Paper Title:

Comparison of the Three–Zone Evaporation Model with Boiling Heat Transfer in a Compact Tube Bundle

Periodical International Journal of Engineering Research in Africa (Volume 5)
Main Theme International Journal of Engineering Research in Africa Vol. 5
Pages 53-63
DOI 10.4028/www.scientific.net/JERA.5.53
Citation Ebenezer Adom et al., 2011, International Journal of Engineering Research in Africa, 5, 53
Online since July, 2011
Authors Ebenezer Adom, Peter Kew, Keith Cornwell
Keywords Compact Heat Exchanger, Process Intensification, Thin Film Evaporation
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Abstract

The recent interest in boiling heat transfer in small diameter tubes has led to the study of boiling heat transfer outside a compact tube bundle of diameter 3mm. The bank comprised 3 columns each of 10 stainless steel electrically heated tubes of 3mm outside diameter, with pitch to diameter ratio of 1.5 in an in-line arrangement. These tests were carried out using distilled water and R113 at nominal atmospheric pressure over a range of heat fluxes between 4-21 kW/m2 for mass fluxes from G=5.6 - 32.8 kg/m2s. The recent three-zone evaporation model developed by Thome, Dupont and Jacobi for boiling inside micro channels was used to compare with experimental results as photographic study showed that bubbles confined within the bundle were responsible for the heat transfer enhancement observed. It was observed that the three state model was promising in its application to the bundle arrangement as the confinement number Co for bundle has been shown to be in the order of 0.63