Publication:
An experimental study of dropwise condensation on horizontal condenser tubes

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Authors
Manvel, John Talbot Jr.
Subjects
dropwise condensation
enhanced heat transfer
condensers
promoters
coatings
Advisors
Marto, P.J.
Date of Issue
1979-06
Date
June 1979
Publisher
Monterey, California : Naval Postgraduate School
Language
en_US
Abstract
Three types of drop promoting coatings were applied to the outside of 15.9 mm (5/8 in) outside-diameter condenser tubes to determine their effect on heat transfer performance. The coatings included a new fluoroepoxy, a commercial series of fluorocarbon coatings, and sputtered TFE. Coating thickness varied from 0.0 2 to 12.7 microns. Steam at about 21 KPa (3 psia) was condensed on the outside surface of each coated tube, horizontally mounted in the center of a dummy tube bundle. Each test tube was cooled on the inside by water at velocities of 0.80 to 7.60 m/sec (3 to 25 ft/sec). The overall heat transfer coefficient was determined directly from experimental data. The inside and outside, heat transfer coefficients were determined by using the Wilson Plot technique. Of the commercial fluorocarbon coatings, the "Nedox" coating on a copper-nickel tube enhanced the outside heat transfer coefficient by 53% and improved the corrected overall heat transfer coefficient by 27%. Of the sputtered TFE coated tubes, the 0.08-micron thick coating on a copper-nickel tube enhanced the outside heat transfer coefficient by 45% and improved the corrected overall heat transfer coefficient by 21%. Evidence of the effect of the thermal conductivity of the condensing surface substrate, and evidence of an optimum coating thickness were found.
Type
Thesis
Description
Series/Report No
Department
Mechanical Engineering
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
NPS 69-79-004
Sponsors
Naval Sea Systems Command, work request N0002479-WR9G078
Funder
Naval Sea Systems Command, work request N0002479-WR9G078
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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