Effects of Sloshing Motions on Condensation Heat Transfer Characteristics of Integral-Fin Tubes Under Sea Conditions

Integral-fin tubes with high heat transfer capability are a promising solution for improving the compactness of condensers used in the exploitation of offshore natural gas at sea, and the sloshing motions including rolling and pitching would inevitably affect the performance of tubes. For applying integral-fin tubes offshore, the effects of rolling and pitching motions on condensation heat transfer characteristics of integral-fin tubes should be known. In this study, the condensation heat transfer characteristics of integral-fin tubes under rolling and pitching motions are experimentally investigated and the effects of motion angle and frequency are quantitatively analyzed. The results show that the sloshing motions have both positive and negative effects on the heat transfer of integral-fin tubes during a period, and the pitching motion has a greater influence than the rolling motion. As the sloshing angle increases from 0 deg to 12 deg, the maximum increase and reduction rates of the ratio of local wall subcooling temperature under pitching motion to that under static conditions are 10.9% and 12.5%, respectively, and the time-averaged condensation heat transfer coefficient (HTC) increases by 3.5% maximally. As the sloshing frequency increases from 0 to 0.25 Hz, the maximum increase and reduction rates of the ratio of local wall subcooling temperature under pitching motion to that under static conditions are 7.7% and 15.2%, respectively, and the increase rate of the time-averaged condensation HTC remains about 2%.