Refrigeration Apparatus

Abstract

In an air conditioner ( 10 ), a refrigerant adjustment tank ( 14 ) is disposed in a refrigerant circuit ( 11 ). The refrigerant adjustment tank ( 14 ) is disposed just after an expander ( 16 ). In the refrigerant circuit ( 11 ), a liquid injection line ( 31 ) and a gas injection line ( 33 ) are arranged. When a liquid side control valve ( 32 ) is placed in the open state, liquid refrigerant in the refrigerant adjustment tank ( 14 ) is supplied through the liquid injection line ( 31 ) to the suction side of a compressor ( 15 ). On the other hand, when a gas side control valve ( 34 ) is placed in the open state, gas refrigerant in the refrigerant adjustment tank ( 14 ) is supplied through the gas injection line ( 33 ) to the suction side of the compressor ( 15 ). The opening of the liquid and gas side control valves ( 32, 34 ) is controlled to thereby make a change in the state of refrigerant drawn into the compressor ( 15 ), whereby the amount of refrigerant passing through the compressor ( 15 ) and the amount of refrigerant passing through the expander ( 16 ) are balanced with each other.

1 . A refrigeration apparatus, equipped with a refrigerant circuit ( 11 ) in which an expander ( 16 ) for the recovery of power is connected, for performing a refrigeration cycle by causing refrigerant to circulate within the refrigerant circuit ( 11 ), the refrigeration apparatus comprising:
 (a) a refrigerant adjustment tank ( 14 ), disposed along a refrigerant circulation pathway extending from the expander ( 16 ) to a compressor ( 15 ) in the refrigerant circuit ( 11 ), for controlling the amount of refrigerant circulating in the refrigerant circuit ( 11 );   (b) a liquid injection passageway ( 31 ) for supplying liquid refrigerant in the refrigerant adjustment tank ( 14 ) to the suction side of the compressor ( 15 ); and   (c) a liquid flow rate control mechanism ( 32 ) for controlling the flow rate of refrigerant in the liquid injection passageway ( 31 ).   
   
   
       2 . The refrigeration apparatus of  claim 1 , wherein the refrigerant adjustment tank ( 14 ) is disposed downstream of an evaporator in a refrigerant circulation pathway extending from the expander ( 16 ) to the compressor ( 15 ). 
   
   
       3 . The refrigeration apparatus of  claim 1 , wherein the refrigerant adjustment tank ( 14 ) is disposed upstream of an evaporator in a refrigerant circulation pathway extending from the expander ( 16 ) to the compressor ( 15 ). 
   
   
       4 . The refrigeration apparatus of  claim 3  comprising:
 (a) a gas injection passageway ( 33 ) for supplying gas refrigerant in the refrigerant adjustment tank ( 14 ) to the suction side of the compressor ( 15 ); and   (b) a gas flow rate control mechanism ( 34 ) for controlling the flow rate of refrigerant in the gas injection passageway ( 33 ).   
   
   
       5 . The refrigeration apparatus of any one of  claims 1  to  4 , wherein the high pressure of the refrigeration cycle performed by causing refrigerant to circulate in the refrigerant circuit ( 11 ) is set to a higher pressure level value than the critical pressure of the refrigerant. 
   
   
       6 . The refrigeration apparatus of any one of  claims 1  to  3 , wherein:
 (a) the high pressure of the refrigeration cycle performed by causing refrigerant to circulate in the refrigerant circuit ( 11 ) is set to a higher pressure level value than the critical pressure of the refrigerant; and   (b) the refrigeration apparatus includes controller means ( 90 ) for controlling the liquid flow rate control mechanism ( 32 ) so that the temperature of refrigerant discharged from the compressor ( 15 ) has a predetermined control target value.   
   
   
       7 . The refrigeration apparatus of  claim 4 , wherein:
 (a) the high pressure of the refrigeration cycle performed by causing refrigerant to circulate in the refrigerant circuit ( 11 ) is set to a higher pressure level value than the critical pressure of the refrigerant; and   (b) the refrigeration apparatus includes controller means ( 90 ) for controlling the liquid flow rate control mechanism ( 32 ) and the gas flow rate control mechanism ( 34 ) so that the temperature of refrigerant discharged from the compressor ( 15 ) has a predetermined control target value.   
   
   
       8 . The refrigeration apparatus of any one of  claims 1  to  3 , wherein:
 (a) the high pressure of the refrigeration cycle performed by causing refrigerant to circulate in the refrigerant circuit ( 11 ) is set to a higher pressure level value than the critical pressure of the refrigerant; and   (b) the refrigeration apparatus includes controller means ( 90 ) for controlling the liquid flow rate control mechanism ( 32 ) so that the high pressure of the refrigeration cycle performed in the refrigerant circuit ( 11 ) has a predetermined control target value.   
   
   
       9 . The refrigeration apparatus of  claim 4 , wherein:
 (a) the high pressure of the refrigeration cycle performed by causing refrigerant to circulate in the refrigerant circuit ( 11 ) is set to a higher pressure level value than the critical pressure of the refrigerant; and   (b) the refrigeration apparatus includes controller means ( 90 ) for controlling the liquid flow rate control mechanism ( 32 ) and the gas flow rate control mechanism ( 34 ) so that the high pressure of the refrigeration cycle performed in the refrigerant circuit ( 11 ) has a predetermined control target value.   
   
   
       10 . The refrigeration apparatus of  claim 6 , wherein the controller means ( 90 ) sets, based on the refrigeration cycle operational state, a control target value so that the coefficient of performance of the refrigeration cycle performed in the refrigerant circuit ( 11 ) has an optimal value obtainable in an operational state at the time. 
   
   
       11 . The refrigeration apparatus of  claim 7  or  claim 9 , wherein the controller means ( 90 ) sets, based on the refrigeration cycle operational state, a control target value so that the coefficient of performance of the refrigeration cycle performed in the refrigerant circuit ( 11 ) has an optimal value obtainable in an operational state at the time. 
   
   
       12 . The refrigeration apparatus of  claim 8 , wherein the controller means ( 90 ) sets, based on the refrigeration cycle operational state, a control target value so that the coefficient of performance of the refrigeration cycle performed in the refrigerant circuit ( 11 ) has an optimal value obtainable in an operational state at the time. 
   
   
       13 . The refrigeration apparatus of  claim 5 , wherein the refrigerant circuit ( 11 ) is charged with carbon dioxide as a refrigerant.