Molten salt heat exchangers are pivotal components in advanced energy systems, where their high-temperature stability and efficient heat transfer performance are critical for system reliability. This paper provides a comprehensive review of recent advancements in molten salt heat exchanger technology, focusing on their application in nuclear energy, concentrated solar power, and thermal energy storage systems. Key design considerations, including thermophysical properties of molten salts and operational conditions, are analyzed to highlight performance optimization strategies. The review traces the evolution from traditional shell-and-tube heat exchangers to compact designs like printed circuit heat exchangers, emphasizing improvements in heat transfer efficiency and power density. Challenges such as material corrosion, manufacturing complexities, and flow dynamics are critically examined. Furthermore, future research directions are proposed, including the development of high-performance materials, advanced manufacturing techniques, and optimized geometries. This review aims to consolidate dispersed research findings, address technological bottlenecks, and provide a roadmap for the continued development of molten salt heat exchangers in high-temperature energy systems.

Printed circuit heat exchanger could be used as pre-cooler in the supercritical carbon dioxide (S-CO₂) Brayton power cycle. Due to the drastic variations of S-CO₂ properties in pre-cooler, segmental design method is used to investigate the thermal-hydraulic performance of PCHE. When the heat duty is given, the local heat transfer entropy generation number has extreme value, which appears near the intersection point of the heat capacity flow rates of both sides. In addition, the local and total entropy generation mainly depend on the local and total heat transfer entropy generation, and the flow imbalance increases entropy generation, especially under conditions of the higher local heat capacity flow rate of water.

Based on the theory of heat transfer enhancement, a novel film-cooling method for turbine blades that involves a chemical heat sink generated by the use of oxalic acid as a cooling stream has been proposed. Experiments were conducted on a flat plate with a row of 30° angled holes, and the conventional method using air as the cooling stream was examined for comparison. Overall, the results of this study demonstrate that the proposed cooling method involving an oxalic acid-induced chemical heat sink is more effective than the conventional method.