Ejector refrigeration circuit

Abstract

An ejector refrigeration circuit includes a compressor, a heating heat exchanger, a first decompressor, an exterior heat exchanger, a second decompressor, a cooling heat exchanger, a heating ejector, a heating-side gas-liquid separator, and a refrigerant circuit switch. The refrigerant circuit switch switches between a refrigerant circuit in a first dehumidifying-heating mode and a refrigerant circuit in a second dehumidifying-heating mode. A flow direction of the refrigerant through the exterior heat exchanger in the first dehumidifying-heating mode is the same as a flow direction of the refrigerant through the exterior heat exchanger in the second dehumidifying-heating mode. The flow direction of the refrigerant through the exterior heat exchanger in the first dehumidifying-heating mode is different from a flow direction of the refrigerant through the exterior heat exchanger in the heating mode.

1 . An ejector refrigeration circuit for an air conditioner, comprising:
 a compressor that compresses a refrigerant mixed with a refrigerant oil to be the refrigerant having a high pressure and discharges the refrigerant having the high pressure;   a heating heat exchanger that heats air flowing to an air-conditioning object space by using the refrigerant having the high pressure as a heat source;   a first decompressor that is disposed downstream of the heating heat exchanger and decompresses the refrigerant;   an exterior heat exchanger that exchanges heat between the refrigerant flowing out of the first decompressor and an outside air;   a second decompressor that is disposed downstream of the heating heat exchanger and decompresses the refrigerant;   a cooling heat exchanger that is configured to evaporate the refrigerant flowing out of the second decompressor and to cool the air before passing through the heating heat exchanger;   a heating ejector that includes:
 a heating-side nozzle that is disposed downstream of the heating heat exchanger, decompresses the refrigerant, and injects the refrigerant as a heating-side injected refrigerant; 
 a heating-side suction port that draws in the refrigerant as a heating-side suction refrigerant by suction force of the heating-side injected refrigerant; and 
 a heating-side pressure increasing portion that pressurizes a mixed refrigerant of the heating-side injected refrigerant and the heating-side suction refrigerant; 
   a heating-side gas-liquid separator that separates the refrigerant flowing out of the heating-side pressure increasing portion into a gas refrigerant and a liquid refrigerant; and   a refrigerant circuit switch that is configured to set a plurality of refrigerant circuits, wherein   the refrigerant circuit switch is configured to
 set a refrigerant circuit that allows the refrigerant flowing out of the heating heat exchanger to flow through in order of the first decompressor, the exterior heat exchanger, the second decompressor, the cooling heat exchanger, and the compressor in a first dehumidifying-heating mode in which the heating heat exchanger reheats the air cooled by the cooling heat exchanger, 
 set a refrigerant circuit that allows the refrigerant flowing out of the heating heat exchanger to flow through in order of the second decompressor, the cooling heat exchanger, the first decompressor, the exterior heat exchanger, and the compressor in a second dehumidifying-heating mode in which the heating heat exchanger reheats the air cooled by the cooling heat exchanger, and 
 set a refrigerant circuit that allows the refrigerant flowing out of the heating heat exchanger to flow into the heating-side nozzle, allows the gas refrigerant flowing out of the heating-side gas-liquid separator to be drawn into the compressor, allows the liquid refrigerant flowing out of the heating-side gas-liquid separator to flow into the exterior heat exchanger, and allows the refrigerant flowing out of the exterior heat exchanger to be drawn into the heating-side suction port in a heating mode in which the heating heat exchanger heats the air, 
   a flow direction of the refrigerant through the exterior heat exchanger in the first dehumidifying-heating mode is the same as a flow direction of the refrigerant through the exterior heat exchanger in the second dehumidifying-heating mode, and   the flow direction of the refrigerant through the exterior heat exchanger in the first dehumidifying-heating mode is different from a flow direction of the refrigerant through the exterior heat exchanger in the heating mode.   
     
     
         2 . The ejector refrigeration circuit according to  claim 1 , wherein
 the exterior heat exchanger defines a refrigerant passage therein, and   the refrigerant passage has a cross-sectional area decreasing from a refrigerant inlet toward a refrigerant outlet in the heating mode.   
     
     
         3 . The ejector refrigeration circuit according to  claim 1 , further comprising:
 a cooling ejector including
 a cooling-side nozzle that is disposed downstream of the heating heat exchanger, decompresses the refrigerant, and injects the refrigerant as a cooling-side injected refrigerant, 
 a cooling-side suction port that draws in the refrigerant through the cooling-side suction port as a cooling-side suction refrigerant by suction force of the cooling-side injected refrigerant, and 
 a cooling-side pressure increasing portion that pressurizes a mixed refrigerant of the cooling-side injected refrigerant and the cooling-side suction refrigerant; and 
   a cooling-side gas-liquid separator that separates the refrigerant flowing out of the cooling-side pressure increasing portion into a gas refrigerant and a liquid refrigerant, wherein   the refrigerant circuit switch sets a refrigerant circuit that allows the refrigerant flowing out of the exterior heat exchanger to flow into the cooling-side nozzle, allows the gas refrigerant flowing out of the cooling-side gas-liquid separator to be drawn into the compressor, allows the liquid refrigerant flowing out of the cooling-side gas-liquid separator to flow into the cooling heat exchanger, and allows the refrigerant flowing out of the cooling heat exchanger to be drawn into the cooling-side suction port in a cooling mode in which the cooling heat exchanger cools the air,   a flow direction of the refrigerant through the cooling heat exchanger in the first dehumidifying-heating mode is the same as a flow direction of the refrigerant through the cooling heat exchanger in the second dehumidifying-heating mode, and   the flow direction of the refrigerant through the cooling heat exchanger in the first dehumidifying-heating mode is different from a flow direction of the refrigerant through the cooling heat exchanger in the cooling mode.   
     
     
         4 . The ejector refrigeration circuit according to  claim 3 , wherein
 the cooling heat exchanger defines a refrigerant passage therein, and   the refrigerant passage has a cross-sectional area decreasing from a refrigerant inlet toward a refrigerant outlet in the cooling mode.   
     
     
         5 . An ejector refrigeration circuit for an air conditioner, comprising:
 a compressor that compresses a refrigerant mixed with a refrigerant oil to be the refrigerant having a high pressure and discharges the refrigerant having the high pressure;   a heating heat exchanger that heats air to be blown into an air-conditioning object space by using the refrigerant having the high pressure as a heat source;   a first decompressor that is disposed downstream of the heating heat exchanger and decompresses the refrigerant;   an exterior heat exchanger that exchanges heat between the refrigerant flowing out of the first decompressor and an outside air;   a second decompressor that is disposed downstream of the heating heat exchanger and decompresses the refrigerant;   a cooling heat exchanger that is configured to evaporate the refrigerant flowing out of the second decompressor and to cool the air before passing through the heating heat exchanger;   a cooling ejector including
 a cooling-side nozzle that decompresses the refrigerant downstream of the heating heat exchanger and injects the refrigerant as a cooling-side injected refrigerant, 
 a cooling-side suction port that draws in the refrigerant through the cooling-side suction port as a cooling-side suction refrigerant by suction force of the cooling-side injected refrigerant, and 
 a cooling-side pressure increasing portion that pressurizes a mixed refrigerant of the cooling-side injected refrigerant and the cooling-side suction refrigerant; 
   a cooling-side gas-liquid separator that separates the refrigerant flowing out of the cooling-side pressure increasing portion into a gas refrigerant and a liquid refrigerant; and   a refrigerant circuit switch that is configured to set a plurality of refrigerant circuits, wherein   the refrigerant circuit switch is configured to
 set a refrigerant circuit that allows the refrigerant flowing out of the heating heat exchanger to flow through in order of the first decompressor, the exterior heat exchanger, the second decompressor, the cooling heat exchanger, and the compressor in a first dehumidifying-heating mode in which the heating heat exchanger reheats the air cooled by the cooling heat exchanger, 
 set a refrigerant circuit that allows the refrigerant flowing out of the heating heat exchanger to flow through in order of the second decompressor, the cooling heat exchanger, the first decompressor, the exterior heat exchanger, and the compressor in a second dehumidifying-heating mode in which the heating heat exchanger reheats the air cooled by the cooling heat exchanger, and 
 set a refrigerant circuit that allows the refrigerant flowing out of the exterior heat exchanger to flow into the cooling-side nozzle, allows the gas refrigerant flowing out of the cooling-side gas-liquid separator to be drawn into the compressor, allows the liquid refrigerant flowing out of the cooling-side gas-liquid separator to flow into the cooling heat exchanger, and allows the refrigerant flowing out of the cooling heat exchanger to be drawn into the cooling-side suction port in a cooling mode in which the cooling heat exchanger cools the air, 
   a flow direction of the refrigerant through the cooling heat exchanger in the first dehumidifying-heating mode is the same as a flow direction of the refrigerant through the cooling heat exchanger in the second dehumidifying-heating mode, and   the flow direction of the refrigerant through the cooling heat exchanger in the first dehumidifying-heating mode is different from a flow direction of the refrigerant through the cooling heat exchanger in the cooling mode.   
     
     
         6 . The ejector refrigeration circuit according to  claim 4 , wherein
 the cooling heat exchanger defines a refrigerant passage therein, and   the refrigerant passage has a cross-sectional area decreasing from a refrigerant inlet toward a refrigerant outlet in the cooling mode.