An air conditioning system comprising: a phase separator arranged to separate a gaseous refrigerant and a liquid refrigerant from a flowing refrigerant; an evaporator arranged to evaporate the liquid refrigerant separated by the phase separator; and at least one compressor comprising: a first compressing part arranged to receive the refrigerant via the evaporator; and a second compressing part arranged to receive both of the gaseous refrigerant separated by the phase separator and the refrigerant via the first compressing part, wherein the phase separator comprises: a storage container for storing the gaseous and liquid refrigerants mixed with each other therein; a mixed refrigerant pipe connecting part for guiding the mixed refrigerant to the storage container; a first refrigerant pipe connecting part for discharging the separated gaseous refrigerant; and a second refrigerant pipe connecting part for discharging the separated liquid refrigerant, characterised in that each of a lower end portion of the mixed refrigerant pipe connecting part and a lower end portion of the second refrigerant pipe connecting part is bent in a circumferential direction along a lower wall of the storage container such that refrigerant introduced into the storage container rotate and flow along the lower wall of the storage container. a phase separator arranged to separate a gaseous refrigerant and a liquid refrigerant from a flowing refrigerant; an evaporator arranged to evaporate the liquid refrigerant separated by the phase separator; and at least one compressor comprising: a first compressing part arranged to receive the refrigerant via the evaporator; and a second compressing part arranged to receive both of the gaseous refrigerant separated by the phase separator and the refrigerant via the first compressing part, a first compressing part arranged to receive the refrigerant via the evaporator; and a second compressing part arranged to receive both of the gaseous refrigerant separated by the phase separator and the refrigerant via the first compressing part, wherein the phase separator comprises: a storage container for storing the gaseous and liquid refrigerants mixed with each other therein; a mixed refrigerant pipe connecting part for guiding the mixed refrigerant to the storage container; a first refrigerant pipe connecting part for discharging the separated gaseous refrigerant; and a second refrigerant pipe connecting part for discharging the separated liquid refrigerant, a storage container for storing the gaseous and liquid refrigerants mixed with each other therein; a mixed refrigerant pipe connecting part for guiding the mixed refrigerant to the storage container; a first refrigerant pipe connecting part for discharging the separated gaseous refrigerant; and a second refrigerant pipe connecting part for discharging the separated liquid refrigerant, characterised in that each of a lower end portion of the mixed refrigerant pipe connecting part and a lower end portion of the second refrigerant pipe connecting part is bent in a circumferential direction along a lower wall of the storage container such that refrigerant introduced into the storage container rotate and flow along the lower wall of the storage container.