Homogeneous molten salt formulations as thermal energy storage media and heat transfer fluid

Abstract

Homogeneous ternary and quaternary molten nitrate salts with low melting points (<110 °C) with enhanced thermo-physical properties were synthesized for thermal energy storage media and heat transfer fluids. The ternary and quaternary molten salts were synthesized by varying the contents of the individual salts. Specifically, one ternary mixture KNO3 (50%), NaNO2 (40%) & Ca (NO3)2 (10%) and two quaternary mixtures KNO3 (50.25%), NaNO2 (35.5%), LiNO3 (9.5%) & Ca (NO3)2.4H2O (4.75%) and KNO3 (50.25%), NaNO2 (35.5%), LiNO3 (4.75%) & Ca (NO3)2.4H2O (9.5%) were synthesized. Experimental results have shown that ternary and quaternary molten salts exhibiting melting point below 110 °C and higher thermal stability greater than 550 °C. Synthesized quaternary salts are showing high heat capacity, low viscosity at higher temperatures. Corrosion studies of synthesized salts shown that QUAT-1 is showing low corrosion compared to other formulations. Among three formulations, QUAT-1 salt has shown higher specific heat capacity and low viscosity, and lower corrosion rate.