Patent ID: 8820103

Claim:
An air conditioner comprising: a plurality of compressors; discharge pipes to discharge a fluid compressed in the plurality of compressor; oil separators connected to the discharge pipes to separate oil from the fluid; oil recycle pipes to introduce the oil to the plurality of compressors; an intake passageway configured to distribute the fluid to each of the compressors; a bypass unit to guide the fluid from the plurality of compressors to the intake passageway, the bypass unit including: a plurality of bypass pipes connected respectively to the compressors to discharge the fluid from the compressors; a common bypass pipe to connect the plurality of bypass pipes with the intake passageway, the common bypass pipe being disposed between the plurality of bypass pipes and the intake passageway; depressurization parts installed at the plurality of bypass pipes to depressurize the fluid; and a plurality of temperature sensors configured to sense temperatures of the fluids discharged from the depressurizing parts, an expansion valve disposed between the common bypass pipe and the intake passageway to control a flow rate of fluid from the common bypass pipe to the intake passageway; a memory to store information of a reference refrigerant temperature range R 1 of the refrigerant discharged from the depressurizing parts and a reference oil balance temperature range R 2 of a mixed fluid of the refrigerant and oil discharged from the depressurizing parts, the R 2 being higher than the R 1 ; and a control part configured to control the operation of the expansion valve, based upon result of comparison of the temperature sensed at the temperature sensors with at least one of the R 1 or R 2 .