Abstract In this study, an experiment was conducted to obtain the heat flux and heat transfer coefficient of a mixed molten salt (60% NaNO3, 40% KNO3) and water at subcritical pressure in a tube in tube heat exchanger. The control variable method was used in this study. Experimental parameters covered the molten salt and water flow fluxes of 283.1–305.9 kg/m2s, 38.7–64.4 kg/m2s, the water pressures of 15–19 MPa, the water and molten salt inlet temperature of 260 °C/ 360–560 °C, and heat fluxes of 43–266 kW/m2, respectively. The heat transfer performance of molten salt and water in the single-phase and subcooled boiling regions were analysed with respect to molten salt flow fluxes and inlet temperature, water flow fluxes and pressure. Based on the experimental data, the heat transfer characteristics of molten salt to subcooled water was compared to the classical Grimson correlation, with a maximum deviation of −20%. Finally, the fitting correlation of the thermal performance of molten salt to the subcooled boiling water was presented, the fitting values demonstrated good consistency with the experimental data, with a maximum deviation of –10%.

中文翻译：

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熔盐对过冷沸水传热特性的实验研究

摘要 本研究通过实验获得了管式换热器管内亚临界压力下混合熔盐（60% NaNO3、40% KNO3）和水的热通量和传热系数。本研究采用控制变量法。实验参数涵盖熔盐和水流通量283.1-305.9 kg/m2s、38.7-64.4 kg/m2s，水压15-19 MPa，水和熔盐入口温度260°C/360-560° C 和热通量分别为 43–266 kW/m2。从熔盐流通量和入口温度、水流通量和压力等方面分析了熔盐和水在单相和过冷沸腾区的传热性能。根据实验数据，熔盐到过冷水的传热特性与经典的 Grimson 相关性进行了比较，最大偏差为 -20%。最后，给出了熔盐热性能与过冷沸水的拟合关系，拟合值与实验数据具有良好的一致性，最大偏差为–10%。