Abstract:
An experimental study of convective condensation heat transfer of R134a was conducted in an inclined smooth
copper tube of inner diameter of 8.38 mm. The test condenser had a straight copper tube section with an effective
length of 1.488 m and was cooled by water circulated in the surrounding annulus in a counter-flow arrangement. The
rate of heat transfer was maintained at an average of 250 W throughout the experiment while the mean vapour qualities
ranged between 0.1 and 0.9, mass flux between 200 kg/m2s and 400 kg/m2s for inclination angles varied between -90o
(vertical downward) and +90o (vertical upward) covering the whole range of inclination at saturation temperature of
50oC. The results show that the inclination angles and mean vapour qualities strongly influence the coefficient of heat
transfer and an optimum inclination angle was found to be between -15o and -30o (downward flow). The developed
correlation gave an average and mean deviations of -3.44% and 9.22% respectively for horizontal flow and, 5.25% and
19.41% respectively for vertical downward flow.
