Analytical study of heat transfer for liquid metals in a turbulent tube flow

摘要

Research on turbulent heat transfer of liquid metals has been lasting for decades since 1940s. Although it had developed various heat transfer relations of liquid metals, most of them are based on the structure of semi-empirical correlation proposed by Lyon in 1949 and fitted according to their respective experimental data. Due to the differences between the experimental data, there are inevitably obvious differences between the empirical correlations, especially in the range of high Peclet numbers. Therefore, reliable relation for turbulent heat transfer of liquid metals is still missing. Focused on this problem, a theoretical analysis of heat transfer for liquid metals in a fully developed turbulent tube flow has been performed following the method of Lyon, but use the velocity and vortex flow diffusivity profile obtained by theoretical analysis. Based on a reasonably determined turbulent Prandtl number, a theoretical heat transfer relation for liquid metals is obtained and validated with experimental data of various liquid metals. The most difference between the theoretical relation and existing relations is the "thermal conductive term" of theoretical relation has a relationship with the Peclet number, while for most of the existing relations this term is constant. Further, it reveals the turbulent Prandtl number has significant impacts on turbulent heat transfer of liquid metals while the molecular Prandtl number has little impact. Therefore, the turbulent heat transfer of Heavy Liquid Metals (HLM) is different from other liquid metals because their turbulent Prandtl number is found to be larger than other liquid metals by existing research.