A numerical investigation of convective condensation in micro-fin tubes of different geometries

Abstract

A numerical investigation was conducted to determine the effects of fin shape on heat transfer coefficients during in-tube condensation of R410A. Four micro-fin tubes of different geometries were selected for this study, including a straight-finned one and three helical tubes, and two different helical angles of 18° and 31° were included to explore the influence of helical angles. The numerical results were verified by previous experimental results. It was found that there was a positive relationship between heat transfer coefficients and mass velocities and vapor quality, while the helical angle seemed to improve the heat transfer coefficients especially for medium vapor quality. A nearly symmetrical liquid film distribution was found along the circumference for all three micro-fin tubes due to the centrifugal force, while the liquid tends to accumulate at the bottom of the straight-finned tube.

Additional information

Funding

This work is supported by the National Science Foundation of Zhejiang Province (grant no. Q15E090001).