HEAT STORAGE COMPOSITION BASED ON ZINC NITRATE HEXAHYDRATE AND COBALT NITRATE HEXAHYDRATE Russian patent published in 2023 - IPC C09K5/06 C01G3/00 C01G51/00 

FIELD: heat storage materials.

SUBSTANCE: invention is related to materials capable of storing and dissipating heat due to phase transition processes and can be used in air conditioning and heating systems, including car interiors. The heat storage composition is based on zinc and cobalt hexahydrates with the addition of expanded graphite (EG) and carboxymethyl cellulose (CMC) or polyvinyl alcohol (PVA). The invention proposes the following formulations: 1: (95 wt.% of Zn(NO₃)2rpm 6H₂O + 5 wt.% of Co(NO₃)₂⋅6H₂O) followed by the addition of 1 wt.% of CMC + 1 wt.% of EG; 2: (93 wt.% of Zn(NO₃)₂⋅6H₂O + 7 wt.% of Co(NO₃)₂⋅6H₂O) followed by the addition of 1 wt.% of PVA + 1 wt.% of EG; 3. (93 wt.% of Zn(NO₃)₂⋅6H₂O + 7 wt.% of Co(NO₃)₂⋅6H₂O) followed by the addition of 5 wt.% of CMC + 1 wt.% of EG. The mixture is prepared by heating a mixture of Zn(NO₃)₂⋅6H₂O and Co(NO₃)₂⋅6H₂O at 60°C followed by melting for 30 minutes, holding for 10 minutes and successive introduction of additives to the mixture, then the mixture is stirred for 3 hours at 60°C. The proposed composition has improved stability due to a long accumulation time, constant crystallization temperature, low supercooling, as well as improved thermal cycling properties, such as the heat capacity of the solid and liquid phases, accumulation density, and enthalpy of the liquid phase.

EFFECT: resulting material does not have phase segregation and does not have excessive supercooling, which is confirmed in the process of thermal cycling under practical operating conditions with natural cooling.

1 cl, 10 dwg, 3 tbl, 3 ex