Ejector

An ejector to be used for a refrigeration cycle device, the refrigeration cycle device including a compressor that compresses and discharges a refrigerant, and a heating heat exchanger that heats a fluid to be heat-exchanged using a high-pressure refrigerant discharged from the compressor as a heat source, the ejector comprising:

• a nozzle portion that decompresses a refrigerant and injects the refrigerant from a refrigerant injection port;
• and
• a body portion including a refrigerant suction port drawing a refrigerant by a suction effect of the injection refrigerant injected from the nozzle portion at high velocity, and a pressure-increasing portion pressurizing a mixed refrigerant including the injection refrigerant and the suction refrigerant drawn from the refrigerant suction port, wherein
• the refrigeration cycle device is adapted to adjust a dryness of the refrigerant flowing into the nozzle portion in such a manner that the heating capacity approaches a maximum value, when (i) Δicond is an enthalpy difference obtained by subtracting an enthalpy of the refrigerant on an outlet side of the heating heat exchanger from an enthalpy of the refrigerant on an inlet side of the heating heat exchanger;
• (ii) Gr is a flow rate of the refrigerant flowing into the heating heat exchanger;
• and (iii) Qc is a heating capacity of the fluid to be heat-exchanged in the heating heat exchanger that is obtained by multiplying the refrigerant flow rate by the enthalpy difference,
• the body portion is provided with a mixing portion that mixes the injection refrigerant and the suction refrigerant, in a range of an internal space of the body portion from the refrigerant injection port of the nozzle portion to an inlet of the pressure-increasing portion,
• the mixing portion is formed in a shape that gradually reduces a refrigerant passage area toward a downstream side of a refrigerant flow, and
• a refrigerant passage area of the inlet of the pressure-increasing portion is set smaller than that of the refrigerant injection port of the nozzle portion.

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

• a nozzle portion that decompresses a refrigerant and injects the refrigerant from a refrigerant injection port;
• and
• a body portion including a refrigerant suction port drawing a refrigerant by a suction effect of the injection refrigerant injected from the nozzle portion at high velocity, and a pressure-increasing portion pressurizing a mixed refrigerant including the injection refrigerant and the suction refrigerant drawn from the refrigerant suction port, wherein
• a dryness X of the refrigerant flowing into the nozzle portion in the refrigeration cycle device is adjusted to not less than 0.5 nor more than 0.8 in the refrigeration cycle device,
• a mixing portion that mixes the injection refrigerant and the suction refrigerant is provided in a range of an internal space of the body portion from the refrigerant injection port to an inlet of the pressure-increasing portion,
• a refrigerant passage formed in the nozzle portion includes a tapered portion in which a refrigerant passage area gradually decreases toward a refrigerant downstream side, and an injection portion that guides the refrigerant from the tapered portion to the refrigerant injection port, and
• the nozzle portion is provided to flexibly expand the injection refrigerant to be injected into the mixing portion by setting a spreading angle on a section of the injection portion in an axial direction to 0° or more.

An ejector to be used for a refrigeration cycle device, the refrigeration cycle device including a compressor that compresses and discharges a refrigerant, and a heating heat exchanger that heats a fluid to be heat-exchanged using a high-pressure refrigerant discharged from the compressor as a heat source, the ejector comprising:

• a nozzle portion that decompresses a refrigerant and injects the refrigerant from a refrigerant injection port;
• and
• a body portion including a refrigerant suction port drawing a refrigerant by a suction effect of the injection refrigerant injected from the nozzle portion at high velocity, and a pressure-increasing portion pressurizing a mixed refrigerant including the injection refrigerant and the suction refrigerant drawn from the refrigerant suction port, wherein
• the refrigeration cycle device is adapted to adjust a dryness of the refrigerant flowing into the nozzle portion in such a manner that the heating capacity approaches a maximum value, when (i) Δicond is an enthalpy difference obtained by subtracting an enthalpy of the refrigerant on an outlet side of the heating heat exchanger from an enthalpy of the refrigerant on an inlet side of the heating heat exchanger;
• (ii) Gr is a flow rate of the refrigerant flowing into the heating heat exchanger;
• and (iii) Qc is a heating capacity of the fluid to be heat-exchanged in the heating heat exchanger that is obtained by multiplying the refrigerant flow rate by the enthalpy difference,
• a mixing portion that mixes the injection refrigerant and the suction refrigerant is provided in a range of an internal space of the body portion from the refrigerant injection port to an inlet of the pressure-increasing portion,
• a refrigerant passage formed in the nozzle portion includes a tapered portion in which a refrigerant passage area gradually decreases, and an injection portion that guides the refrigerant from the tapered portion to the refrigerant injection port, and
• the nozzle portion is provided to flexibly expand the injection refrigerant to be injected into the mixing portion by setting a spreading angle on a section of the injection portion in an axial direction to 0° or more.