Cold storage agent, cold storage body containing the cold storage agent, cold storage device using the cold storage body, cold storage method, and BOG reliquefaction method

摘要

PROBLEM TO BE SOLVED: To store cold due to a phase change in a specific cryogenic tempera ture area by mixing CH2 FCF3 with CHF3 so as to have molar fraction within a specific range. SOLUTION: A preasure vessel 10 is filled with a cold storage medium 1 to form a cold storage body. In this case, as the cold storage medium 1, is used a mixture obtain by mixing CH2 FCF3 (HFC-134a) and CHF3 (HFC-23) so that the molar fraction of each component is 0.8 to 0.4/0.2 to 0.6. The mixture of HFC-134a and HFC-23 forms an eutectic. Thus, a liquid state is maintained at cryogenic temperature not higher than-100 deg.C because of the fall of a melting point and a large quantity of cold can be efficiently stored under the phase change of freezing and melting. The material and the wall thickness of the pressure vessel 10 are selected so as to endure the repetition of cooling and heating between the cryogenic temperature not higher that-100 deg.C and normal temperature for a long period.