Turbo chiller

Abstract

A turbo chiller that has an oil-free configuration, which reduces the frequency of maintenance and maintenance-induced release of refrigerant, and can achieve a reduced environmental impact by utilizing the characteristics of the low-pressure refrigerant R1233zd(E) that reaches negative pressure at a saturation temperature of 18° C. or lower. The turbo chiller comprises a refrigeration cycle that includes a turbo compressor, a condenser, a decompression device, and an evaporator connected in sequence via piping and is filled with a refrigerant; wherein the refrigerant is a low-pressure refrigerant R1233zd(E) refrigerant with low global warming potential and low ozone depletion potential; the turbo compressor has a direct drive configuration in which a rotating shaft of impellers is directly joined to a motor; and the rotating shaft is supported by magnetic bearings.

1 . A turbo chiller comprising:
 a closed refrigeration cycle that includes a turbo compressor, a condenser, a decompression device, and an evaporator connected in sequence via piping and is filled with a refrigerant; wherein   the refrigerant is a low-pressure refrigerant R1233zd(E) refrigerant with low global warming potential and low ozone depletion potential;   the turbo compressor has a direct drive configuration in which a rotating shaft of an impeller is directly joined to a motor; and   the rotating shaft is supported by a magnetic bearing.   
     
     
         2 . A turbo chiller comprising:
 a closed refrigeration cycle that includes a turbo compressor, a condenser, a decompression device, and an evaporator connected in sequence via piping and is filled with a refrigerant; wherein   the refrigerant is a low-pressure refrigerant R1233zd(E) refrigerant with low global warming potential and low ozone depletion potential;   the turbo compressor has a direct drive configuration in which a rotating shaft of an impeller is directly joined to a motor; and   the rotating shaft is supported by an oil-free ceramic bearing.   
     
     
         3 . The turbo chiller according to  claim 1 , wherein a liquid refrigerant from the refrigeration cycle can be circulated as a cooling and lubricating medium for at least one of a bearing housing of the bearing and an air gap of the motor. 
     
     
         4 . The turbo chiller according to  claim 1 , wherein, a low-pressure gas refrigerant from the refrigeration cycle can be circulated as a cooling and lubricating medium for an air gap of the motor. 
     
     
         5 . The turbo chiller according to  claim 3 ,
 wherein a helical groove which allows the liquid refrigerant supplied to the air gap of the motor to flow axially outward is provided on at least one of an inner peripheral surface of a stator of the motor, an outer peripheral surface of a rotor, and an outer peripheral surface of a balance ring provided on an end surface of the rotor.   
     
     
         6 . The turbo chiller according to  claim 4 , wherein a helical groove which allows the low-pressure gas refrigerant supplied to the air gap of the motor to flow axially outward is provided on at least one of an inner peripheral surface of a stator of the motor, an outer peripheral surface of a rotor, and an outer peripheral surface of a balance ring provided on an end surface of the rotor. 
     
     
         7 . The turbo chiller according to  claim 2 , wherein a liquid refrigerant from the refrigeration cycle can be circulated as a cooling and lubricating medium for at least one of a bearing housing of the bearing and an air gap of the motor. 
     
     
         8 . The turbo chiller according to  claim 2 , wherein a low-pressure gas refrigerant from the refrigeration cycle can be circulated as a cooling and lubricating medium for an air gap of the motor. 
     
     
         9 . The turbo chiller according to  claim 7 , wherein a helical groove which allows the low-pressure gas refrigerant supplied to the air gap of the motor to flow axially outward is provided on at least one of an inner peripheral surface of a stator of the motor, an outer peripheral surface of a rotor, and an outer peripheral surface of a balance ring provided on an end surface of the rotor. 
     
     
         10 . The turbo chiller according to  claim 8 , wherein a helical groove which allows the liquid refrigerant supplied to the air gap of the motor to flow axially outward is provided on at least one of an inner peripheral surface of a stator of the motor, an outer peripheral surface of a rotor, and an outer peripheral surface of a balance ring provided on an end surface of the rotor.