New molten salt heat transfer fluid for solar thermal power plant

In order to remove the oxidation of nitrite salt and reduce the cost of lithium nitrate relative to previously available materials, new molten salt heat transfer fluid (KCl-KNO₃-NaNO₃) is prepared by static fusion method. Eutectic point and component of molten salt are determined firstly from phase diagram that is calculated by using conformal ionic solution (CIS) theory. Then thermal stability of this mixture is investigated by thermo-gravimetric analysis (DSC-TGA) device. Experimental results show the agreement between measurements and calculations is found to be very good. This kind of molten salt has a lower melting point (210°C), compared to Solar Salt (220°C). It is thermally stable at temperatures up to 500°C, and may be used up to 550°C for short periods. So that was suitable for heat transfer and thermal storage medium.