ABSTRACT

Molten salts are used as heat transfer fluids (HTFs) as well as thermal storage materials in high-temperature energy generation, storage, and transmission applications. However, molten salts, in general, present low thermal properties compared to lower-temperature fluids such as water and glycols. Molten salt–based nanofluids (NFs) are of particular interest because they can improve both thermal conductivity and heat capacity of the base fluid. In addition, they are of great interest in the thermal engineering community due to their potential uses in concentrated solar power applications as HTFs as well as thermal storage materials. However, a limited number of papers about this topic have been published due to the difficulties found in high-temperature NF characterization and stabilization. In this regard, the mechanism underlying the enhancement of these thermal properties is still a matter of controversy, and no theoretical model or experimental evidence is available at this moment. In addition, only small-scale laboratory experiments have been performed so far, and neither the effect of adding nanoparticles to other important requirements of salts (corrosion, thermal cycling stability, etc.) nor full validation in the laboratory environment has been evaluated. Despite these limitations, the importance of molten salt–based NF potential applications is increasing the research efforts in this research topic.