COOLING SYSTEM, AND COOLING METHOD OF REFRIGERANT

PROBLEM TO BE SOLVED: To provide a cooling system and a cooling method of a refrigerant that minimize a cooling cost using a plurality of kinds of refrigerant cooling units.SOLUTION: A cooling system 10 includes: a refrigerant storage 20 for storing a refrigerant to cool an object 110 to be cooled; a plurality of kinds of refrigerant cooling units 31 each of which is connected to the refrigerant storage 20 via a circulation passage 32 and is fed from a different power source; and a control unit 40. The control unit 40 actuates a necessary number of refrigerant cooling units 31 for keeping the refrigerant stored in the refrigerant storage 20 at a predetermined temperature or below in the order of refrigerant cooling units 31 with smaller refrigerant cooling unit prices calculated based on a temperature of a refrigerant flowing into each refrigerant cooling unit 31, a temperature of a refrigerant flowing from each refrigerant cooling unit 31, a flow rate of a refrigerant in each circulation passage 32, an amount of power to be fed to each refrigerant cooling unit 31, and a unit price of power.