Thermal-Hydraulic Performance and Optimization of Printed Circuit Heat Exchangers for High-Temperature/High-Pressure Applications

Recently, the printed circuit heat exchanger (PCHE) is considered as one of the most potential candidates for the intermediate heat exchanger in the helium and supercritical carbon dioxide (SCO2) Brayton cycles in the nuclear application. The operating temperature in the helium Brayton cycle is up to 900^◦C, while the operating pressure in the supercritical carbon dioxide Brayton cycle is up to 8 MPa. The ultra high temperature and high pressure give a significant challenge to the design and fabrication of PCHE. In the first part, the PCHE using helium as the working fluid is studied in the laminar flow region. The effect of fluid-solid coupled thermal boundary on the local thermal-hydraulic performance is analyzed and compared to that of the constant temperature boundary. A two-sided etched zigzag-type PCHE is proposed to reduce the thermal stress produced at high temperature. In the second part, the PCHE using SCO2 as the working...