Air conditioning apparatus

Abstract

An air conditioning apparatus is filled with a supercritical refrigerant, and includes a compression mechanism, a radiator, an expansion mechanism, an evaporator, a first temperature detector, a target refrigerant temperature derivation unit, and a control unit. The target refrigerant temperature derivation unit uses at least a set temperature to determine a target refrigerant temperature, the set temperature being a temperature that is set relative to the air in the space in which the radiator is disposed, and the target refrigerant temperature being the target temperature of the refrigerant flowing between the outlet side of the radiator and the refrigerant inflow side of the expansion mechanism. The control unit controls the expansion mechanism so that the temperature detected by the first temperature detector corresponds to the target refrigerant temperature.

1 . An air conditioning apparatus filled with a supercritical refrigerant, the air conditioning apparatus comprising:
 a compression mechanism configured to compress the refrigerant;   a radiator connected to a refrigerant intake side of the compression mechanism;   an expansion mechanism connected to an outlet side of the radiator;   an evaporator connected to refrigerant outflow side of the expansion mechanism and connected to the refrigerant intake side of the compression mechanism;   a first temperature detector arranged to detect a refrigerant temperature between the outlet side of the radiator and a refrigerant inflow side of the expansion mechanism;   a target refrigerant temperature derivation unit configured to use at least a set temperature to determine a target refrigerant temperature, the set temperature being a temperature that is set relative to air temperature in a space in which the radiator is disposed, and the target refrigerant temperature being a target temperature of the refrigerant flowing between the outlet side of the radiator and the refrigerant inflow side of the expansion mechanism; and   a control unit configured to control the expansion mechanism so that the refrigerant temperature detected by the first temperature detector corresponds to the target refrigerant temperature.   
   
   
       2 . The air conditioning apparatus according to  claim 1 , wherein
 the radiator includes a plurality of separate radiators with each having a separate outlet side;   the expansion mechanism includes a plurality of separate expansion mechanisms with each separate radiator having one of the separate expansion mechanisms connected to the separate outlet side thereof; and   the first temperature detector includes a plurality of separate temperature detectors with each of the separate temperature detectors being arranged to detect a refrigerant temperature between one of the separate radiators and the separate expansion mechanism connected to the separate outlet side thereof.   
   
   
       3 . The air conditioning apparatus according to  claim 1 , wherein
 the target refrigerant temperature derivation unit is configured to determine the target refrigerant temperature using at least the set temperature, which is one of a plurality of parameters including
 the set temperature, 
 a refrigerant temperature detected by a second temperature detector disposed in proximity to an air blower configured to blow air to the radiator, 
 a pressure of refrigerant flowing from the refrigerant discharge side of the compression mechanism to the refrigerant inflow side of the expansion mechanism, 
 a temperature of refrigerant discharged from the compression mechanism, 
 a pressure of refrigerant flowing into the radiator, and 
 a temperature of refrigerant flowing into the radiator. 
   
   
   
       4 . The air conditioning apparatus according to  claim 1 , further comprising:
 a first gain-varying unit configured to vary gain with respect to control of the expansion mechanism in accordance with the refrigerant temperature detected by the first temperature detector and at least one of
 a pressure of refrigerant flowing from the refrigerant discharge side of the compression mechanism to the refrigerant inflow side of the expansion mechanism, and 
 a temperature of refrigerant discharged from the compression mechanism. 
   
   
   
       5 . The air conditioning apparatus according to  claim 1 , further comprising:
 a second gain-varying unit configured to vary gain pertaining to the determination of the target refrigerant temperature by the target refrigerant temperature derivation unit in accordance with the refrigerant temperature detected by the first temperature detector and at least one of
 a pressure of refrigerant flowing from the refrigerant discharge side of the compression mechanism to the refrigerant inflow side of the expansion mechanism, and 
 a temperature of refrigerant discharged from the compression mechanism. 
   
   
   
       6 . The air conditioning apparatus according to  claim 2 , wherein
 the target refrigerant temperature derivation unit is configured to determine the target refrigerant temperature by using at least the set temperature, which is one of a plurality of parameters including
 the set temperature, 
 a refrigerant temperature detected by a second temperature detector disposed in proximity to an air blower configured to blow air to the radiator, 
 a pressure of refrigerant flowing from the refrigerant discharge side of the compression mechanism to the refrigerant inflow side of the expansion mechanism, 
 a temperature of refrigerant discharged from the compression mechanism, 
 a pressure of refrigerant flowing into the radiator, and 
 a temperature of refrigerant flowing into the radiator. 
   
   
   
       7 . The air conditioning apparatus according to  claim 6 , further comprising:
 a first gain-varying unit configured to vary gain with respect to control of the expansion mechanism in accordance with the refrigerant temperature detected by the first temperature detector and at least one of
 a pressure of refrigerant flowing from the refrigerant discharge side of the compression mechanism to the refrigerant inflow side of the expansion mechanism, and 
 a temperature of refrigerant discharged from the compression mechanism. 
   
   
   
       8 . The air conditioning apparatus according to  claim 6 , further comprising:
 a second gain-varying unit configured to vary gain pertaining to the determination of the target refrigerant temperature by the target refrigerant temperature derivation unit in accordance with the refrigerant temperature detected by the first temperature detector and at least one of
 a pressure of refrigerant flowing from the refrigerant discharge side of the compression mechanism to the refrigerant inflow side of the expansion mechanism, and 
 a temperature of refrigerant discharged from the compression mechanism. 
   
   
   
       9 . The air conditioning apparatus according to  claim 2 , further comprising:
 a first gain-varying unit configured to vary gain with respect to control of the expansion mechanism in accordance with the refrigerant temperature detected by the first temperature detector and at least one of
 a pressure of refrigerant flowing from the refrigerant discharge side of the compression mechanism to the refrigerant inflow side of the expansion mechanism, and 
 a temperature of refrigerant discharged from the compression mechanism. 
   
   
   
       10 . The air conditioning apparatus according to  claim 2 , further comprising:
 a second gain-varying unit configured to vary gain pertaining to the determination of the target refrigerant temperature by the target refrigerant temperature derivation unit in accordance with the refrigerant temperature detected by the first temperature detector and at least one of
 a pressure of refrigerant flowing from the refrigerant discharge side of the compression mechanism to the refrigerant inflow side of the expansion mechanism, and 
 a temperature of refrigerant discharged from the compression mechanism. 
   
   
   
       11 . The air conditioning apparatus according to  claim 3 , further comprising:
 a first gain-varying unit configured to vary gain with respect to control of the expansion mechanism in accordance with the refrigerant temperature detected by the first temperature detector and at least one of
 a pressure of refrigerant flowing from the refrigerant discharge side of the compression mechanism to the refrigerant inflow side of the expansion mechanism, and 
 a temperature of refrigerant discharged from the compression mechanism. 
   
   
   
       12 . The air conditioning apparatus according to  claim 3 , further comprising:
 a second gain-varying unit configured to vary gain pertaining to the determination of the target refrigerant temperature by the target refrigerant temperature derivation unit in accordance with the refrigerant temperature detected by the first temperature detector and at least one of
 a pressure of refrigerant flowing from the refrigerant discharge side of the compression mechanism to the refrigerant inflow side of the expansion mechanism, and 
 a temperature of refrigerant discharged from the compression mechanism.