Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

CONDENSATION HEAT TRANSFER OUTSIDE A VERTICAL TUBE WITH TEMPERATURE VARIATION IN THE PRESENCE OF NONCONDENSABLE GAS

Get access (open in a dialog) DOI: 10.1615/IHTC16.cod.023787
pages 2267-2274

Abstrakt

In previous studies on tube condensation, the tube temperature has been assumed to be constant. However, it is rather natural to suppose that the tube has temperature variation if one considers the fact that coolant flows within the tube. In this study, we investigate condensation heat transfer on the exterior surface of a vertical tube in the presence of noncondensable gas taking into account temperature variation of the tube and the coolant. We derive a heat transfer model of the condenser tube by employing energy conservation and the heat transfer coefficients of the inside and the outside of the tube, which have been previously proposed. We fit a numerical solution of the model into experimental data to estimate a correction factor of the condensation heat transfer coefficient. As a result, it is shown that the correction factor depends on the concentration of the ambient gas mixture or the subcooling of the tube. Furthermore, we propose a simplified expression of the condensation heat transfer coefficient, whose correction factor varies smaller than the previous one against the subcooling. Moreover, we can fit a numerical solution of the model into experimental values of the tube temperature by suitably adjusting unknown parameters. Finally, the correction factor of the proposed condensation heat transfer coefficient represents the reciprocal of the thickness of the diffusion boundary layer.