Cooling system

A cooling system, comprising:

• a refrigerant circulator which circulates a refrigerant,
• wherein the refrigerant circulator comprises:
• a first compressor configured to pressurize the refrigerant in gaseous state;
• a first cooler configured to cool the refrigerant pressurized by the first compressor;
• a first gas-liquid separator configured to separate the refrigerant cooled by the first cooler into a first refrigerant flow of a gas component and a second refrigerant flow of a liquid component;
• a second compressor configured to pressurize the first refrigerant flow;
• a second cooler configured to cool the first refrigerant flow pressurized by the second compressor;
• a second gas-liquid separator configured to separate the refrigerant cooled by the second cooler into a third refrigerant flow of a gas component and a fourth refrigerant flow of a liquid component;
• a first expansion member configured to decompress the fourth refrigerant flow;
• an economizer configured to separate the fourth refrigerant flow decompressed by the first expansion member into a fifth refrigerant flow of a gas component and a sixth refrigerant flow of a liquid component;
• and
• a first circulation line configured to supply the fifth refrigerant flow separated by the economizer to the first gas-liquid separator;
• wherein the refrigerant is a mixed refrigerant.