Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 0-89116-909-1

International Heat Transfer Conference 9
August, 19-24, 1990 , Jerusalem, Israel

NUCLEATE POOL BOILING TO VISCOELASTIC FLUIDS

Get access (open in a dialog) DOI: 10.1615/IHTC9.80
pages 45-50

Abstrakt

The nucleate pool boiling behavior of viscoelastic aqueous polymer solutions has been measured and compared with results for pure water. Two polymers were studied, a polyacrylamide (Separan) and a hydroxyethyl cellulose (Natrosol) in concentrations ranging from 60 to 5,000 wppm. The conventional q" vs ΔΤ boiling curves were measured using a electrically heated horizontal platinum wire of diameter 0.0254 cm submerged in a saturated pool of liquid at atmospheric pressure. The rheological properties of each polymer solution were measured carefully to ensure that they were stable during the boiling process.
The water boiling data are in good agreement with Kutateladze's correlation and in fair agreement with Nishikawa's correlation. The boiling heat transfer performance of the Separan solutions was inferior to the performance of water, exhibiting larger values of ΔΤ at a fixed heat flux, q". In the case of the Natrosol solutions the 500 wppm solution showed a slight improvement over the performance of water; for concentrations above 1000 wppm dramatically different behavior was observed. For these higher concentration Natrosol solutions heat transfer enhancement was observed at heat fluxes above 13 W/cm2. In this region, the surface temperature of the platinum wire actually decreased with an increase in the heat flux. A series of photographs provided additional support for the measured behavior.