Abstract
The boiling heat transfer coefficients of two horizontally installed heat transfer enhancing tubes were measured respectively. One of the tubes is with internal helical threads and the other is with a fin-module insert. The measured data were compared to those of a smooth tube for acquiring the heat transfer enhancement index (γ). The test tubes were exerted with constant surface heat flux. The evaporation temperature was in the range of −12 to −13°C and the mass flux (G) of the refrigerant was in the range of 20.1–57.6kg/m2-s. The result shows that, for the tube with internal helical threads, the h¯ value is proportional to [(G/4.0)−4.4]0.146; for the tube with a fin-module insert, the h¯ value is proportional to [(G/4.0)−4.4]0.113. The γ value of the tube with internal helical threads was found to be in the range of 1.36–1.73 and that of the tube with a fin-module insert was in the range of 1.76–2.4. The γ value tends to decrease with an increase of the G value.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Communications in Heat and Mass Transfer
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
