| Abstract: | Variations of the vapor concentration of a water‐ethanol mixture during saturated nucleate pool boiling were studied. The temperature changes of the vapor in bubbles produced by the boiling were measured at several different positions near the boiling surface by using a thin thermocouple having high responsivity. The superheat of the bubbles was initially higher in the superheated liquid layer near the heat transfer surface and then approached the bulk temperature along the upward direction. It was clarified that the temperature and concentration differences of the bubbles from the bulk almost disappeared at a height of 3 to 5 mm from the heat transfer surface and within 20 ms after the appearance of the bubbles. Thus, the former result of the liquid‐vapor equilibrium with the bulk condition was confirmed. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(6): 475–485, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10047 |
