Air conditioning apparatus

Abstract

An air conditioning apparatus includes: a refrigerant circuit that includes a compressor, an outdoor heat exchanger, an indoor heat exchanger, and a pressure reducing device, and that is configured to circulate refrigerant; a plurality of sensors configured to detect a state of the refrigerant circuit; and a controller configured to control the refrigerant circuit based on detection results of the plurality of sensors, and the controller is configured to compare a determination value that is obtained based on a detection value of a sensor selected from the plurality of sensors, with a threshold value that is obtained based on a detection value of a sensor selected from the plurality of sensors, and determine, based on a comparison result, whether or not a reference amount of refrigerating machine oil is stored in the compressor.

1 . An air conditioning apparatus comprising:
 a refrigerant circuit,
 the refrigerant circuit comprising a compressor, an outdoor heat exchanger, an indoor heat exchanger, and a pressure reducing device, and configured to circulate refrigerant; 
   a plurality of sensors configured to detect a state of the refrigerant circuit; and   a controller configured to control the refrigerant circuit based on detection results of the plurality of sensors, wherein   the controller is configured to compare a determination value that is obtained based on a detection value of a sensor selected from the plurality of sensors, with a threshold value that changes based on a detection value of a sensor selected from the plurality of sensors, and determine, based on a comparison result, whether or not a reference amount of refrigerating machine oil is stored in the compressor.   
     
     
         2 . The air conditioning apparatus according to  claim 1 , wherein the determination value is a temperature difference that is obtained based on a detection value of an air intake temperature of the indoor heat exchanger and a detection value of an air output temperature of the indoor heat exchanger. 
     
     
         3 . The air conditioning apparatus according to  claim 1 , wherein the determination value is a discharge temperature that is obtained based on a detection value of a refrigerant discharge temperature of the compressor. 
     
     
         4 . The air conditioning apparatus according to  claim 1 , wherein the determination value is a detection value of a refrigerant outlet temperature of the indoor heat exchanger. 
     
     
         5 . The air conditioning apparatus according to  claim 1 , wherein the determination value is a detection value of a pressure difference due to a pressure loss in a part of a section between the compressor and the pressure reducing device. 
     
     
         6 . The air conditioning apparatus according to  claim 2 , wherein the controller is configured to obtain the threshold value based on a detection value of an operating frequency of the compressor, a detection value of a refrigerant suction temperature of the compressor, a detection value of a refrigerant discharge temperature of the compressor, a detection value of a refrigerant condensation temperature of the indoor heat exchanger, a detection value of a refrigerant outlet temperature of the indoor heat exchanger, and a detection value of an air output temperature of the indoor heat exchanger. 
     
     
         7 . The air conditioning apparatus according to  claim 3 , wherein the controller is configured to obtain the threshold value based on an average value of the refrigerant discharge temperature that is obtained from the detection value of the refrigerant discharge temperature of the compressor. 
     
     
         8 . The air conditioning apparatus according to  claim 4 , wherein the controller is configured to obtain the threshold value based on an average value of the refrigerant outlet temperature that is obtained from the detection value of the refrigerant outlet temperature of the indoor heat exchanger. 
     
     
         9 . The air conditioning apparatus according to  claim 5 , wherein the controller is configured to obtain the threshold value based on a detection value of an operating frequency of the compressor, a detection value of a refrigerant suction temperature of the compressor, and a pressure difference that is obtained based on a detection value of a pressure loss in a part of the section between the compressor and the pressure reducing device. 
     
     
         10 . The air conditioning apparatus according to  claim 1 , wherein when the controller determines that the reference amount of refrigerating machine oil is not stored, the controller is configured to control the compressor to operate in a collecting operation mode of collecting refrigerating machine oil having flown out of the compressor into the refrigerant circuit.