Abstract
The quantification of the condensate heat resistance is
studied for dropwise condensation from flowing air-steam
mixtures. Flows are essentially laminar and stable with gas
Reynolds numbers around 900 and 2000. The condensate shaping
up as hemispheres on a plastic plane wall and the presence
of inert gases make it possible that thermocapillary convection
occurs making the resistance less than the mean condensate
thickness (ca. 0.185 mm) divided by the heat conduction coefficient.
The analysis of experiments shows that the effective
mean condensate resistance might indeed be less, by a factor of
0.8+0.2. The analysis takes account of the sensible heat transfer
which may be as large as 35% of the total heat transfer if inlet
vapor concentration, cin, is low (ca. 0.07). A method is presented
to determine the gas-condensate interface temperature,
ti, that is needed in the analysis of the heat resistance. The
highest temperature differences (t i- tw), t w being the mean
temperature of the condenser plate at the gas side, have been
found to occur for relatively high values of Cin (ca. 0.3).
| Original language | English |
|---|---|
| Pages (from-to) | 435-445 |
| Number of pages | 11 |
| Journal | Heat and mass transfer |
| Volume | 30 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 1995 |
Keywords
- METIS-124511
- IR-20838