High temperature properties of molten nitrate salt for solar thermal energy storage application

Molten alkali nitrate salts as a heat transfer and storage fluid is promising in concentrated solar power plants because of their negligible vapor pressure and optimum fluid velocity. A ternary sodium-potassium-lithium nitrate salt has been proposed using a thermo chemical package, which has low melting point (120.8°C) compared to binary solar salt (220°C). The purpose of this study is to increase the degradation limit of proposed ternary salt using oxygen as a cover gas to obtain broader operating temperature range (to increase the steam-Rankine cycle efficiency) and for potential use in thermal energy storage systems as a heat transfer fluid.