Abstract of "HIGH SPEED FLOW VISUALIZATION OF POOL BOILING FROM STRUCTURED TUBULAR HEAT TRANSFER SURFACES"

DOI: 10.1615/ICHMT.2000.TherSieProcVol2.640
146 pages

Rudi Kulenovic
Institute of Nuclear Technology and Energy Systems (IKE), University of Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart, Germany

Rainer Mertz
Institute of Nuclear Technology and Energy Systems (IKE), University of Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart, Germany

Manfred Groll
Institute of Nuclear Technology and Energy Systems, University of Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart, Germany

Sinopsis

Experimental investigations of pool boiling from novel tubular heat transfer surfaces (structured tubes with re-entrant cavities) are carried out with the hydrocarbon propane as working fluid operating under moderate heat fluxes (<100 W/m²) and saturation conditions.
The heat transfer coefficients determined by thermocouple measurements are presented. The evaporation phenomena are visualized by a high speed video system and by means of digital image processing techniques (e.g. Fourier-analyses, correlation-techniques). The bubble departure diameter at the surface, the bubble generation frequency at corresponding nucleation sites and the bubble upward flow velocity are quantitatively determined.