Development of accelerated PCHE off-design performance model for optimizing power system control strategies in nuclear systems

Abstract

Recently, Printed Circuit Heat Exchanger (PCHE) has attracted attention as a heat exchanger for the nuclear power conversion system such as supercritical $CO_2 (S-CO_2)$ Brayton cycle. The reason is due to the excellent structural rigidity with extremely compactness of PCHE. The conventional heat exchanger analysis methods yield substantial error in heat exchanger performance prediction for the PCHEs utilized in the $S-CO_2$ Brayton cycle due to substantial change of properties. KAIST_HXD was developed to analyze a PCHE in such condition. However, KAIST_HXD has a limitation which significant amount of computational resource is required for the off-design analysis. This problem becomes more pronounced if it is expanded to the level of power system analysis from component level due to many iterations. With these reasons, a methodology is required to perform a heat exchanger analysis promptly even when the fluid properties change considerably. Therefore, the objectives of this study is to develop a PCHE off-design performance model, which can accelerate the computation time while preserving similar accuracy. This new model will be compared with the results of the analysis with the reference code, KAIST_HXD.