Experimental study on optimized composition of mixed carbonate salt for sensible heat storage in solar thermal power plant

Thirty six kinds of mixed carbonate molten salts were prepared by mixing potassium carbonate, lithium carbonate, sodium carbonate in accordance with different proportions. The data of melting point, decomposition temperature, specific heat are measured by the analysis of the TGA and DSC curves of 36 kinds of salts, which show that melting points of major ternary carbonate are close at around 400 °C and decomposition temperatures of most ternary carbonate are between 800 and 850 °C. Twleve kinds of eutectic molten salts with low melting point were selected among 36 kinds of salts. The correlations of the eutectic salts between specific heat and temperature were obtained by fitting the experimental data of specific heat. The costs for sensible heat storage of 12 kinds of carbonate salts are obtained. The optimum preparation ratio is recommended for sensible heat storage.

► Thirty six kinds of mixed Carbonate molten salts were prepared.
► The data of melting point, decomposition temperature, specific heat are measured.
► Twelve kinds of eutectic molten salts with low melting point were selected.
► The correlations between specific heat and temperature were obtained.
► The optimum preparation ratio is recommended for sensible heat storage.