Ejector

An ejector for a vapor compression refrigeration cycle device, the ejector comprising:

• a body part including a swirling space in which a refrigerant flowing from a refrigerant inlet port is swirled, a depressurizing space in which the refrigerant flowing out of the swirling space is depressurized, a suction passage that communicates with a downstream side of the depressurizing space in a refrigerant flow and draws a refrigerant from an external, and a pressurizing space in which a jet refrigerant jetted from the depressurizing space is mixed with a suction refrigerant drawn from the suction passage;
• and
• a passage formation member which includes at least a part disposed inside the depressurizing space and the pressurizing space, and has a conical shape such that a cross-sectional area increases with distance from the depressurizing space, wherein
• the body part has a nozzle passage that is a refrigerant passage defined between an inner peripheral surface of a portion defining the depressurizing space and an outer peripheral surface of the passage formation member, and the nozzle passage functions as a nozzle that depressurizes and ejects the refrigerant flowing out of the swirling space,
• the body part has a diffuser passage that is a refrigerant passage defined between an inner peripheral surface of a portion defining the pressurizing space and the outer peripheral surface of the passage formation member and the diffuser passage functions as a diffuser that mixes the jet refrigerant and the suction refrigerant together and pressurizes the mixed refrigerant, and
• the diffuser passage has an annular shape in a cross-section perpendicular to an axial direction of the passage formation member,
• the ejector further comprising a swirling promotion part that promotes a swirling flow of the refrigerant flowing in the diffuser passage.