Experimental heat transfer performance of a drainage-integrated fluoride salt-to-salt heat exchanger

作者：Qi-Ming Li, Yao Fu, Jian Tian, Chong Zhou, Yang Zou, Yuan Fu, Jie Hou, Xiaohan Yu, Hongjie Xu · 发表于：Results in Engineering · 年份：2025 · DOI：10.1016/j.rineng.2025.107206 · 被引用次数：3 · 研究领域：Geothermal Energy Systems and Applications、Heat Transfer and Optimization、Adsorption and Cooling Systems

• First experimental validation of a drainage-integrated SSHX under prototypical MSR conditions. • Development of revised heat transfer correlations for both tube-side and shell-side fluoride salt flow. • Compact drainage ports enable complete salt evacuation without significant heat transfer degradation. • Comparison with classical heat transfer models identifies best-fit correlation for engineering application. This study experimentally investigates a novel shell-and-tube fluoride Salt-to-Salt Heat Exchanger (SSHX) with triangular drainage ports integrated into segmental baffles to enable complete passive drainage. Utilizing a scaled experimental platform with fluoride salt as the working fluid, a tube-side heat transfer correlation was derived as Nu = 0.0246 Re 0.8 Pr 0.267 ( Re = 9000–15,000, Pr = 8–12), demonstrating excellent agreement with experimental data, within a maximum deviation of 5 %. Comparative analysis revealed that the modified Dittus-Boelter equation remains a suitable model for predicting fluoride salt convective heat transfer behavior in tubular geometries. It outperformed both the Gnielinski and Sieder-Tate models, which overpredicted Nu by 17–25 %. Shell-side heat transfer was accurately predicted by a Kern correlation enhanced by 31 % ( ε = 1.31), with errors ranging from -6.0 % to 7.0 %. The drainage ports demonstrated a negligible impact on thermal performance while effectively eliminating molten salt retention risks. These findings provide essentia...