Numerical study of crossed airfoil fins in a printed circuit heat exchanger

Abstract

Airfoil fin is a new type of discontinuous fin that can provide better thermal–hydraulic performance than Zigzag fin and S-shaped fin when used in a printed circuit heat exchanger with supercritical CO2 as the working fluid. However, previous studies were limited to two-dimensional shape optimization of the airfoil fin and did not consider the shape adjustment in the height direction. In this study, we proposed a new fin consisting of crossed fins on the upper and lower heat exchanger plates to achieve shape change in the height direction. We compare the heat transfer and flow resistance of this new fin with the traditional airfoil fin using numerical simulation method. The results show that the crossed airfoil fin can generate longitudinal vortex that destroy the boundary layer of the heat transfer wall, improving the heat transfer performance. Under the multiple inlet Re number conditions studied in this paper, the heat exchanger with crossed airfoil fins has a 25.5%-30.8% higher Nu number than the traditional airfoil fins, and the thermal performance factor is increased by more than 10%. It concludes that significantly improves the thermal performance and has good engineering application value.