Molten salts have the advantages of a wide range of liquid temperatures and high heat storage capacity, which have been widely used in the field of solar thermal utilization. The significant disadvantage of molten salts is their low thermal conductivity, and the addition of nanoparticles can effectively enhance the heat transfer ability of molten salts. In this paper, novel composite molten salt materials are prepared by adding zero-dimensional Al2O3 nanoparticles, one-dimensional multi-walled carbon nanotubes, and two-dimensional graphene nanosheets with different combinations of multidimensional nanoparticles, respectively, using ternary carbonates as the base salt. The thermal diffusivity of the composite carbonates in the liquid state was measured by the laser flash method at different temperatures to analyze the effect of multidimensional nanoparticles on the thermophysical properties of ternary carbonates. The experimental results show that zero-dimensional alumina nanoparticles and two-dimensional graphene sheets have a synergistic strengthening effect. With the addition of zero-dimensional alumina nanoparticles and an additional 0.5% mass fraction of two-dimensional graphene nanosheets, the thermal diffusivity of the composite carbonate can be enhanced by a maximum of 54.08%, and the prepared composite carbonate has a better stability.
Keywords nanoparticles, molten salts, heat transfer enhancement, thermal diffusivity