Thermo-hydraulic performance of SCO2 in PCHE with NACA 4822 asymmetric airfoil fins under ocean rolling conditions

Abstract

To enhance the heat transfer efficiency of a printed circuit heat exchanger (PCHE) under ocean rolling conditions, a fractal structure of the NACA 4822 asymmetric airfoil fins was proposed innovatively. This new configuration features two layers of channels: the upper is dedicated to hot CO2 while the lower is aimed for cold CO2. Notably, the asymmetric airfoil fin structure exhibits a remarkable improvement factor of heat transfer ranging from 1.0 to 3.5, accompanied by a friction factor ratio varying between 0.6 and 1.3, which signifies a dual benefit of reduced pressure drop and augmented heat transfer. Under rigorous analysis of the fractal-structured asymmetric airfoil fins in the PCHE, their performance is evaluated through varying rolling periods and angles. Our findings reveal that a rolling period of 2.0 s outperforms a rolling period of 4.0 s in terms of heat transfer performance. Specifically, at a rolling angle of 30°, the thermal performance soars by approximately 2.0 to 4.7 times, which indicates a positive correlation between a larger rolling angle and enhanced heat transfer. Intriguingly, the influence of the rolling angle on heat transfer performance eclipses that of the rolling period.