External condensation heat transfer coefficients of R22 alternative refrigerants on enhanced tubes at three saturation temperatures

Title
External condensation heat transfer coefficients of R22 alternative refrigerants on enhanced tubes at three saturation temperatures
Authors
Park, K.J.; Jung, D.
Keywords
condensation heat transfer, alternative refrigerants, low fin tube
Issue Date
2008-06
Publisher
PROFESSIONAL ENGINEERING PUBLISHING LTD
Abstract
In this study, external condensation heat transfer coefficients (HTCs) of R22, R410A, R407C, and R134a are measured on a 1024 fins per meter (26 fins per inch) low fin tube and Turbo-C tube at saturation temperatures of 30, 39, and 50 degrees C with wall subcooling of 3-8 degrees C. Test results show that condensation HTCs of all refrigerants decrease as the saturation temperature increases from 30 to 50 degrees C. This trend is due to the degradation of thermophysical properties of the liquid phase with an increase in saturation temperature. For the low fin tube data, Beatty and Katzs prediction equation showed a reasonably good agreement for all fluids with less than 20 per cent deviation. The performance of Turbo-C tube is better than that of the low fin tube for R22, R410A, and R134a due to the efficient removal of the condensate. For Turbo-C tube, HTCs of R407C were much lower than those of the other three fluids due to a unique condensation phenomenon associated with non-azeotropic mixtures at vapour-liquid interface. The average heat transfer enhancement ratios for the low fin tube and Turbo-C tube against the plain tube are 4.0-5.5 and 3.0-8.1, respectively, for all refrigerants tested.
URI
http://dspace.inha.ac.kr/handle/10505/1703
ISSN
0954-4062
Appears in Collections:
College of Engineering(공과대학) > Mechanical Engineering(기계공학) > Journal Papers, Reports(기계공학 논문, 보고서)
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