Library Subscription: Guest

ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

EXPERIMENTAL FLOW BOILING STUDY IN MINI-CHANNELS

Get access (open in a dialog) DOI: 10.1615/IHTC13.p28.80
13 pages

Abstract

The present study is both supported by scientific and industrial issues. The lack of universal experimental correlations specific to confined spaces requires extending existing scientific knowledge. Technologic field is related to compactness induced by thermal efficiency improvements. As an example, compact heat exchangers are widely used in evaporators for many applications such as microelectronic or automobile. Consequently, industrial applications require a better understanding of boiling phenomenon in confined spaces. Thus, the aim of this study is to acquire a more accurate vision of frictional pressure drop and heat transfer coefficient dependencies in mini channels. Experimental frictional pressure drop and heat transfer during flow boiling in vertical mini-channels are studied. The experimental test section consists of a vertical aluminum heat exchanger composed of 40 parallel rectangular channels having a hydraulic diameter equal to 0.84 mm. The fluid (HFE-7100) enters at the bottom of the test section and is subsequently vaporised in the channels. A specific instrumentation supplies local heat transfer coefficient and frictional pressure drop values. The hydraulic study shows that homogeneous model and Mishima et al. (1993) model well apply. Additionally, the influence of vapour quality, mass velocity and heat flux on the heat transfer coefficient is studied. It is shown that plotting the heat transfer coefficient as a function of the superficial velocity allows a meaningful presentation of all the experimental data.