Published 8 issues per year
ISSN Print: 1065-5131
ISSN Online: 1563-5074
Indexed in
Pool Boiling of R-11 Refrigerant and Water on Oxidized Enhanced Tubes
ABSTRACT
The effects of oxidation on pool boiling on an oxidized enhanced boiling tube (GEWA-SE) have been studied. Water and a refrigerant R-11 were boiled at subatmospheric pressure. Oxidation increases the pool boiling heat transfer coefficient for both fluids. The pool boiling heat transfer coefficient increased as much as a factor of 2.4 for water, and 1.5 for the refrigerant. For the R-11 refrigerant, a highly wetting fluid, the boiling heat transfer coefficient increases with increase in the level of oxidation. The increase in the heat transfer coefficient with increasing level of oxidation for water as the boiling fluid was slightly less than that recorded for R-11. This study includes contact angle measurement and its influence on oxidation. The contact angle of different levels of oxidation and of various surface grades of copper and aluminum in contact with water, and refrigerants were measured. Contact angles can be used as a rough guide or indicator of the level of surface oxidation or the degree of wettability of fluids on a surface. With the depth of the roughness below 0.5 μm, no surface roughness effect on contact angle were observed.
-
Kim Nae-Hyun, An Experimental Study on Pool Boiling Heat Transfer Enhancement of Structured Tubes Having Three-Dimensional Roughness, Korean Journal of Air-Conditioning and Refrigeration Engineering, 28, 5, 2016. Crossref
-
Eckert E.r.g, Goldstein R.J, Ibele W.e, Patankar S.V, Simon T.W, Strykowski P.J, Tamma K.K, Kuehn T.H, Bar-Cohen A, Heberlein J.V.R, Davidson J.H, Bischof J, Kulacki F, Kortshagen U, Heat transfer—a review of 1995 literature, International Journal of Heat and Mass Transfer, 42, 15, 1999. Crossref
-
Saha Sujoy Kumar, Ranjan Hrishiraj, Emani Madhu Sruthi, Bharti Anand Kumar, Pool Boiling Enhancement Techniques, in Two-Phase Heat Transfer Enhancement, 2020. Crossref
-
Vadgama Bhavin, Harris Daniel K., Measurements of the contact angle between R134a and both aluminum and copper surfaces, Experimental Thermal and Fluid Science, 31, 8, 2007. Crossref
-
Deb Sandipan, Pal Sagnik, Das Dipak Chandra, Das Mantu, Das Ajoy Kumar, Das Ranjan, Surface wettability change on TF nanocoated surfaces during pool boiling heat transfer of refrigerant R-141b, Heat and Mass Transfer, 56, 12, 2020. Crossref