Refrigeration cycle device

Abstract

According to one embodiment, a refrigeration cycle device includes a refrigeration cycle with a plurality of expansion valves and a detector. The detector predicts a first total degree of opening of the valves at a first time point on the assumption that there is no refrigerant leakage in the cycle, based on a change to a first state quantity of the cycle at the first time point from a second state quantity of the cycle at a second time point. The detector detects refrigerant leakage of the cycle by comparing the first total degree of opening with a second total degree of opening which is an actual total degree of opening of the valves at the first time point.

What is claimed is: 
     
         1 . A refrigeration cycle device comprising:
 a refrigeration cycle which returns a refrigerant discharged from a compressor to the compressor via a condenser, a plurality of expansion valves and a plurality of evaporators connected to the expansion valves, respectively; and   a detector which predicts a first total degree of opening of the expansion valves at a first time point on the assumption that there is no refrigerant leakage in the refrigeration cycle, based on a change to a first state quantity of the refrigeration cycle at the first time point from a second state quantity of the refrigeration cycle at a second time point earlier than the first time point, the detector detecting refrigerant leakage of the refrigeration cycle by comparing the first total degree of opening with a second total degree of opening which is an actual total degree of opening of the expansion valves at the first time point.   
     
     
         2 . The refrigeration cycle device of  claim 1 , further comprising a plurality of indoor units each comprising an indoor heat exchanger functioning as the condenser in a heating operation, wherein
 in the heating operation, the detector performs the detection of refrigerant leakage in a state where an operating rate of the indoor units is higher than a setting value related to the operating rate.   
     
     
         3 . The refrigeration cycle device of  claim 2 , further comprising an updater which updates the setting value in accordance with the operating rate of the indoor units in a state where the degree of opening of each of the expansion valves is less than a maximum degree of opening and constantly stable for a certain time in the heating operation. 
     
     
         4 . The refrigeration cycle device of  claim 1 , wherein
 the detector performs the detection of refrigerant leakage in a state where a frequency of the compressor is greater than or equal to a setting value related to the frequency.   
     
     
         5 . The refrigeration cycle device of  claim 1 , wherein
 in a cooling operation, the detector performs the detection of refrigerant leakage in a state where an outside air temperature is greater than or equal to a setting value related to the outside air temperature.   
     
     
         6 . A refrigeration cycle device comprising:
 a refrigeration cycle which returns a refrigerant discharged from a compressor to the compressor via a condenser, an expansion valve and an evaporator; and   a detector which predicts a first amount of supercooling of the condenser at a first time point on the assumption that there is no refrigerant leakage in the refrigeration cycle, based on a change to a first state quantity of the refrigeration cycle at the first time point from a second state quantity of the refrigeration cycle at a second time point earlier than the first time point, the detector detecting refrigerant leakage of the refrigeration cycle by comparing the first amount of supercooling with a second amount of supercooling which is an actual amount of supercooling of the condenser at the first time point.   
     
     
         7 . The refrigeration cycle device of  claim 6 , further comprising a plurality of indoor units each comprising an indoor heat exchanger functioning as the condenser in a heating operation, wherein
 in the heating operation, the detector performs the detection of refrigerant leakage in a state where an operating rate of the indoor units is higher than a setting value related to the operating rate.   
     
     
         8 . The refrigeration cycle device of  claim 7 , further comprising an updater which updates the setting value in accordance with the operating rate of the indoor units in a state where a degree of opening of the expansion valve is less than a maximum degree of opening and constantly stable for a certain time in the heating operation. 
     
     
         9 . The refrigeration cycle device of  claim 6 , wherein
 the detector performs the detection of refrigerant leakage in a state where a frequency of the compressor is greater than or equal to a setting value related to the frequency.   
     
     
         10 . The refrigeration cycle device of  claim 6 , wherein
 in a cooling operation, the detector performs the detection of refrigerant leakage in a state where an outside air temperature is greater than or equal to a setting value related to the outside air temperature.