Ejector refrigeration cycle

An ejector refrigeration cycle comprising:

• a compressor configured to compress a refrigerant and discharge the refrigerant;
• a radiator configured to release heat of the refrigerant that flowed out of the compressor;
• a branch portion configured to divide a flow of the refrigerant that flowed out of the radiator into one flow and another flow;
• an ejector that has
• a nozzle portion configured to decompress the refrigerant of the one flow that was divided at the branch portion, the refrigerant being ejected from the nozzle portion,
• a refrigerant suction port through which the refrigerant is drawn by a suction force of the ejected refrigerant, and
• a pressure increasing portion in which the refrigerant ejected from the nozzle portion and the refrigerant drawn through the refrigerant suction port are mixed, the pressure increasing portion being configured to increase a pressure of the mixture;
• a suction side decompressor configured to decompress the refrigerant of the other flow that was divided at the branch portion;
• a windward evaporator configured to exchange heat between the refrigerant ejected and a cooling target fluid to evaporate the refrigerant;
• and
• a leeward evaporator configured to exchange heat between the refrigerant of the other flow and the cooling target fluid that passed through the windward evaporator to evaporate the refrigerant, wherein
• the windward evaporator includes at least one outflow side evaporation portion of a plurality of outflow side evaporation portions configured to evaporate the refrigerant that flowed out of the pressure increasing portion and allow the refrigerant to flow to an inlet of the compressor,
• the leeward evaporator includes
• at least one outflow side evaporation portion of the plurality of outflow side evaporation portions, and
• a suction side evaporation portion configured to evaporate the refrigerant that was decompressed by the suction side decompressor and allow the refrigerant to flow to the refrigerant suction port,
• at least one of the nozzle portion or the suction side decompressor is configured to change an area of a refrigerant passage,
• a nozzle side refrigerant flow rate is a flow rate of the refrigerant flowing from the branch portion into the nozzle portion,
• a suction side refrigerant flow rate is a flow rate of the refrigerant flowing from the branch portion into the suction side decompressor,
• an outflow side heat exchange area is an area of a heat exchange portion of the at least one outflow side evaporation portion of the leeward evaporator,
• a suction side heat exchange area is an area of a heat exchange portion of the suction side evaporation portion of the leeward evaporator,
• an outflow side evaporation temperature is a refrigerant evaporation temperature in the at least one of the plurality of outflow side evaporation portions of the leeward evaporator,
• a suction side evaporation temperature is a refrigerant evaporation temperature in the suction side evaporation portion of the leeward evaporator,
• the at least one of the nozzle portion or the suction side decompressor is configured to adjust the area of the refrigerant passage such that a flow rate proportion of the suction side refrigerant flow rate in a sum of the suction side refrigerant flow rate and the nozzle side refrigerant flow rate is equal to a predetermined reference flow rate proportion, and
• an area proportion of the suction side heat exchange area in a sum of the suction side heat exchange area and the outflow side heat exchange area is designed such that a temperature difference between the outflow side evaporation temperature and the suction side evaporation temperature is at or below a predetermined reference temperature difference while the flow rate proportion is equal to the reference flow rate proportion.