Turbo refrigerator

Abstract

A turbo refrigerator includes a condenser that cools and liquefies a compressed refrigerant, an evaporator that vaporizes the liquefied refrigerant and takes away heat of vaporization from a cooling object, thereby cooling the cooling object, and a turbo compressor that compresses the refrigerant vaporized by the evaporator by rotation of an impeller driven to rotate by an electric motor, and supplies the compressed refrigerant to the condenser. Moreover, the turbo refrigerator includes a braking device that operates the electric motor as a generator when the impeller is urged to rotate by the vaporized refrigerant, so as to brake the rotation of the impeller.

1 . A turbo refrigerator comprising:
 a condenser that cools and liquefies a compressed refrigerant;   an evaporator that vaporizes the liquefied refrigerant and takes away heat of vaporization from a cooling object, thereby cooling the cooling object;   a turbo compressor that compresses the refrigerant vaporized by the evaporator by rotation of an impeller driven to rotate by an electric motor, and supplies the compressed refrigerant to the condenser; and   a braking device that operates the electric motor as a generator when the impeller is urged to rotate by the vaporized refrigerant, so as to brake the rotation of the impeller.   
     
     
         2 . The turbo refrigerator according to  claim 1 , wherein the braking device has a regeneration circuit that recovers electrical energy generated by the electric motor. 
     
     
         3 . The turbo refrigerator according to  claim 1 , wherein the braking device has a resistance circuit that converts the electrical energy generated by the electric motor into heat energy. 
     
     
         4 . The turbo refrigerator according to  claim 2 , wherein the braking device has a resistance circuit that converts the electrical energy generated by the electric motor into heat energy.