Refrigeration cycle apparatus

Abstract

A refrigeration cycle apparatus includes a compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, an expansion device, a gas-liquid separator, a first flow rate control device, and a switch device configured to switch a route in which refrigerant circulates between a first route and a second route. In the first route, the refrigerant flows in order of the compressor, the first heat exchanger, the expansion device, the second heat exchanger, and the gas-liquid separator, and then, the refrigerant in liquid state discharged from the gas-liquid separator flows into the third heat exchanger. In the second route, the refrigerant flows in order of the compressor, the second heat exchanger, and the gas-liquid separator, and then, the refrigerant in gaseous state discharged from the gas-liquid separator flows through the first flow rate control device into the third heat exchanger.

1 . A refrigeration cycle apparatus comprising:
 a compressor;   a first heat exchanger;   a second heat exchanger;   a third heat exchanger;   an expansion device;   a gas-liquid separator;   a first flow rate control device; and   a switch device configured to switch a refrigerant circulation path between a first route corresponding to a first operation mode and a second route corresponding to a second operation mode, wherein   in the first route,
 refrigerant flows in order of the compressor, the first heat exchanger, the expansion device, the second heat exchanger, and the gas-liquid separator, 
 the refrigerant in liquid state discharged from the gas-liquid separator flows into the third heat exchanger, 
 the refrigerant in gaseous state discharged from the gas-liquid separator joins, through the first flow rate control device, the refrigerant discharged from the third heat exchanger at a first junction point, and 
 the refrigerant after joining at the first junction point flows to the compressor, and in the second route, 
 the refrigerant flows in order of the compressor, the second heat exchanger, and the gas-liquid separator, 
 the refrigerant in gaseous state discharged from the gas-liquid separator flows through the first flow rate control device into the third heat exchanger, 
 the refrigerant in liquid state discharged from the gas-liquid separator joins the refrigerant discharged from the third heat exchanger at a second junction point, and 
 the refrigerant after joining at the second junction point flows in order of the expansion device, the first heat exchanger, and the compressor. 
   
     
     
         2 . The refrigeration cycle apparatus according to  claim 1 , wherein
 the switch device comprises
 a four-way valve, 
 a first valve mechanism, and 
 a second valve mechanism, 
   the four-way valve has a first switch port, a second switch port, a third switch port, and a fourth switch port, an outlet port of the compressor is connected to the first switch port, and an inlet port of the compressor is connected to the second switch port,   the four-way valve is configured to
 in the first operation mode, cause the first switch port to communicate with the third switch port and cause the second switch port to communicate with the fourth switch port, and 
 in the second operation mode, cause the first switch port to communicate with the fourth switch port and cause the second switch port to communicate with the third switch port, 
   the first valve mechanism is configured to
 in the first operation mode, open a flow of the refrigerant from the first junction point to the fourth switch port and interrupt a flow of the refrigerant from the expansion device to the fourth switch port, and 
 in the second operation mode, open a flow of the refrigerant from the fourth switch port to the second heat exchanger and interrupt a flow of the refrigerant from the fourth switch port to the first junction point, and 
   the second valve mechanism is configured to
 in the first operation mode, open a flow of the refrigerant from the expansion device to the second heat exchanger and interrupt a flow of the refrigerant from the expansion device to the second junction point, and 
 in the second operation mode, open a flow of the refrigerant from the second junction point to the expansion device and interrupt a flow of the refrigerant from the fourth switch port to the expansion device. 
   
     
     
         3 . The refrigeration cycle apparatus according to  claim 2 , wherein
 the first valve mechanism comprises
 a first check valve provided between the fourth switch port and the first junction point and configured to interrupt a flow of the refrigerant from the fourth switch port toward the first junction point, and 
 a second check valve provided among the expansion device, the fourth switch port, and the second heat exchanger and configured to interrupt the flow of the refrigerant from the expansion device to the fourth switch port, and 
   the second valve mechanism comprises
 a third check valve provided among the fourth switch port, the expansion device, and the second heat exchanger and configured to interrupt the flow of the refrigerant from the fourth switch port to the expansion device, and 
 a fourth check valve provided between the expansion device and the second junction point and configured to interrupt the flow of the refrigerant from the expansion device to the second junction point. 
   
     
     
         4 . The refrigeration cycle apparatus according to  claim 2 , wherein
 the first valve mechanism comprises a first three-way valve,   the second valve mechanism comprises a second three-way valve,   the first three-way valve is provided among the fourth switch port, the second heat exchanger, and the first junction point and is configured to switch a target to be connected to the fourth switch port between the second heat exchanger and the first junction point, and   the second three-way valve is provided among the expansion device, the second heat exchanger, and the second junction point and is configured to switch a target to be connected to the expansion device between the second heat exchanger and the second junction point.   
     
     
         5 . The refrigeration cycle apparatus according to  claim 1 , further comprising:
 a first temperature sensor provided between the first flow rate control device and a side of the gas-liquid separator on which the refrigerant in gaseous state is discharged;   a second temperature sensor provided between the third heat exchanger and the first junction point; and   a controller configured to control the first flow rate control device,   wherein the controller is configured to, in the first operation mode,
 calculate a degree of superheat of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the second temperature sensor, and 
 adjust a degree of opening of the first flow rate control device to control the degree of superheat of the third heat exchanger. 
   
     
     
         6 . The refrigeration cycle apparatus according to  claim 5 , further comprising a third temperature sensor provided between the third heat exchanger and the second junction point,
 wherein the controller is configured to, in the second operation mode,
 calculate a degree of supercool of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the third temperature sensor, and 
 adjust the degree of opening of the first flow rate control device to control the degree of supercool of the third heat exchanger. 
   
     
     
         7 . The refrigeration cycle apparatus according to  claim 5 , further comprising:
 a second flow rate control device provided between the second junction point and a side of the gas-liquid separator on which the refrigerant in liquid state is discharged;   a third temperature sensor provided between the third heat exchanger and the second junction point; and   a fourth temperature sensor provided between the second flow rate control device and a side of the gas-liquid separator on which the refrigerant in liquid state is discharged,   wherein the controller is configured to, in the second operation mode,
 calculate a degree of supercool of the third heat exchanger based on a detected value of the third temperature sensor and a detected value of the fourth temperature sensor, and 
 adjust degrees of opening of the first flow rate control device and the second flow rate control device to control the degree of supercool of the third heat exchanger. 
   
     
     
         8 . The refrigeration cycle apparatus according to  claim 2 , further comprising:
 a first temperature sensor provided between the first flow rate control device and a side of the gas-liquid separator on which the refrigerant in gaseous state is discharged;   a second temperature sensor provided between the third heat exchanger and the first junction point; and   a controller configured to control the first flow rate control device,   wherein the controller is configured to, in the first operation mode,
 calculate a degree of superheat of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the second temperature sensor, and 
 adjust a degree of opening of the first flow rate control device to control the degree of superheat of the third heat exchanger. 
   
     
     
         9 . The refrigeration cycle apparatus according to  claim 3 , further comprising:
 a first temperature sensor provided between the first flow rate control device and a side of the gas-liquid separator on which the refrigerant in gaseous state is discharged;   a second temperature sensor provided between the third heat exchanger and the first junction point; and   a controller configured to control the first flow rate control device,   wherein the controller is configured to, in the first operation mode,
 calculate a degree of superheat of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the second temperature sensor, and 
 adjust a degree of opening of the first flow rate control device to control the degree of superheat of the third heat exchanger. 
   
     
     
         10 . The refrigeration cycle apparatus according to  claim 4 , further comprising:
 a first temperature sensor provided between the first flow rate control device and a side of the gas-liquid separator on which the refrigerant in gaseous state is discharged;   a second temperature sensor provided between the third heat exchanger and the first junction point; and   a controller configured to control the first flow rate control device,   wherein the controller is configured to, in the first operation mode,
 calculate a degree of superheat of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the second temperature sensor, and 
 adjust a degree of opening of the first flow rate control device to control the degree of superheat of the third heat exchanger. 
   
     
     
         11 . The refrigeration cycle apparatus according to  claim 2 , further comprising:
 a first temperature sensor provided between the first flow rate control device and a side of the gas-liquid separator on which the refrigerant in gaseous state is discharged;   a second temperature sensor provided between the third heat exchanger and the first junction point;   a controller configured to control the first flow rate control device; and   a third temperature sensor provided between the third heat exchanger and the second junction point,   wherein the controller is configured to, in the first operation mode,
 calculate a degree of superheat of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the second temperature sensor, and 
 adjust a degree of opening of the first flow rate control device to control the degree of superheat of the third heat exchanger, 
   wherein the controller is configured to, in the second operation mode,
 calculate a degree of supercool of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the third temperature sensor, and 
 adjust the degree of opening of the first flow rate control device to control the degree of supercool of the third heat exchanger. 
   
     
     
         12 . The refrigeration cycle apparatus according to  claim 3 , further comprising:
 a first temperature sensor provided between the first flow rate control device and a side of the gas-liquid separator on which the refrigerant in gaseous state is discharged;   a second temperature sensor provided between the third heat exchanger and the first junction point;   a controller configured to control the first flow rate control device; and   a third temperature sensor provided between the third heat exchanger and the second junction point,   wherein the controller is configured to, in the first operation mode,
 calculate a degree of superheat of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the second temperature sensor, and 
 adjust a degree of opening of the first flow rate control device to control the degree of superheat of the third heat exchanger, 
   wherein the controller is configured to, in the second operation mode,
 calculate a degree of supercool of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the third temperature sensor, and 
 adjust the degree of opening of the first flow rate control device to control the degree of supercool of the third heat exchanger. 
   
     
     
         13 . The refrigeration cycle apparatus according to  claim 4 , further comprising:
 a first temperature sensor provided between the first flow rate control device and a side of the gas-liquid separator on which the refrigerant in gaseous state is discharged;   a second temperature sensor provided between the third heat exchanger and the first junction point;   a controller configured to control the first flow rate control device; and   a third temperature sensor provided between the third heat exchanger and the second junction point,   wherein the controller is configured to, in the first operation mode,
 calculate a degree of superheat of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the second temperature sensor, and 
 adjust a degree of opening of the first flow rate control device to control the degree of superheat of the third heat exchanger, 
   wherein the controller is configured to, in the second operation mode,
 calculate a degree of supercool of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the third temperature sensor, and 
 adjust the degree of opening of the first flow rate control device to control the degree of supercool of the third heat exchanger. 
   
     
     
         14 . The refrigeration cycle apparatus according to  claim 2 , further comprising:
 a first temperature sensor provided between the first flow rate control device and a side of the gas-liquid separator on which the refrigerant in gaseous state is discharged;   a second temperature sensor provided between the third heat exchanger and the first junction point;   a controller configured to control the first flow rate control device,   a second flow rate control device provided between the second junction point and a side of the gas-liquid separator on which the refrigerant in liquid state is discharged;   a third temperature sensor provided between the third heat exchanger and the second junction point; and   a fourth temperature sensor provided between the second flow rate control device and a side of the gas-liquid separator on which the refrigerant in liquid state is discharged,   wherein the controller is configured to, in the first operation mode,
 calculate a degree of superheat of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the second temperature sensor, and 
 adjust a degree of opening of the first flow rate control device to control the degree of superheat of the third heat exchanger, 
   wherein the controller is configured to, in the second operation mode,
 calculate a degree of supercool of the third heat exchanger based on a detected value of the third temperature sensor and a detected value of the fourth temperature sensor, and 
 adjust degrees of opening of the first flow rate control device and the second flow rate control device to control the degree of supercool of the third heat exchanger. 
   
     
     
         15 . The refrigeration cycle apparatus according to  claim 3 , further comprising:
 a first temperature sensor provided between the first flow rate control device and a side of the gas-liquid separator on which the refrigerant in gaseous state is discharged;   a second temperature sensor provided between the third heat exchanger and the first junction point;   a controller configured to control the first flow rate control device,   a second flow rate control device provided between the second junction point and a side of the gas-liquid separator on which the refrigerant in liquid state is discharged;   a third temperature sensor provided between the third heat exchanger and the second junction point; and   a fourth temperature sensor provided between the second flow rate control device and a side of the gas-liquid separator on which the refrigerant in liquid state is discharged,   wherein the controller is configured to, in the first operation mode,
 calculate a degree of superheat of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the second temperature sensor, and 
 adjust a degree of opening of the first flow rate control device to control the degree of superheat of the third heat exchanger, 
   wherein the controller is configured to, in the second operation mode,
 calculate a degree of supercool of the third heat exchanger based on a detected value of the third temperature sensor and a detected value of the fourth temperature sensor, and 
 adjust degrees of opening of the first flow rate control device and the second flow rate control device to control the degree of supercool of the third heat exchanger. 
   
     
     
         16 . The refrigeration cycle apparatus according to  claim 4 , further comprising:
 a first temperature sensor provided between the first flow rate control device and a side of the gas-liquid separator on which the refrigerant in gaseous state is discharged;   a second temperature sensor provided between the third heat exchanger and the first junction point;   a controller configured to control the first flow rate control device,   a second flow rate control device provided between the second junction point and a side of the gas-liquid separator on which the refrigerant in liquid state is discharged;   a third temperature sensor provided between the third heat exchanger and the second junction point; and   a fourth temperature sensor provided between the second flow rate control device and a side of the gas-liquid separator on which the refrigerant in liquid state is discharged,   wherein the controller is configured to, in the first operation mode,
 calculate a degree of superheat of the third heat exchanger based on a detected value of the first temperature sensor and a detected value of the second temperature sensor, and 
 adjust a degree of opening of the first flow rate control device to control the degree of superheat of the third heat exchanger, 
   wherein the controller is configured to, in the second operation mode,
 calculate a degree of supercool of the third heat exchanger based on a detected value of the third temperature sensor and a detected value of the fourth temperature sensor, and 
 adjust degrees of opening of the first flow rate control device and the second flow rate control device to control the degree of supercool of the third heat exchanger.