CFD Design and Analysis on Circular Slotted Fin Surfaces of Two-Row Tubes Heat Exchangers
A numerical investigation of the flow and heat transfer in a two-row finned-tube heat exchanger is conducted with a three-dimensional conjugated model using the CFD software. The results show that, compared to the quadrate slotted fin, the circular slotted fin have good heat transfer performance in that the percentage increase in heat transfer is higher than that in the friction factor. Within the Reynolds number range compared ( from 1,270 to 8,892), the Nusselt number of new slit 1 is about 25.6-61.6% and 20.8-57.5%, while new slit 2 is about 26.8-33.6% and 25.8-33.0%, higher than that of the quadrate slotted fin surface at identical pressure drop and the identical pumping power, respectively. For the two-row plate fin-and-tube heat exchanger, new slit 2 is recommended for the use in air-conditioning because its integrative design.