Air conditioner

An air conditioner comprising:

• a plurality of compressors for compressing refrigerant;
• a condenser for condensing the refrigerant discharged from the compressors;
• an expansion mechanism for expanding the refrigerant discharged from the condenser;
• an evaporator for evaporating the refrigerant passing through the expansion mechanism;
• and a four-way valve for guiding flow of the refrigerant according to heating operation mode or cooling operation mode, wherein the air conditioner further comprises:
• an oil separator mounted on a confluent discharging channel, which is connected to discharging channels provided at the respective compressors for guiding the refrigerant discharged through the discharging channels to the condenser, for separating oil from the refrigerant;
• and
• an oil collection pipe for guiding the oil separated by the oil separator to the inlets of the respective compressors.

An air conditioner comprising:

• a plurality of compressors for compressing refrigerant;
• a condenser for condensing the refrigerant discharged from the compressors;
• an expansion mechanism for expanding the refrigerant discharged from the condenser;
• an evaporator for evaporating the refrigerant passing through the expansion mechanism;
• and a four-way valve for guiding flow of the refrigerant according to heating operation mode or cooling operation mode, wherein the air conditioner further comprises:
• an oil separator mounted on a confluent discharging channel, which is connected to discharging channels provided at the respective compressors for guiding the refrigerant discharged through the discharging channels to the condenser, for separating oil from the refrigerant;
• an oil collection pipe for guiding the oil separated by the oil separator to the inlets of the respective compressors;
• an electronic expansion valve mounted on the oil collection pipe for opening/closing the oil collection pipe;
• a controller for controlling the opening level of the electronic expansion valve;
• and
• check valves mounted on the respective discharging channels for preventing back-flow of the compressed refrigerant.