Abstract:
This paper presents an experimental investigation on the
condensation of steam on vertical flat surfaces with arrays of
micro-fins. Three micro-fin surfaces (MF1, MF2 and MF3) of
the same fin diameter and fin height but with different fin pitch
were fabricated by selective laser melting. The surfaces were
tested in a condensation chamber where the gravity driven
condensate flow and vapor velocity are orthogonal to one
another. The effects of fin pitch and vapor velocity on the heat
transfer performances of the surfaces were examined. Our
results suggest that fin pitch has significant influence on the
condensate drainage path as compared to the increase in heat
transfer area. In addition, above a certain wall subcooled
temperature, the increase in vapor velocity also resulted in the
systematic increase in condensation heat flux indicating the
significant effects of vapor shear force. In all, up to 1.4 times
enhancement in the heat transfer coefficient was achieved with
the micro-fin surface with a fin pitch of 300 μm as compared to
a plain Al-6061 surface at constant vapor velocity.
Description:
Papers presented at the 13th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Portoroz, Slovenia on 17-19 July 2017 .
