The use of enhanced surface in flow boiling heat transfer in a rectangular minichannel

Abstract

The results of flow boiling heat transfer in a 1-mm-deep vertical minichannel are presented. The heating element for an FC-72 laminar flow in a minichannel is a single-sided enhanced foil with various depressions; liquid crystal thermography was used for measuring temperature distribution of the foil. The void fraction and vapor quality were determined for some cross-sections of two-phase flow images. Results presented in the form of boiling curves were analyzed. Both typical and untypical shapes of boiling curves were found. The suitability of classical methods of two-phase pressure drop determination using experimental verification was confirmed.

Keywords:

• flow boiling
• minichannel
• enhanced heating wall
• liquid crystal thermography
• void fraction
• two-phase pressure drop

Acknowledgements

This research has been financially supported by the Polish Ministry of Science and Higher Education (grant N N512 354037 for years 2009–2012).