TY - JOUR
T1 - Effects of surface roughness and tube materials on the filmwise condensation heat transfer coefficient at low heat transfer rates
AU - Yun, Rin
AU - Heo, Jaeheok
AU - Kim, Yongchan
N1 - Funding Information:
This work was jointly supported by the Korea Science and Engineering Foundation (Grant No. R01-2002-000-00481-0), and the Carbon Dioxide Reduction and Sequestration Center, one of the 21st Century Frontier R&D Programs in the Ministry of Science and Technology of Korea.
PY - 2006/4
Y1 - 2006/4
N2 - The laminar filmwise condensation heat transfer coefficient on the horizontal tubes of copper and stainless steel was investigated. The outside diameter of the tubes was 15.88 mm, and the tube thickness ranged from 1.07 to 1.6 mm. The polished stainless steel tube had an RMS surface roughness of 0.37 μm, and commercial stainless steel tubes had maximum surface roughness of 15 μm. The tests were conducted at saturation temperatures of 20 and 30 °C, and liquid wall subcoolings from 0.4 to 2.1 °C. The measured condensation heat transfer coefficients were significantly lower than the predicted data by the Nusselt analysis when the ratio of the condensate liquid film thickness to the surface roughness, δ/Rp-v, was relatively low. When the condensate liquid film was very thin, tube material affected the condensation heat transfer coefficient in the filmwise condensation.
AB - The laminar filmwise condensation heat transfer coefficient on the horizontal tubes of copper and stainless steel was investigated. The outside diameter of the tubes was 15.88 mm, and the tube thickness ranged from 1.07 to 1.6 mm. The polished stainless steel tube had an RMS surface roughness of 0.37 μm, and commercial stainless steel tubes had maximum surface roughness of 15 μm. The tests were conducted at saturation temperatures of 20 and 30 °C, and liquid wall subcoolings from 0.4 to 2.1 °C. The measured condensation heat transfer coefficients were significantly lower than the predicted data by the Nusselt analysis when the ratio of the condensate liquid film thickness to the surface roughness, δ/Rp-v, was relatively low. When the condensate liquid film was very thin, tube material affected the condensation heat transfer coefficient in the filmwise condensation.
KW - Condensate liquid film thickness
KW - Filmwise condensation heat transfer
KW - Surface roughness
KW - Tube thermal conductivity
UR - http://www.scopus.com/inward/record.url?scp=33645843047&partnerID=8YFLogxK
U2 - 10.1016/j.icheatmasstransfer.2006.01.009
DO - 10.1016/j.icheatmasstransfer.2006.01.009
M3 - Article
AN - SCOPUS:33645843047
VL - 33
SP - 445
EP - 450
JO - International Communications in Heat and Mass Transfer
JF - International Communications in Heat and Mass Transfer
SN - 0735-1933
IS - 4
ER -