JP5929814B2 - Ejector - Google Patents

Description

  The present invention relates to an ejector that sucks fluid by a high-speed jet fluid jetted from a nozzle.

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

  Therefore, in a refrigeration cycle apparatus including an ejector as a decompression device (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 a decompression device.

  For example, in Patent Document 1, as an ejector applied to an ejector refrigeration cycle, a needle-shaped valve body (passage forming member) is disposed in a refrigerant passage of a nozzle, and according to load fluctuations of the ejector refrigeration cycle, Disclosed is a configuration in which the refrigerant passage area of the nozzle (passage area in the minimum passage area portion) can be changed by displacing the valve body.

  Furthermore, in the ejector of Patent Document 1, the tapered tip of the needle-like valve body is protruded from the coolant injection port of the nozzle to the downstream side of the refrigerant flow, and the injected refrigerant injected from the refrigerant injection port is directed to the tapered tip of the valve body. To flow along. As a result, in this ejector, the jet of the injection refrigerant injected from the refrigerant injection port is brought close to proper expansion regardless of the load fluctuation of the ejector-type refrigeration cycle, and the nozzle tries to exhibit high nozzle efficiency.

  The nozzle efficiency is energy conversion efficiency when the pressure energy of the refrigerant is converted into kinetic energy at the nozzle.

JP 2004-270460 A

  However, in the configuration in which the refrigerant passage area of the nozzle is changed by displacing the valve body as in the ejector of Patent Document 1, even if the valve body is displaced according to the load fluctuation of the ejector refrigeration cycle, Operation delay (response delay) may occur. For this reason, when the valve body is displaced, the jet flow of the injected refrigerant injected from the refrigerant injection port may slightly underexpand or overexpand with respect to the appropriate expansion.

  Such slight underexpansion or overexpansion is unlikely to cause a significant decrease in nozzle efficiency, but if the jet of injected refrigerant becomes underexpanded, the refrigerant immediately after being injected from the refrigerant injection port Causes an expansion wave that spreads in the radial direction of the nozzle, which causes a large operating noise in the ejector.

  In view of the above, an object of the present invention is to reduce the operating noise of an ejector configured to be able to change the refrigerant passage area of a nozzle.

The present invention has been devised to achieve the above object, and in the invention described in claim 1, an ejector applied to the vapor compression refrigeration cycle apparatus (10a),
A nozzle (531) for injecting refrigerant, a refrigerant suction port (532a) for sucking refrigerant from outside by the jet refrigerant injected from the nozzle (531), and a suction refrigerant sucked from the jet refrigerant and the refrigerant suction port (532a) And a body (30) formed with a diffuser portion (532b) for increasing pressure and a shape extending in the axial direction of the nozzle (531), and at least a part thereof is in the refrigerant passage of the nozzle (531). A disposed passage forming member (533) and driving means (534) for displacing the passage forming member (533);
The refrigerant passage formed between the inner peripheral surface of the nozzle (531) and the outer peripheral surface of the passage forming member (533) is a nozzle passage (513a) that depressurizes the refrigerant, and the nozzle passage (513a) 531) is formed in an annular shape in a cross section perpendicular to the axial direction, and the nozzle passage (513a) includes a minimum passage area portion (53a) and a minimum passage area portion (53a) in which the refrigerant passage area is reduced most. Is provided on the downstream side of the refrigerant flow, and a divergent portion (53c) is provided in which the refrigerant passage area gradually increases, and the driving means (534) displaces the passage formation member (533) to displace the minimum passage area. The refrigerant passage area in the portion (53a) is changed,
Further, at least one of a portion of the inner peripheral surface of the nozzle (531) that forms the divergent portion (53c) and a portion of the outer peripheral surface of the passage forming member (533) that forms the divergent portion (53c) has a nozzle passage. Grooves (531a, 533a) recessed to the side of enlarging the passage sectional area of (513a) are formed.

  According to this, at least one of the site | part which forms a divergent part (53c) among the internal peripheral surfaces of a nozzle (531), and the site | part which forms a divergent part (53c) among the outer peripheral surfaces of a channel | path formation member (533), Since the groove portions (531a, 533a) that are recessed toward the side of enlarging the passage cross-sectional area of the nozzle passage (513a) are formed, an expansion wave generated by the refrigerant flowing through the nozzle passage (513a) is generated by the refrigerant of the nozzle (531). It is possible to reduce the operating sound of the ejector by suppressing the outflow from the injection port.

  More specifically, in the vicinity of the minimum passage area (53a) of the nozzle passage (513a), the refrigerant in the gas-liquid mixed state is blocked (choked), and the flow rate of the refrigerant in the gas-liquid mixed state is increased in two phases. Acceleration can be performed until the value becomes higher than the sound speed (until the supersonic state is reached). Therefore, the refrigerant in the gas-liquid mixed state can be accelerated in the divergent portion (53c) where the refrigerant passage area gradually increases.

  When the supersonic state refrigerant flowing through the divergent portion (53c) flows into the groove portions (531a, 533a), the refrigerant flow area is enlarged, and the flow velocity of the refrigerant is suddenly accelerated, so that the inside of the groove portions (531a, 533a). Generate expansion waves. Further, when the refrigerant that has flowed into the grooves (531a, 533a) flows out of the grooves (531a, 533a) and returns to the divergent part (53c), the refrigerant is rapidly decelerated due to the reduction of the refrigerant passage area, and the divergent part (53c) ) Shock waves are generated inside.

  This shock wave suppresses the progress of the expansion wave generated in the grooves (531a, 533a), and suppresses the expansion wave from flowing out from the refrigerant injection port of the nozzle (531). As a result, the jet flow of the injection refrigerant injected from the refrigerant injection port can be appropriately expanded or overexpanded, and the operating noise caused by the expansion wave colliding with the inner peripheral wall surface of the body (30) is reduced. be able to.

  That is, according to the invention described in this claim, it is possible to reduce the operating noise of an ejector configured to be able to change the refrigerant passage area of the nozzle passage (the refrigerant passage of the nozzle in the prior art).

The invention according to claim 2 is an ejector applied to the vapor compression refrigeration cycle apparatus (10),
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 mixes the refrigerant injected from the decompression space (30b) and the suction refrigerant sucked from the suction passage (13b). ) Is formed, and at least a part of the body (30) is disposed in the decompression space (30b) and the boosting space (30e), and the body (30) is disconnected as the distance from the decompression space (30b) increases. A passage forming member (35) formed in a conical shape with an increased area, and a drive means (37) for displacing the passage 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 for depressurizing and injecting, 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) The refrigerant passage formed between them is a diffuser passage (13c) that functions as a diffuser for mixing and increasing the pressure of the injected refrigerant and the suction refrigerant, and the nozzle passage (13a) is perpendicular to the axial direction of the passage forming member (35). The cross-sectional shape in a simple cross section is formed in an annular shape, and the refrigerant flow from the smallest passage area portion (30 m) and the smallest passage area portion (30 m) in which the refrigerant passage area is reduced most in the nozzle passage (13a). A divergent part (132) formed on the flow side and gradually expanding the refrigerant passage area is provided, and the driving means (37) displaces the passage forming member (35) to displace the minimum passage area part (30 m). ) To change the refrigerant passage area.
Further, at least one of a portion forming the divergent portion (132) in the inner peripheral surface of the body (30) and a portion forming the divergent portion (132) in the outer peripheral surface of the passage forming member (35) includes a nozzle. Grooves (32a, 35a) that are recessed to the side of enlarging the passage cross-sectional area of the passage (13a) are formed.

  According to this, at least one of the site | part which forms a divergent part (132) among the internal peripheral surfaces of a body (30), and the site | part which forms a divergent part (132) among the outer peripheral surfaces of a channel | path formation member (35). Since the groove portions (32a, 35a) that are recessed on the side of enlarging the passage cross-sectional area of the nozzle passage (13a) are formed, the refrigerant that flows through the nozzle passage (13a) as in the invention of claim 1 It is possible to suppress the expansion wave caused by the outflow from the nozzle passage (13a) and to reduce the operating noise of the ejector.

  That is, according to the invention described in this claim, it is possible to reduce the operating noise of an ejector configured to be able to change the refrigerant passage area of the nozzle passage (the refrigerant passage of the nozzle in the prior art).

  In addition, in this claim, the passage forming member (35) is not limited to one that is formed only from a shape whose cross-sectional area expands strictly as it is separated from the decompression space (30b). The shape of the diffuser passage (13c) is made to expand outward as it moves away from the decompression space (30b) by including a shape in which the cross-sectional area increases as it moves away from the decompression space (30b). Including those that can.

  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.

It is a typical whole block diagram of the ejector-type refrigerating cycle of 1st Embodiment. It is an axial sectional view of the ejector of the first embodiment. It is typical sectional drawing for demonstrating the function of each refrigerant path of the ejector of 1st Embodiment. It is a typical expanded sectional view of the X section of FIG. It is a Mollier diagram which shows the state of the refrigerant | coolant in the ejector-type refrigerating cycle of 1st Embodiment. It is a typical whole block diagram of the ejector-type refrigerating cycle of 2nd Embodiment. It is an axial sectional view of the ejector of the second embodiment. It is a typical expanded sectional view of the Y section of FIG.

(First embodiment)
1st Embodiment of this invention is described using FIGS. As shown in the overall configuration diagram of FIG. 1, the ejector 13 of the present embodiment is applied to a 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 the blown air blown into the vehicle interior, which is the air-conditioning target space.

  The ejector refrigeration cycle 10 employs an HFC refrigerant (specifically, R134a) as a refrigerant, and constitutes a vapor compression subcritical refrigeration cycle in which the high-pressure side refrigerant pressure does not exceed the critical pressure of the refrigerant. doing. Of course, you may employ | adopt HFO type refrigerant | coolants (for example, R1234yf). 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 side 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.

  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. 3 and 4 are schematic cross-sectional views for explaining the function and shape of each refrigerant passage of the ejector 13, and the same parts 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. Specifically, the body 30 includes a housing body 31 that is formed of a prismatic or cylindrical metal or resin and forms an outer shell of the ejector 13. A nozzle body 32 is provided inside the housing body 31. The middle body 33, the lower body 34, etc. 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 tapering in the refrigerant flow direction, and is press-fitted into the housing body 31 so that the axial direction is parallel to the vertical direction (vertical direction in FIG. 2). It is fixed by means of 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 extends in the tangential direction of the inner wall surface of the swirling space 30a when viewed from the central axis direction of the swirling space 30a. Thereby, the refrigerant that has flowed into the swirl space 30a from the refrigerant inflow passage 31e flows along the inner wall surface of the swirl space 30a and swirls in 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.

  And as shown in FIG. 3, FIG. 4, as a refrigerant path formed between the internal peripheral surface of the site | part which forms the pressure reduction space 30b of the nozzle body 32, and the outer peripheral surface of the upper side of the channel | path formation member 35, It is formed on the downstream side of the refrigerant flow from the minimum passage area portion 30m, and the taper 131 where the refrigerant passage area is gradually reduced from the minimum passage area portion 30m to the minimum passage area portion 30m. Thus, a divergent portion 132 is formed in which the refrigerant passage area gradually increases.

  In the tapered portion 131 and the divergent portion 132, the decompression space 30b and the passage forming member 35 are overlapped (overlapped) when viewed from the radial direction, so the shape of the axial cross section of the refrigerant passage is annular (circular) The shape is a donut shape excluding a small-diameter circular shape arranged coaxially. 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.

  In addition, as shown in the schematic enlarged view of FIG. 4, the refrigerant passage formed between the inner peripheral surface of the decompression space 30 b and the outer peripheral surface on the top side of the passage forming member 35 in the present embodiment, This is a refrigerant passage formed in a range where a line segment extending in the normal direction from the outer peripheral surface of the passage forming member 35 intersects the pressure reducing space 30 b of the nozzle body 32.

  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.

  Furthermore, in this embodiment, as shown in FIGS. 2 to 4, of the inner peripheral surface of the nozzle body 32 that forms the pressure reducing space 30 b, the portion that forms the divergent portion 132, and the outer peripheral surface of the passage forming member 35. A nozzle body side groove portion 32a and a passage forming member side groove portion 35a formed so as to be recessed toward the side where the passage cross-sectional area of the nozzle passage 13a is enlarged are formed in each portion where the divergent portion 132 is formed.

  More specifically, the nozzle body side groove portion 32a is disposed at a position closer to the most downstream portion of the nozzle passage 13a than the minimum passage area portion 30m on the inner peripheral surface of the nozzle body 32, and the entire circumference of the passage forming member 35 around the axis thereof. It is formed in an annular shape over the circumference. On the other hand, the channel forming member side groove 35a is disposed on the outer peripheral surface of the channel forming member 35 at a position closer to the most downstream portion of the nozzle channel 13a than the minimum channel area portion 30m, It is formed in an annular shape over the circumference.

  Further, the nozzle body side groove portion 32a and the passage forming member side groove portion 35a are both formed in a V-shaped circumferential cross-sectional shape. For this reason, the nozzle body side groove portion 32a and the passage forming member side groove portion 35a rapidly expand the refrigerant passage area in the divergent portion 132 of the nozzle passage 13a with a degree of enlargement larger than the degree of enlargement of the refrigerant passage area of the divergent portion 132 itself. The site is formed. As described above, the refrigerant generates a shock wave in the divergent portion 132 in the portion where the refrigerant passage area rapidly increases.

  Therefore, in this embodiment, even if the shock wave generated by the refrigerant flowing into the nozzle body side groove 32a and the shock wave generated by flowing into the passage forming member side groove 35a are displaced in the nozzle passage 13a. The nozzle body side groove 32a and the passage forming member side groove 35a are arranged so as to collide with each other.

  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 is arranged coaxially with the central axes of the swirling 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.

  Between the upper surface of the middle body 33 and the inner wall surface of the housing body 31 facing the middle body 33, an inflow space 30c for retaining the refrigerant flowing in from the refrigerant suction port 31b is formed. 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 is viewed from the central axis direction of the swirl space 30a and the decompression space 30b. The cross section is formed in an annular shape.

  The suction refrigerant inflow passage 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. Thus, in the present embodiment, the refrigerant that has flowed into the inflow space 30c from the refrigerant suction port 31b via the suction refrigerant inflow passage 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.

  Thus, a suction passage 30d is formed between the inner peripheral surface of the through hole and the outer peripheral surface on the lower side of the nozzle body 32 so as to communicate the inflow space 30c and the downstream side of the refrigerant flow in the decompression space 30b. That is, in this embodiment, the suction passage 13b that sucks the refrigerant from the outside is formed by the inflow space 30c and the suction passage 30d. Furthermore, the central axis vertical cross section of the suction passage 13b is also formed in an annular shape, and the suction refrigerant flows while swirling from the outer peripheral side to the inner peripheral side of the central shaft in the suction passage 13b.

  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 pressurizing space 30e is a space for mixing the refrigerant injected from the nozzle passage 13a and the suction refrigerant sucked from the suction passage 30d.

  Inside the pressure increasing space 30e, the lower side of the passage forming member 35 described above is disposed. 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, the refrigerant passage formed between the inner peripheral surface of the middle body 33 forming the pressurizing space 30e and the outer peripheral surface on the lower side of the passage forming member 35 by expanding the refrigerant passage area in this manner. Is used as a diffuser passage 13c functioning as a diffuser, and the velocity energy of the mixed refrigerant of the injection refrigerant and the suction refrigerant is converted into pressure energy. That is, in the diffuser passage 13c, the injection refrigerant and the suction refrigerant are mixed and pressurized. Further, the cross-sectional shape perpendicular to the central axis of the diffuser passage 13c is also formed in an annular shape.

  Note that the refrigerant injected from the nozzle 13a to the diffuser passage 13c and the refrigerant sucked from the suction passage 13b have a velocity component in the direction of swirling in the same direction as the refrigerant swirling in the swirling space 30a. Therefore, the refrigerant flowing through the diffuser passage 13c and the refrigerant flowing out of the diffuser passage 13c also have a velocity component in the direction of turning 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 enclosed space 37b through the lid member 37d and the diaphragm 37a that partition the inflow space 30c and the enclosed 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 from above and below by the suction passage 13b and the diffuser passage 13c when viewed from the radial direction of the 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 actuating rod 37e is joined to the center portion of the diaphragm 37a by means such as welding, and the outer peripheral side of the lowermost side (bottom side) of the passage forming member 35 is joined to the lower end side of the actuating rod 37e. It is fixed. 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.

  Further, the bottom surface of the passage forming member 35 receives a load of a coil spring 40 fixed to the lower body 34. 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.

  In the present embodiment, a plurality (specifically, two as shown in FIGS. 2 and 3) of columnar spaces are provided on the outer peripheral side of the middle body 33, and each of the circular thin plate-like shapes is provided inside the space. Although the diaphragm 37a is fixed and the two drive means 37 are 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 lower body 34 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. As shown in FIGS. 2 and 3, a gas-liquid separation space 30f is formed between the upper side of the lower body 34 and the middle body 33 to separate the gas and liquid refrigerant flowing out of the diffuser passage 13c. Yes.

  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 central axis of the swirl space 30a, the decompression space 30b, the passage forming member 35, and the like. And are arranged on the same axis.

  Further, 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 of turning in the same direction as the refrigerant swirling in the swirling space 30a. Therefore, the gas-liquid refrigerant is separated in the gas-liquid separation space 30f by the action of centrifugal force.

  At the center of the lower body 34, a cylindrical pipe 34a is provided coaxially with the gas-liquid separation space 30f and extending upward. And the liquid phase refrigerant | coolant isolate | separated in the gas-liquid separation space 30f is stored by the outer peripheral side of the pipe 34a. A gas-phase refrigerant outflow passage 34b is formed in the pipe 34a to guide the gas-phase refrigerant separated in the gas-liquid separation space 30f to the gas-phase refrigerant outlet 31d of the housing body 31.

  Further, the above-described coil spring 40 is fixed to the upper end portion of the pipe 34a. 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 34b is formed in the root part (lowermost part) of the pipe 34a.

  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, the suction 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 discharged from the compressor 11 (point a5 in FIG. 5) 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 from the 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 (FIG. 5). a5 point → b5 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 (b5 point → c5 point in FIG. 5). 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 that has flowed out of the evaporator 14 due to the suction action of the jet refrigerant jetted from the nozzle passage 13a passes through the suction passage 13b (more specifically, the inflow space 30c and the suction passage 30d). Sucked. Furthermore, 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 c5 → d5 point, point h5 → d5 point in FIG. 5).

  In the diffuser passage 13c, the velocity 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 injected refrigerant and the suction refrigerant are mixed (point d5 → point e5 in FIG. 5). The refrigerant flowing out of the diffuser passage 13c is gas-liquid separated in the gas-liquid separation space 30f (point e5 → f5, point e5 → g5 in FIG. 5).

  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 (g5 point → h5 point in FIG. 5). On the other hand, the gas-phase refrigerant separated in the gas-liquid separation space 30f flows out of the gas-phase refrigerant outlet 31d, is sucked into the compressor 11, and is compressed again (point f5 → a5 in FIG. 5).

  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, 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 between the suction passage 13b and the diffuser passage 13c, the space between the suction passage 13b and the diffuser passage 13c is disposed. The space formed can be effectively used. Therefore, the enlargement of the physique as the whole ejector can be 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.

  Further, according to the ejector 13 of the present embodiment, since the nozzle body side groove portion 32a and the passage forming member side groove portion 35a are formed, the expansion wave generated by the refrigerant flowing through the nozzle passage 13a is the maximum refrigerant flow in the nozzle passage 13a. The operating noise of the ejector 13 can be reduced by suppressing the outflow from the downstream portion (corresponding to the refrigerant nozzle of a normal nozzle).

  Explaining this in more detail, as described above, in the vicinity of the minimum passage area 30m of the nozzle passage 13a, the refrigerant is blocked (choked), and the flow rate of the refrigerant in the gas-liquid mixed state is higher than the two-phase sound velocity. It can be accelerated until it reaches a value (until it reaches a supersonic state). Therefore, the refrigerant in the gas-liquid mixed state can be accelerated in the divergent portion 132 where the refrigerant passage area gradually increases.

  Then, when the refrigerant in the supersonic state flowing through the divergent portion 132 flows into the nozzle body side groove portion 32a and the passage forming member side groove portion 35a, the flow velocity of the refrigerant is rapidly accelerated due to the sudden expansion of the refrigerant passage area, as shown in FIG. Thus, an expansion wave is generated inside the nozzle body side groove 32a and the passage forming member side groove 35a. Further, when the refrigerant that has flowed into the nozzle body side groove portion 32 a and the passage forming member side groove portion 35 a returns to the divergent portion 132, the refrigerant is rapidly decelerated due to the reduction of the refrigerant passage area, and a shock wave is generated in the divergent portion 132.

  Since this shock wave suppresses the progress of the expansion wave generated in the nozzle body side groove 32a and the passage forming member side groove 35a, the expansion wave is suppressed from flowing out from the most downstream portion of the refrigerant flow in the nozzle passage 13a. As a result, the jet flow of the jet refrigerant injected from the most downstream portion of the refrigerant flow in the nozzle passage 13a can be appropriately expanded or overexpanded, and the operation caused by the expansion wave colliding with the inner peripheral wall surface of the nozzle body 32, etc. Sound can be reduced.

  That is, according to the ejector 13 of the present embodiment, it is possible to reduce the operating noise of an ejector configured to be able to change the refrigerant passage area of the nozzle passage 13a (passage area in the minimum passage area portion 30m).

  Further, in the ejector of the present embodiment, the nozzle body side groove portion 32a and the passage forming member side groove portion 35a are provided over the entire circumference of the nozzle body 32 and the passage forming member 35 around the axis, respectively, so that the respective groove portions 32a, 35a are provided. It is possible to effectively suppress the expansion wave from flowing out from the most downstream portion of the refrigerant flow in the nozzle passage 13a as compared with the case where the expansion wave is provided in a part without being provided over the entire circumference.

  Further, in the ejector of the present embodiment, the nozzle body side groove portion 32a is provided on the nozzle body 32 side, and the passage forming member side groove portion 35a is provided on the passage forming member 35 side, so shock waves generated by both groove portions collide with each other. By doing so, the progression of the expansion wave can be stopped at a relatively short distance from the location where the expansion wave is generated.

  Further, in the ejector according to the present embodiment, the nozzle body is configured such that the shock wave generated when the refrigerant flows into the nozzle body side groove portion 32a and the shock wave generated when the refrigerant flows into the passage forming member side groove portion 35a collide with each other in the nozzle passage 13a. The side groove portion 32a and the passage forming member side groove portion 35a are disposed. Therefore, even if the drive means 37 displaces the passage forming member 35, the progression of the expansion wave can be stopped at a relatively short distance from the location where the expansion wave is generated.

  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.

  As a result, the dimension of the diffuser passage 13c in the axial direction (the axial direction of the passage forming member 35) is increased compared to the case where the diffuser portion is formed in a shape extending in the axial direction of the nozzle portion as in the prior art. This can be suppressed. As a result, an increase in size of the ejector 13 as a whole can be suppressed.

  Further, 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, a gas-liquid separation means is provided separately from the ejector 13. In contrast, the volume of the gas-liquid separation space 30f can be effectively reduced.

  In other words, 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 velocity component in the direction of swirling, so that the refrigerant flows in the gas-liquid separation space 30f. It is not necessary to provide a space for generating a swirling 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.

(Second Embodiment)
In the ejector refrigeration cycle 10a of the present embodiment, as shown in the overall configuration diagram of FIG. 6, an ejector 53 and a gas-liquid separator 60 are employed instead of the ejector 13 of the first embodiment.

  Although the ejector 53 of this embodiment does not have a function as a gas-liquid separation unit, it functions as a refrigerant decompression unit and also serves as a refrigerant circulation unit (refrigerant transport unit) like the ejector 13 of the first embodiment. ). A specific configuration of the ejector 53 will be described with reference to FIGS.

  First, the ejector 53 includes a nozzle 531 and a body 532 as shown in FIG. The nozzle 531 is for depressurizing and injecting the refrigerant, and is formed of a substantially cylindrical metal (for example, stainless steel alloy) or the like that gradually tapers in the refrigerant flow direction.

  Further, a needle valve 533 formed in the shape of a needle (elongated column) extending in the axial direction of the nozzle 531 is disposed in the refrigerant passage of the nozzle 531. A nozzle passage 513a is formed between the inner peripheral surface of the refrigerant passage of the nozzle 531 and the outer peripheral surface of the needle valve 533 to decompress the refrigerant in an isentropic manner. Therefore, the needle valve 533 of this embodiment is a passage forming member that forms the nozzle passage 513 a in the nozzle 531.

  More specifically, the nozzle passage 513a has a minimum passage area 53a having the smallest refrigerant passage area, and is formed on the upstream side of the refrigerant flow with respect to the minimum passage area 53a and reaches the minimum passage area 53a. A tapered portion 53b where the refrigerant passage area gradually decreases and a divergent portion 53c which is formed on the downstream side of the refrigerant flow from the minimum passage area portion 53a and gradually expands the refrigerant passage area are formed.

  That is, the refrigerant passage area of the nozzle passage 513a of the present embodiment is configured to change in the same manner as the Laval nozzle. Further, in the present embodiment, the one that is set so that the refrigerant flow rate is equal to or higher than the two-phase sonic speed αh (supersonic state) in the minimum passage area 53a during the normal operation of the ejector refrigeration cycle 10a is adopted. Yes.

  The needle valve 533 is arranged coaxially with respect to the nozzle axis. Therefore, the nozzle passage 513a has an annular cross-section in a cross section perpendicular to the axial direction of the nozzle 531. Further, the end of the needle valve 533 on the upstream side of the refrigerant flow is connected to a stepping motor 534 as a driving means for displacing the needle valve 533 in the axial direction of the nozzle 531.

  The stepping motor 534 displaces the needle valve 533 in the axial direction of the nozzle 531, thereby adjusting the refrigerant passage area of the nozzle passage 513a (passage area in the minimum passage area portion 53a). The operation of the stepping motor 534 is controlled by a control signal (control pulse) output from the control device.

  Further, in the present embodiment, as shown in FIGS. 7 and 8, a portion of the inner peripheral surface of the refrigerant passage of the nozzle 531 that forms the divergent portion 53 c and a divergent portion 53 c of the outer peripheral surface of the needle valve 533 are formed. A nozzle side groove portion 531a and a needle valve side groove portion 533a formed so as to be recessed on the side where the passage cross-sectional area of the nozzle passage 513a is enlarged are formed in each part.

  More specifically, the nozzle-side groove portion 531a is disposed at a position closer to the refrigerant injection port 531b of the nozzle 531 than the minimum passage area portion 53a on the inner peripheral surface of the refrigerant passage of the nozzle 531, and around the axis of the needle valve 533. Is formed in an annular shape over the entire circumference. On the other hand, the needle valve side groove 533a is disposed at a position closer to the most downstream portion (that is, the refrigerant injection port 531b) of the nozzle passage 513a than the minimum passage area portion 53a of the outer peripheral surface of the needle valve 533, and the needle valve 533. It is formed in an annular shape over the entire circumference around the axis.

  Further, the nozzle side groove portion 531a and the needle valve side groove portion 533a are both formed in a V-shaped circumferential cross-sectional shape. For this reason, like the nozzle body side groove 32a and the passage forming member side groove 35a of the first embodiment, the nozzle side groove 531a and the needle valve side groove 533a are located within the divergent portion 53c of the nozzle passage 513a. The site | part which expands a refrigerant path area rapidly with the expansion degree larger than the expansion degree of a refrigerant path area is formed.

  Furthermore, in this embodiment, the shock wave generated by the refrigerant flowing into the nozzle side groove 531a and the shock wave generated by flowing into the needle valve side groove 533a collide with each other in the nozzle passage 513a even if the needle valve 533 is displaced. As shown, the nozzle side groove 531a and the needle valve side groove 533a are arranged.

  Next, the body 532 is formed of a substantially cylindrical metal (for example, aluminum) or the like, and functions as a fixing member that supports and fixes the nozzle 531 inside and forms an outer shell of the ejector 13. . More specifically, the nozzle 531 is fixed by press-fitting or the like so as to be accommodated inside the longitudinal end of the body 532.

  In addition, a refrigerant suction port 532 a provided so as to penetrate the inside and outside of the outer peripheral side surface of the body 532 and communicate with the refrigerant injection port 531 b of the nozzle 531 is formed in the portion corresponding to the outer peripheral side of the nozzle 531. ing. The refrigerant suction port 532 a is a through hole through which the refrigerant flowing out of the evaporator 14 due to the suction action of the refrigerant injected from the refrigerant injection port 531 b of the nozzle 531 is sucked into the ejector 53.

  Further, inside the body 532, a diffuser part 532b as a boosting part for mixing and increasing the pressure of the refrigerant injected from the refrigerant injection port 531b and the suction refrigerant sucked from the refrigerant suction port 532a, and suction from the refrigerant suction port 532a. A suction passage 532c and the like for guiding the sucked refrigerant to the diffuser portion 532b are formed.

  The suction passage 532c is formed by a space between the outer peripheral side around the tapered tip of the nozzle 531 and the inner peripheral side of the body 532, and the refrigerant passage area of the suction passage 532c is directed toward the refrigerant flow direction. It is gradually shrinking. Thereby, the flow rate of the suction refrigerant flowing through the suction passage 532c is gradually increased, and energy loss (mixing loss) when the suction refrigerant and the injection refrigerant are mixed in the diffuser portion 532b is reduced.

  The diffuser portion 532b is disposed so as to be continuous with the outlet side of the suction passage 532c, and is formed so that the refrigerant passage area gradually increases. Thus, the function of converting the velocity energy of the mixed refrigerant of the injection refrigerant and the suction refrigerant into the pressure energy, that is, the function of increasing the pressure of the mixed refrigerant by reducing the flow velocity of the mixed refrigerant is achieved.

  Moreover, the wall surface shape of the inner peripheral wall surface of the body 532 forming the diffuser portion 532b is formed by combining a plurality of curves as shown in FIG. And since the degree of spread of the refrigerant passage cross-sectional area of the diffuser portion 532b gradually increases in the refrigerant flow direction and then decreases again, the refrigerant can be increased in an isentropic manner.

  The refrigerant inlet of the gas-liquid separator 60 is connected to the outlet side of the diffuser portion 532b of the ejector 53. The gas-liquid separator 60 is a gas-liquid separation unit that separates the gas-liquid of the refrigerant flowing into the interior. Furthermore, the gas-liquid separator 60 of the present embodiment functions as a liquid storage unit that stores excess liquid-phase refrigerant in the cycle.

  The refrigerant inlet side of the evaporator 14 is connected to the liquid phase refrigerant outlet of the gas-liquid separator 60. The gas-phase refrigerant outlet of the gas-liquid separator 60 is connected to the suction port side of the compressor 11. Other configurations are the same as those of the first embodiment.

  Next, the operation of this embodiment in the above configuration will be described. The operation of the ejector refrigeration cycle 10a of the present embodiment is basically the same as that of the ejector refrigeration cycle 10 of the first embodiment. Accordingly, the high-temperature and high-pressure gas-phase refrigerant discharged from the compressor 11 is cooled by the radiator 12 until it becomes a supercooled liquid-phase refrigerant and flows into the ejector 53.

  The refrigerant that has flowed into the ejector 53 is isentropically decompressed and injected in a nozzle passage 513a formed between the nozzle 531 and the needle valve 533. At this time, the control device controls the operation of the stepping motor 53d so that the degree of superheat of the refrigerant on the outlet side of the evaporator 14 approaches a predetermined value.

  Similarly to the first embodiment, the refrigerant flowing out of the evaporator 14 is sucked into the ejector 53 through the refrigerant suction port 532a by the suction action of the refrigerant injected from the nozzle passage 13a, and the refrigerant is injected. The refrigerant mixture of the refrigerant injected from the port 531b and the refrigerant sucked from the refrigerant suction port 532a is boosted by the diffuser portion 532b.

  The refrigerant that has flowed out of the diffuser portion 532b of the ejector 53 is gas-liquid separated by the gas-liquid separator 60, the separated liquid-phase refrigerant flows into the evaporator 14, and the separated gas-phase refrigerant is sucked into the compressor 11. And compressed again. Other operations are the same as those in the first embodiment. Therefore, in the ejector type refrigeration cycle 10a of the present embodiment, the blown air blown into the vehicle compartment can be cooled as in the first embodiment.

  Further, according to the ejector 53 of the present embodiment, since the nozzle side groove portion 531a and the needle valve side groove portion 533a are formed, the expansion wave generated by the refrigerant flowing through the nozzle passage 513a, as in the first embodiment, It is possible to reduce the operating sound of the ejector 53 by suppressing the outflow from the refrigerant injection port 531b of the nozzle 531.

  That is, even in the configuration of the ejector 53 of the present embodiment, similarly to the first embodiment, the operation of the ejector configured so that the refrigerant passage area of the nozzle passage 513a (passage area in the minimum passage area portion 53a) can be changed. Sound can be reduced.

(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 first embodiment, the example in which both the nozzle body side groove 32a and the passage forming member side groove 35a are provided has been described. However, at least one of the nozzle body side groove 32a and the passage forming member side groove 35a is provided. Just do it.

  The reason is that by providing at least one of the nozzle body side groove portion 32a and the passage forming member side groove portion 35a, a shock wave can be generated to suppress the progress of the expansion wave, and the refrigerant passage area of the nozzle passage 13a can be changed. This is because the operating sound of the ejector 13 configured as described above can be reduced.

  Similarly, in 2nd Embodiment, what is necessary is just to provide at least one among the nozzle side groove part 531a and the needle valve side groove part 533a.

  Moreover, in the above-mentioned embodiment, as each groove part 32a, 35a, 531a, 533a, what was formed cyclically | annularly over the perimeter of an axis | shaft was employ | adopted, Of course, it is not necessary to be formed cyclically, When viewed from the axial direction, it may be formed in a shape that is divided into a plurality of arcs.

  In the above-described embodiment, the example in which the grooves 32a, 35a, 531a, and 533a are disposed closer to the most downstream portion of the nozzle passages 13a and 513a than the minimum passage area portions 30m and 53a has been described. Each groove part 32a, 35a, 531a, 533a will not be limited to this, if it is arrange | positioned at the divergent part 132, 53a.

  In the above-described embodiment, the example in which the circumferential cross-sectional shape of each of the groove portions 32a, 35a, 531a, and 533a is formed in a V shape has been described. However, the circumferential cross-section of each of the groove portions 32a, 35a, 531a, and 533a is described. The shape is not limited to this. For example, the circumferential cross-sectional shape may be U-shaped or U-shaped.

  (2) In the first embodiment described above, the refrigerant passage formed in the range where the line segment extending in the normal direction from the outer peripheral surface of the passage forming member 35 intersects the inner peripheral surface of the pressure reducing space 30b of the nozzle body 32 is the nozzle passage. The nozzle passage 13a may be a refrigerant passage formed in a range where a line segment extending in the normal direction from the inner peripheral surface of the decompression space 30b intersects the outer peripheral surface of the passage forming member 35.

  Also in the second embodiment, a refrigerant passage formed in a range where a line segment extending in the normal direction from the outer peripheral surface of the needle valve 533 intersects the inner peripheral surface of the nozzle 531 or the normal direction from the inner peripheral surface of the nozzle 531 A refrigerant passage formed in a range where a line segment extending in a direction intersects with the outer peripheral surface of the needle valve 533 may be a nozzle passage 513a.

  In the second embodiment, FIG. 8 illustrates an example in which the needle valve 533 is disposed so as to protrude downstream from the refrigerant injection port 531b of the nozzle 531. However, the refrigerant injection port 531b of the nozzle 531 is illustrated. Rather than projecting downstream of the refrigerant flow.

  (3) In the first embodiment described above, as the drive means 37 for displacing the passage forming member 35, the enclosed space 37b in which the temperature sensitive medium that changes in pressure with temperature change is enclosed, and 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 the pressure of this was 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 structure having a shape memory alloy elastic member as the driving means may be employed. Further, as in the second embodiment, a drive unit that displaces the passage forming member 35 by an electric motor may be employed.

  Further, the needle valve 533 of the ejector 53 of the second embodiment may be displaced by a driving means configured to have a diaphragm, as in the first embodiment.

  (4) In the above-described embodiment, details of the liquid-phase refrigerant outlet 31c of the ejector 13 and the liquid-phase refrigerant outlet of the gas-liquid separator 60 are not described. Means (for example, a side fixed throttle made of an orifice or a capillary tube) may be arranged.

  (5) In the above-described embodiment, the example in which the ejector refrigeration cycle 10 including the ejector 13 of the present invention is applied to a vehicle air conditioner has been described. However, the application of the ejector refrigeration cycle 10 including the ejector 13 of the present invention is described. 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.

  (6) In the above-described embodiment, an example in which a subcool type heat exchanger is employed as the radiator 12 has been described. However, an ordinary radiator including only the condensing unit 12a may be employed. Moreover, although the above-mentioned embodiment demonstrated the example which formed the structural member of the body 30 of the ejector 13, the nozzle 531 of the ejector 53, and the body 532 etc. with the metal, the function of each structural member can be exhibited. The material is not limited as long as it is present. Therefore, you may form these structural members with resin.

DESCRIPTION OF SYMBOLS 10 Ejector-type refrigeration cycle 13 Ejector 13a Nozzle passage 13b Suction passage 13c Diffuser passage 30 Body 35 Passage formation member 38 Actuating rod 38b Plate-like part

Claims (5)

An ejector applied to a vapor compression refrigeration cycle apparatus (10a),
A nozzle (531) for injecting refrigerant;
The refrigerant suction port (532a) that sucks the refrigerant from the outside by the jetted refrigerant jetted from the nozzle (531), and the jetted refrigerant and the sucked refrigerant sucked from the refrigerant suction port (532a) are mixed to increase the pressure. A body (30) in which a diffuser portion (532b) is formed;
A passage forming member (533) which is formed in a shape extending in the axial direction of the nozzle (531) and at least a part of which is disposed in the refrigerant passage of the nozzle (531);
Drive means (534) for displacing the passage forming member (533),
The refrigerant passage formed between the inner peripheral surface of the nozzle (531) and the outer peripheral surface of the passage forming member (533) is a nozzle passage (513a) for decompressing the refrigerant,
The nozzle passage (513a) has an annular cross-sectional shape in a cross section perpendicular to the axial direction of the nozzle (531),
The nozzle passage (513a) has a minimum passage area portion (53a) having the smallest refrigerant passage area, and a divergent passage formed gradually downstream from the minimum passage area portion (53a) so that the refrigerant passage area gradually increases. Part (53c) is provided,
The driving means (534) changes the refrigerant passage area in the minimum passage area portion (53a) by displacing the passage forming member (533),
Further, at least one of a portion of the inner peripheral surface of the nozzle (531) that forms the divergent portion (53c) and a portion of the outer peripheral surface of the passage forming member (533) that forms the divergent portion (53c). The ejector is characterized in that groove portions (531a, 533a) that are recessed on the side of enlarging the passage sectional area of the nozzle passage (513a) are formed. An ejector applied to a vapor compression refrigeration cycle apparatus (10),
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) The suction passage (13b) that communicates with the outside and sucks the refrigerant from the outside, and the pressure rising that mixes the injection refrigerant injected from the decompression space (30b) and the suction refrigerant sucked from the suction passage (13b) A body (30) in which a space (30e) is formed;
At least a portion is disposed in the decompression space (30b) and in the pressurization space (30e), and is formed in a conical shape whose cross-sectional area increases with distance from the decompression space (30b). A passage forming member (35),
Drive means (37) for displacing the passage forming member (35),
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
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 the injection refrigerant and the suction A diffuser passage (13c) that functions as a diffuser for mixing and increasing the pressure of the refrigerant;
The nozzle passage (13a) has an annular cross-sectional shape perpendicular to the axial direction of the passage forming member (35),
The nozzle passage (13a) has a minimum passage area portion (30m) in which the refrigerant passage area is most reduced, and a divergent passage that is formed on the downstream side of the refrigerant flow from the minimum passage area portion (30m) to gradually increase the refrigerant passage area. Part (132) is provided,
The drive means (37) changes the refrigerant passage area in the minimum passage area portion (30m) by displacing the passage forming member (35),
Further, at least one of a part of the inner peripheral surface of the body (30) forming the divergent part (132) and a part of the outer peripheral surface of the passage forming member (35) forming the divergent part (132). In the ejector, groove portions (32a, 35a) that are recessed on the side of enlarging the cross-sectional area of the nozzle passage (13a) are formed.   The groove portions (32a, 35a), when viewed from the axial direction of the passage forming member (35), a portion forming the divergent portion (132) of the inner peripheral surface of the body (30), and the passage 3. The ejector according to claim 2, wherein the ejector is formed in an annular shape over the entire circumference of at least one of the portions forming the divergent portion (132) of the outer circumferential surface of the forming member (35).   The groove portions (32a, 35a) are formed on the inner peripheral surface of the body (30) where the divergent portion (132) is formed, and on the outer peripheral surface of the passage forming member (35), the divergent portion (132). 4. The ejector according to claim 2, wherein the ejector is provided at both of the portions forming the.   The groove (32a, 35a) formed on the inner peripheral surface of the decompression space (30b) and the groove (32a, 35a) formed on the outer peripheral surface of the passage forming member (35) 32. The ejector according to claim 4, wherein shock waves generated by the flow of the refrigerant into 32a and 35a) collide with each other in the nozzle passage (13a).

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