Numerical Research on Heat Transfer Characteristics of Helium-Xenon Mixture in 19-Rod Bundle

Abstract Helium-xenon mixture is one of the coolant options for high-temperature gas-cooled reactors (HTGR). As an important factor affecting reactor core design, the convective heat transfer performance of the coolant has always been the focus of research on HTGR. The helium-xenon mixture is a low Prandtl number gas, and its thermodynamic properties deviate from the ideal gas equation. Based on the experimental parameters in the literature, this study used FLUENT to construct a CFD model, and introduced the polynomial function obtained by fitting the physical property data calculated by the Tournier formula into the model. By comparing the wall temperature, fluid center temperature and average temperature in the experimental results and simulation results, the effects and errors of different turbulence models and particle transport models on the convective heat transfer results of helium-xenon mixture are studied. It is found that the standard k-ϵ model can well simulate the flow and heat transfer process of helium-xenon mixture in the tube, and the maximum local temperature difference does not exceed 5%. Based on this research, a helium-xenon mixture flow heat transfer model of 19-rod bundle is established. This study observe the convective heat transfer process of helium-xenon mixture under extreme conditions and reference helium-xenon reactor design parameters, and explore the changes in the average Nu number, local Nu number, and frictional resistance coefficient with temperature, pressure, and flow field. It provides a reference for the design and optimization of future HTGR.