| Abstract: | Pool boiling experiments with small diameter wires were conducted in earth gravity and microgravity conditions. Bare wire and fouled wire with a scale deposition of calcium carbonate was used. The wettability on the scale wire was higher than that on the bare wire. Though more vigorous bubbling was observed on the scale wire when compared to that on the bare wire at the same heat flux, the boiling curve for the scale wire was approximately the same as that on the bare wire. However, the critical heat flux (CHF) on the scale wire was higher than that of the bare wire. On the scale wire, the departure diameter of bubbles was relatively smaller than that on the bare wire. The smaller diameter of bubbles detaching from the scale wire is considered to be due to the high wettability and high nucleation site density. As the result, the coalescence of bubbles near the wire was prevented, and the CHF was delayed and increased on the scale wire when compared to that on the bare wire. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(5): 316–329, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20016 |
