Thermal-hydraulic Design and Evaluation of Printed Circuit Heat Exchangers for a N2 Brayton cycle Recuperator coupled with Sodium-cooled Fast Reactor

Abstract

In order to eliminate the reaction with sodium, Nitrogen (N2) Brayton cycle is an alternative option for Sodium-cooled Fast Reactor power conversion system. A recuperator is the essential component for increasing cycle thermal efficiency in N2 Brayton cycle. However, it has largest volume in the power conversion system due to gas-to-gas heat exchange. Printed Circuit Heat Exchanger (PCHE) is a promising heat exchanger which has good synergies with N2 Brayton cycle due to its high compactness and operating conditions. To evaluate the effects of recuperator volume on a N2 Brayton cycle, the thermal-hydraulic correlation experimental validation, PCHE 1-D code development, and design of recuperator were performed. The minimum volumes of recuperator with respect to target effectiveness were derived. The results showed that the Straight type recuperator had about 1.3 times larger volume than Airfoil type at the same target effectiveness. And also it can conclude that the importance of PCHE type is more significant when higher cycle thermal efficiency is required.