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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Experimental Investigation on Pressure Drop and Friction Factor in Tubes at Different Inclination Angles During the Condensation of R134a

Get access (open in a dialog) DOI: 10.1615/IHTC15.cds.009363
pages 657-670

摘要

An experimental investigation on the pressure drops and friction factor characteristics during the condensation of R134a in a smooth copper tube of inner diameter of 8.38 mm was conducted. Tests were done for vapour qualities ranging between 0.1 and 0.9, mass fluxes between 50 kg/m2s and 400 kg/m2s, saturation temperatures between 30oC and 50oC for a range of inclination angles from –90 degrees (downward flow) to +90 degrees (upward flow). The pressure drop was measured directly by means of a calibrated differential pressure transducer connected between the inlet and the outlet of the test condenser. It was found that mean vapour quality, mass flux, inclination angle and saturation temperature have significant influences on the measured pressure drop. The frictional pressure gradient result for horizontal flow was compared with some pressure gradient correlations available in the literature. A good agreement was found for horizontal flow especially for high-pressure drop (high mass flux, high mean quality). Similarly, the friction factor data for horizontal and upward vertical flow were compared with some friction factor models available and the results are presented.