Advancements in thermo-hydraulic characteristics of printed circuit heat exchangers for extreme operating conditions: a review

Printed circuit heat exchangers (PCHEs) are critical components in high temperature-pressure applications, such as nuclear energy systems and supercritical carbon dioxide (sCO2) Brayton power cycles. Their compact design, high efficiency, and robust construction make them ideal for these demanding environments. The article provides an extensive survey on the thermo-hydraulic characteristics and optimization strategies of PCHEs, highlighting their importance and potential in advanced energy systems. It classifies PCHEs into continuous and discontinuous flow paths based on their channel designs. For continuous channels, designs such as straight, zigzag, and wavy are analyzed, while the discontinuous category includes S-shaped and airfoil fin-based flow paths. The article evaluates the thermo-hydraulic performance of these configurations under various operating conditions and geometrical parameters through numerical simulations and experimental methods. This evaluation includes a comparative analysis of the overall performance of different PCHE types with a focus on local fluid dynamics. A detailed summary of key parameters from numerical and experimental studies is provided, encompassing geometrical features, operating conditions, flow arrangements, material types, working fluids, and major outcomes. Additionally, the article examines existing correlations and discusses traditional modeling strategies, one-dimensional discretized approaches, and analytical methods. By identifying gaps in current research, the article proposes areas for improvement and future research directions. This comprehensive review offers researchers and engineers valuable insights into PCHE technologies suitable for high temperature-pressure applications. Printed circuit heat exchangers (PCHEs) are critical components in high temperature-pressure applications, such as nuclear systems and supercritical carbon dioxide (sCO2) Brayton power cycles.