COLD STORAGE METHOD AND SYSTEM EMPLOYING INCLUSION HYDRATE AND COLD STORAGE AGENT

摘要

PROBLEM TO BE SOLVED: To stabilize thermal characteristics while enhancing economy and safety and facilitating handling by preparing an aqueous solution where the concentration of an inclusion hydrate producing substance is set at a level for providing a congruent melting point and cooling the aqueous solution to produce an inclusion hydrate thereby increasing the heat storage density of a heat storage material. SOLUTION: As shown on the drawing, an aqueous solution containing an inclusion hydrate producing substance has a maximum melting point of 11.8 deg.C at about 40% concentration. Melting point at that concentration is referred to a congruent melting point where the concentration of aqueous solution is equal to the salinity concentration of the inclusion hydrate. When an aqueous solution having concentration set at a level for providing the congruent melting point is used for cooling, the inclusion hydrate begins to be produced at the congruent melting point (11.8 deg.C) which is sustained until the inclusion hydrate occupies the aqueous solution entirely. Cold heat is emitted at the constant melting point at the time of decomposition (melting). Latent heat is about 46 kcal/kg and when upper limit temperature is 12 deg.C, volumetric ratio of hydrate is 56% and heat storage density is 26 kcal/kg.