Abstract
The liquid sodium has been used as the working media for high-temperature heat pipe and the generation IV sodium cooled fast reactor due to the extremely high conductivity. The heat transfer characteristics of sodium in a circular pipe is one of the most essential focuses in engineering applications. In this paper, a model to predict the heat transfer coefficient of fully developed sodium flowing in tube was developed based on the universal velocity, turbulent eddy diffusivity and the linear law inside the thermal boundary layer. The Kays correlation for turbulent Prandtl number was used to predict the turbulent Prandtl in the bulk flow with y + larger than 60. This model was validated by the experiment data of Hg, NaK and sodium, showing superior accuracy than other available models. Besides, the dependence of the accuracy on the model parameters was also analyzed, demonstrating the universal applicability of the current model.
Highlights
Especially liquid sodium, have been widely used in high-temperature heat transfer process in industry and power applications, such as sodium cooled fast reactors in France, China, and Russia, and the high temperature heat pipe used in space facilities
The traditional computational fluids dynamics treatment on the energy equation based on Reynolds analogy and the unit turbulent Prandtl number is not validated in liquid metals
The results show a noticeable divergence even for the same working fluid, especially for sodium and NaK eutectic, which means the investigation on the heat transfer characteristics of sodium has still not matured
Summary
Especially liquid sodium, have been widely used in high-temperature heat transfer process in industry and power applications, such as sodium cooled fast reactors in France, China, and Russia, and the high temperature heat pipe used in space facilities. To ensure the safety of the facilities, the heat transfer coefficient should be accurately estimated in the thermal design process of industrial applications. The heat transfer characteristics of liquid metal are quite different from traditional fluids. The difference in Prandtl number changes the heat transfer characteristics in the near wall and bulk regions. The thermal boundary layers of liquid metal are much thicker than the momentum boundary layer, resulting in the failure of correlations for heat transfer of traditional fluids in the applications of liquid metals. The traditional computational fluids dynamics treatment on the energy equation based on Reynolds analogy and the unit turbulent Prandtl number is not validated in liquid metals
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have