Refrigerator

A refrigerator comprising:

• a first compressor configured to compress first refrigerant;
• a first condenser configured to condense the first refrigerant compressed by the first compressor;
• a first expansion valve configured to reduce a temperature and a pressure of the first refrigerant condensed by the first condenser;
• a first evaporator configured to evaporate the first refrigerant having passed through the first expansion valve;
• a second compressor configured to compress second refrigerant;
• a second condenser configured to condense the second refrigerant compressed by the second compressor;
• a second expansion valve configured to reduce a temperature and a pressure of the second refrigerant condensed by the second condenser;
• a second evaporator configured to evaporate the second refrigerant having passed through the second expansion valve;
• a first heat exchanger arranged after and connected to the first expansion valve;
• and
• a second heat exchanger arranged after and connected to the second expansion valve,
• wherein the first heat exchanger and the second heat exchanger are configured to exchange heat with each other,
• wherein the first heat exchanger is configured to evaporate the first refrigerant, and
• wherein the second heat exchanger is configured to reduce the temperature of the second refrigerant based on the first heat exchanger evaporating the first refrigerant.