COST REDUCTION AND PERFORMANCE IMPROVEMENT OF LOW MELTING POINT MOLTEN SALTS FOR HIGH TEMPERATURE HEAT TRANSFER AND STORAGE
19 kinds of binary mixed molten salts with different ratio have been prepared and a low melting point binary
molten salt was obtained, the melting point and decomposition point of which are 117°C and 561°C respectively, and the melting point is much lower compared with the current commonly used Salt Solar and Hitec salt.
Thermal physical tests and X-ray diffraction (XRD) tests of sampling at different stages under 500 °C constant
temperature for 1200 hours were carried out, the results show that the variation rate of the thermal physical
properties of the mixed molten salt before and after the experiment is within ±10%; there is no metamorphism
after 1200h high-constant temperature test. Based on the original preparation of the low melting point quaternary
nitrates (KNO3-NaNO3-LiNO3-Ca(NO3)2.4H2O), 16 formulations were prepared by replacing lithium nitrate
by low cost additive., a low cost and low melting point quaternary salts was obtained, and its specific heat and
latent heat of fusion were tested. Results show that its melting point and decomposition point is 90.4°C and 688°C respectively. Compared with Solar salt, low melting point salt (K:Na:Ca:Li NO3) increases thermal storage density by 58%, but increase thermal storage cost by 15%. low melting point salt (K:Na:CaNO3:additive) increases thermal storage density by 98%, and reduce thermal storage cost by 51%. Binary low melting point salts increases thermal storage density by 19%, and reduce thermal storage cost by 22%.