Refrigeration cycle apparatus

Abstract

A refrigeration cycle apparatus includes a main refrigerant circuit, a changer, and a controller. The main refrigerant circuit uses a non-azeotropic refrigerant mixture containing a first refrigerant and a second refrigerant. The changer changes a composition ratio between the first refrigerant and the second refrigerant in a refrigerant flowing through the main refrigerant circuit. The controller controls an operation of the changer. The controller executes a first mode and a second mode. The first mode is a mode in which the operation of the changing unit is controlled to cause substantially the second refrigerant alone to flow through the main refrigerant circuit. The second mode is a mode in which the operation of the changing unit is controlled to cause a refrigerant mixture of the first refrigerant and the second refrigerant to flow through the main refrigerant circuit.

1 . A refrigeration cycle apparatus comprising:
 a refrigeration cycle configured to use a non-azeotropic refrigerant mixture containing a first refrigerant and a second refrigerant;   a changer configured to change a composition ratio between the first refrigerant and the second refrigerant in a refrigerant flowing through the refrigeration cycle; and   a controller configured to control an operation of the changer t, wherein   the controller configured to execute a first mode in which the operation of the changer is controlled to cause substantially the second refrigerant alone to flow through the refrigeration cycle, and a second mode in which the operation of the changer is controlled to cause a refrigerant mixture of the first refrigerant and the second refrigerant to flow through the refrigeration cycle.   
     
     
         2 . The refrigeration cycle apparatus according to  claim 1 , wherein,
 in the first mode, a refrigerant in which a concentration of the second refrigerant is more than or equal to 92 wt % flows through the refrigeration cycle.   
     
     
         3 . The refrigeration cycle apparatus according to  claim 2 , wherein, in the first mode, a refrigerant in which a concentration of the second refrigerant is more than or equal to 98 wt % flows through the refrigeration cycle. 
     
     
         4 . The refrigeration cycle apparatus according to  claim 1 , further comprising a detector configured to detect a composition ratio between the first refrigerant and the second refrigerant in the refrigerant flowing through the refrigeration cycle,
 wherein   the controller is configured to control the operation of the changer so that the composition ratio of the first refrigerant and the second refrigerant detected by the detector becomes a target composition ratio.   
     
     
         5 . The refrigeration cycle apparatus according to  claim 1 , wherein
 a boiling point of the second refrigerant is higher than a boiling point of the first refrigerant.   
     
     
         6 . The refrigeration cycle apparatus according to  claim 5 , wherein
 the refrigeration cycle includes a utilization heat exchanger configured to perform a temperature adjustment of an object for temperature adjustment,   when the utilization heat exchanger is utilized as an evaporator, the controller is configured to execute the first mode, and   when the utilization heat exchanger is utilized as a radiator, the controller is configured to execute the second mode.   
     
     
         7 . The refrigeration cycle apparatus according to  claim 6 , wherein,
 when the utilization heat exchanger is utilized as the radiator, the controller is configured to execute the first mode or the second mode according to a capacity required of the refrigeration cycle apparatus.   
     
     
         8 . The refrigeration cycle apparatus according to  claim 7 , wherein
 the refrigeration cycle includes a compressor,   the controller is further configured to control a number of revolutions of the compressor, and   the controller is configured to execute the second mode if the required capacity cannot be obtained even when the number of revolutions of the compressor is increased to a predetermined number of revolutions during execution of the first mode.   
     
     
         9 . The refrigeration cycle apparatus according to  claim 6 , wherein
 the controller is configured to control, when executing the second mode, the operation of the changer to change the composition ratio between the first refrigerant and the second refrigerant in the refrigerant flowing through the refrigeration cycle between a first composition ratio and a second composition ratio in which a ratio of the first refrigerant is higher than in the first composition ratio.   
     
     
         6 . The refrigeration cycle apparatus according to  claim 9 , wherein
 the refrigeration cycle includes a compressor,   the controller is further configured to control a number of revolutions of the compressor, and   the controller is configured to change either a number of revolutions of the compressor or a composition ratio between the first refrigerant and the second refrigerant in the refrigerant flowing through the refrigeration cycle, in accordance with a change in the capacity required of the refrigeration cycle apparatus.   
     
     
         11 . The refrigeration cycle apparatus according to claim  10 , wherein,
 when the required capacity increases, the controller is configured to change one of the number of revolutions of the compressor and the composition ratio between the first refrigerant and the second refrigerant in the refrigerant flowing through the refrigeration cycle that causes a smaller amount of increase in electric power of the compressor when being changed.   
     
     
         12 . The refrigeration cycle apparatus according to claim  10 , wherein,
 when the required capacity decreases, the controller is configured to control the changer to lower the ratio of the first refrigerant in the refrigerant flowing through the refrigeration cycle when the ratio of the first refrigerant in the refrigerant flowing through the refrigeration cycle is higher than a predetermined value, and to lower the number of revolutions of the compressor when the ratio of the first refrigerant in the refrigerant flowing through the refrigeration cycle is lower than or equal to the predetermined value.   
     
     
         13 . The refrigeration cycle apparatus according to  claim 1 , wherein
 the first refrigerant is CO 2 , and   the second refrigerant is R1234Ze or R1234yf.   
     
     
         14 . The refrigeration cycle apparatus according to  claim 1 , wherein
 the first refrigerant is R1132(E) or R1123, and   the second refrigerant is R1234Ze or R1234yf.   
     
     
         15 . The refrigeration cycle apparatus according to  claim 2 , further comprising a detector configured to detect a composition ratio between the first refrigerant and the second refrigerant in the refrigerant flowing through the refrigeration cycle,
 wherein   the controller is configured to control the operation of the changer so that the composition ratio of the first refrigerant and the second refrigerant detected by the detector becomes a target composition ratio.   
     
     
         16 . The refrigeration cycle apparatus according to  claim 3 , further comprising a detector configured to detect a composition ratio between the first refrigerant and the second refrigerant in the refrigerant flowing through the refrigeration cycle,
 wherein   the controller is configured to control the operation of the changer so that the composition ratio of the first refrigerant and the second refrigerant detected by the detector becomes a target composition ratio.   
     
     
         17 . The refrigeration cycle apparatus according to  claim 2 , wherein
 a boiling point of the second refrigerant is higher than a boiling point of the first refrigerant.   
     
     
         18 . The refrigeration cycle apparatus according to  claim 3 , wherein
 a boiling point of the second refrigerant is higher than a boiling point of the first refrigerant.   
     
     
         19 . The refrigeration cycle apparatus according to  claim 4 , wherein
 a boiling point of the second refrigerant is higher than a boiling point of the first refrigerant.   
     
     
         20 . The refrigeration cycle apparatus according to  claim 7 , wherein
 the controller is configured to control, when executing the second mode, the operation of the changer to change the composition ratio between the first refrigerant and the second refrigerant in the refrigerant flowing through the refrigeration cycle between a first composition ratio and a second composition ratio in which a ratio of the first refrigerant is higher than in the first composition ratio.