Optimization of thermophysical properties of molten salt-based date-occupied composites based on orthogonal tests

Molten salt is an efficient thermal storage material with broad applications in energy storage and transmission. In this paper, a molten salt-based date-occupied composite model was constructed using NaaCOs-KaCOs as the base molten salt, combined with high-performance SiOananoparticles. Based on the molecular dynamics (MD) method and a three-factor, five-level orthogonal experimental design, the effects of temperature, nanoparticle radius, and molten salt ratio on the thermal conductivity and viscosity of the composites were systematically studied. The results showed that the molar percentage of carbonate and the nanoparticle radius were the main factors affecting thermal conductivity, with Ftest values of 132.6 and 43.07, respectively; temperature had the most significant impact on viscosity. Meanwhile, increasing NaaCOs content significantly enhanced the viscosity of the composites at larger nanoparticle radii. The proposed objective function offers a theoretical foundation for optimizing the balance between thermal conductivity and viscosity. This balance is especially crucial during the periodic heat storage and release process, playing a key role in the development and application of new heat storage materials.