Refrigeration cycle apparatus, refrigerant amount determination system, and refrigerant amount determination method

Abstract

The technique in PTL 1 is incapable of grasping a decrease in the amount of a refrigerant from an initial amount of the refrigerant, and the determination of the amount of the refrigerant is insufficient for the purpose other than protection of a compressor. A refrigeration cycle apparatus includes an air temperature sensor, and a condensation temperature sensor. The air temperature sensor detects an air temperature, which is a temperature of air that flows into a condenser. The condensation temperature sensor detects a condensation temperature of the refrigerant that flows through the condenser. The apparatus is configured to acquire a temperature difference between the air temperature and the condensation temperature. The apparatus is further configured to determine an amount of the refrigerant included in the refrigerant circuit by comparing a first temperature difference and a second temperature difference with each other. The first temperature difference is a temperature difference at a first timing. The second temperature difference is a temperature difference at a second timing.

1 . A refrigeration cycle apparatus in which a refrigerant circulates in a refrigerant circuit constituted by a compressor, a condenser, an expansion mechanism, and an evaporator being connected, the refrigeration cycle apparatus comprising:
 an air temperature sensor that detects an air temperature, which is a temperature of air that flows into the condenser; and   a condensation temperature sensor that detects a condensation temperature of the refrigerant that flows through the condenser; wherein said refrigeration cycle apparatus is configured to:   acquire a temperature difference between the air temperature and the condensation temperature; and   determine an amount of the refrigerant included in the refrigerant circuit by comparing a first temperature difference and a second temperature difference with each other, the first temperature difference being a temperature difference acquired at a first timing, the second temperature difference being a temperature difference acquired at a second timing.   
     
     
         2 . The refrigeration cycle apparatus according to  claim 1 , wherein said apparatus is further configured to:
 store at least one of the first temperature difference or the air temperature and the condensation temperature acquired at the first timing.   
     
     
         3 . The refrigeration cycle apparatus according to  claim 1 ,
 wherein the first timing is any of a time at which the refrigeration cycle apparatus is installed, at a time of initial operation of the refrigeration cycle apparatus, or a time of maintenance of the refrigeration cycle apparatus.   
     
     
         4 . The refrigeration cycle apparatus according to  claim 1 ,
 wherein, if a difference between the first temperature difference and the second temperature difference is greater than or equal to a threshold that is any value from 2° C. to 4° C., the apparatus determines that the amount of the refrigerant included in the refrigerant circuit is insufficient.   
     
     
         5 . The refrigeration cycle apparatus according to  4   claim 1 , wherein said apparatus is further configured to:
 notify insufficiency of the amount of the refrigerant if it is determined that the amount of the refrigerant is insufficient.   
     
     
         6 . The refrigeration cycle apparatus according to  claim 1 , wherein said apparatus is further configured to:
 corrects the first temperature difference and the second temperature difference by using at least either one of the air temperature or an evaporation temperature of the refrigerant.   
     
     
         7 . A refrigerant amount determination system that determines an amount of a refrigerant included in a refrigeration cycle apparatus in which the refrigerant circulates in a refrigerant circuit constituted by a compressor, a condenser, an expansion mechanism, and an evaporator being connected, the refrigerant amount determination system comprising:
 an air temperature sensor that detects an air temperature, which is a temperature of air that flows into the condenser; and   a condensation temperature sensor that detects a condensation temperature of the refrigerant that flows through the condenser; wherein said system is configured to:   acquire a temperature difference between the air temperature and the condensation temperature; and   determine a change in the amount of the refrigerant included in the refrigerant circuit by comparing a first temperature difference and a second temperature difference with each other, the first temperature difference being a temperature difference acquired at a first timing, the second temperature difference being a temperature difference acquired at a second timing.   
     
     
         8 . The refrigerant amount determination system according to  claim 7 , wherein said system is further configured to:
 store at least one of the first temperature difference or the air temperature and the condensation temperature acquired at the first timing.   
     
     
         9 . The refrigerant amount determination system according to  claim 7 ,
 wherein the first timing is any of a time at which the refrigeration cycle apparatus is installed, at a time of initial operation of the refrigeration cycle apparatus, or a time of maintenance of the refrigeration cycle apparatus.   
     
     
         10 . The refrigerant amount determination system according to  claim 7 ,
 wherein, if a difference between the first temperature difference and the second temperature difference is greater than or equal to a threshold that is any value from 2° C. to 4° C., the system determines that the amount of the refrigerant included in the refrigerant circuit is insufficient.   
     
     
         11 . The refrigerant amount determination system according to  claim 7 , wherein said system is further configured to:
 notify insufficiency of the amount of the refrigerant if it is determined that the amount of the refrigerant is insufficient.   
     
     
         12 . The refrigerant amount determination system according to  claim 7 , wherein said system is further configured to:
 correct the first temperature difference and the second temperature difference by using at least either one of the air temperature or an evaporation temperature of the refrigerant.   
     
     
         13 . A refrigerant amount determination method for determining an amount of a refrigerant included in a refrigeration cycle apparatus in which the refrigerant circulates in a refrigerant circuit constituted by a compressor, a condenser, an expansion mechanism, and an evaporator being connected, the refrigerant amount determination method comprising:
 acquring a first temperature difference, which is a temperature difference detected at a first timing, between an air temperature and a condensation temperature, the air temperature being a temperature of air that flows into the condenser, the condensation temperature being a condensation temperature of the refrigerant that flows through the condenser;   acquiring a second temperature difference, which is a temperature difference detected at a second timing, between the air temperature and the condensation temperature, the air temperature being a temperature of air that flows into the condenser, the condensation temperature being a condensation temperature of the refrigerant that flows through the condenser; and   of determining a change in the amount of the refrigerant included in the refrigerant circuit by comparing the first temperature difference and the second temperature difference with each other.   
     
     
         14 . The refrigeration cycle apparatus according to  claim 1 , wherein said apparatus comprises a processor that is configured to acquire the temperature difference between the air temperature and the condensation temperature and determine the amount of the refrigerant included in the refrigerant circuit. 
     
     
         15 . The refrigerant amount determination system according to  claim 7 , wherein said system comprises a processor that is configured to acquire the temperature difference between the air temperature and the condensation temperature and determine the change in the amount of the refrigerant included in the refrigerant circuit. 
     
     
         16 . The refrigeration cycle apparatus according to  claim 2 ,
 wherein the first timing is any of a time at which the refrigeration cycle apparatus is installed, at a time of initial operation of the refrigeration cycle apparatus, or a time of maintenance of the refrigeration cycle apparatus.   
     
     
         17 . The refrigeration cycle apparatus according to  claim 2 ,
 wherein, if a difference between the first temperature difference and the second temperature difference is greater than or equal to a threshold that is any value from 2° C. to 4° C., the determination unit determines that the amount of the refrigerant included in the refrigerant circuit is insufficient.   
     
     
         18 . The refrigeration cycle apparatus according to  claim 3 ,
 wherein, if a difference between the first temperature difference and the second temperature difference is greater than or equal to a threshold that is any value from 2° C. to 4° C., the determination unit determines that the amount of the refrigerant included in the refrigerant circuit is insufficient.   
     
     
         19 . The refrigeration cycle apparatus according to  claim 2 , further comprising:
 a notification unit that notifies insufficiency of the amount of the refrigerant if the determination unit determines that the amount of the refrigerant is insufficient.   
     
     
         20 . The refrigeration cycle apparatus according to  claim 3 , further comprising:
 a notification unit that notifies insufficiency of the amount of the refrigerant if the determination unit determines that the amount of the refrigerant is insufficient.