METHOD FOR PRODUCING HEAT STORAGE MATERIAL BASED ON CALCIUM-POTASSIUM NITRATE DOUBLE SALT TRIHYDRATE (VERSIONS) Russian patent published in 2023 - IPC C09K5/06 

FIELD: thermal power engineering and chemical technology.

SUBSTANCE: invention relates to thermal power engineering and chemical technology, in particular, to the field of heat-saving and energy-saving technologies. A method for obtaining a heat storage material based on calcium-potassium nitrate double salt trihydrate is proposed, characterized in that according to the first variant of the method, calcium-potassium nitrate double salt trihydrate KNO₃⋅Ca(NO₃)₂⋅3Н₂O is heated to a temperature of 65°C and its subsequent melting for an hour with constant stirring, barium sulfate is introduced into the resulting KNO₃⋅Ca(NO₃)₂⋅3Н₂O melt in a ratio of 0.1 wt.% to the melt mass, the mixture is further stirred for 30 minutes with a temperature control of 65°C. According to the second version of the method, calcium nitrate tetrahydrate Ca(NO₃)₂⋅4Н₂O is added to the trihydrate of the double salt of calcium-potassium nitrates KNO₃⋅Ca(NO₃)₂⋅3Н₂O in a mass ratio of (75-99):(1-25) wt.%, respectively , the mixture is heated to a temperature of 65°C and its subsequent melting for an hour with constant stirring.

EFFECT: proposed variants of the method make it possible to obtain a heat storage material with a phase transition temperature that ensures the performance of the material in the range of 50-60°C, stable during long-term use in melting/crystallization cycles, with a melting enthalpy of 122-134 J/g at a melting temperature of 51°C, melt density at 60°C 1.84-1.85 g/cm3, supercooling not higher than 3°C.

2 cl, 12 dwg, 1 tbl