Numerical investigation on the thermal-hydraulic performance of supercritical CO₂ in a modified airfoil fins heat exchanger

The numerical studies on the modified airfoil fins channel using supercritical CO2 as working fluid showed that front-dense and rear-sparse (FDRS) and front-sparse and rear-dense (FSRD) distributions of fins could enhance heat transfer by improving the distribution uniformity of temperature difference in channel. The match of local dense distribution of fins with the region near pseudocritical point could obtain better overall thermal performance in the modified airfoil fins heat exchanger. The differences of thermal-hydraulic performance among channels with uniform, FDRS and FSRD distributions of fins could be explained with field synergy principle. The FSRD distribution of fins is the optimum scheme in the three distributions of the modified airfoil fins channel, because its comprehensive performance is 23–29 % higher than that of the uniform distribution of fins and 2–7.6 % higher than that of the FDRS distribution of fins. The present work provides insights into the mechanisms of supercritical CO2 heat transfer characteristics as well as practical guidance on the design and optimisation of relevant components.