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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

HEAT TRANSFER AND CRITICAL HEAT FLUX ENHANCEMENT AT BOILING AND EVAPORATION IN THE LIQUID FILM FLOWS ON MICROSTRUCTURED SURFACES

Get access (open in a dialog) DOI: 10.1615/IHTC16.bae.022930
pages 755-762

Sinopsis

The report presents the results of experimental studies of heat transfer and crisis phenomena at boiling and evaporation in the liquid film flows on the microstructured surfaces.
In the first part of the report, there is the comparative analysis of heat transfer efficiency and critical heat flux in the film flows of refrigerant R21 and refrigerants mixture R21/R114 over a vertical cylinder with the horizontal microtexture, diamond-shaped cut, and mesh covers of various forms. Experimental data on heat transfer enhancement during boiling in the conditions of film flow of liquid on the new microstructured surfaces generated by the method of deforming cutting with subsequent knurling on the tops of the ribs also are presented. The mechanisms of heat transfer enhancement at evaporation and boiling at different irrigation degrees are discussed for the used methods of modification of the heat transfer surface. These results are compared with data of other authors obtained for different microstructured surfaces and well-known calculation dependences for the coefficients of heat transfer and critical heat flux.
In the second part of the report the experimental results on rewetting of significantly superheated bodies by the falling liquid films, when the cooled surface is covered by the new capillary-porous structures of various forms or low heat-conducting coatings are presented.