WO2016185664A1 - Ejector, and ejector-type refrigeration cycle - Google Patents

Abstract

A tapered portion (131) having a passage cross-sectional area that decreases gradually toward a minimum passage area portion (30m), and a divergent portion (132) which is formed on the downstream side, in the refrigerant flow direction, of the minimum passage area portion and which has a passage cross-sectional area that increases gradually, are formed in a nozzle passage (13a) functioning as a nozzle for injecting a refrigerant, wherein the degree of increase in the passage area of the divergent portion increases gradually toward the downstream side in the refrigerant flow direction. Additionally, the shape of a most downstream portion of a suction passage (13b) is configured such that the passage cross-sectional area thereof is constant. This configuration allows particles (droplets) of liquid-phase refrigerant in the injected refrigerant to broaden readily on an outer peripheral side of a passage-forming member (35), suppresses inhibition of broadening of the injected refrigerant by the sucked-in refrigerant, and suppresses a deterioration in the mixing performance between the droplets and gas-phase refrigerant. The configuration also makes it possible for a reduction in the ejector efficiency to be adequately suppressed even if the speed of flow of the injected refrigerant decreases.

Description

Ejector and ejector refrigeration cycle Cross-reference of related applications

This application includes Japanese Patent Application No. 2015-101564 filed on May 19, 2015 and Japanese Patent Application No. 2016- filed on February 8, 2016, the disclosures of which are incorporated herein by reference. Based on 022119.

The present disclosure relates to an ejector that sucks a fluid by a suction action of a jet fluid ejected at a high speed, and an ejector-type refrigeration cycle including the ejector.

Conventionally, in Patent Document 1, an ejector that sucks a refrigerant from a refrigerant suction port by a suction action of an ejected refrigerant that is injected at supersonic speed, and mixes the injected refrigerant and the sucked refrigerant to increase the pressure, and a vapor compression type equipped with the ejector. An ejector refrigeration cycle, which is a refrigeration cycle apparatus, is disclosed.

In the ejector of Patent Document 1, a substantially conical passage forming member is disposed inside the body, and a refrigerant passage having an annular cross section is formed in a gap between the body and the conical side surface of the passage forming member. In this refrigerant passage, the portion on the most upstream side of the refrigerant flow is used as a nozzle passage for depressurizing and injecting the high-pressure refrigerant, and the portion on the downstream side of the refrigerant flow in the nozzle passage is mixed with the injected refrigerant and the suction refrigerant. This is used as a mixing passage, and a portion of the mixing passage on the downstream side of the refrigerant flow is used as a diffuser passage for increasing the pressure of the mixed refrigerant of the injection refrigerant and the suction refrigerant.

Furthermore, in the ejector of Patent Document 1, the shape of the mixing passage is formed so that the passage cross-sectional area gradually decreases toward the downstream side of the refrigerant flow. Thereby, the mixing property of the liquid-phase refrigerant particles (hereinafter referred to as droplets) in the injection refrigerant in the mixing passage and the gas-phase refrigerant is improved, and the energy conversion efficiency (hereinafter referred to as ejector efficiency) of the ejector as a whole. ) Is trying to control the decline.

JP 2015-28395 A

In order to further improve the ejector efficiency, the present inventors have studied the ejector of Patent Document 1. As a result, when the load fluctuation occurs in the ejector refrigeration cycle, the ejector of Patent Document 1 reduces the ejector efficiency. In some cases, it could not be sufficiently suppressed.

Therefore, the present inventors investigated the cause, and in the ejector of Patent Document 1, when the heat load of the ejector type refrigeration cycle is reduced and the flow rate of the refrigerant flowing into the nozzle passage is reduced, the nozzle passage is supersonic. It has been found that this is because the Mach number of the injected refrigerant to be injected is lowered. The Mach number is a dimensionless number (u / c) defined by the fluid flow velocity u relative to the sound velocity c in the fluid.

The reason for this is that when the Mach number is decreased in the jet refrigerant injected at supersonic speed, the gas phase refrigerant in the jet refrigerant becomes difficult to spread to the outer peripheral side of the passage forming member, and moves due to the drag from the gas phase refrigerant. This is because it becomes difficult to distribute the droplets to be distributed to the outer peripheral side of the passage forming member. As a result, the droplets and the gas-phase refrigerant cannot be sufficiently mixed in the mixing passage, and the decrease in ejector efficiency cannot be sufficiently suppressed.

This indication aims at providing the ejector which can fully suppress decline in ejector efficiency, even if the flow velocity of an injection refrigerant falls in view of the above-mentioned point.

Another object of the present disclosure is to provide an ejector-type refrigeration cycle including an ejector that can sufficiently suppress a decrease in ejector efficiency even when a thermal load is lowered.

According to one aspect of the present disclosure, the ejector is applied to a vapor compression refrigeration cycle apparatus. The ejector includes a decompression space for decompressing the refrigerant, a suction passage that communicates with the downstream side of the refrigerant flow in the decompression space, and sucks the refrigerant from the refrigerant suction port, an injection refrigerant injected from the decompression space, and a suction passage. A body having a mixing space into which the suctioned refrigerant sucked in and a pressure increasing space into which the refrigerant flowing out from the mixing space flows are provided. The ejector further has a conical shape in which at least a part is disposed in the decompression space, the mixing space, and the pressurization space, and the cross-sectional area increases as the distance from the decompression space increases. A forming member is provided. The refrigerant passage formed between the inner peripheral surface of the part of the body that forms the decompression space and the outer peripheral surface of the passage forming member is a nozzle passage that functions as a nozzle that decompresses and injects the refrigerant. The refrigerant passage formed between the inner peripheral surface of the part of the body that forms the mixing space and the outer peripheral surface of the passage forming member is a mixing passage that mixes the injected refrigerant and the suction refrigerant. The refrigerant passage formed between the inner peripheral surface of the part of the body that forms the pressurizing space and the outer peripheral surface of the passage forming member is a diffuser passage that functions as a diffuser that converts the kinetic energy of the mixed refrigerant into pressure energy. is there. The nozzle passage has a minimum passage area with the smallest passage cross-sectional area, a tapered portion formed on the upstream side of the refrigerant flow in the minimum passage area and gradually reducing the cross-sectional area toward the minimum passage area. It has a divergent part that is provided on the downstream side of the refrigerant flow in the area part and in which the passage sectional area gradually increases. The degree of expansion of the passage cross-sectional area of the divergent part is larger on the outlet side than on the inlet side of the divergent part.

According to this, since the degree of expansion of the cross-sectional area of the divergent portion is larger on the outlet side than on the inlet side of the divergent portion, the refrigerant injected from the nozzle passage to the mixing passage is allowed to flow through the passage forming member. Easy to spread to the outer periphery.

As a result, even if the flow rate of the injection refrigerant is reduced, it is possible to suppress a decrease in the mixing property between the droplets and the gas phase refrigerant in the mixing passage, and it is possible to sufficiently suppress a decrease in the ejector efficiency.

Further, according to another aspect of the present disclosure, the ejector is applied to a vapor compression refrigeration cycle apparatus. The ejector includes a decompression space for decompressing the refrigerant, a suction passage that communicates with the downstream side of the refrigerant flow in the decompression space, and sucks the refrigerant from the refrigerant suction port, an injection refrigerant injected from the decompression space, and a suction passage. A body having a mixing space into which the suctioned refrigerant sucked in and a pressure increasing space into which the refrigerant flowing out from the mixing space flows are provided. Furthermore, the ejector has a conical shape in which at least a part thereof is disposed in the decompression space, the mixing space, and the pressurization space, and the cross-sectional area increases as the distance from the decompression space increases. A forming member is provided. The refrigerant passage formed between the inner peripheral surface of the part of the body that forms the decompression space and the outer peripheral surface of the passage forming member is a nozzle passage that functions as a nozzle that decompresses and injects the refrigerant. The refrigerant passage formed between the inner peripheral surface of the part of the body that forms the mixing space and the outer peripheral surface of the passage forming member is a mixing passage that mixes the injected refrigerant and the suction refrigerant. The refrigerant passage formed between the inner peripheral surface of the part of the body that forms the pressurizing space and the outer peripheral surface of the passage forming member is a diffuser passage that functions as a diffuser that converts the kinetic energy of the mixed refrigerant into pressure energy. is there. The most downstream portion of the suction passage has a shape in which the passage cross-sectional area is constant or expands toward the downstream side of the refrigerant flow.

According to this, since the shape of the most downstream portion of the suction passage is formed in a shape in which the passage cross-sectional area is constant or expands toward the downstream side of the refrigerant flow, suction is performed from the suction passage to the mixing passage. It is possible to suppress the contraction of the velocity distribution of the suctioned refrigerant. Therefore, it can suppress that a suction | inhalation refrigerant | coolant inhibits an injection refrigerant | coolant spreading to the outer peripheral side of a channel | path formation member.

As a result, even if the flow rate of the injection refrigerant is reduced, it is possible to suppress a decrease in the mixing property between the droplets and the gas phase refrigerant in the mixing passage, and it is possible to sufficiently suppress a decrease in the ejector efficiency.

In addition, the ejector having the above-described features may include a swirl flow generating unit that swirls the refrigerant flowing into the nozzle passage around the central axis of the nozzle passage.

According to this, when the flow rate of the refrigerant flowing into the nozzle passage is increased and the flow rate of the injected refrigerant becomes relatively high, the refrigerant on the turning center side is boiled under reduced pressure, and the gas phase refrigerant is placed on the turning center side. The unevenly distributed two-phase separated refrigerant can flow into the nozzle passage. Therefore, the energy conversion efficiency in the nozzle passage can be improved.

Further, in the ejector type refrigeration cycle having the above-described ejector having the swirl flow generating unit, the ejector refrigeration cycle includes a radiator that cools the high-pressure refrigerant discharged from the compressor that compresses the refrigerant until it becomes a supercooled liquid phase refrigerant, and generates swirl flow The supercooled liquid phase refrigerant may flow into the part.

According to this, it is possible to provide an ejector-type refrigeration cycle including an ejector that can sufficiently suppress a decrease in ejector efficiency even when a thermal load is lowered.

It is a schematic diagram showing an ejector type refrigerating cycle of a 1st embodiment of this indication. It is sectional drawing parallel to the axial direction of the ejector of 1st Embodiment. It is typical sectional drawing of the X section of FIG. It is a Mollier diagram which shows the change of the state of the refrigerant | coolant in the ejector type refrigeration cycle of 1st Embodiment. It is the schematic which shows the speed distribution of the refrigerant | coolant which flows out out of the channel | path for suction of the ejector of 1st Embodiment. It is the schematic which shows the speed distribution of the refrigerant | coolant which flows out out of the channel | path for suction of the ejector of the comparative example of this indication. It is a typical sectional view showing each refrigerant passage of an ejector of a 2nd embodiment of this indication. It is a typical sectional view showing each refrigerant passage of an ejector of a 3rd embodiment of this indication. It is the schematic which shows the speed distribution of the refrigerant | coolant which flows out out of the channel | path for suction of the ejector of the modification of this indication.

Hereinafter, a plurality of modes for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not explicitly stated unless there is a problem with the combination. Is also possible.

(First embodiment)
A first embodiment of the present disclosure will be described with reference to FIGS. 1 to 6. As shown in FIG. 1, the ejector 13 of the present embodiment is applied to a vapor compression refrigeration cycle apparatus including an ejector as a refrigerant decompression apparatus, 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. Therefore, the cooling target fluid of the ejector refrigeration cycle 10 of the present embodiment is blown air.

The ejector refrigeration cycle 10 employs an HFO refrigerant (specifically, R1234yf) as a refrigerant, and the high-pressure side refrigerant pressure of the cycle from the discharge port of the compressor 11 to the ejector 13 is the criticality of the refrigerant. The subcritical refrigeration cycle does not exceed the pressure. 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.

First, in the ejector-type refrigeration cycle 10, the compressor 11 sucks the refrigerant and discharges it until it becomes a high-pressure refrigerant. The compressor 11 according to the present embodiment is disposed in an engine room together with an engine (internal combustion engine) that outputs a driving force for vehicle travel. Further, the compressor 11 is an engine-driven compressor that is driven by a rotational driving force output from the engine via a pulley, a belt, or the like.

More specifically, in the present embodiment, a swash plate type variable displacement compressor configured such that the refrigerant discharge capacity can be adjusted by changing the discharge capacity is adopted as the compressor 11. The compressor 11 has a discharge capacity control valve (not shown) for changing the discharge capacity. The operation of the discharge capacity control valve is controlled by a control current output from a control device described later.

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.

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 decompression device that decompresses the supercooled high-pressure liquid-phase refrigerant that has flowed out of the radiator 12 and causes the refrigerant to flow downstream, and is also described later by the suction action of the refrigerant flow injected at a high speed. It functions as a refrigerant circulation device (refrigerant transport device) that sucks (transports) and circulates the refrigerant that has flowed out of the evaporator 14.

Furthermore, the ejector 13 of the present embodiment also functions as a gas-liquid separation device that separates the gas-liquid of the decompressed refrigerant. That is, the ejector 13 of the present embodiment is configured as an ejector with a gas-liquid separation function (ejector module).

The 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 enlarged cross-sectional view for explaining the function and shape of each refrigerant passage of the ejector 13, and the same reference numerals are given to portions that perform the same functions as those in FIG. 2. .

First, as shown in FIG. 2, the ejector 13 of the present embodiment includes a body 30 configured by combining a plurality of constituent members. The body 30 has a housing body 31 that forms the outer shell of the ejector 13. The housing body 31 is formed of a hollow prismatic or hollow cylindrical metal or resin. The body 30 is configured by fixing a nozzle body 32, a middle body 33, a lower body 34, and the like inside a housing body 31.

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.

Furthermore, in the present embodiment, an orifice 30i as a pressure reducing device that depressurizes the refrigerant flowing into the evaporator 14 is disposed in the liquid phase refrigerant passage connecting the gas-liquid separation space 30f and the liquid phase refrigerant outlet 31c. .

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 the central axis direction is parallel to the vertical direction (vertical direction in FIG. 2). It is fixed by the method of etc. 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.

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. For this reason, the refrigerant that has flowed into the swirl space 30a from the refrigerant inflow passage 31e flows along the outer peripheral wall surface of the swirl space 30a, and swirls around the central axis in the swirl space 30a. Therefore, the site | part which forms the turning space 30a among the housing body 31 and the nozzle body 32 of this embodiment comprises the turning flow generation | occurrence | production part.

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.

Inside 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.

Inside the decompression space 30b, a passage forming member 35 that forms a minimum passage area portion 30m having the smallest refrigerant passage area in the decompression space 30b and changes the passage area of the minimum passage area portion 30m is disposed. ing. That is, the passage forming member 35 is formed of a substantially conical resin member that gradually spreads toward the downstream side of the refrigerant flow, and its central axis 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 a refrigerant passage formed between the inner peripheral surface of the part 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. And the divergent part 132 is formed. The tapered portion 131 is a refrigerant passage that is formed on the upstream side of the refrigerant flow with respect to the minimum passage area portion 30m and that the passage cross-sectional area up to the minimum passage area portion 30m gradually decreases. The divergent portion 132 is a refrigerant passage that is formed on the downstream side of the refrigerant flow from the minimum passage area portion 30m, and the passage cross-sectional area gradually increases.

Furthermore, as shown in FIG. 3, the degree of expansion of the cross-sectional area of the divergent portion 132 of the present embodiment is larger on the outlet side than on the inlet side of the divergent portion 132. In other words, the degree of expansion of the passage cross-sectional area of the divergent portion 132 is gradually increased toward the downstream side of the refrigerant flow. More specifically, in this embodiment, the degree of expansion of the passage cross-sectional area of the divergent portion 132 is increased stepwise.

At the downstream side and the divergent portion 132 of the tapered portion 131, 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 circular. It becomes an annular shape (a donut shape excluding a small-diameter circular shape arranged coaxially from a large-diameter circular shape).

In the present embodiment, the refrigerant passage formed between the inner peripheral surface of the pressure reducing space 30b and the outer peripheral surface on the top side of the passage forming member 35 by such a passage shape is the nozzle passage 13a that functions as a Laval nozzle, and the refrigerant The pressure of the refrigerant is increased and the flow rate of the refrigerant is increased to a supersonic speed (a flow speed faster than the two-phase sound speed).

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 the present embodiment is, for example, as shown in the divergent portion 132 of FIG. A line segment extending in the normal direction from the outer peripheral surface of the passage forming member 35 is a refrigerant passage formed including a range where the portion of the nozzle body 32 that forms the decompression space 30b intersects.

Next, as shown in FIG. 2, the middle body 33 is provided with a rotating body-shaped through hole penetrating the front and back (up and down) at the center thereof. Further, the middle body 33 is formed of a metal disk-like member that houses a drive mechanism 37 that displaces the passage forming member 35 on the outer peripheral side of the through hole.

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 a method 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 opposite to 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 32a 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. It is formed in an annular cross section.

Among the through holes of the middle body 33, 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, the inflow space 30c and the decompression space 30b A suction passage 30d that communicates with the downstream side of the refrigerant flow is formed. The suction passage 30d is also formed in an annular cross section when viewed from the central axis direction of the swirling space 30a and the decompression space 30b.

That is, in this embodiment, the suction passage 13b for sucking the refrigerant from the outside is formed by the suction refrigerant inflow passage connecting the refrigerant suction port 31b and the inflow space 30c, the inflow space 30c, and the suction passage 30d. 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.

Furthermore, the shape of the most downstream portion of the refrigerant flow in the suction passage 13b (that is, the most downstream portion of the refrigerant flow in the suction passage 30d) has a constant passage sectional area toward the downstream side of the refrigerant flow, as shown in FIG. It is formed into a shape.

Further, in the through hole of the middle body 33, a mixing space 30h formed in a substantially truncated cone shape is formed on the downstream side of the refrigerant flow in the suction passage 30d as shown in FIG. The mixing space 30h includes an injection refrigerant injected from the above-described decompression space 30b (specifically, the nozzle passage 13a) and a suction refrigerant sucked from the suction passage 13b (specifically, the suction passage 30d). It is a space that joins.

Inside the mixing space 30h, the intermediate portion in the vertical direction of the passage forming member 35 described above is disposed. As shown in FIG. 3, the inner portion of the through hole of the middle body 33 that forms the mixing space 30h is arranged. The refrigerant passage formed between the peripheral surface and the outer peripheral surface of the passage forming member 35 forms a mixing passage 13d that promotes mixing of the injected refrigerant and the suction refrigerant.

The mixing passage 13d is arranged continuously in the refrigerant flow direction of the nozzle passage 13a (that is, arranged immediately after the refrigerant flow in the nozzle passage 13a), and the passage cross-sectional area is substantially toward the refrigerant flow downstream side. It is formed to be constant.

In addition, the refrigerant passage formed between the inner peripheral surface of the mixing space 30h and the outer peripheral surface of the passage forming member 35 in this embodiment is a method from the outer peripheral surface of the passage forming member 35 as shown in FIG. A line segment extending in the linear direction is a refrigerant passage formed to include a range where the middle body 33 intersects with a portion forming the mixing space 30h.

Further, in the through hole of the middle body 33, a pressure increasing space 30e formed in a substantially truncated cone shape gradually spreading toward the refrigerant flow direction is formed on the downstream side of the refrigerant flow in the mixing space 30h. The pressurizing space 30e is a space into which the refrigerant that has flowed out of the mixing space 30h (specifically, the mixing passage 13d) flows.

The lower portion of the passage forming member 35 is disposed inside the pressurizing space 30e. Further, the refrigerant passage formed between the inner peripheral surface of the portion forming the pressurizing space 30e of the middle body 33 and the outer peripheral surface on the lower side of the passage forming member 35 has a passage sectional area toward the downstream side of the refrigerant flow. It is formed into a shape that gradually expands. Thereby, in this refrigerant path, the velocity energy of the mixed refrigerant of the injection refrigerant and the suction refrigerant can be converted into pressure energy.

Therefore, 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 has the kinetic energy of the mixed refrigerant of the injection refrigerant and the suction refrigerant. A diffuser passage 13c is formed that functions as a diffuser (a pressure increasing unit) that converts pressure energy. The diffuser passage 13c is also formed in an annular cross section like the suction passage 13b.

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

Of the two spaces partitioned by the diaphragm 37a, the space on the upper side (the inflow space 30c side) changes in pressure according to the temperature of the refrigerant on the outlet side of the evaporator 14 (specifically, the refrigerant that has flowed out of the evaporator 14). An enclosed space 37b in which a temperature sensitive medium is enclosed is configured. 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 the present embodiment is a medium mainly composed of R1234yf.

On the other hand, the lower space of the two spaces partitioned by the diaphragm 37a constitutes an introduction space 37c for introducing the refrigerant on the outlet side of the evaporator 14 via a communication path (not shown). Accordingly, the temperature of the refrigerant on the outlet side of the evaporator 14 is transmitted to the temperature sensitive medium enclosed in the enclosed space 37b via the lid member 37d and the diaphragm 37a that partition the inflow space 30c and the enclosed space 37b.

Furthermore, the diaphragm 37a is deformed according to a differential pressure between the internal pressure of the enclosed space 37b and the pressure of the evaporator 14 outlet side refrigerant that has flowed into the introduction space 37c. For this reason, it is preferable that the diaphragm 37a is made of a tough material that is rich in elasticity and has good heat conduction. Accordingly, a thin metal plate such as stainless steel (SUS304) may be used as the diaphragm 37a, or a rubber made material such as EPDM (ethylene propylene diene copolymer rubber) containing a base fabric that is excellent in pressure resistance and sealability. May be.

One end side (upper side end) of a cylindrical actuating rod 37e is joined to the central part of the diaphragm 37a. The actuating rod 37e transmits a driving force for displacing the passage forming member 35 from the drive mechanism 37 to the passage forming member 35. The other end (lower end) of the actuating rod 37e is fixed to the outer peripheral side of the lowermost side (bottom) of the passage forming member 35.

Further, as shown in FIG. 2, the bottom surface of the passage forming member 35 receives a load of the coil spring 40. The coil spring 40 is an elastic member that applies a load that biases the passage forming member 35 upward (the passage forming member 35 reduces the passage cross-sectional area of the minimum passage area 30m). Therefore, the passage forming member 35 is displaced so that the load received from the operating rod 37e and the load received from the coil spring 40 are balanced.

More specifically, when the temperature of the refrigerant on the outlet side of the evaporator 14 (superheat degree) increases, the saturation pressure of the temperature-sensitive medium enclosed in the enclosed space 37b increases, and the pressure in the introduction space 37c increases from the internal pressure of the enclosed space 37b. The differential pressure after subtracting is increased. As a result, the diaphragm 37a is displaced toward the introduction space 37c, and the load that the passage forming member 35 receives from the operating rod 37e increases. For this reason, if the temperature of the evaporator 14 outlet side refrigerant | coolant rises, the channel | path formation member 35 will be displaced to the direction (vertical direction lower side) which expands 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 on the outlet side of the evaporator 14 is lowered, the saturation pressure of the temperature sensitive medium enclosed in the enclosed space 37b is lowered, and the pressure of the introduction space 37c is subtracted from the internal pressure of the enclosed space 37b. The differential pressure is reduced. Thereby, the diaphragm 37a is displaced to the enclosure space 37b side, and the load that the passage forming member 35 receives from the operating rod 37e decreases. For this reason, if the temperature of the evaporator 14 outlet side refrigerant | coolant falls, the channel | path formation member 35 will be displaced to the direction (vertical direction upper side) which reduces the channel | path cross-sectional area in the minimum channel | path area part 30m.

In the drive mechanism 37 of the present embodiment, the diaphragm 37a displaces the passage forming member 35 in accordance with the degree of superheat of the evaporator 14 outlet side refrigerant in this way, so that the degree of superheat of the evaporator 14 outlet side refrigerant is predetermined. The passage cross-sectional area in the minimum passage area 30m is adjusted so as to approach the reference superheat degree KSH. The reference superheat degree KSH can be changed by adjusting the load of the coil spring 40.

The gap between the actuating 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 actuating rod 37e is displaced.

In the present embodiment, a plurality of (three in this embodiment) columnar spaces are provided in the middle body 33, and a circular thin plate-like diaphragm 37a is fixed inside each of the spaces, so that the plurality of drive mechanisms 37 are provided. Although configured, the number of drive mechanisms 37 is not limited to this. When the drive mechanisms 37 are provided at a plurality of locations as in the present embodiment, it is desirable that they are arranged at equiangular intervals with respect to the central axis.

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 a method such as screwing so as to close the bottom surface of the housing body 31. Between the upper side of the lower body 34 and the middle body 33, there is formed a gas-liquid separation space 30f for separating the gas-liquid refrigerant flowing out from the diffuser passage 13c formed in the pressure increasing space 30e.

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 swirl space 30a, the decompression space 30b, the mixing space 30h, and the pressurization space 30e. It is arranged on the same axis as the central axis. In the gas-liquid separation space 30f, the refrigerant that has flowed out of the diffuser passage 13c is swung around the central axis, and the gas-liquid refrigerant is separated by the action of centrifugal force.

Furthermore, the internal volume of the gas-liquid separation space 30f is such a volume that the surplus refrigerant cannot be substantially accumulated even when a load fluctuation occurs in the cycle and the refrigerant circulation flow rate circulating in the cycle fluctuates.

At the center of the lower body 34, there is provided a cylindrical pipe 34a that is arranged coaxially with the gas-liquid separation space 30f and extends upward. The liquid refrigerant separated in the gas-liquid separation space 30f temporarily stays on the outer peripheral side of the pipe 34a and flows out from the liquid refrigerant outlet 31c. 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.

The coil spring 40 described above is fixed to the upper end of the pipe 34a. The coil spring 40 also functions as a vibration buffer member that attenuates 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 a portion forming the bottom surface of the gas-liquid separation space 30f of the lower body 34. Yes.

Further, the refrigerant inlet side of the evaporator 14 is connected to the liquid-phase refrigerant outlet 31c of the ejector 13 as shown in FIG. 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 in which the rotation speed (the 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 its peripheral circuits. This control device performs various calculations and processes based on the control program stored in the ROM, and controls the operations of the above-described various electric actuators 11, 12d, 14a and the like.

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 a control unit that controls the operation of various control target devices connected to the output side of the control device. A configuration (hardware and software) for controlling the operation constitutes a control unit of each control target device. For example, in this embodiment, the structure which controls the action | operation of the discharge capacity | capacitance control valve of the compressor 11 comprises the discharge capacity control part.

Next, the operation of the present embodiment in the above configuration will be described using the Mollier diagram of FIG. First, when the operation switch of the operation panel is turned on (ON), the control device operates the discharge capacity control valve of the compressor 11, the cooling fan 12d, the blower fan 14a, and the like. When the rotational driving force output from the engine is transmitted to the compressor 11, the compressor 11 sucks the refrigerant, compresses it, and discharges it.

The high-temperature and high-pressure refrigerant (point a in FIG. 4) discharged from the compressor 11 flows into the condenser 12a of the radiator 12, exchanges heat with the outside air blown from the cooling fan 12d, and dissipates heat to condense. The refrigerant condensed 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 outside air blown from the cooling fan 12d in the supercooling unit 12c, and further dissipates heat to become a supercooled liquid-phase refrigerant (a in FIG. 4). Point → b).

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 b → point c in FIG. 4). At this time, the passage cross-sectional area in the minimum passage area 30m of the decompression space 30b is adjusted so that the superheat degree of the evaporator 14 outlet side refrigerant (point h in FIG. 4) approaches a predetermined reference superheat degree.

Then, the refrigerant (point h in FIG. 4) that has flowed out of the evaporator 14 by the suction action of the refrigerant injected from the nozzle passage 13a causes the refrigerant suction port 31b and the suction passage 13b (more specifically, the inflow space 30c). And is sucked through the suction passage 30d). 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 and merge (point c → d point, point h → d point in FIG. 4). .

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

The liquid-phase refrigerant separated in the gas-liquid separation space 30f is decompressed by the orifice 30i (point g → point g ′ in FIG. 4) and flows into the evaporator 14. The refrigerant that has flowed into the evaporator 14 absorbs heat from the blown air blown by the blower fan 14a and evaporates (point g ′ → point h in FIG. 4). Thereby, blowing air is cooled. The gas-phase refrigerant separated in the gas-liquid separation space 30f flows out from the gas-phase refrigerant outlet 31d, is sucked into the compressor 11, and is compressed again (point f → a 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.

At this time, in the ejector refrigeration cycle 10 of the present embodiment, the refrigerant whose pressure has been increased in the diffuser passage 13c is sucked into the compressor 11. Therefore, according to the ejector-type refrigeration cycle 10, the power consumption of the compressor 11 can be reduced compared with the normal refrigeration cycle apparatus in which the refrigerant evaporation pressure in the evaporator and the pressure of the refrigerant sucked by the compressor are substantially equal. Coefficient of performance (COP) can be improved.

Further, according to the ejector 13 of the present embodiment, by turning the refrigerant in the swirling space 30a, the refrigerant pressure on the turning center side in the swirling space 30a is reduced to the pressure that becomes the 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. Thereby, the refrigerant flowing into the minimum passage area 30m of the nozzle passage 13a is in 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, the energy conversion efficiency in the nozzle passage 13a can be improved by efficiently accelerating the gas-liquid mixed state refrigerant to the sound speed by the boiling promotion by both the wall surface boiling and the interface boiling.

By the way, in the ejector which injects supersonic refrigerant from the nozzle passage 13a as in the ejector 13 of the present embodiment, the heat load of the ejector refrigeration cycle 10 decreases and the flow rate of refrigerant flowing into the nozzle passage 13a decreases. As a result, the Mach number of the injected refrigerant decreases. Further, in the refrigerant injected at supersonic speed, when the Mach number decreases, the gas-phase refrigerant in the injected refrigerant is less likely to spread to the outer peripheral side of the passage forming member 35.

For this reason, when the flow velocity (Mach number) of the injected refrigerant decreases, it is difficult to distribute the particles (droplets) of the liquid phase refrigerant that moves due to the drag from the gas phase refrigerant to the outer peripheral side of the passage forming member 35. turn into. Therefore, the mixing property between the droplets in the mixing passage 13d and the gas-phase refrigerant deteriorates, and the velocity energy of the droplets in the injection refrigerant is changed to the gas-phase refrigerant in the mixed refrigerant (that is, the gas-phase refrigerant in the injection refrigerant). And suction refrigerant) cannot be efficiently transmitted.

Therefore, even if the energy conversion efficiency in the nozzle passage 13a can be improved, the energy conversion efficiency (ejector efficiency) of the ejector 13 as a whole may be reduced. As a result, the boosting performance of the ejector 13 as a whole is lowered, and the COP improvement effect of the ejector refrigeration cycle 10 may not be sufficiently obtained.

On the other hand, in the ejector 13 of the present embodiment, the degree of expansion of the cross-sectional area of the divergent portion 132 of the nozzle passage 13a is larger on the outlet side than on the inlet side of the divergent portion (132). The flow of the refrigerant injected from the nozzle passage 13a to the mixing passage 13d can be easily spread to the outer peripheral side of the passage forming member 35 as shown by the thick practical arrows in FIG.

Therefore, even if the flow rate (Mach number) of the injection refrigerant is reduced, it is possible to suppress a decrease in the mixing property between the droplets in the mixing passage 13d and the gas-phase refrigerant, and it is possible to suppress a decrease in the ejector efficiency.

Furthermore, in the ejector 13 of the present embodiment, the shape of the most downstream portion of the suction passage 13b is formed so that the cross-sectional area of the passage is constant toward the downstream side of the refrigerant flow. The contraction of the velocity distribution of the suction refrigerant sucked into the passage 13d can be suppressed. Accordingly, it is possible to prevent the suction refrigerant from inhibiting the injection refrigerant from spreading to the outer peripheral side of the passage forming member 35.

This will be described in detail with reference to FIGS. FIG. 5 shows the velocity distribution (velocity profile) of the refrigerant flowing out from the suction passage 13b of the ejector 13 of the present embodiment. FIG. 6 shows the velocity distribution of the refrigerant flowing out from the suction passage of the comparative ejector in which the shape of the most downstream portion of the suction passage 13b is gradually reduced toward the refrigerant flow downstream side ( Speed profile).

As is apparent from FIGS. 5 and 6, the refrigerant flowing out from the suction passage of the comparative example has a faster flow rate of the refrigerant in the vicinity of the passage wall surface of the suction passage, resulting in contraction in the velocity distribution. For this reason, the flow rate of the suction refrigerant that has flowed into the mixing passage 13d is difficult to quickly decelerate, and the suction refrigerant inhibits the injection refrigerant from spreading to the outer peripheral side of the passage forming member 35.

In contrast, the refrigerant flowing out from the suction passage 13b of the present embodiment does not cause a contraction in the velocity distribution, and the flow velocity of the suction refrigerant flowing into the mixing passage 13d can be quickly reduced. As a result, it is possible to prevent the suction refrigerant from inhibiting the injection refrigerant from spreading to the outer peripheral side of the passage forming member 35.

Therefore, even if the flow rate (Mach number) of the injection refrigerant is reduced, it is possible to suppress a drop in the mixing property between the droplets and the gas-phase refrigerant in the mixing passage 13d, and to further effectively reduce the ejector efficiency. Can be suppressed.

(Second Embodiment)
In the present embodiment, an example in which the cross-sectional shapes parallel to the axial direction of the middle body 33 and the passage forming member 35 are changed as shown in FIG. 7 with respect to the first embodiment will be described. FIG. 7 is an enlarged cross-sectional view corresponding to FIG. 3 described in the first embodiment. In FIG. 7, the same or equivalent parts as those in the first embodiment are denoted by the same reference numerals. The same applies to the following drawings.

More specifically, in the present embodiment, in the cross section parallel to the axial direction of the passage forming member 35, a part of the passage forming member 35 that forms a part of the nozzle passage 13a on the downstream side of the refrigerant flow and the mixing passage 13d. The curve drawn by the curve gradually decreases the degree of increase in the distance L from the central axis of the passage forming member 35 toward the downstream side of the refrigerant flow.

Also, the mixing passage 13d of the present embodiment is formed so that the passage cross-sectional area becomes substantially constant toward the downstream side of the refrigerant flow, as in the first embodiment. Therefore, in the present embodiment, in the cross section parallel to the axial direction of the passage forming member 35, the line drawn by the portion forming the mixing space 30 h in the middle body 33 forms the mixing space 30 h in the passage forming member 35. It is curved along the line drawn by the part.

Other configurations are the same as those in the first embodiment. Therefore, when the ejector refrigeration cycle 10 of the present embodiment is operated, the same effect as that of the first embodiment can be obtained. Furthermore, according to the ejector 13 of the present embodiment, even if the flow rate (Mach number) of the injection refrigerant is reduced, it is possible to suppress a drop in the mixing property between the droplet and the gas-phase refrigerant in the mixing passage 13d. A decrease in efficiency can be suppressed.

Further, in the ejector 13 of the present embodiment, the degree of increase in the distance L between the central axis and the part of the passage forming member 35 on the downstream side of the refrigerant flow of the nozzle passage 13a and the portion forming the mixing passage 13d is gradually reduced. Yes. As a result, the shape of the mixing passage 13d can be bent toward the center side of the passage forming member 35 toward the downstream side of the refrigerant flow, so that the droplets in the injected refrigerant are moved to the outer peripheral side of the mixing passage 13d. Easy to reach.

This will be explained in more detail. Since the inertial force of the liquid droplet is larger than that of the gas phase refrigerant, the liquid droplet ejected from the refrigerant outlet of the nozzle passage 13a is as shown by a two-dot chain line in FIG. It has straightness. For this reason, when the shape of the mixing passage 13d is bent to the center side of the passage forming member 35, the outer peripheral side wall surface of the mixing passage 13d is relatively close to the liquid droplets distributed on the center side. Therefore, it is easy to make the injection refrigerant reach the outer peripheral side of the mixing passage 13d.

As a result, it is possible to suppress a decrease in the mixing property between the droplets and the gas phase refrigerant in the mixing passage 13d, and it is possible to more effectively suppress the decrease in the ejector efficiency.

(Third embodiment)
In the first embodiment, the example in which the degree of enlargement of the passage cross-sectional area of the divergent portion 132 has been described in stages, but in this embodiment, as shown in FIG. An example in which is continuously increased will be described. For this reason, the cross-sectional shape parallel to the axial direction of the site | part which forms the divergent part 132 in the taper front-end | tip part of the nozzle body 32 of this embodiment is formed in curve shape (or circular arc shape).

Other configurations and operations of the ejector 13 and the ejector refrigeration cycle 10 are the same as those in the first embodiment. As in the present embodiment, the same effect as in the first embodiment can be obtained even when the degree of expansion of the passage sectional area of the divergent portion 132 is continuously increased. FIG. 8 is an enlarged cross-sectional view corresponding to FIG. 3 described in the first embodiment.

The present disclosure is not limited to the above-described embodiment, and various modifications can be made as follows without departing from the spirit of the present disclosure.

In the above-described first embodiment, as a configuration for suppressing a decrease in the mixing property between the injection refrigerant and the suction refrigerant in the mixing passage 13d, a configuration in which the degree of expansion of the passage sectional area of the divergent portion 132 of the nozzle passage 13a is gradually increased. Both of the configurations in which the cross-sectional area of the most downstream portion of the suction passage 13b is constant have been described, but it is not necessary to employ both of these configurations at the same time. The same applies to the configuration described in the second embodiment in which the shape of the mixing passage 13d is bent toward the center of the passage forming member 35.

That is, a configuration in which the degree of expansion of the cross-sectional area of the divergent portion 132 is gradually increased, a configuration in which the cross-sectional area of the most downstream portion of the suction passage 13b is constant, and the shape of the mixing passage 13d is the center of the passage-forming member 35 Even if it adopts any one of the configurations or functions by combining a plurality of configurations, the configuration that is bent to the side has the effect of suppressing the deterioration of the mixing property of the droplets and the gas-phase refrigerant. be able to.

Further, according to the study by the present inventors, it has been found that the effects of these configurations can be effectively obtained in the ejector refrigeration cycle 10 in which the Mach number of the injected refrigerant is 2.0 or less. .

In the above-described first embodiment, the example in which the degree of expansion of the passage cross-sectional area of the divergent portion 132 is increased stepwise has been described, but may of course be increased continuously.

In the first and second embodiments described above, the example has been described in which the passage cross-sectional area of the most downstream portion of the refrigerant flow in the suction passage 13b is constant. However, the change in the passage cross-sectional area of the suction passage 13b is not limited thereto. It is not limited. As described with reference to FIGS. 5 and 6, if the contraction of the velocity distribution can be suppressed, the most downstream portion of the refrigerant flow in the suction passage 13b (specifically, the suction passage 30d) is the downstream of the refrigerant flow. You may form in the shape which a channel | path cross-sectional area expands toward the side.

Even in such a shape, as shown in FIG. 9, no contraction occurs in the velocity distribution (velocity profile), and the flow rate of the suction refrigerant flowing into the mixing passage 13d can be quickly reduced. As a result, it is possible to prevent the suction refrigerant from inhibiting the injection refrigerant from spreading to the outer peripheral side of the passage forming member 35.

Further, in the second embodiment described above, the degree of increase in the distance L between the central axis and the part of the passage forming member 35 on the downstream side of the refrigerant flow of the nozzle passage 13a and the portion forming the mixing passage 13d and the central axis gradually decreases. However, if the degree of increase in the distance L between at least the part forming the mixing passage 13d and the central axis is gradually reduced, the same effect can be obtained.

The configuration of the ejector 13 is not limited to that disclosed in the above embodiment.

For example, in the above-described embodiment, the drive device for displacing the passage forming member 35 corresponds to 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 the drive mechanism 37 comprised by having the diaphragm 37a displaced is demonstrated, a drive device is not limited to this.

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

Further, a swirl promoting device that promotes the swirling flow of the refrigerant flowing through the diffuser passage 13c may be added to the ejector 13. According to this, since the spiral refrigerant flow path can be formed in the diffuser passage 13c, it is possible to prevent the refrigerant flow path in the diffuser passage 13c from being shortened and the pressure increase performance of the ejector 13 from being lowered. . Furthermore, the swirling flow of the refrigerant flowing into the gas-liquid separation space 30f can be promoted, and the gas-liquid separation performance in the gas-liquid separation space 30f can be improved.

Such a swirl promoting device may be configured by arranging a rectifying plate in a portion where the diffuser passage of the passage forming member 35 and the middle body 33 is formed, or may be constituted by providing a groove portion in the portion. Good.

Each component device constituting the ejector refrigeration cycle 10 is not limited to that disclosed in the above-described embodiment.

For example, in the above-described embodiment, an example in which an engine-driven variable displacement compressor is employed as the compressor 11 has been described. However, as the compressor 11, the operating rate of the compressor is changed by the on / off of an electromagnetic clutch. You may employ | adopt the fixed capacity type compressor which adjusts a refrigerant | coolant discharge capability. Furthermore, you may employ | adopt an electric compressor provided with a fixed displacement type compression mechanism and an electric motor, and act | operating by supplying electric power. In the electric compressor, the refrigerant discharge capacity can be controlled by adjusting the rotation speed of the electric motor.

In the above-described embodiment, an example in which a subcool type heat exchanger is employed as the radiator 12 has been described, but a normal radiator including only the condensing unit 12a may be employed. In addition to a normal radiator, a receiver-integrated condenser that integrates a receiver (receiver) that separates the gas-liquid of the refrigerant radiated by this radiator and stores excess liquid phase refrigerant is adopted. Also good.

Furthermore, with respect to the ejector-type refrigeration cycle 10 described above, internal heat exchange that lowers the enthalpy of the refrigerant flowing into the ejector 13 by exchanging heat between the refrigerant flowing out of the radiator 12 and the refrigerant sucked into the compressor 11. A vessel may be added.

In the above-described embodiment, the example in which R1234yf is adopted as the refrigerant has been described, but the refrigerant is not limited to this. For example, R134a, R600a, R410A, R404A, R32, R407C, HFO-1234ze, HFO-1234zd, or the like may be employed. Or you may employ | adopt the mixed refrigerant | coolant etc. which mixed multiple types among these refrigerant | coolants.

In the above-described embodiment, the example in which the ejector-type refrigeration cycle 10 including the ejector 13 according to the present disclosure is applied to a vehicle air conditioner has been described. However, the application of the ejector-type refrigeration cycle 10 including the ejector 13 according to the present disclosure is as follows. It 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 present disclosure relates 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. The ejector 13 may be applied.

Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims (7)

An ejector applied to a vapor compression refrigeration cycle apparatus (10),
A decompression space (30b) for decompressing the refrigerant, a suction passage (13b) communicating with the downstream side of the refrigerant flow in the decompression space (30b) and sucking the refrigerant from the refrigerant suction port (31b), and the decompression space ( The mixing space (30h) into which the injection refrigerant injected from 30b) and the suction refrigerant sucked through the suction passage (13b) flow in, and the refrigerant flowing out from the mixing space (30h) into A body (30) having a boosting space (30e);
At least a portion is disposed in the decompression space (30b), in the mixing space (30h), and in the pressurization space (30e), and away from the decompression space (30b). A passage forming member (35) having a conical shape with an enlarged cross-sectional area,
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) depressurizes and injects the refrigerant. A nozzle passage (13a) that functions as a nozzle to
The refrigerant passage formed between the inner peripheral surface of the body (30) forming the mixing space (30h) and the outer peripheral surface of the passage forming member (35) is formed by the injection refrigerant and the suction. It is a mixing passage (13d) that mixes with the refrigerant to make a mixed refrigerant,
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 kinetic energy of the mixed refrigerant. A diffuser passage (13c) that functions as a diffuser for converting the pressure to pressure energy;
The nozzle passage (13a) is formed in the minimum passage area portion (30m) having the smallest passage cross-sectional area, and is formed on the upstream side of the refrigerant flow of the minimum passage area portion (30m) and heads toward the minimum passage area portion (30m). And a tapered portion (131) where the passage cross-sectional area gradually decreases and a divergent portion (132) which is provided on the downstream side of the refrigerant flow of the minimum passage area portion (30m) and where the passage cross-sectional area gradually increases. And
An ejector in which the degree of expansion of the cross-sectional area of the divergent portion (132) is larger on the outlet side than on the inlet side of the divergent portion (132). An ejector applied to a vapor compression refrigeration cycle apparatus (10),
A decompression space (30b) for decompressing the refrigerant, a suction passage (13b) communicating with the downstream side of the refrigerant flow in the decompression space (30b) and sucking the refrigerant from the refrigerant suction port (31b), and the decompression space ( The mixing space (30h) into which the injection refrigerant injected from 30b) and the suction refrigerant sucked through the suction passage (13b) flow in, and the refrigerant flowing out from the mixing space (30h) into A body (30) having a boosting space (30e);
At least a portion is disposed in the decompression space (30b), in the mixing space (30h), and in the pressurization space (30e), and away from the decompression space (30b). A passage forming member (35) having a conical shape with an enlarged cross-sectional area,
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) depressurizes and injects the refrigerant. A nozzle passage (13a) that functions as a nozzle to
The refrigerant passage formed between the inner peripheral surface of the body (30) forming the mixing space (30h) and the outer peripheral surface of the passage forming member (35) is formed by the injection refrigerant and the suction. It is a mixing passage (13d) that mixes with the refrigerant to make a mixed refrigerant,
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 kinetic energy of the mixed refrigerant. A diffuser passage (13c) that functions as a diffuser for converting the pressure to pressure energy;
The most downstream portion of the suction passage (13b) is an ejector having a shape in which the passage cross-sectional area is constant or expands toward the downstream side of the refrigerant flow. The nozzle passage (13a) is formed in the minimum passage area portion (30m) having the smallest passage cross-sectional area, and is formed on the upstream side of the refrigerant flow of the minimum passage area portion (30m) and heads toward the minimum passage area portion (30m). And a tapered portion (131) where the passage cross-sectional area gradually decreases and a divergent portion (132) which is provided on the downstream side of the refrigerant flow of the minimum passage area portion (30m) and where the passage cross-sectional area gradually increases. And
The ejector according to claim 2, wherein the degree of expansion of the cross-sectional area of the divergent section (132) gradually increases toward the downstream side of the refrigerant flow. The mixing passage (13d) has a shape in which the cross-sectional area of the passage is constant or gradually reduced toward the downstream side of the refrigerant flow,
In a cross section parallel to the axial direction of the passage forming member (35), a curve drawn by at least a portion forming the mixing passage (13d) of the passage forming member (35) is directed toward the downstream side of the refrigerant flow. The ejector according to any one of claims 1 to 3, wherein the degree of increase in the distance (L) from the central axis of the passage forming member (35) is gradually reduced. The mixing passage (13d) is continuously arranged in the refrigerant flow direction of the nozzle passage (13a),
In the cross section parallel to the axial direction of the passage forming member (35), a part of the nozzle passage (13a) on the downstream side of the refrigerant flow and the mixing passage (13d) of the passage forming member (35) are formed. 5. The ejector according to claim 4, wherein the curve drawn by the part gradually decreases in the distance (L) from the central axis of the passage forming member (35) toward the downstream side of the refrigerant flow. Further, according to any one of claims 1 to 5, further comprising a swirl flow generating section (30a, 31, 32) for swirling the refrigerant flowing into the nozzle passage (13a) around a central axis of the nozzle passage (13a). The ejector described. An ejector (13) according to claim 6;
A radiator (12) for cooling the high-pressure refrigerant discharged from the compressor (11) for compressing the refrigerant until it becomes a supercooled liquid phase refrigerant,
An ejector type refrigeration cycle in which the supercooled liquid phase refrigerant flows into the swirl flow generating portions (30a, 31, 32).

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