal tubes is studied. General experimental observations are highlighted as are theoretical models for predicting the heat transfer coefficients on single tubes and tube banks. The advantages and disadvantages of these approaches are shown with reference to results from various studies. The review reveals that historically, flooded evaporators have been designed with pool boiling data for single tubes which is inherently inaccurate due to the large enhancement from rising vapour bubbles in tube banks. It also reveals that the application of forced convection boiling models is still tentative and requires further investigation. (C) 1999 Elsevier Science Ltd. All rights reserved.