Refrigeration cycle apparatus

Abstract

A refrigeration cycle apparatus includes a circulation path in which a working fluid containing 1,1,2-trifluoroethylene is circulated from a compressor through a condenser, an expansion valve and an evaporator back to the compressor. The refrigeration cycle apparatus includes a composition change detection unit, a composition adjustment unit, and a control unit. The composition change detection unit detects a change of a composition of the working fluid from a steady composition thereof. The composition adjustment unit adjusts the composition of the working fluid. The control unit controls the composition adjustment unit based on a detection result obtained by the composition change detection unit.

1 . A refrigeration cycle apparatus comprising a circulation path in which a working fluid containing 1,1,2-trifluoroethylene is circulated from a compressor through a condenser, an expansion valve and an evaporator back to the compressor, the refrigeration cycle apparatus comprising:
 a composition change detection unit which detects a change of a composition of the working fluid from a steady composition thereof;   a composition adjustment unit which adjusts the composition of the working fluid; and   a control unit which controls the composition adjustment unit,   wherein the control unit controls the composition adjustment unit based on a detection result obtained by the composition change detection unit.   
     
     
         2 . The refrigeration cycle apparatus according to  claim 1 , wherein the composition change detection unit is a discharge temperature sensor which detects a discharge temperature of the compressor, and judges that the composition of the working fluid is changed from the steady composition when the discharge temperature detected by the discharge temperature sensor exceeds a predetermined temperature. 
     
     
         3 . The refrigeration cycle apparatus according to  claim 1 , wherein the composition change detection unit is a superheat detection unit which detects a superheating degree of the working fluid sucked into the compressor, and judges that the composition of the working fluid is changed when the superheating degree detected by the superheat detection unit exceeds a predetermined value. 
     
     
         4 . The refrigeration cycle apparatus according to  claim 1 , wherein the composition change detection unit is a supercool detection unit which detects a supercooling degree of the working fluid sucked into the compressor, and judges that the composition of the working fluid is changed when the supercooling degree detected by the supercool detection unit is deviated from a predetermined range. 
     
     
         5 . The refrigeration cycle apparatus according to  claim 1 , further comprising:
 an accumulator provided between the evaporator and the compressor in the circulation path for storing an excess of the working fluid,   wherein the composition adjustment unit is a heater attached to the accumulator, and   wherein the control unit allows electric current to flow through the heater when the composition change detection unit judges that the composition of the working fluid is changed.   
     
     
         6 . The refrigeration cycle apparatus according to  claim 1 , further comprising:
 an accumulator provided between the evaporator and the compressor in the circulation path for storing an excess of the working fluid,   wherein the composition adjustment unit includes: a hot gas bypass which diverts a part of a hot gas discharged from the compressor and introduces the diverted hot gas into the accumulator; and an on-off valve provided in the hot gas bypass, and   wherein the control unit controls the on-off valve so as to change a state of the on-off valve from a closed state to an open state when the composition change detection unit judges that the composition of the working fluid is changed.   
     
     
         7 . The refrigeration cycle apparatus according to  claim 1 , wherein the composition adjustment unit is a motor which drives a compression mechanism of the compressor, and the control unit controls the motor so as to increase the number of revolutions of the motor when the composition change detection unit judges that the composition of the working fluid is changed. 
     
     
         8 . The refrigeration cycle apparatus according to  claim 1 , wherein the composition adjustment unit is the expansion valve, and the control unit controls the expansion valve so as to increase an opening degree of the expansion valve when the composition change detection unit judges that the composition of the working fluid is changed. 
     
     
         9 . The refrigeration cycle apparatus according to  claim 1 , further comprising:
 a receiver provided between the condenser and the expansion valve in the circulation path for storing an excess of the working fluid,   wherein the composition adjustment unit includes a liquid refrigerant bypass for extracting a liquid refrigerant stored in the receiver and injecting the extracted liquid refrigerant to an intermediate pressure portion of the compressor through an auxiliary expansion valve, and   wherein the control unit controls the auxiliary expansion valve so as to increase an opening degree of the auxiliary expansion valve when the composition change detection unit judges that the composition of the working fluid is changed.   
     
     
         10 . The refrigeration cycle apparatus according to  claim 2 , further comprising:
 an accumulator provided between the evaporator and the compressor in the circulation path for storing an excess of the working fluid,   wherein the composition adjustment unit is a heater attached to the accumulator, and   wherein the control unit allows electric current to flow through the heater when the composition change detection unit judges that the composition of the working fluid is changed.   
     
     
         11 . The refrigeration cycle apparatus according to  claim 3 , further comprising:
 an accumulator provided between the evaporator and the compressor in the circulation path for storing an excess of the working fluid,   wherein the composition adjustment unit is a heater attached to the accumulator, and   wherein the control unit allows electric current to flow through the heater when the composition change detection unit judges that the composition of the working fluid is changed.   
     
     
         12 . The refrigeration cycle apparatus according to  claim 4 , further comprising:
 an accumulator provided between the evaporator and the compressor in the circulation path for storing an excess of the working fluid,   wherein the composition adjustment unit is a heater attached to the accumulator, and   wherein the control unit allows electric current to flow through the heater when the composition change detection unit judges that the composition of the working fluid is changed.   
     
     
         13 . The refrigeration cycle apparatus according to  claim 2 , further comprising:
 an accumulator provided between the evaporator and the compressor in the circulation path for storing an excess of the working fluid,   wherein the composition adjustment unit includes: a hot gas bypass which diverts a part of a hot gas discharged from the compressor and introduces the diverted hot gas into the accumulator; and an on-off valve provided in the hot gas bypass, and   wherein the control unit controls the on-off valve so as to change a state of the on-off valve from a closed state to an open state when the composition change detection unit judges that the composition of the working fluid is changed.   
     
     
         14 . The refrigeration cycle apparatus according to  claim 3 , further comprising:
 an accumulator provided between the evaporator and the compressor in the circulation path for storing an excess of the working fluid,   wherein the composition adjustment unit includes: a hot gas bypass which diverts a part of a hot gas discharged from the compressor and introduces the diverted hot gas into the accumulator; and an on-off valve provided in the hot gas bypass, and   wherein the control unit controls the on-off valve so as to change a state of the on-off valve from a closed state to an open state when the composition change detection unit judges that the composition of the working fluid is changed.   
     
     
         15 . The refrigeration cycle apparatus according to  claim 4 , further comprising:
 an accumulator provided between the evaporator and the compressor in the circulation path for storing an excess of the working fluid,   wherein the composition adjustment unit includes: a hot gas bypass which diverts a part of a hot gas discharged from the compressor and introduces the diverted hot gas into the accumulator; and an on-off valve provided in the hot gas bypass, and   wherein the control unit controls the on-off valve so as to change a state of the on-off valve from a closed state to an open state when the composition change detection unit judges that the composition of the working fluid is changed.   
     
     
         16 . The refrigeration cycle apparatus according to  claim 2 , wherein the composition adjustment unit is a motor which drives a compression mechanism of the compressor, and the control unit controls the motor so as to increase the number of revolutions of the motor when the composition change detection unit judges that the composition of the working fluid is changed. 
     
     
         17 . The refrigeration cycle apparatus according to  claim 3 , wherein the composition adjustment unit is a motor which drives a compression mechanism of the compressor, and the control unit controls the motor so as to increase the number of revolutions of the motor when the composition change detection unit judges that the composition of the working fluid is changed. 
     
     
         18 . The refrigeration cycle apparatus according to  claim 4 , wherein the composition adjustment unit is a motor which drives a compression mechanism of the compressor, and the control unit controls the motor so as to increase the number of revolutions of the motor when the composition change detection unit judges that the composition of the working fluid is changed. 
     
     
         19 . The refrigeration cycle apparatus according to  claim 2 , wherein the composition adjustment unit is the expansion valve, and the control unit controls the expansion valve so as to increase an opening degree of the expansion valve when the composition change detection unit judges that the composition of the working fluid is changed. 
     
     
         20 . The refrigeration cycle apparatus according to  claim 3 , wherein the composition adjustment unit is the expansion valve, and the control unit controls the expansion valve so as to increase an opening degree of the expansion valve when the composition change detection unit judges that the composition of the working fluid is changed.