Condensation heat transfer characteristics of zeotropic refrigerant mixture R407C on single, three-row petal-shaped finned tubes and helically baffled condenser

Condensation heat transfer coefficients (HTCs) of zeotropic refrigerant mixture R407C on single horizontal petal-shaped finned (PF) tube and three rows of PF tubes with an in-line arrangement were experimentally measured. All measurements were taken at the vapour temperature 39 °C with the wall subcooling of 2–8 °C. The results showed that the average enhancement factor provided by the PF tube was about 5.02, and the effect of condensate inundation was significant for the PF tube. Furthermore, the experiments also were performed to compare the shell-side condensation HTCs of an integrally helical baffle condenser with PF tubes to those of that with low fin (LF) tubes at vapour temperature of 39 °C, the condensation HTCs of helically baffled condenser with PF tubes were about 1.56 times as large as that of helically baffled condenser with LF tubes at the same heat flux. Correlations have been suggested for both the shell-side condensation HTCs for the two condensers with different tube types and give very good agreement with experimental results. It is a promising route to use PF tubes instead of LF tubes for improving the performance of an integrally helical baffle condenser.