Abo Bibliothek: Guest

ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Heat transfer model for pool boiling on a horizontal tube

Get access (open in a dialog) DOI: 10.1615/IHTC12.4630
6 pages

Abstrakt

Pool boiling on horizontal cylinders is one of the most extensively studied problems in the recent past due to its direct relevance to equipment such as heat exchangers, chemical reboilers and boiling water nuclear reactors. Even though experimental correlations are available for such cases, they offer little insight to the mechanism of heat transfer. In the present work an effort has been made to present a comprehensive heat transfer model for pool boiling on horizontal tubes. It is well established that sliding bubbles play a major role in the heat transfer process during boiling on a horizontal tube. By combining sliding bubble mechanism with natural convection, microlayer evaporation and transient conduction during boundary layer reformation, a model has been built to predict the boiling heat flux for a given wall superheat. It is found that the performance of this model critically depends on the assessment of nucleation site density on the tube. They are needed to be taken from experimental observations. The model has been compared to experimental results from literature for R134a. Even with a number of simplified assumptions a reasonably good agreement has been observed between model and experiments in the low and medium heat flux region and moderate pressure.