Compression system and clothing treatment device including same

A clothing treatment device comprising:

• a washing unit that is supplied with a refrigerant and performs washing of laundry;
• a distillation unit comprising a shell forming, inside the shell, a distillation space for receiving the refrigerant which is discharged from the washing unit and comprising a heater positioned inside the shell to heat the refrigerant received in the distillation space;
• a compression system for compressing the refrigerant which is distilled in the distillation space and supplying the refrigerant to the heater;
• a freezing unit that freezes the refrigerant which is discharged from the heater;
• and
• a storage unit that stores the refrigerant which is liquefied by the freezing unit,
• wherein the compression system comprises:
• a compressor configured to compress and discharge a refrigerant and comprising a refrigerant inflow port through which the refrigerant flows in and an oil recovery port for recovering oil;
• a plurality of oil separator configured to separate the oil which is included in the refrigerant discharged from the compressor and comprising a first oil separator into which the refrigerant discharged from the compressor flows and a second oil separator connected to the first oil separator in series along a travelling path of the refrigerant;
• a first recovery pipe configured to recover the oil from the first oil separator to the oil recovery port;
• and
• a second recovery pipe configured to recover the oil from the second oil separator to the refrigerant inflow port.