Abo Bibliothek: Guest

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

STUDY ON CHARACTERISTICS OF FORMATION AND EVAPORATION OF MICROLAYER USING LASER INTERFEROMETRY DURING NUCLEATE POOL BOILING FOR WATER AND ETHANOL

Get access (open in a dialog) DOI: 10.1615/IHTC16.bae.023120
pages 917-924

Abstrakt

As an effective heat transfer mode, nucleate boiling has become one of the hottest research topics in heat and mass transfer fields. It was confirmed that a thin liquid film with the thickness in micron meter scale (microlayer), which is thought to play an important role in boiling heat transfer, was formed beneath the boiling bubbles. Since the difficulty in the experimental measurement on microlayer evaporation, the characteristics of the microlayer and its contribution to boiling heat transfer was primarily examined by numerical simulation. The experimental study on the characteristics of microlayer evaporation is quite limited. In this study, by using the laser interferometric method, the 2-dimensional distribution of microlayer and its variation during one bubble cycle was observed and measured. Furthermore, the microlayer evaporation was analyzed based on the volume change of microlayer by ignoring the internal flow of microlayer. As the results, it was shown that the depletion of microlayer was quicker for ethanol than that of water, since the latent heat of ethanol was smaller. In addition, it was also shown that the quicker depletion of microlayer occurred for the conditions of higher heat flux. It was confirmed that the microlayer evaporation occupied significant proportion in total evaporation, during the nucleate boiling for water and ethanol, for the experimental conditions adopted in this study.