PERFORMANCE STUDY ON A PRINTED CIRCUIT HEAT EXCHANGER COMPOSED OF NOVEL AIRFOIL FINS FOR SUPERCRITICAL CO2 CYCLE COOLING SYSTEM

Abstract

The printed circuit heat exchanger (PCHE) plays a vital role in the supercritical CO2 cooling system for hypersonic aircraft, which significantly affects the efficiency and stability of the cooling system. In this study, a novel structure is proposed to improve the overall performance of airfoil fin PCHE. The RP-3 aviation kerosene and SCO2 are used as working fluids to study the thermal-hydraulic performance and the enhancement mechanism. The results indicate that the overall performance of the PCHE can be improved by slotting the airfoil fin. With the increase in groove thickness, the thermal performance of the new airfoil fin PCHE first improves and then worsens, while the hydraulic performance of the PCHE first worsens and then improves. Compared with the original airfoil fin, the fin with a groove thickness of 0.6 mm reduces the pressure drop by up to 15% without affecting the thermal performance, while the fin with a groove thickness of 0.1 mm increases the heat transfer by 4%-5%. In addition, the optimal mass-flow ratio of SCO2 to kerosene is obtained by thermal resistance matching under different working conditions, which is helpful for the design and optimization of airfoil fin PCHE based on the SCO2 cycle cooling system for scramjets.