JP6011484B2 - Ejector - Google Patents

Description

  The present invention relates to an ejector that sucks a fluid by reducing the pressure of the fluid and sucking a jet fluid ejected at a high speed.

  Conventionally, an ejector is known as a decompression device applied to a vapor compression refrigeration cycle apparatus. This type of ejector has a nozzle part that decompresses the refrigerant, sucks the gas-phase refrigerant that has flowed out of the evaporator by the suction action of the jetted refrigerant jetted from the nozzle part, and injects it at the booster (diffuser part) The pressure can be increased by mixing the refrigerant and the suction refrigerant.

  Therefore, in a refrigeration cycle apparatus including an ejector as a decompression apparatus (hereinafter referred to as an ejector-type refrigeration cycle), the power consumption of the compressor can be reduced by utilizing the refrigerant pressure-increasing action in the pressure-increasing section of the ejector. The coefficient of performance (COP) of the cycle can be improved as compared with a normal refrigeration cycle apparatus provided with an expansion valve or the like as the apparatus.

  Furthermore, Patent Document 1 discloses an ejector that is applied to an ejector-type refrigeration cycle and that has a nozzle portion that depressurizes the refrigerant in two stages. More specifically, in the ejector disclosed in Patent Document 1, the refrigerant in the high-pressure liquid phase is decompressed by the first nozzle until the gas-liquid two-phase state is obtained, and the refrigerant in the gas-liquid two-phase state is supplied to the second nozzle. Inflow.

  Thereby, in the ejector of patent document 1, the boiling of the refrigerant | coolant in a 2nd nozzle is accelerated | stimulated, the nozzle efficiency as the whole nozzle part is improved, and it is going to aim at the further improvement of COP as the whole ejector type refrigeration cycle. Yes.

  Moreover, in a general ejector, the diffuser part (pressure | voltage rise part) is arrange | positioned coaxially on the extension line | wire of the axial direction of a nozzle part. Further, Patent Document 2 describes that the ejector efficiency can be improved by relatively reducing the spread angle of the diffuser portion arranged in this way.

  The nozzle efficiency is the energy conversion efficiency when the pressure energy of the refrigerant is converted into kinetic energy in the nozzle portion, and the ejector efficiency is the energy conversion efficiency of the entire ejector.

Japanese Patent No. 3331604 JP 2003-14318 A

  However, in the ejector of Patent Document 1, for example, when the thermal load of the ejector-type refrigeration cycle becomes low, and the pressure difference (high-low pressure difference) between the pressure of the high-pressure side refrigerant and the pressure of the low-pressure side refrigerant in the cycle is reduced, There is a case where the first nozzle is depressurized by a high-low pressure difference, and the refrigerant is hardly depressurized by the second nozzle.

  In such a case, the nozzle efficiency improvement effect due to the flow of the gas-liquid two-phase refrigerant into the second nozzle cannot be obtained, and the refrigerant cannot be sufficiently boosted in the diffuser section.

  On the other hand, by applying the diffuser portion having a relatively small spread angle disclosed in Patent Literature 2 to the ejector of Patent Literature 1 and improving the ejector efficiency, the diffuser portion is also at a low load of the ejector refrigeration cycle. A means for sufficiently increasing the pressure of the refrigerant can be considered.

  However, when such a diffuser portion is applied, the length of the nozzle portion in the axial direction as a whole becomes longer, so that the size of the ejector becomes unnecessarily large at the normal load of the ejector refrigeration cycle. Is a problem.

Therefore, the present inventors previously described Japanese Patent Application No. 2012-184950 (hereinafter referred to as a prior application example).
An ejector applied to an ejector refrigeration cycle,
A swirling space for swirling the refrigerant flowing out of the radiator, a decompression space for depressurizing the refrigerant flowing out of the swirling space, and a suction passage for sucking the refrigerant flowing out of the evaporator in communication with the refrigerant flow downstream side of the depressurizing space , And a body formed with a pressure increasing space through which the injected refrigerant injected from the depressurizing space and the suction refrigerant sucked from the suction passage are formed,
A passage forming member that is at least partially disposed in the decompression space and in the pressurization space, and has a conical shape whose cross-sectional area expands with distance from the decompression space;
Nozzle passage functioning as a nozzle in which a refrigerant passage formed between an inner peripheral surface of a portion of the body forming a decompression space and an outer peripheral surface of the passage forming member decompresses and injects the refrigerant flowing out of the swirling space. Form the
A refrigerant passage formed between an inner peripheral surface of a part of the body that forms a pressure increasing space and an outer peripheral surface of the passage forming member serves as a diffuser passage that functions as a diffuser that increases the pressure by mixing the injected refrigerant and the suction refrigerant. Forming,
Furthermore, an ejector is proposed in which a gas-liquid separation space is formed in the body to separate the gas-liquid refrigerant flowing out of the diffuser passage by the action of centrifugal force.

  In the ejector of this prior application, by turning the refrigerant in the swirling space, the refrigerant pressure on the turning center side in the swirling space is reduced to the pressure that becomes the saturated liquid phase refrigerant or the pressure at which the refrigerant boils at a reduced pressure (causes cavitation). Can be reduced. As a result, the gas phase refrigerant is present in the swirl space in the vicinity of the swirl center line so that the gas phase refrigerant is present more on the inner circumference side than the outer circumference side of the swirl center axis, and the liquid single phase is around the gas phase. It can be.

  Then, the refrigerant in the two-phase separation state flows into the nozzle passage, and the boiling is promoted by wall surface boiling and interface boiling, so that the gas phase and the liquid phase are homogeneously mixed in the vicinity of the minimum flow path area of the nozzle passage. It becomes a gas-liquid mixed state. Further, the refrigerant in the gas-liquid mixed state in the vicinity of the minimum flow path area of the nozzle passage is blocked (choking), and the refrigerant is accelerated until the flow rate of the refrigerant in the gas-liquid mixed state becomes a two-phase sound speed.

  Thus, the refrigerant accelerated to the two-phase sonic velocity becomes an ideal two-phase spray flow that is homogeneously mixed downstream from the minimum flow path area of the nozzle passage, and can further increase the flow velocity. it can. As a result, the energy conversion efficiency (equivalent to the nozzle efficiency of the prior art) when converting the pressure energy of the refrigerant into kinetic energy in the nozzle passage can be improved.

  Further, in the ejector of the prior application example, a conical shape is adopted as the passage forming member, and the shape of the diffuser passage is widened along the outer periphery of the passage forming member as the distance from the decompression space increases. Thereby, it can suppress that the axial direction dimension of a diffuser channel expands, and can suppress the enlargement of the physique as the whole ejector.

  Furthermore, in the ejector of the prior application, the gas-liquid refrigerant flowing out of the diffuser passage is separated by the action of centrifugal force in the gas-liquid separation space formed inside the body. In contrast to the case where the separation means is disposed, the gas-liquid refrigerant can be efficiently separated in the gas-liquid separation space, and the volume of the gas-liquid separation space can be effectively reduced.

  In other words, according to the ejector of the prior application example, the energy conversion efficiency in the nozzle passage (corresponding to the nozzle efficiency of the prior art) is reduced even if the load fluctuation of the ejector type refrigeration cycle occurs without increasing the size of the physique. An ejector integrated with a gas-liquid separation means that can be suppressed can be realized.

  However, when the ejector-type refrigeration cycle to which the ejector of the prior application is applied is actually operated, vibration and noise may be generated in the evaporator that evaporates the liquid-phase refrigerant separated in the gas-liquid separation space. It was.

  Therefore, the present inventors investigated the cause, and in the ejector-type refrigeration cycle to which the ejector of the prior application was applied, the cycle configuration in which the compressor sucks the gas-phase refrigerant separated in the gas-liquid separation space. It was found that this is the cause.

  The reason for this is that, in the cycle configuration in which the gas-phase refrigerant separated in the gas-liquid separation space is sucked into the compressor, the pressure pulsation of the compressor suction refrigerant is transmitted to the refrigerant in the gas-liquid separation space, This is because the pressure pulsation of the refrigerant is transmitted to the refrigerant in the evaporator.

  Furthermore, in the ejector of the prior application example, since efficient gas-liquid separation can be performed in the gas-liquid separation space, a gas-liquid interface is formed in the gas-liquid separation space. If the pressure pulsation of the refrigerant sucked from the compressor is transmitted to the gas-liquid interface, the pressure pulsation is directly transmitted to the liquid-phase refrigerant in the evaporator. Easy to grow.

  In the present invention, in view of the above points, in the gas-liquid separation unit integrated ejector applied to the vapor compression refrigeration cycle, the pressure pulsation of the compressor suction refrigerant connected to the gas-liquid separation unit is generated in the gas-liquid separation unit. The purpose is to prevent the refrigerant from being transmitted to the refrigerant.

The present invention has been devised to achieve the above object, and in the invention according to claim 1, a vapor compression refrigeration cycle apparatus (10) having a compressor (11) for compressing and discharging a refrigerant. ) Ejector applied to
A swirling space (30a) for swirling the refrigerant flowing in from the refrigerant inlet (31a), a decompression space (30b) for decompressing the refrigerant flowing out of the swirling space (30a), and a refrigerant flow downstream of the decompression space (30b). A suction passage (13b) that communicates and sucks refrigerant from the outside, and a pressurization space (30e) that flows in the injected refrigerant injected from the decompression space (30b) and the suction refrigerant sucked from the suction passage (13b) ), A gas-liquid separation space (30f) that separates the gas-liquid refrigerant flowing out from the pressurizing space (30e), and the gas-phase refrigerant separated in the gas-liquid separation space (30f) A body (30) having a gas-phase refrigerant outlet (31d) to be discharged to the side,
A passage formed in a conical shape in which at least a part thereof is disposed in the decompression space (30b) and the pressurization space (30e), and the cross-sectional area increases as the distance from the decompression space (30b) increases. A forming member (35),
The refrigerant passage formed between the inner peripheral surface of the part forming the decompression space (30b) in the body (30) and the outer peripheral surface of the passage forming member (35) is a refrigerant that has flowed out of the swirling space (30a). Is a nozzle passage (13a) that functions as a nozzle that injects under reduced pressure,
The refrigerant passage formed between the inner peripheral surface of the body (30) forming the pressurizing space (30e) and the outer peripheral surface of the passage forming member (35) is a mixed refrigerant of the injection refrigerant and the suction refrigerant. A diffuser passage (13c) that functions as a diffuser that converts the kinetic energy of
Further, the body (30) has a buffer space (30j) for attenuating pressure pulsations transmitted from the suction port side of the compressor (11) into the gas-liquid separation space (30f). To do.

  According to this, the energy conversion efficiency (equivalent to nozzle efficiency) in the nozzle passage (13a) can be improved by swirling the refrigerant in the swirling space (30a). Moreover, since the diffuser passage (13c) has a shape that expands along the outer peripheral side of the passage forming member (35), the expansion of the axial dimension of the diffuser passage (13c) can be suppressed. Moreover, since the gas-liquid separation space (30f) is formed in the body (30), the volume of the gas-liquid separation space (30f) can be reduced.

  In addition, according to the invention described in this claim, since the buffer space (30j) is formed, it is transmitted from the suction port side of the compressor (11) into the gas-liquid separation space (30f). The pressure pulsation of the refrigerant can be attenuated. That is, it is possible to suppress the pressure pulsation of the refrigerant sucked by the compressor (11) connected to the gas-liquid separation space (30f) from being transmitted to the refrigerant in the gas-liquid separation space (30f).

  As a result, the pressure pulsation of the refrigerant sucked in the compressor (11) is transmitted to the refrigerant in the evaporator that evaporates the refrigerant separated in the gas-liquid separation space (30f), causing vibration and noise in the evaporator. Can be suppressed.

  In the above claims, the gas-phase refrigerant outlet (31d) is not limited to the one directly connected to the suction port of the compressor (11) via the refrigerant pipe. It includes those indirectly connected through a low-pressure refrigerant passage or the like of an internal heat exchanger that exchanges heat with the low-pressure refrigerant.

  Further, the passage forming member (35) is not limited to the one having a shape in which the cross-sectional area expands as it is strictly separated from the decompression space (30b), and at least partially includes the decompression space (30b). The shape of the diffuser passage (13c) includes a shape that expands outward as the distance from the decompression space (30b) increases. .

  Further, “conically formed” is not limited to the meaning that the passage forming member (35) is formed in a complete conical shape, and includes a shape close to a cone or a portion of the cone. It also includes the meaning of being formed. Specifically, the shape in which the axial cross-sectional shape is not limited to an isosceles triangle, the shape in which the two sides sandwiching the apex are convex on the inner peripheral side, the shape in which the two sides sandwiching the apex are convex on the outer peripheral side, Furthermore, it is meant to include those having a semicircular cross section.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

1 is an overall configuration diagram of an ejector refrigeration cycle according to an embodiment. It is an axial sectional view of the ejector of one embodiment. It is typical sectional drawing for demonstrating the function of each refrigerant path of the ejector of one Embodiment. It is a Mollier diagram which shows the state of the refrigerant | coolant in the ejector-type refrigerating cycle of one Embodiment.

  An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the ejector 13 of this embodiment is applied to a vapor compression refrigeration cycle apparatus including an ejector as a refrigerant decompression unit, that is, an ejector refrigeration cycle 10. Furthermore, this ejector-type refrigeration cycle 10 is applied to a vehicle air conditioner, and fulfills a function of cooling blown air that is blown into a vehicle interior that is a space to be air-conditioned.

  The ejector refrigeration cycle 10 employs an HFC refrigerant (specifically, R134a) as the refrigerant, and constitutes a subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the refrigerant critical pressure. . Of course, an HFO refrigerant (specifically, R1234yf) or the like may be adopted as the refrigerant. Furthermore, refrigeration oil for lubricating the compressor 11 is mixed in the refrigerant, and a part of the refrigeration oil circulates in the cycle together with the refrigerant.

  In the ejector-type refrigeration cycle 10, the compressor 11 sucks the refrigerant and discharges it until it becomes high-pressure refrigerant. Specifically, the compressor 11 of the present embodiment is an electric compressor configured by housing a fixed capacity type compression mechanism 11a and an electric motor 11b for driving the compression mechanism 11a in one housing.

  As the compression mechanism 11a, various compression mechanisms such as a scroll-type compression mechanism and a vane-type compression mechanism can be employed. Further, the electric motor 11b is controlled in its operation (number of rotations) by a control signal output from a control device to be described later, and may adopt either an AC motor or a DC motor.

  The compressor 11 may be an engine-driven compressor that is driven by a rotational driving force transmitted from a vehicle travel engine via a pulley, a belt, or the like. As this type of engine-driven compressor, a variable displacement compressor that can adjust the refrigerant discharge capacity by changing the discharge capacity, or adjusting the refrigerant discharge capacity by changing the operating rate of the compressor by intermittently connecting the electromagnetic clutch. A fixed capacity compressor can be employed.

  The refrigerant inlet side of the condenser 12 a of the radiator 12 is connected to the discharge port of the compressor 11. The radiator 12 is a heat exchanger for heat radiation that radiates and cools the high-pressure refrigerant by exchanging heat between the high-pressure refrigerant discharged from the compressor 11 and outside air (outside air) blown by the cooling fan 12d. .

  More specifically, the radiator 12 is a condensing unit that exchanges heat between the high-pressure gas-phase refrigerant discharged from the compressor 11 and the outside air blown from the cooling fan 12d to radiate and condense the high-pressure gas-phase refrigerant. 12a, a receiver 12b that separates the gas-liquid refrigerant flowing out of the condensing unit 12a and stores excess liquid-phase refrigerant, and a liquid-phase refrigerant that flows out of the receiver unit 12b and the outside air blown from the cooling fan 12d exchange heat. This is a so-called subcool condenser that includes a supercooling section 12c that supercools the liquid-phase refrigerant.

  Further, the cooling fan 12d is an electric blower in which the rotation speed (the amount of blown air) is controlled by a control voltage output from the control device. A refrigerant inlet 31 a of the ejector 13 is connected to the refrigerant outlet side of the supercooling portion 12 c of the radiator 12.

  The ejector 13 functions as a refrigerant pressure reducing means for reducing the pressure of the supercooled high-pressure liquid-phase refrigerant that has flowed out of the radiator 12 and flowing it to the downstream side, and is described later by the suction action of the refrigerant flow injected at a high speed. It functions as a refrigerant circulating means (refrigerant transporting means) that sucks (transports) and circulates the refrigerant flowing out of the evaporator 14 that circulates. Furthermore, the ejector 13 according to the present embodiment also functions as a gas-liquid separation unit that separates the gas-liquid of the decompressed refrigerant.

  A specific configuration of the ejector 13 will be described with reference to FIGS. In addition, the up and down arrows in FIG. 2 indicate the up and down directions in a state where the ejector refrigeration cycle 10 is mounted on the vehicle air conditioner. FIG. 3 is a schematic cross-sectional view for explaining the function of each refrigerant passage of the ejector 13, and parts having the same functions as those in FIG. 2 are denoted by the same reference numerals.

  First, the ejector 13 of this embodiment is provided with the body 30 comprised by combining a some structural member, as shown in FIG. More specifically, the body 30 has a housing body 31 that is formed of a prismatic or columnar metal or resin and forms the outer shell of the ejector 13, and a nozzle body 32 is provided inside the housing body 31. The structural members such as the middle body 33, the middle plate 34, and the lower body 36 are fixed.

  The housing body 31 includes a refrigerant inlet 31 a that allows the refrigerant flowing out of the radiator 12 to flow into the interior, a refrigerant suction port 31 b that sucks the refrigerant flowing out of the evaporator 14, and a gas-liquid separation space formed inside the body 30. The liquid-phase refrigerant outlet 31c that causes the liquid-phase refrigerant separated in 30f to flow out to the refrigerant inlet side of the evaporator 14 and the gas-phase refrigerant separated in the gas-liquid separation space 30f flow out to the suction side of the compressor 11. The gas-phase refrigerant outlet 31d to be made is formed.

  The nozzle body 32 is formed of a substantially conical metal member or the like that tapers in the refrigerant flow direction, and is press-fitted into the housing body 31 so that its axial direction is parallel to the vertical direction (vertical direction in FIG. 2). It is fixed by means such as. Between the upper side of the nozzle body 32 and the housing body 31, a swirling space 30a for swirling the refrigerant flowing from the refrigerant inlet 31a is formed.

  The swirling space 30a is formed in a rotating body shape, and the central axis shown by the one-dot chain line in FIG. 2 extends in the vertical direction. The rotating body shape is a three-dimensional shape formed when a plane figure is rotated around one straight line (central axis) on the same plane. More specifically, the swirl space 30a of the present embodiment is formed in a substantially cylindrical shape. Of course, you may form in the shape etc. which combined the cone or the truncated cone, and the cylinder.

  Furthermore, the refrigerant inflow passage 31e that connects the refrigerant inlet 31a and the swirling space 30a is tangent to the inner peripheral wall surface of the body 30 that forms the swirling space 30a when viewed from the central axis direction of the swirling space 30a. Extending in the direction. Thereby, the refrigerant that has flowed into the swirl space 30a from the refrigerant inflow passage 31e flows along the inner peripheral wall surface of the part of the body 30 that forms the swirl space 30a, and swirls within the swirl space 30a.

  The refrigerant inflow passage 31e does not need to be formed so as to completely coincide with the tangential direction of the swirl space 30a when viewed from the central axis direction of the swirl space 30a, and at least in the tangential direction of the swirl space 30a. As long as a component is included, it may be formed including a component in another direction (for example, a component in the axial direction of the swirling space 30a).

  Here, since centrifugal force acts on the refrigerant swirling in the swirling space 30a, the refrigerant pressure on the central axis side is lower than the refrigerant pressure on the outer peripheral side in the swirling space 30a. Therefore, in the present embodiment, during normal operation of the ejector refrigeration cycle 10, the refrigerant pressure on the central axis side in the swirling space 30a is set to the pressure that becomes the saturated liquid phase refrigerant, or the refrigerant boils under reduced pressure (causes cavitation). The pressure is lowered to the pressure.

  Such adjustment of the refrigerant pressure on the central axis side in the swirling space 30a can be realized by adjusting the swirling flow velocity of the refrigerant swirling in the swirling space 30a. Further, the swirl flow rate can be adjusted by adjusting the area ratio between the passage sectional area of the refrigerant inflow passage 31e and the vertical sectional area in the axial direction of the swirling space 30a, for example. Note that the swirling flow velocity in the present embodiment means the flow velocity in the swirling direction of the refrigerant in the vicinity of the outermost peripheral portion of the swirling space 30a.

  Further, in the nozzle body 32, a decompression space 30b is formed in which the refrigerant that has flowed out of the swirl space 30a is decompressed and flows out downstream. The decompression space 30b is formed in a rotating body shape in which a cylindrical space and a frustoconical space that continuously spreads from the lower side of the cylindrical space and gradually expands in the refrigerant flow direction. The central axis of the working space 30b is arranged coaxially with the central axis of the swirling space 30a.

  Further, inside the decompression space 30b, there is formed a minimum passage area portion 30m having the smallest refrigerant passage area in the decompression space 30b, and a passage forming member 35 that changes the passage area of the minimum passage area portion 30m. Has been placed. The passage forming member 35 is formed in a substantially conical shape that gradually expands toward the downstream side of the refrigerant flow, and the central axis thereof is arranged coaxially with the central axis of the decompression space 30b. In other words, the passage forming member 35 is formed in a conical shape whose cross-sectional area increases as the distance from the decompression space 30b increases.

  As the refrigerant passage formed between the inner peripheral surface of the portion forming the pressure reducing space 30b of the nozzle body 32 and the outer peripheral surface on the upper side of the passage forming member 35, as shown in FIG. The tip 131 is formed on the upstream side of the refrigerant flow from the portion 30m and gradually decreases in the refrigerant passage area until reaching the minimum passage area 30m, and the refrigerant passage is formed on the downstream side of the refrigerant flow from the minimum passage area 30m. A divergent portion 132 whose area gradually increases is formed.

  In the downstream side portion and the divergent portion 132 of the tapered portion 131, the decompression space 30 b and the passage forming member 35 are overlapped (overlapped) when viewed from the radial direction, so that the shape of the axial cross section of the refrigerant passage is vertical. It becomes an annular shape (a donut shape excluding a small-diameter circular shape arranged coaxially from a large-diameter circular shape). Furthermore, since the spread angle of the passage forming member 35 of the present embodiment is smaller than the spread angle of the frustoconical space of the decompression space 30b, the refrigerant passage area in the divergent portion 132 is directed toward the downstream side of the refrigerant flow. Gradually expanding.

  In the present embodiment, a nozzle passage 13a that functions as a nozzle is a refrigerant passage formed between the inner peripheral surface of the decompression space 30b and the outer peripheral surface on the top side of the passage forming member 35 by this passage shape. Further, in the nozzle passage 13a, the refrigerant is decompressed, and the flow rate of the refrigerant in the gas-liquid two-phase state is increased so as to be higher than the two-phase sound velocity, and is injected.

  Note that the refrigerant passage formed between the inner peripheral surface of the decompression space 30b and the outer peripheral surface on the top side of the passage forming member 35 in this embodiment is the outer periphery of the passage forming member 35 as shown in FIG. This is a refrigerant passage formed so as to include a range where a line segment extending in the normal direction from the surface intersects a portion of the nozzle body 32 forming the decompression space 30b.

  Further, since the refrigerant flowing into the nozzle passage 13a swirls in the swirling space 30a, the refrigerant flowing through the nozzle passage 13a and the jet refrigerant injected from the nozzle passage 13a are the same as the refrigerant swirling in the swirling space 30a. It has a velocity component in the direction of turning in the direction.

  Next, as shown in FIG. 2, the middle body 33 is provided with a rotating body-shaped through hole penetrating the front and back at the center, and driving the passage forming member 35 to be displaced to the outer peripheral side of the through hole. It is formed of a metal disk-like member that accommodates the means 37. The central axis of the through hole of the middle body 33 is arranged coaxially with the central axes of the swirl space 30a and the decompression space 30b. The middle body 33 is fixed inside the housing body 31 and below the nozzle body 32 by means such as press fitting.

  Furthermore, an inflow space 30c is formed between the upper surface of the middle body 33 and the inner wall surface of the housing body 31 facing the middle body 33 for retaining the refrigerant flowing in from the refrigerant suction port 31b. In the present embodiment, since the tapered tip portion on the lower side of the nozzle body 32 is positioned inside the through hole of the middle body 33, the inflow space 30c has a cross section when viewed from the central axis direction of the swirl space 30a and the decompression space 30b. It is formed in an annular shape.

  The suction refrigerant inflow passage 30h connecting the refrigerant suction port 31b and the inflow space 30c extends in the tangential direction of the inner peripheral wall surface of the inflow space 30c when viewed from the central axis direction of the inflow space 30c. Thereby, in this embodiment, the refrigerant that has flowed into the inflow space 30c from the refrigerant suction port 31b via the suction refrigerant inflow passage 30h is swirled in the same direction as the refrigerant in the swirling space 30a.

  Further, in the range where the lower side of the nozzle body 32 is inserted, that is, in the range where the middle body 33 and the nozzle body 32 overlap when viewed from the radial direction perpendicular to the axis among the through holes of the middle body 33, the tapered tip of the nozzle body 32 is formed. The refrigerant passage area gradually decreases in the refrigerant flow direction so as to conform to the outer peripheral shape.

  As a result, a suction passage 30d is formed between the inner peripheral surface of the through hole and the outer peripheral surface of the tapered tip portion on the lower side of the nozzle body 32 to communicate the inflow space 30c and the downstream side of the refrigerant flow in the decompression space 30b. Is done. That is, in this embodiment, the suction passage 13b for sucking the refrigerant from the outside is formed by the suction refrigerant inflow passage 30h, the inflow space 30c, and the suction passage 30d that connect the refrigerant suction port 31b and the inflow space 30c. .

  The cross section of the suction passage 30d perpendicular to the central axis is formed in an annular shape, and the refrigerant flowing through the suction passage 30d also has a speed component in the direction of swirling in the same direction as the refrigerant swirling in the swirling space 30a. . Further, the refrigerant outlet of the suction passage 13b (specifically, the refrigerant outlet of the suction passage 30d) opens in an annular shape on the outer peripheral side of the refrigerant outlet (refrigerant injection port) of the nozzle passage 13a.

  Further, in the through hole of the middle body 33, a pressure increasing space 30e formed in a substantially truncated cone shape gradually spreading in the refrigerant flow direction is formed on the downstream side of the refrigerant flow in the suction passage 30d. The pressure increasing space 30e is a space into which the injected refrigerant injected from the pressure reducing space 30b (specifically, the nozzle passage 13a) and the suction refrigerant sucked from the suction passage 13b flow.

  A lower portion of the above-described passage forming member 35 is disposed inside the pressure increasing space 30e. Further, the expansion angle of the conical side surface of the passage forming member 35 in the pressure increasing space 30e is smaller than the expansion angle of the frustoconical space of the pressure increasing space 30e. The flow gradually expands toward the downstream side.

  In the present embodiment, by expanding the refrigerant passage area in this way, as shown in FIG. 3, the inner peripheral surface of the middle body 33 that forms the pressurizing space 30 e and the outer peripheral surface on the lower side of the passage forming member 35 are formed. A refrigerant passage formed between them serves as a diffuser passage 13c that functions as a diffuser. And in this diffuser channel | path 13c, the kinetic energy of the mixed refrigerant | coolant of an injection refrigerant | coolant and a suction refrigerant | coolant is converted into pressure energy.

  Further, the axial vertical cross-sectional shape of the diffuser passage 13c is also formed in an annular shape, and the refrigerant flowing through the diffuser passage 13c is also from the speed component in the swirling direction of the injection refrigerant injected from the nozzle passage 13a and the suction passage 13b. The speed component in the swirling direction of the sucked suction refrigerant has a speed component in the direction swirling in the same direction as the refrigerant swirling in the swirling space 30a.

  Next, the drive means 37 which is disposed inside the middle body 33 and displaces the passage forming member 35 will be described. The driving means 37 is configured to have a circular thin plate-like diaphragm 37a which is a pressure responsive member. More specifically, as shown in FIG. 2, the diaphragm 37a is fixed by means such as welding so as to partition a cylindrical space formed on the outer peripheral side of the middle body 33 into two upper and lower spaces.

  Of the two spaces partitioned by the diaphragm 37a, the space on the upper side (the inflow space 30c side) constitutes an enclosed space 37b in which a temperature-sensitive medium whose pressure changes according to the temperature of the refrigerant flowing out of the evaporator 14 is enclosed. Yes. A temperature sensitive medium having the same composition as the refrigerant circulating in the ejector refrigeration cycle 10 is enclosed in the enclosed space 37b so as to have a predetermined density. Therefore, the temperature sensitive medium in this embodiment is R134a.

  On the other hand, the lower space of the two spaces partitioned by the diaphragm 37a constitutes an introduction space 37c into which the refrigerant flowing out of the evaporator 14 is introduced via a communication path (not shown). Therefore, the temperature of the refrigerant flowing out of the evaporator 14 is transmitted to the temperature-sensitive medium enclosed in the enclosure space 37b via the lid member 37d and the diaphragm 37a that partition the inflow space 30c and the enclosure space 37b.

  Here, as is apparent from FIGS. 2 and 3, the suction passage 13 b is disposed on the upper side of the middle body 33 of the present embodiment, and the diffuser passage 13 c is disposed on the lower side of the middle body 33. Accordingly, at least a part of the driving means 37 is disposed at a position sandwiched between the suction passage 13b and the diffuser passage 13c when viewed from the radial direction of the central axis.

  More specifically, the enclosed space 37b of the driving means 37 is a position where it overlaps with the suction passage 13b and the diffuser passage 13c when viewed from the central axis direction of the swivel space 30a, the passage forming member 35, etc. It arrange | positions in the position enclosed by the channel | path 13b for diffusers, and the diffuser channel | path 13c. As a result, the temperature of the refrigerant flowing out of the evaporator 14 is transmitted to the enclosed space 37b, and the internal pressure of the enclosed space 37b becomes a pressure corresponding to the temperature of the refrigerant flowing out of the evaporator 14.

  Further, the diaphragm 37a is deformed according to a differential pressure between the internal pressure of the enclosed space 37b and the pressure of the refrigerant flowing out of the evaporator 14 flowing into the introduction space 37c. For this reason, the diaphragm 37a is preferably formed of a tough material having high elasticity and good heat conduction, and is preferably formed of a thin metal plate such as stainless steel (SUS304).

  Further, the upper end side of a columnar operating rod 37e is joined to the center of the diaphragm 37a by means such as welding, and the outer peripheral side of the lowermost side (bottom) of the passage forming member 35 is fixed to the lower end side of the operating rod 37e. Has been. Thereby, the diaphragm 37a and the passage forming member 35 are connected, and the passage forming member 35 is displaced in accordance with the displacement of the diaphragm 37a, and the refrigerant passage area of the nozzle passage 13a (passage sectional area in the minimum passage area portion 30m) is adjusted. The

  Specifically, when the temperature (superheat degree) of the refrigerant flowing out of the evaporator 14 increases, the saturation pressure of the temperature-sensitive medium enclosed in the enclosed space 37b increases, and the pressure in the introduction space 37c is subtracted from the internal pressure of the enclosed space 37b. Increased differential pressure. Thereby, the diaphragm 37a displaces the channel | path formation member 35 in the direction (vertical direction lower side) which enlarges the channel | path cross-sectional area in the minimum channel | path area part 30m.

  On the other hand, when the temperature (superheat degree) of the refrigerant flowing out of the evaporator 14 is lowered, the saturation pressure of the temperature sensitive medium enclosed in the enclosed space 37b is lowered, and the difference obtained by subtracting the pressure of the introduction space 37c from the internal pressure of the enclosed space 37b. The pressure is reduced. Thereby, the diaphragm 37a displaces the passage forming member 35 in a direction (vertical direction upper side) in which the passage sectional area in the minimum passage area portion 30m is reduced.

  In this way, the diaphragm 37a displaces the passage forming member 35 in the vertical direction according to the superheat degree of the refrigerant flowing out of the evaporator 14, so that the superheat degree of the refrigerant flowing out of the evaporator 14 approaches a predetermined value. The passage sectional area in the minimum passage area portion 30m can be adjusted. The gap between the operating rod 37e and the middle body 33 is sealed by a sealing member such as an O-ring (not shown), and the refrigerant does not leak from the gap even if the operating rod 37e is displaced.

  The bottom surface of the passage forming member 35 receives a load of a coil spring 40 fixed to the lower body 36. The coil spring 40 applies a load that urges the passage forming member 35 toward the side that reduces the cross-sectional area of the passage in the minimum passage area portion 30m (the upper side in FIG. 2). It is also possible to change the valve opening pressure of the passage forming member 35 to change the target degree of superheat.

  Further, in the present embodiment, a plurality of (specifically, two) cylindrical spaces are provided on the outer peripheral side of the middle body 33, and a circular thin plate-like diaphragm 37a is fixed inside each of these spaces to drive two drives. Although the means 37 is comprised, the number of the drive means 37 is not limited to this. In addition, when providing the drive means 37 in multiple places, it is desirable to arrange | position at equal angle intervals with respect to a central axis, respectively.

  Alternatively, a diaphragm formed by an annular thin plate may be fixed in a space formed in an annular shape when viewed from the axial direction, and the diaphragm and the passage forming member 35 may be connected by a plurality of operating rods. Good.

  Next, the middle plate 34 is formed of a substantially disk-shaped metal member or the like, and its outer peripheral side is fixed inside the housing body by means such as press fitting. Further, the middle plate 34 is disposed below the passage forming member 35. As shown in FIG. 2, the middle plate 34 flows out from the diffuser passage 13c between the upper surface side of the middle plate 34 and the bottom surface side of the middle body 33. A gas-liquid separation space 30f for separating the gas-liquid of the refrigerant is formed.

  That is, the middle plate 34 forms the bottom of the gas-liquid separation space 30f, and constitutes the first constituent member recited in the claims. The gas-liquid separation space 30f is formed as a substantially cylindrical rotating body-shaped space, and the central axis of the gas-liquid separation space 30f is also the center of the swirl space 30a, the decompression space 30b, the passage forming member 35, and the like. It is arranged coaxially with the shaft.

  As described above, the refrigerant flowing out of the diffuser passage 13c and flowing into the gas-liquid separation space 30f has a velocity component in the direction swirling in the same direction as the refrigerant swirling in the swirling space 30a or the refrigerant flowing in the diffuser passage 13c. doing. Therefore, the gas-liquid refrigerant is separated in the gas-liquid separation space 30f by the action of centrifugal force.

  In addition, a cylindrical pipe 34a is provided at the center of the middle plate 34 so as to be coaxial with the gas-liquid separation space 30f and project upward (toward the passage forming member 35). Therefore, the liquid-phase refrigerant separated in the gas-liquid separation space 30f is temporarily stored on the outer peripheral side of the pipe 34a.

  Further, an upper side (upstream side) of the gas-phase refrigerant outflow passage 30i that guides the gas-phase refrigerant separated in the gas-liquid separation space 30f to the gas-phase refrigerant outlet 31d is formed in the pipe 34a. Further, a fixing member 41 for fixing the above-described coil spring 40 is disposed at the upper end portion of the pipe 34a, and the gas phase refrigerant separated in the gas-liquid separation space 30f is supplied to the fixing member 41 as a gas phase refrigerant. An inflow hole is provided for flowing into the outflow passage 30i.

  The coil spring 40 also functions as a vibration buffer member that attenuates the vibration of the passage forming member 35 caused by pressure pulsation when the refrigerant is depressurized. Further, an oil return hole 34c for returning the refrigeration oil in the liquid-phase refrigerant into the compressor 11 through the gas-phase refrigerant outflow passage 30i is formed in the root part (lowermost part) of the pipe 34a.

  Next, the lower body 36 is formed of a cylindrical metal member, and is fixed in the housing body 31 by means such as screwing so as to close the bottom surface of the housing body 31.

  Further, as shown in FIG. 2, a buffer space 30 j is formed between the upper surface of the lower body 36 and the bottom surface of the middle plate 34 to enlarge the passage sectional area of the gas-phase refrigerant outflow passage 30 i. In other words, the lower body 36 is disposed on the lower side of the middle plate 34 to form the buffer space 30j, and constitutes the second constituent member recited in the claims.

  The buffer space 30j is a space provided to attenuate the pressure pulsation of the refrigerant transmitted from the suction port side of the compressor 11 connected to the gas phase refrigerant outlet 31d of the housing body 31 into the gas-liquid separation space 30f. In this case, the space is formed as a substantially cylindrical rotating body-shaped space. Further, the central axis of the buffer space 30j is also arranged coaxially with the central axes of the swirling space 30a, the decompression space 30b, the passage forming member 35, and the like.

  The passage cross-sectional area of the buffer space 30j is the minimum passage cross-sectional area in the upstream portion of the buffer space 30j in the gas-phase refrigerant outflow passage 30i (in this embodiment, the total opening of the inflow holes formed in the fixing member 41). Area). Furthermore, it is formed larger than the minimum passage area portion (in this embodiment, the opening area of the housing body 31 on the buffer space 30j side) in the downstream portion of the buffer space 30j in the gas-phase refrigerant outflow passage 30i.

  As the passage sectional area of the gas-phase refrigerant outflow passage 30i or the buffer space 30j, a passage area or the like in a cross section perpendicular to the mainstream flow direction of the gas-phase refrigerant flowing through the gas-phase refrigerant outflow passage 30i or the buffer space 30j is adopted. May be. Further, a passage sectional area perpendicular to the center line of the gas-phase refrigerant outflow passage 30i or the center axis of the buffer space 30j may be employed.

  As shown in FIG. 1, the inlet side of the evaporator 14 is connected to the liquid-phase refrigerant outlet 31 c of the ejector 13. The evaporator 14 performs heat exchange between the low-pressure refrigerant decompressed by the ejector 13 and the blown air blown into the vehicle interior from the blower fan 14a, thereby evaporating the low-pressure refrigerant and exerting an endothermic effect. It is a vessel.

  The blower fan 14a is an electric blower whose rotation speed (amount of blown air) is controlled by a control voltage output from the control device. A refrigerant suction port 31 b of the ejector 13 is connected to the outlet side of the evaporator 14. Further, as described above, the suction port side of the compressor 11 is connected to the gas-phase refrigerant outlet 31 d of the ejector 13.

  Next, a control device (not shown) includes a known microcomputer including a CPU, a ROM, a RAM, and the like and peripheral circuits thereof. This control device performs various calculations and processes based on the control program stored in the ROM, and controls the operations of the various electric actuators 11b, 12d, 14a and the like described above.

  In addition, the control device includes an internal air temperature sensor that detects the temperature inside the vehicle, an external air temperature sensor that detects the outside air temperature, a solar radiation sensor that detects the amount of solar radiation in the vehicle interior, and an air temperature (evaporator temperature) of the evaporator 14. A sensor group for air conditioning control such as an evaporator temperature sensor to detect, an outlet side temperature sensor to detect the temperature of the radiator 12 outlet side refrigerant, and an outlet side pressure sensor to detect the pressure of the radiator 12 outlet side refrigerant are connected, Detection values of these sensor groups are input.

  Furthermore, an operation panel (not shown) disposed near the instrument panel in the front part of the vehicle interior is connected to the input side of the control device, and operation signals from various operation switches provided on the operation panel are input to the control device. The As various operation switches provided on the operation panel, there are provided an air conditioning operation switch for requesting air conditioning in the vehicle interior, a vehicle interior temperature setting switch for setting the vehicle interior temperature, and the like.

  Note that the control device of the present embodiment is configured integrally with control means for controlling the operation of various control target devices connected to the output side of the control device. The configuration (hardware and software) for controlling the operation constitutes the control means of each control target device. For example, in this embodiment, the structure (hardware and software) which controls the action | operation of the electric motor 11b of the compressor 11 comprises the discharge capability control means.

  Next, the operation of the present embodiment in the above configuration will be described using the Mollier diagram of FIG. The vertical axis of the Mollier diagram shows pressures corresponding to P0, P1, and P2 in FIG. First, when the operation switch of the operation panel is turned on (ON), the control device operates the electric motor 11b, the cooling fan 12d, the blower fan 14a, and the like of the compressor 11. Thereby, the compressor 11 sucks the refrigerant, compresses it, and discharges it.

  The high-temperature and high-pressure gas-phase refrigerant (point a4 in FIG. 4) discharged from the compressor 11 flows into the condenser 12a of the radiator 12 and exchanges heat with the blown air (outside air) blown from the cooling fan 12d. , Dissipates heat and condenses. The refrigerant that has dissipated heat in the condensing unit 12a is gas-liquid separated in the receiver unit 12b. The liquid-phase refrigerant separated by gas and liquid in the receiver unit 12b exchanges heat with the blown air blown from the cooling fan 12d in the supercooling unit 12c, and further dissipates heat to become a supercooled liquid-phase refrigerant (see FIG. 4). a4 point → b4 point).

  The supercooled liquid-phase refrigerant that has flowed out of the supercooling portion 12c of the radiator 12 passes through the nozzle passage 13a formed between the inner peripheral surface of the decompression space 30b of the ejector 13 and the outer peripheral surface of the passage forming member 35. The pressure is reduced entropically and injected (point b4 → point c4 in FIG. 4). At this time, the refrigerant passage area in the minimum passage area 30m of the decompression space 30b is adjusted so that the superheat degree of the refrigerant on the outlet side of the evaporator 14 approaches a predetermined value.

  The refrigerant flowing out of the evaporator 14 by the suction action of the refrigerant injected from the nozzle passage 13a passes through the refrigerant suction port 31b and the suction passage 13b (more specifically, the inflow space 30c and the suction passage 30d). Sucked. Further, the refrigerant injected from the nozzle passage 13a and the suction refrigerant sucked through the suction passage 13b and the like flow into the diffuser passage 13c (point c4 → d4, point h4 → d4 in FIG. 4).

  In the diffuser passage 13c, the kinetic energy of the refrigerant is converted into pressure energy by expanding the refrigerant passage area. As a result, the pressure of the mixed refrigerant rises while the injection refrigerant and the suction refrigerant are mixed (d4 point → e4 point in FIG. 4). The refrigerant flowing out of the diffuser passage 13c is gas-liquid separated in the gas-liquid separation space 30f (point e4 → f4, point e4 → g4 in FIG. 4).

  The liquid-phase refrigerant separated in the gas-liquid separation space 30f flows out from the liquid-phase refrigerant outlet 31c and flows into the evaporator 14. The refrigerant flowing into the evaporator 14 absorbs heat from the blown air blown by the blower fan 14a and evaporates, and the blown air is cooled (point g4 → h4 in FIG. 4). On the other hand, the gas-phase refrigerant separated in the gas-liquid separation space 30f flows out from the gas-phase refrigerant outlet 31d and is sucked into the compressor 11 and compressed again (point f4 → a4 in FIG. 4).

  The ejector refrigeration cycle 10 of the present embodiment operates as described above and can cool the blown air blown into the vehicle interior. Further, in the ejector refrigeration cycle 10, since the refrigerant whose pressure is increased in the diffuser passage 13c is sucked into the compressor 11, the driving power of the compressor 11 can be reduced and the cycle efficiency (COP) can be improved. .

  Furthermore, according to the ejector 13 of the present embodiment, by turning the refrigerant in the swirl space 30a, the refrigerant pressure on the swivel center side in the swirl space 30a is reduced to the pressure that becomes a saturated liquid phase refrigerant, or the refrigerant is depressurized. The pressure can be reduced to boiling (causing cavitation). Thus, the gas phase refrigerant is present in the swirl space 30a in the vicinity of the swirl center line, and the liquid single phase is surrounded by the two-phase separation so that a larger amount of gas-phase refrigerant exists on the inner periphery side than the outer periphery side of the swirl center shaft. State.

  As the refrigerant in the two-phase separation state flows into the nozzle passage 13a in this manner, the tip 131 of the nozzle passage 13a has a wall surface boiling that occurs when the refrigerant is separated from the outer peripheral side wall surface of the annular refrigerant passage. Boiling of the refrigerant is promoted by interfacial boiling by boiling nuclei generated by cavitation of the refrigerant on the central axis side of the annular refrigerant passage. As a result, the refrigerant flowing into the minimum passage area 30m of the nozzle passage 13a approaches a gas-liquid mixed state in which the gas phase and the liquid phase are uniformly mixed.

  Then, the flow of refrigerant in the gas-liquid mixed state is choked in the vicinity of the minimum passage area portion 30m, and the gas-liquid mixed state refrigerant that has reached the speed of sound by this choking is accelerated by the divergent portion 132 and injected. The Thus, by promoting boiling by both wall boiling and interfacial boiling, the gas-liquid mixed refrigerant can be efficiently accelerated until it reaches the speed of sound, so that the energy conversion efficiency in the nozzle passage 13a (corresponding to the nozzle efficiency of the prior art) is increased. Can be improved.

  Further, in the ejector 13 of the present embodiment, the passage forming member 35 is formed in a conical shape in which the cross-sectional area increases with distance from the decompression space 30b, and the cross-sectional shape of the diffuser passage 13c is annular. Therefore, the shape of the diffuser passage 13c can be made to expand along the outer periphery of the passage forming member 35 as the distance from the decompression space 30b increases. Thereby, it can suppress that the dimension of the axial direction of the diffuser channel | path 13c (axial direction of the channel | path formation member 35) expands with respect to a prior art.

  In addition to this, since the body 30 of the ejector 13 of the present embodiment is formed with a gas-liquid separation space 30f for separating the gas-liquid of the refrigerant flowing out from the diffuser passage 13c, the gas-liquid separation is performed separately from the ejector 13. The volume of the gas-liquid separation space 30f can be effectively reduced as compared with the case where means are provided.

  That is, in the gas-liquid separation space 30f of the present embodiment, the refrigerant flowing out of the diffuser passage 13c formed in an annular cross section already has a speed component in the swirling direction, so that the refrigerant swirls in the gas-liquid separation space 30f. It is not necessary to provide a space for generating a flow. Therefore, the volume of the gas-liquid separation space 30f can be effectively reduced as compared with the case where the gas-liquid separation means is provided separately from the ejector 13. Therefore, in the ejector 13 of this embodiment, the enlargement of the physique as the ejector 13 whole can be suppressed.

  Here, like the ejector 13 of the present embodiment, the refrigerant inlet side of the evaporator 14 is connected to the liquid-phase refrigerant outlet 31c of the ejector 13, and the inlet side of the compressor 11 is connected to the gas-phase refrigerant outlet 31d. In the configuration, the pressure pulsation of the refrigerant sucked by the compressor 11 is transmitted to the refrigerant in the gas-liquid separation space 30f, and further, the pressure pulsation of the refrigerant in the gas-liquid separation space 30f is transmitted to the evaporator 14 and vibrates to the evaporator 14. There is a concern that it may cause noise.

  On the other hand, according to the ejector 13 of the present embodiment, since the buffer space 30j is formed, the pressure pulsation of the refrigerant transmitted from the suction port side of the compressor 11 into the gas-liquid separation space 30f is attenuated. be able to.

  More specifically, the passage cross-sectional area of the buffer space 30j is formed larger than the minimum passage cross-sectional area of the portion upstream of the buffer space 30j in the gas-phase refrigerant outflow passage 30i, and further, the gas-phase refrigerant outflow passage 30i. Is formed larger than the minimum passage area of the portion downstream of the buffer space 30j. That is, the buffer space 30j is formed as a space for enlarging the passage sectional area in the middle of the gas-phase refrigerant outflow passage 30i.

  Therefore, the buffer space 30j functions as a so-called muffler, and the pressure pulsation of the refrigerant sucked by the compressor 11 can be suppressed from being transmitted to the refrigerant in the gas-liquid separation space 30f. As a result, it is possible to suppress the pressure pulsation of the refrigerant sucked by the compressor 11 from being transmitted to the refrigerant in the evaporator 14 and causing vibration and noise in the evaporator 14.

  Further, in the ejector 13 of the present embodiment, the cylindrical buffer space 30j is formed by the space between the bottom surface of the middle plate 34 and the upper surface of the lower body 36 constituting the body 30 of the ejector 13, so The buffer space 30j can be formed by effectively utilizing the internal space.

  Further, according to the ejector 13 of the present embodiment, since the drive means 37 is provided, the passage forming member 35 is displaced according to the load fluctuation of the ejector refrigeration cycle 10, and the refrigerant passage of the nozzle passage 13a and the diffuser passage 13c. The area can be adjusted. Therefore, the ejector 13 can be appropriately operated in accordance with the load fluctuation of the ejector refrigeration cycle 10.

  Furthermore, since the enclosed space 37b in which the temperature sensitive medium is enclosed in the driving means 37 is disposed at a position sandwiched between the suction passage 13b and the diffuser passage 13c, the space between the suction passage 13b and the diffuser passage 13c is arranged. The space formed can be effectively used. As a result, the enlargement of the physique as the whole ejector can be further suppressed.

  Moreover, since the enclosed space 37b is disposed at a position surrounded by the suction passage 13b and the diffuser passage 13c, the temperature of the refrigerant flowing out of the evaporator 14 flowing through the suction passage 13b without being affected by the outside air temperature or the like. Can be satisfactorily transmitted to the temperature sensitive medium, and the pressure in the enclosed space 37b can be changed. That is, the pressure in the enclosed space 37b can be accurately changed according to the temperature of the refrigerant flowing out of the evaporator 14.

(Other embodiments)
The present invention is not limited to the above-described embodiment, and can be variously modified as follows without departing from the spirit of the present invention.

  (1) In the above-described embodiment, the example in which the buffer space 30j is formed by the space between the bottom surface of the middle plate 34 and the upper surface of the lower body 36 constituting the body 30 has been described, but the buffer space 30j is not limited to this. . For example, the middle plate 34 and the lower body 36 may be formed of a single member, and the buffer space 30j may be formed inside the member by cutting or electric discharge machining.

  Moreover, what was formed in the cup shape as a lower body 36 may be employ | adopted, and you may fix so that a part of lower body 36 may protrude below the housing body 31. FIG. According to this, since the buffer space 30j can be formed inside the lower body 36 formed in a cup shape, the volume of the buffer space 30j can be changed according to the ejector refrigeration cycle to which the ejector 13 is applied.

  (2) In the above-described embodiment, as the driving means 37 for displacing the passage forming member 35, the enclosed space 37b in which the temperature-sensitive medium whose pressure changes with temperature change is enclosed, and the pressure of the temperature-sensitive medium in the enclosed space 37b Although the example which employ | adopted what was comprised with the diaphragm 37a displaced according to is demonstrated, a drive means is not limited to this.

  For example, a thermowax that changes in volume depending on temperature may be employed as the temperature-sensitive medium, or a drive unit that includes a shape memory alloy elastic member may be employed. As a means, a member that displaces the passage forming member 35 by an electric mechanism such as an electric motor or a solenoid may be adopted.

  (3) Although the details of the liquid-phase refrigerant outlet 31c of the ejector 13 are not described in the above-described embodiment, a decompression unit (for example, a side made of an orifice or a capillary tube) that depressurizes the refrigerant at the liquid-phase refrigerant outlet 31c. A fixed aperture) may be arranged.

  (4) In the above-described embodiment, the example in which the ejector refrigeration cycles 10 and 50 including the ejector 13 of the present invention are applied to the vehicle air conditioner has been described. However, the ejector refrigeration cycle 10 including the ejector 13 of the present invention is described. The application of is not limited to this. For example, the present invention may be applied to a stationary air conditioner, a cold storage container, a cooling / heating device for a vending machine, and the like.

  In the above-described embodiment, the radiator 12 is an outdoor heat exchanger that exchanges heat between the refrigerant and the outside air, and the evaporator 14 is used as a use-side heat exchanger that cools the blown air. The ejector of the present invention is applied to a heat pump cycle in which the evaporator 14 is configured as an outdoor heat exchanger that absorbs heat from a heat source such as outside air, and the radiator 12 is configured as an indoor heat exchanger that heats a heated fluid such as air or water. 13 may be applied.

  (5) In the above-mentioned embodiment, although the example which employ | adopted the subcool type heat exchanger as the heat radiator 12 was demonstrated, you may employ | adopt the normal heat radiator which consists only of the condensation part 12a. Moreover, although the above-mentioned embodiment demonstrated the example which formed structural members, such as the body 30 of the ejector 13, the channel | path formation member 35, etc. with the metal, a material will not be limited if the function of each structural member can be exhibited. Therefore, you may form these structural members with resin.

DESCRIPTION OF SYMBOLS 10 Ejector type refrigeration cycle 11 Compressor 13 Ejector 13a Nozzle passage 13b Suction passage 13c Diffuser passage 30 Body 30j Buffer space 35 Passage forming member

Claims (3)

An ejector applied to a vapor compression refrigeration cycle apparatus (10) having a compressor (11) for compressing and discharging a refrigerant,
A swirling space (30a) for swirling the refrigerant flowing in from the refrigerant inlet (31a), a decompression space (30b) for decompressing the refrigerant flowing out of the swirling space (30a), and a refrigerant flow downstream of the decompression space (30b) A suction passage (13b) that communicates with the outside and sucks the refrigerant from the outside, and a booster that flows in the injected refrigerant injected from the decompression space (30b) and the suction refrigerant sucked from the suction passage (13b) Space (30e), a gas-liquid separation space (30f) for separating the gas-liquid refrigerant flowing out of the pressurizing space (30e), and the gas-phase refrigerant separated in the gas-liquid separation space (30f) is compressed. A body (30) formed with a gas-phase refrigerant outlet (31d) for flowing out to the inlet side of the machine (11);
At least a portion is disposed in the decompression space (30b) and in the pressurization space (30e), and is formed in a conical shape in which a cross-sectional area increases as the distance from the decompression space (30b) increases. A passage forming member (35) formed,
The refrigerant passage formed between the inner peripheral surface of the body (30) forming the decompression space (30b) and the outer peripheral surface of the passage forming member (35) is the swirling space (30a). A nozzle passage (13a) that functions as a nozzle for depressurizing and injecting the refrigerant flowing out from
A refrigerant passage formed between an inner peripheral surface of a portion of the body (30) forming the pressurizing space (30e) and an outer peripheral surface of the passage forming member (35) includes the injection refrigerant and the suction A diffuser passage (13c) that functions as a diffuser that converts the kinetic energy of the refrigerant mixed with the refrigerant into pressure energy;
Further, the body (30) has a buffer space (30j) for attenuating pressure pulsations transmitted from the suction port side of the compressor (11) into the gas-liquid separation space (30f). Ejector characterized by. The buffer space (30j) is provided in a gas-phase refrigerant outflow passage (30i) connecting the gas-liquid separation space (30f) and the gas-phase refrigerant outlet (31d),
A passage sectional area of the buffer space (30j) is formed larger than a minimum passage sectional area in a portion of the gas-phase refrigerant outflow passage (30i) on the upstream side of the buffer space (30j). 2. The ejector according to claim 1, wherein the ejector is formed larger than a minimum passage area portion in a downstream portion of the buffer space (30 j) in the phase refrigerant outflow passage (30 i). As the body (30), a first component member (34) that forms the bottom of the gas-liquid separation space (30f), and a second component member (36) disposed below the first component member (34). )
The ejector according to claim 1 or 2, wherein the buffer space (30j) is formed by a space between the first component member (34) and the second component member (36).

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