Refrigeration apparatus

Abstract

A refrigerant circuit ( 11 ) includes an oil separator ( 60 ) configured to separate oil from high pressure refrigerant, and an oil feed circuit ( 70 ) configured to feed the oil separated in the oil separator ( 60 ) to a compression mechanism ( 20 ) so as to cool the refrigerant in the course of a compression phase of the compression mechanism ( 20 ). The oil feed circuit ( 70 ) includes a recovery mechanism ( 40 ) configured to recover energy of the oil separated in the oil separator ( 60 ). In the compression mechanism ( 20 ), the refrigerant is cooled by the oil, thereby reducing power of the compression mechanism ( 20 ). Simultaneously, in the recovery mechanism ( 40 ), power required to increase pressure of the oil in the compression mechanism ( 20 ) is recovered.

1 . A refrigeration apparatus comprising:
 a refrigerant circuit which includes a compression mechanism connected thereto, and performs a refrigeration cycle, wherein   the refrigerant circuit includes an oil separating section configured to separate oil from high pressure refrigerant compressed in the compression mechanism, and an oil feed circuit configured to feed the oil separated in the oil separating section to the compression mechanism so as to cool the refrigerant in the course of a compression phase of the compression mechanism, and   the oil feed circuit includes a recovery mechanism configured to recover energy of the oil flowing in the oil feed circuit.   
     
     
         2 . The refrigeration apparatus of  claim 1 , wherein
 the oil feed circuit feeds the oil to the compression mechanism in such a manner that the refrigerant is isothermally compressed for at least part of a period of the compression phase of the compression mechanism.   
     
     
         3 . The refrigeration apparatus of  claim 1  or  2 , wherein
 the refrigerant circuit is configured to perform a refrigeration cycle in which the refrigerant is compressed in the compression mechanism to a critical pressure.   
     
     
         4 . The refrigeration apparatus of  claim 1  or  2 , wherein
 the oil feed circuit is configured to feed the oil in the course of the compression phase of the compression mechanism.   
     
     
         5 . The refrigeration apparatus of  claim 1  or  2 , wherein
 the oil feed circuit is configured to feed the oil to a suction side of the compression mechanism.   
     
     
         6 . The refrigeration apparatus of  claim 1  or  2 , wherein
 the recovery mechanism includes a movable part which is driven to rotate by the oil, and an output shaft coupled to the movable part.   
     
     
         7 . The refrigeration apparatus of  claim 6 , wherein
 the compression mechanism is coupled to, and is driven by the output shaft of the recovery mechanism.   
     
     
         8 . The refrigeration apparatus of  claim 6 , wherein
 the refrigerant circuit includes an expansion mechanism having a movable part which is driven to rotate by the refrigerant, and is coupled to the output shaft of the recovery mechanism.   
     
     
         9 . The refrigeration apparatus of  claim 6 , further comprising:
 a power generator which is coupled to, and is driven by the output shaft of the recovery mechanism.   
     
     
         10 . The refrigeration apparatus of  claim 1  or  2 , wherein
 an oil cooling heat exchanger configured to cool the oil separated in the oil separating section is connected to the oil feed circuit.   
     
     
         11 . The refrigeration apparatus of  claim 10 , wherein
 the refrigerant circuit includes an indoor heat exchanger placed inside a room, and is configured to perform heating operation of heating room air by the refrigerant flowing in the indoor heat exchanger, and   the oil cooling heat exchanger is placed inside the room, and is configured to dissipate heat of the oil into the room air in the heating operation.   
     
     
         12 . The refrigeration apparatus of  claim 10 , wherein
 the refrigerant circuit includes an indoor heat exchanger placed inside a room, and is configured to perform heating operation of heating room air by the refrigerant flowing in the indoor heat exchanger, and cooling operation of cooling the room air by the refrigerant flowing in the indoor heat exchanger in a switchable manner, and   the oil feed circuit includes a first oil cooling heat exchanger which is placed inside the room, and dissipates heat of the oil into the room air in the heating operation, and a second oil cooling heat exchanger which is placed outside the room, and dissipates the heat of the oil into outside air in the cooling operation, both of which are connected to the oil feed circuit.