Hits:

Indexed by:期刊论文

Date of Publication:2016-01-01

Journal:2nd International Workshop on Heat Transfer Advances for Energy Conservation and Pollution Control (IWHT)

Included Journals:SCIE、CPCI-S、Scopus

Volume:47

Issue:3

Page Number:243-258

ISSN No.:1064-2285

Key Words:pool boiling; space-confined structure; temperature fluctuation; heat transfer enhancement; liquid microlayer

Abstract:In this paper, the surface temperature fluctuation magnitude and frequency at the nucleation sites in the process of boiling a specially designed space-confined structure is investigated using infrared thermography. Water and ethanol are used as working fluids. The results show that the magnitude of temperature fluctuations is less than 1 K in experiments, while the theoretical prediction of this value is equal to at least 5 K if bubbles are in direct contact with the heating surface. The average temperature fluctuation frequencies and the average bubble departure frequencies on plain and E0.15 surfaces are close in value to each other. A remarkable discrepancy can be found between the surface temperature fluctuation frequency and the bubble departure frequency. The experimental results illustrate that bubbles are not in direct contact with the heating surface, instead, a microlayer of liquid exists between bubbles and heating surface all the time. The bubbles predominately affect the boiling heat transfer characteristics through the temperature fluctuation of the liquid layer.