Freezing apparatus

Abstract

A freezing apparatus according to the present disclosure operates while switching the gas cooler used, the freezing apparatus comprising: a refrigerant circuit which is composed of a low-stage compression mechanism, a water-cooled intercooler that cools a refrigerant discharged from the low-stage compression mechanism, a high-stage compression mechanism that suctions and compresses the refrigerant that has passed through the water-cooled intercooler, a water-cooled gas cooler and an air-cooled gas cooler that cool the refrigerant discharged from the high-stage compression mechanism, an expansion mechanism, and an evaporator; and an injection circuit which connects a refrigerant pipe on the upstream side of the expansion mechanism and a suction refrigerant pipe of the high-stage compression mechanism via an injection expansion mechanism.

1 . A refrigeration device that operates while switching a gas cooler to be used, the refrigeration device comprising:
 a refrigerant circuit that is constituted by a low-stage compression mechanism, a water-cooling-type intercooler that cools a refrigerant that has been discharged from the low-stage compression mechanism, a high-stage compression mechanism that draws in and compresses a refrigerant that has passed through the water-cooling-type intercooler, a water-cooling-type gas cooler and an air-cooling-type gas cooler that cool the refrigerant that has been discharged from the high-stage compression mechanism, an expansion mechanism, and an evaporator; and   an injection circuit in which a refrigerant pipe on an upstream side of the expansion mechanism and an intake refrigerant pipe of the high-stage compression mechanism are connected to each other via an injection-use expansion mechanism.   
     
     
         2 . The refrigeration device according to  claim 1 , further comprising:
 a discharged gas temperature sensor that detects a temperature of the refrigerant that has been discharged from the high-stage compression mechanism, wherein   the injection-use expansion mechanism is controlled based on the temperature of the refrigerant that has been discharged from the high-stage compression mechanism.   
     
     
         3 . The refrigeration device according to  claim 1 , further comprising:
 a subcooling heat exchanger that causes the refrigerant that has passed through the water-cooling-type gas cooler or the air-cooling-type gas cooler to exchange heat with the refrigerant that has passed through the injection-use expansion mechanism.   
     
     
         4 . The refrigeration device according to  claim 1 , wherein
 the refrigeration device is a refrigeration device that cools a showcase,   the refrigeration device includes an opening portion at a front side of a portion below the showcase, and   air that is taken in through the opening portion is caused to flow into the air-cooling-type gas cooler to thereby cool the refrigerant.   
     
     
         5 . The refrigeration device according to  claim 1 , wherein
 carbon dioxide is used as the refrigerant.