Study on Flow and Heat Transfer Characteristics of an Airfoil Printed Circuit Heat Exchanger With Dimples

In present paper, a novel airfoil printed circuit heat exchanger (PCHE) with dimples was proposed as heat exchanger for supercritical carbon dioxide (S-CO₂) Brayton cycles in the concentrated solar power plant. Firstly, a three-dimensional flow and heat transfer numerical model was developed and validated. Then, the number and arrangement of dimples were optimized, and an optimized airfoil PCHE with dimples was obtained and compared with airfoil PCHE without dimples. The results indicated that airfoil PCHE with dimples achieved the best comprehensive performance when a unit volume had two dimples which were in staggered arrangement with airfoil fins. In the range of Reynolds number studied, the comprehensive performance can be improved by 3.58.7% after replacing the original PCHE by the novel. The above results indicate that the proposed PCHE can achieve good performance in the heat transfer of S-CO₂, and can be used in solar power plant.