Refrigerant leak determination apparatus, control device, computer readable medium, and refrigerant leak determination method

Abstract

A refrigerant leak determination apparatus is provided with a refrigeration cycle device, connection devices, and a control device. The refrigeration cycle device is configured with an indoor unit and an outdoor unit. The refrigeration cycle device includes a refrigerant circuit. Each of the connection devices has a communication opening to an internal space of the refrigerant circuit, and is connected to a pressure sensor that measures a refrigerant pressure in the internal space. The control device causes the refrigeration cycle device to perform oil recovery operation to collect oil inside the refrigerant circuit in a compressor, and determines a leak of the refrigerant from the refrigerant circuit, by comparing a reference pressure with the refrigerant pressure measured by the pressure sensor after the oil recovery operation.

1 . A refrigerant leak determination apparatus comprising:
 a refrigeration cycle device that includes a refrigerant circuit in which a compressor, a condenser, an expansion valve and an evaporator are connected, that performs a refrigeration cycle in which a refrigerant circulates through the refrigerant circuit, and that includes a connection device that includes a communication opening to an internal space of the refrigerant circuit, and to which a pressure sensor that measures a refrigerant pressure in the internal space can be connected;   and   a control device including
 processing circuitry: 
 that causes the refrigeration cycle device to perform oil recovery operation to collect oil inside the refrigerant circuit in the compressor; and 
 to determine a leak of the refrigerant from the refrigerant circuit, by comparing a reference pressure for comparison, with the refrigerant pressure measured by the pressure sensor after the oil recovery operation, wherein 
   the connection device is a service port to which the pressure sensor can be connected, and   a resolution of the pressure sensor is in a range from 5 kPa inclusive to 10 kPa inclusive.   
     
     
         2 . A control device comprising:
 processing circuitry:   that causes a refrigeration cycle device to perform oil recovery operation to collect oil inside a refrigerant circuit of the refrigeration cycle device in a compressor, the refrigeration cycle device including the refrigerant circuit in which the compressor, a condenser, an expansion valve, and an evaporator are connected, performing a refrigeration cycle in which a refrigerant circulates through the refrigerant circuit, and including a connection device that includes a communication opening to an internal space of the refrigerant circuit, and that is connected to a pressure sensor that measures a refrigerant pressure in the internal space; and   to determine a leak of the refrigerant from the refrigerant circuit, by comparing a reference pressure for comparison, with the refrigerant pressure measured by the pressure sensor after the oil recovery operation, wherein   the connection device is a service port to which the pressure sensor can be connected, and   a resolution of the pressure sensor is in a range from 5 kPa inclusive to 10 kPa inclusive.   
     
     
         3 . The control device according to  claim 2 , wherein
 when causing the refrigeration cycle device to perform operation in a mode different from the oil recovery operation, the processing circuitry causes the refrigeration cycle device to continuously perform the oil recovery operation from the mode different from the oil recovery operation, and causes the refrigeration cycle device to suspend operation of the refrigeration cycle device after the oil recovery operation is performed.   
     
     
         4 . (canceled) 
     
     
         5 . The control device according to  claim 2 , wherein
 the processing circuitry uses a measured value of the pressure sensor in a suspended state of the refrigeration cycle device after the oil recovery operation is performed.   
     
     
         6 . The control device according to  claim 2 , wherein
 the refrigeration cycle device requires pump-down operation before operation is suspended, and   the service port to which the pressure sensor is connected, communicates with inside of a system in the condenser in the refrigerant circuit.   
     
     
         7 . The control device according to  claim 2 , wherein
 the processing circuitry controls an opening degree of the expansion valve during the oil recovery operation, so that a liquid refrigerant flows into a pipe in an area where the refrigerant is directed from the evaporator to the compressor, and a pipe from the compressor to the condenser, in the refrigerant circuit.   
     
     
         8 . The control device according to  claim 2 , wherein
 the refrigeration cycle device includes a temperature sensor that measures a refrigerant temperature of the refrigerant circuit, and   the processing circuitry calculates a saturation pressure of the refrigerant from the refrigerant temperature measured by the temperature sensor, and uses the calculated saturation pressure as the reference pressure.   
     
     
         9 . The control device according to  claim 2 , wherein
 the processing circuitry uses as the reference pressure, a refrigerant pressure retained in advance at time of factory shipment.   
     
     
         10 . A non-transitory computer readable medium storing a refrigerant leak determination program causing a computer to execute:
 an operation control process that causes a refrigeration cycle device to perform oil recovery operation to collect oil inside a refrigerant circuit of the refrigeration cycle device in a compressor, the refrigeration cycle device including the refrigerant circuit in which the compressor, a condenser, an expansion valve, and an evaporator are connected, performing a refrigeration cycle in which a refrigerant circulates through the refrigerant circuit, and including a service port that includes a communication opening to an internal space of the refrigerant circuit, and to which a pressure sensor that measures a refrigerant pressure in the internal space and whose resolution is in a range from 5 kPa inclusive to 10 kPa inclusive, can be connected; and   a determination process to determine a leak of the refrigerant from the refrigerant circuit, by comparing a reference pressure for comparison, with the refrigerant pressure measured by the pressure sensor after the oil recovery operation.   
     
     
         11 . A refrigerant leak determination method comprising:
 connecting a pressure sensor to a service port after oil recovery operation to collect oil inside a refrigerant circuit in a compressor, the oil recovery operation being performed by a refrigeration cycle device including the refrigerant circuit in which the compressor, a condenser, an expansion valve, and an evaporator are connected, performing a refrigeration cycle in which a refrigerant circulates through the refrigerant circuit, and including the service port that includes a communication opening to an internal space of the refrigerant circuit, and to which the pressure sensor that measures a refrigerant pressure in the internal space and whose resolution is in a range from 5 kPa inclusive to 10 kPa inclusive, can be connected; and   determining a leak of the refrigerant from the refrigerant circuit, by comparing a reference pressure for comparison, with the refrigerant pressure measured by the pressure sensor.