HEAT STORAGE COMPOSITION BASED ON A MIXTURE OF CRYSTALLINE HYDRATES OF NICKEL AND CHROMIUM NITRATES Russian patent published in 2023 - IPC C09K5/06 

FIELD: heat-saving and energy-saving technologies.

SUBSTANCE: invention can be used for the accumulation and storage of thermal energy in heating systems, including car interiors. Heat storage composition based on a mixture of crystalline hydrates of nickel and chromium nitrates, consisting of a mixture of 74 wt.% nickel nitrate hexahydrate Ni(NO₃)₂·6H₂O and 26 wt.% chromium nitrate nonahydrate Cr(NO₃)₂·9H₂O with additions of 1 wt.% carboxymethylcellulose and 1 wt.% expanded graphite with respect to a 100% mixture of nickel nitrate hexahydrate and chromium nitrate nonahydrate, characterized by stability during thermal cycling and a phase transition temperature between 45 and 55°C, which ensures the performance of the composition as a heat storage material, prepared by melting a mixture of crystalline hydrates of nickel and chromium nitrates for 30 min with constant stirring until complete melting, holding for 10 min and successive addition of carboxymethyl cellulose and expanded graphite, after which stirring is continued for three hours maintaining the temperature at 80°C.

EFFECT: proposed composition makes it possible to achieve the stability of the material and its properties during thermal cycling, the absence of phase segregation in the phase-transition heat-storing material, which is confirmed in the process of thermal cycling under practical operating conditions with natural cooling.

1 cl, 3 dwg, 2 tbl