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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

BOILING FEATURES OF A NOVEL MICROSTRUCTURE

Get access (open in a dialog) DOI: 10.1615/IHTC13.p28.40
12 pages

要約

A novel family of surface microstructures for nucleate pool boiling has been devised and used in our extended experimental studies. The structures consist of cylindrical pins as basic elements, having diameters of 0.1 μm to 25 μm, height ranging from 10 μm to 100 μm, while the number density of the pins can be varied from 1 × 104 cm−2 to 1 × 109 cm−2.
These structures can be easily generated on cylindrical specimens like tubes in almost all electrochemically depositable materials. Tested with R141b and R134a at pressures up to 9 bar, the structures show a heat transfer enhancement in comparison with plain surfaces ranging up to the factor of 13.5, which is nearly independent on the heat flux. Besides of the heat transfer enhancement, the structures demonstrate the driving temperature difference to be almost constant over a wide range of the heat flux, and in some cases this process quantity even decreases with the increasing heat flux. At most effective boiling mode, the boiling inception occurred as a two-phase front, moving at a high speed along the tube length.