Numerical Simulaion of Heat Transfer in a Spiral-Wound Tube Helium-Xenon/Water Heat Exchanger Based on a Porous Media Model

The wound-tube heat exchanger using Helium-Xenon mixture and water as heat transfer media is capable of withstanding the significant temperature and pressure differences induced by the helium–xenon gas. Integrated into a Brayton cycle for reactor applications, it exhibits advantages such as compact structure and high cycle efficiency. Therefore, the research and design of such heat exchangers are of crucial importance. In this study, a heat transfer correlation suitable for low-Prandtl-number Helium-Xenon mixtures is proposed based on conventional thermal-hydraulic formulas. The simplification methodology for the computational model was investigated using a porous medium model. Results show that the simplified approach combining the porous medium model with a single-layer wound tube significantly improves computational efficiency while keeping the error margin below 5%. Furthermore, temperature field analysis demonstrates that the heat exchanger can effectively remove waste heat from the system. Even under extreme conditions such as zero water flow velocity, it continues to dissipate excess heat through natural circulation, ensuring system safety and demonstrating broad application prospects.