JP2009162116A - Ejector and refrigeration cycle device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ejector installed in a refrigeration cycle device capable of improving nozzle efficiency by reducing a difference of flow speeds between gas and liquid. <P>SOLUTION: The refrigeration cycle device including a compressor 1, a condenser 2, the ejector 5, a gas-liquid separator 6 and an evaporator 8, constitutes a refrigeration cycle. A nozzle 50 of the ejector 5 has a tapered part 54, a throat 55 and a diverging part 56, and has a gas-liquid mixing section 57 upstream of the tapered part 54. The gas-liquid mixing section is configured to mix a liquid refrigerant and a gas refrigerant as a driving flow. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ejector and a refrigeration cycle apparatus using the ejector, and more particularly, to a nozzle structure that controls the flow state in an ejector drive nozzle and achieves high efficiency.

Hereinafter, conventional ejector technology will be described.
There are refrigeration cycle devices that are configured by incorporating an ejector into an air conditioning, refrigeration, or hot water supply device. This is because the suction pressure of the ejector sucks the evaporative gas and raises the pressure, thereby increasing the compressor suction pressure, thereby reducing the compression ratio of the compressor and increasing the efficiency of the refrigeration cycle. The ejector is disposed downstream of the radiator, and includes a drive nozzle (hereinafter referred to as a nozzle) that ejects the refrigerant guided from the radiator at high speed, a diffuser that diffuses the refrigerant ejected from the nozzle, and the like. Yes. Conventionally, as a mechanism for controlling the drive flow rate of the ejector used in this refrigeration cycle apparatus, there has been an ejector-mounted refrigeration cycle that employs a two-stage throttle type flow rate control mechanism in which a throttle mechanism is provided upstream of the ejector. FIG. 10 shows a refrigerant circuit of an ejector-mounted refrigeration cycle that employs the two-stage throttle flow control mechanism. Here, the conventional two-stage throttle flow rate control mechanism is a method in which the expansion valve 3 is provided upstream of the ejector 5 and the drive flow rate is controlled in two stages by the expansion valve 3 and the ejector nozzle throat. In FIG. 10, 1 is a compressor, 2 is a heat radiation side heat exchanger (condenser), 6 is a gas-liquid separator, 7 is an expansion valve, 8 is a load side first heat exchanger (evaporator), 9 Is a load-side second heat exchanger (evaporator), 11 is an outdoor fan, 12 is an indoor first fan, 13 is an indoor second fan, 20 is a control device, 21 is a first temperature detector, and 22 is a second temperature. A detector, 100 is an outdoor unit, 101 is an indoor unit, and 102 and 103 are connection pipes for connecting the outdoor unit 100 and the indoor unit 101.

When a conventional two-stage throttle flow control mechanism is used, if the refrigerant introduced to the nozzle inlet is a liquid phase refrigerant or a low dryness two-phase refrigerant, the liquid component passing through the nozzle throat is a liquid having a large diameter. It consists of droplets and a liquid film, and the average droplet size of the droplet group is large. Looking at the droplet size distribution, a large droplet group is compared at the center of the jet, and the periphery of the jet is compared Small droplet groups are distributed and not uniform. This increased the flow rate difference between the gas and liquid, and contributed to a decrease in nozzle efficiency. FIG. 11 shows an outline of a two-stage throttle flow control mechanism. In FIG. 11, 3 is an expansion valve, 110 is a nozzle, 111 is a tapered portion, 112 is a throat portion, and 113 is a divergent portion.
In the case of such a two-stage throttle type flow control mechanism, the contact area between the driving fluid (liquid refrigerant from the condenser) and the suction fluid (gas refrigerant from the evaporator sucked from an ejector suction unit (not shown)) is reduced. However, the suction fluid cannot be sufficiently sucked, the driving fluid and the suction fluid cannot be mixed homogeneously, and the mixing section is developed from the initial mixing stage of the driving fluid and the suction fluid until the mixing layer develops. Therefore, there is a problem that the mixing performance of the driving fluid and the suction fluid cannot be sufficiently obtained, the pipe friction pressure loss is increased, and the efficiency of the ejector is lowered.
Further, in the vicinity of the inner wall surface of the pipe, the boundary layer becomes thick and peels off due to a large relative flow velocity difference between the high-speed driving fluid and the low-speed suction fluid, and a backflow region may be formed. As a result, there is a problem that the pressure loss increases and the efficiency of the ejector decreases.
Further, if the efficiency of the ejector is low, the ejector cannot sufficiently suck out and pressurize the suction fluid from the evaporator. Therefore, when such an ejector is used in a refrigeration cycle apparatus, the refrigerant gas from the evaporator cannot be sufficiently sucked and the refrigeration capacity is reduced, or the suction pressure of the compressor cannot be sufficiently increased, There was also a problem that the efficiency of the cycle could not be improved.

  In the conventional example, in order to prevent the nozzle efficiency from being lowered, a heating unit is disposed between the radiator and the ejector, and the liquid phase refrigerant is heated by the heating unit, thereby reducing the enthalpy of the liquid phase refrigerant. A method for improving the efficiency by increasing the quantity is known (see, for example, Patent Document 1). However, the method using a heating means such as a heater not only increases the cost of the system, but also reduces the COP (coefficient of performance of the refrigeration cycle).

Japanese Patent Laying-Open No. 2006-17444 (page 2-3, FIG. 1)

The present invention has been made to solve the above-described problems, and provides an ejector that can improve nozzle efficiency by reducing a gas-liquid flow rate difference in an ejector mounted on a refrigeration cycle apparatus. For the purpose.
Another object of the present invention is to obtain an efficient refrigeration cycle apparatus by increasing the refrigeration capacity by increasing the ejector efficiency or increasing the suction pressure of the compressor to reduce the compression ratio of the compressor. .

  In the ejector according to the present invention, the nozzle portion includes a tapered portion, a throat portion, and a divergent portion, and a gas-liquid mixing portion that mixes liquid refrigerant and gas refrigerant as a driving flow upstream of the tapered portion. .

  In the ejector of the present invention, the nozzle portion is configured as described above, so that fine droplets are ejected from the nozzle portion outlet, gas / liquid mixing is promoted, and the ejector efficiency is improved. Further, it is possible to provide a highly efficient refrigeration cycle apparatus without requiring another heat source such as a heater.

Embodiment 1 FIG.
Hereinafter, a refrigeration cycle apparatus according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a refrigerant circuit diagram showing a configuration of a refrigeration cycle apparatus according to Embodiment 1 of the present invention.
This refrigeration cycle apparatus includes an outdoor unit 100 and an indoor unit 101, and the outdoor unit 100 and the indoor unit 101 are connected by connection pipes 102 and 103 to form a closed circuit refrigeration cycle. For example, one of CO ₂ , R404a, R410A, R32, isobutane, and propane is sealed inside the piping constituting the refrigerant circuit.

  In the outdoor unit 100, a first expansion that controls the flow rate of refrigerant flowing as a driving flow from the compressor 1, the heat radiation side heat exchanger 2 that is a condenser, and the ejector 5 on the indoor unit 101 side from the heat radiation side heat exchanger 2. A second expansion that bypasses a part of the gas discharged from the valve 3 and the compressor 1 and mixes with the liquid refrigerant from the heat radiation side heat exchanger 2 to control the flow rate of the gas refrigerant flowing into the ejector 5 as a driving flow. The valve 4 is installed and connected to each end of the connection pipes 102 and 103 by pipes. In addition, the second expansion valve 4 is provided in a bypass pipe 10 that connects the pipe between the compressor 1 and the heat radiation side heat exchanger 2 and the ejector 5. The compressor 1 is a type in which the rotation speed is controlled by an inverter and the capacity is controlled. Each of the first expansion valve 3 and the second expansion valve 4 is an electronic expansion valve whose opening is variably controlled, and constitutes a first variable throttle device and a second variable throttle device, respectively.

  In the indoor unit 101, an ejector 5, a gas-liquid separator 6, a third expansion valve 7, a load side first heat exchanger 8 and a load side second heat exchanger 9 which are evaporators are installed, and these are piped Thus, the connection pipes 102 and 103 are connected to the other ends. A pipe for guiding the liquid refrigerant separated by the gas-liquid separator 6 is connected to the suction part of the ejector 5 via the third expansion valve 7 and the load-side first heat exchanger 8. A pipe for guiding the separated gas refrigerant is connected to the compressor 1 via the load-side second heat exchanger 9. Further, since the load-side second heat exchanger 9 is connected as an auxiliary evaporator between the gas-liquid separator 6 and the compressor 1, even when the gas separation efficiency of the gas-liquid separator 6 is lowered, the load side Since the second heat exchanger 9 absorbs heat, the liquid refrigerant can be prevented from being mixed into the compressor 1.

  The heat radiation side heat exchanger 2, the load side first heat exchanger 8, and the load side second heat exchanger 9 are plate fin tube type heat exchangers composed of plate fins and pipes, and are located outside the heat exchanger. An outdoor blower 11, an indoor first blower 12, and an indoor second blower 13 that blow air to the surface are provided.

  A first temperature detector 21 is installed between the load side first heat exchanger 8 and the ejector 5, and a second temperature detector 22 is installed between the load side second heat exchanger 9 and the compressor 1. The refrigerant temperature at each installation location is detected, and the signal is input to the control device 20 installed in the outdoor unit 100. The control device 20 controls the refrigerant flow rate by controlling the rotation speed of the compressor 1 and the opening degrees of the first expansion valve 3 and the second expansion valve 4 based on the refrigerant temperature detection information.

Next, the structure of the ejector 5 used in this refrigeration cycle apparatus is shown in FIG. FIG. 2A is an explanatory diagram of the structure and operation of the nozzle portion 50 of the ejector 5, and FIG. 2B is a schematic configuration diagram of the ejector 5.
The ejector 5 includes a nozzle unit 50, an ejector mixing unit 51, and a diffuser unit 52, and further includes an ejector suction unit 53 for sucking a refrigerant. The inlet part of the nozzle part 50 is connected to a gas-liquid mixing part 57 to be described later, the ejector suction part 53 is connected to the outlet part of the load side first heat exchanger 8, and the outlet part of the diffuser part 52 is the gas-liquid separator 6. It is connected with the entrance part. And the nozzle part 50 of this ejector 5 has a taper-slow wide structure provided with a gas-liquid mixing mechanism. That is, the nozzle portion 50 includes a tapered portion 54 with a gradually decreasing cross-sectional area, a throat portion 55 with the smallest sectional area, and a divergent portion 56 with a gradually increasing sectional area. The gas-liquid mixing part 57 which mixes a liquid refrigerant and a gas refrigerant as a drive flow is provided.

  In the nozzle section 50 of the ejector 5 configured as described above, the liquid refrigerant flowing out from the heat radiation side heat exchanger (condenser) 2 is decompressed by the first expansion valve 3 and then driven to the gas-liquid mixing section 57. Flows in as a stream. A part of the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 passes through the bypass pipe 10 and is decompressed by the second expansion valve 4, and then flows into the gas-liquid mixing unit 57 as a driving flow to Mix. In this way, after the liquid refrigerant and the gas refrigerant are mixed as a driving flow in the gas-liquid mixing section 57, the mixed two-phase flow is accelerated through the tapered portion 54 and ejected downstream of the throat 55. That is, in the tapered portion 54, the mixed two-phase flow is decompressed and expanded, and the throat portion 55 is sonicated, and the divergent portion 56 is decompressed and ejected as supersonic velocity. At this time, the gas refrigerant absorbed and evaporated by the load-side first heat exchanger 8 is sucked from the ejector suction unit 53, mixed with the mixed two-phase flow, the pressure is recovered by the ejector mixing unit 51, and the diffuser unit 52 is further recovered. Increase the pressure at the outlet.

Here, the operation of the nozzle portion 50 of the ejector 5 will be described in more detail. FIG. 3 is a diagram showing the static pressure distribution in the nozzle in comparison with the conventional example. The solid line in FIG. 3 shows a conventional example, which is a case of a two-stage throttle system without a gas-liquid mixing unit, and shows the static pressure distribution in the nozzle when the refrigerant is supplied in a state of low dryness. The dotted line is the case of this embodiment, and represents the static pressure distribution in the nozzle when the refrigerant is supplied in a state of high dryness. The horizontal axis in FIG. 3 indicates the distance X (mm) from the nozzle inlet (Xin), and the vertical axis indicates the pressure P (MPa) at each position.
In the case of the present embodiment, when the mixed two-phase refrigerant flows into the tapered portion 54 of the nozzle portion 50, it is no longer suddenly decompressed and flushed near the throat portion 55 (a flushing flow). Thereafter, the mixed two-phase refrigerant is further depressurized at the divergent section 56 and accelerated as the dryness increases.
Therefore, compared to the case of simply using the two-stage throttle method as in the conventional example, the gas-liquid mixing portion 57 is further provided as in the present embodiment to mix the liquid refrigerant and the gas refrigerant and then supply the nozzle portion 50 It is possible to further increase the dryness of the refrigerant. It is desirable to adjust the dryness of the refrigerant within the range of 0 to 0.4 by controlling the opening degree of one or both of the first expansion valve 3 and the second expansion valve 4. In addition, the dryness of a refrigerant | coolant is the ratio of the gas mass with respect to the liquid mass of a unit flow, 0 means a saturated liquid and 1 means a saturated vapor | steam.

FIG. 4 is a diagram showing the temperature distribution in the nozzle in comparison with the conventional example. The thick line in FIG. 4 shows a conventional example of a two-stage drawing method without a gas-liquid mixing unit, and the thin line is the case of this embodiment. The thick solid line indicates a low dryness refrigerant, the dotted line indicates a low dryness gas refrigerant, the thin solid line indicates a high dryness liquid refrigerant, and the dotted line indicates a high dryness gas refrigerant. is there. The horizontal axis in FIG. 4 indicates the distance X (mm) from the nozzle inlet (Xin), and the vertical axis indicates the temperature (° C.) at each position.
4 that both the present embodiment and the conventional example have a large thermal non-equilibrium between the liquid refrigerant and the gas refrigerant during the rapid flushing process in a certain section immediately after the throat 55. Thereafter, the thermal non-equilibrium is relaxed and gradually expands in an almost equilibrium state to the nozzle outlet. However, in the case of the present embodiment, it can be seen that the thermal non-equilibrium between the liquid refrigerant and the gas refrigerant is smaller than that of the conventional example and is alleviated earlier.

FIG. 5 is a diagram showing the flow velocity distribution in the nozzle in comparison with the conventional example. The thick line in FIG. 5 shows a conventional example of a two-stage throttle system without a gas-liquid mixing part, and the thin line is the case of this embodiment. The thick solid line indicates a low dryness refrigerant, the dotted line indicates a low dryness gas refrigerant, the thin solid line indicates a high dryness liquid refrigerant, and the dotted line indicates a high dryness gas refrigerant. is there. The horizontal axis in FIG. 5 indicates the distance X (mm) from the nozzle inlet (Xin), and the vertical axis indicates the flow velocity (m / s) at each position.
Similarly, with respect to the flow velocity distribution in the nozzle, in both of the present embodiment and the conventional example, there is a velocity non-equilibrium between the flow velocity of the gas refrigerant and the liquid refrigerant during the rapid flushing process in a certain section immediately after the throat 55. I understand. However, even in the case of the present embodiment, it can be seen that the non-equilibrium of the flow rate between the liquid refrigerant and the gas refrigerant is smaller than that in the conventional example and is alleviated earlier.

Thus, in this embodiment, while supplying a part of high-temperature / high pressure gas refrigerant discharged from the compressor 1 to the gas-liquid mixing part 57 via the bypass pipe 10, the gas refrigerant and the heat radiation side heat exchanger are supplied. Since the liquid refrigerant supplied from the (condenser) 2 is mixed in the gas-liquid mixing part 57 and supplied to the nozzle part 50 of the ejector 5 as a driving flow, the liquid of the gas-liquid two-phase refrigerant after passing through the throat part 55 The component becomes a fine droplet. Therefore, by ejecting the fine liquid droplets from the nozzle part outlet, gas / liquid mixing is further promoted in the ejector mixing part 51, so that the ejector efficiency is improved. In particular, in this embodiment, the effect is large in the refrigerant having a large gas-liquid density difference such as R404A and R410A.
Moreover, since other heat sources such as a heater for heating the liquid refrigerant in the ejector drive flow are not required as in the prior art, an inexpensive and highly efficient refrigeration cycle apparatus can be provided.

FIG. 6 shows the diameter of the throat necessary for flowing the same amount of flow as that of the saturated liquid when flowing at a void rate of 0.6 when the throat diameter flows into a nozzle having a throat diameter of 2.5 mm. Show. Note that the void ratio is the ratio of the gas volume to the total volume.
As can be seen from FIG. 6, the throat diameter is larger when the gas-liquid two-phase flow is performed than when the saturated liquid is flowed. That is, when flowing in with a void rate of 0.6, the throat diameter needs to be 2.5 mm to 3 mm.
Therefore, in the present embodiment, the nozzle throat diameter can be increased with respect to the same amount of flow as compared with the conventional two-stage throttle method, so that an effect of reducing clogging of foreign matters can be obtained. In particular, the present invention is effective for an ejector for an air conditioning / freezing / hot water supply apparatus having a throat diameter of 2 mm or less.
Moreover, since the ejector 5 provided with the gas-liquid mixing part 57 can control the refrigerant state of the suction part of the compressor 1 by being provided with the second expansion valve 4, it can be used in a wide flow range such as an inverter machine. It can be suitably used for a refrigeration cycle.

FIG. 7A shows the structure of the ejector 5, and FIG. 7B is a diagram showing the pressure change inside the ejector 5. The pressure at each position (X1 to X6) of the ejector 5 is shown. FIG. 8 is a ph diagram of the refrigeration cycle apparatus shown in FIG.
The operation of the refrigeration cycle apparatus according to Embodiment 1 will be described with reference to FIGS.

  The high-temperature and high-pressure gas refrigerant R1 discharged from the compressor 1 radiates heat to the air mainly by the heat-radiating side heat exchanger 2 and condenses and liquefies itself to become liquid refrigerant R2. The other part of the gas refrigerant R1 is decompressed by the second expansion valve 4 to be in the state of R2 ', and is bypassed to the gas-liquid mixing part 57 of the ejector 5 through the bypass pipe 10.

  The liquid refrigerant R2 radiated by the heat radiating side heat exchanger 2 flows into the gas-liquid mixing section 57 and is mixed with the gas refrigerant R2 ′ bypassed between the compressor 1 and the heat radiating side heat exchanger 2 inlet to be in the state R3. And flows into the nozzle portion 50 of the ejector 5.

  The refrigerant R3 that has flowed into the ejector 5 is decompressed by the nozzle portion 50 to be in the state R4, and merges with the refrigerant gas R9 that flows in from the ejector suction portion 53. In the present embodiment, as shown in FIG. 3, the gas / liquid mixed flow R3 having a high dryness is caused to flow into the nozzle portion 50 of the ejector 5 to thereby obtain a homogeneous flow having a reduced gas / liquid speed difference in the state R5. Become. Further, since the nozzle portion 50 of the ejector 5 is ejected in the form of fine droplets, the area in which the droplets of the driving flow come into contact with the suction flow gas is increased, and the shearing force causes the load from the first heat exchanger 8 on the load side. It becomes easier to suck the gas refrigerant R9 and the suction flow rate increases. After that, it passes through the ejector mixing section 51 and the diffuser section 52, and becomes a state R6 where the pressure is increased to P2 'as shown in FIGS. That is, in this embodiment, unlike the pressure recovery P2 in the conventional two-stage throttle method, the amount of pressure increase increases because the droplets are small and the gas / liquid is easily mixed for the same amount of suction flow.

The refrigerant that has passed through the diffuser portion 52 of the ejector 5 flows into the gas-liquid separator 6 and is separated into R7 liquid refrigerant and R10 gas refrigerant. The R10 gas refrigerant flowing out from the load-side second heat exchanger 9 flows into the inlet of the compressor 1, and the R7 liquid refrigerant is decompressed by the third expansion valve 7 to become the state R8, and the load-side first heat exchanger 8 absorbs heat from the air and evaporates and vaporizes itself to become a gas refrigerant R9 and is sucked by the ejector 5.
From the above, by using this ejector 5, the suction pressure of the compressor can be increased from P3 to P2 ′, and the suction pressure is increased, enabling highly efficient operation.

  According to the present embodiment, the performance increases and the use of this ejector 5 in a device having a small temperature difference between the refrigerant and the air in the load side first heat exchanger 8, such as a room air conditioner or a refrigerator, This is a useful device that can increase the suction pressure of the compressor 1 without being restricted by the temperature difference of the first heat exchanger 8.

Embodiment 2. FIG.
Next, a refrigeration cycle apparatus according to Embodiment 2 of the present invention will be described.
FIG. 9A is an explanatory diagram of the structure and operation of the nozzle portion of the ejector 5A according to the second embodiment, and FIG. 9B is a schematic configuration diagram of the ejector 5A. Further, since the refrigerant circuit of the refrigeration cycle apparatus using the ejector 5A is the same as that in FIG. 1, detailed description thereof is omitted unless otherwise specified.
The ejector 5 </ b> A includes an inner nozzle portion 50 a and an outer nozzle portion 50 b including a tapered portion 54, a throat portion 55, and a divergent portion 56. The inner nozzle part 50a is arranged with its tip facing the throat 55 of the outer nozzle part 50b. A liquid refrigerant is supplied to the inner nozzle portion 50a as a driving flow through the heat radiation side heat exchanger 2 and the first expansion valve 3 shown in FIG. 1, and is provided between the inner nozzle portion 50a and the outer nozzle portion 50b. A part of the discharge gas from the compressor 1 of FIG. 1 is supplied to the tapered flow path 50 c via the bypass pipe 10 and the second expansion valve 4. Further, the inner nozzle part 50a and the outer nozzle part 50b are arranged coaxially. That is, the ejector 5A of the present embodiment ejects liquid refrigerant as a driving flow from the inner nozzle portion 50a, and gas refrigerant as a driving flow from the tip of the flow path 50c between the inner nozzle portion 50a and the outer nozzle portion 50b. A nozzle structure for jetting is provided, and a space between the tip of the inner nozzle portion 50a and the throat portion 55 is configured as a liquid refrigerant and gas refrigerant gas-liquid mixing portion 57 as a driving flow. That is, the ejector 5A of the present embodiment includes a tapered and divergent nozzle structure that mixes and injects liquid refrigerant and gas refrigerant as a driving flow in a tapered manner with inner and outer double injection pipes.

  In the nozzle structure of the ejector 5A of the present embodiment, a part of the discharged gas refrigerant from the compressor 1 is introduced and accelerated into a tapered flow path 50c between the inner nozzle part 50a and the outer nozzle part 50b. Liquid droplets of the liquid refrigerant are refined by jetting and mixing the high-speed gas refrigerant to the external surface of the liquid refrigerant jetted from the inner nozzle portion 50a. The mixed two-phase flow containing the fine droplets is depressurized by the divergent section 56 and ejected as supersonic speed. At this time, the gas refrigerant absorbed and evaporated by the load-side first heat exchanger 8 is sucked from the ejector suction unit 53, mixed with the mixed two-phase flow, the pressure is recovered by the ejector mixing unit 51, and the diffuser unit 52 is further recovered. Therefore, the ejector efficiency can be improved as in the first embodiment. Moreover, since the refrigerant | coolant state of the compressor 1 suction | inhalation part can be controlled by providing the 2nd expansion valve 4, it can utilize suitably for the refrigerating cycle used in wide flow-rate ranges, such as an inverter machine. .

  As described above, in the present embodiment, since the gas-liquid mixing unit 57 is provided at the inlet of the ejector 5A, fine droplets can be ejected from the inner nozzle unit 50a, and a highly efficient ejector cycle is provided. Can do.

The present invention in the configuration of the first and second embodiments described above, the present invention is not limited to the form, CO ₂ or R404a, R410A, R32, isobutane, propane and the like as a refrigerant, to all of the refrigeration cycle using the ejector Applicable. Further, the present invention can be applied to all refrigeration cycles using a fixed nozzle or a variable nozzle (for example, a nozzle that relatively moves an inner nozzle portion and an outer nozzle portion in the axial direction) as a drive nozzle (nozzle portion of a drive flow). Further, the present invention can be applied regardless of the size of the drive nozzle and the mixing portion.

  The heat exchanger is not limited to the above, and may be a liquid-liquid heat exchanger using water or brine as a heating source or a cooling source such as a double tube or a plate heat exchanger.

It is a refrigerant circuit diagram which shows the structure of the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. (A) is explanatory drawing of the structure and effect | action of the nozzle part of the ejector which concern on Embodiment 1, (b) is a schematic block diagram of an ejector. It is a figure which shows the static pressure distribution in the nozzle of the ejector which concerns on Embodiment 1. FIG. It is a figure which shows the temperature distribution in the nozzle of the ejector which concerns on Embodiment 1. FIG. It is a figure which shows the flow-velocity distribution in the nozzle of the ejector which concerns on Embodiment 1. FIG. It is a figure which shows the relationship between the throat part diameter of the ejector which concerns on Embodiment 1, and a critical flow ratio. (A) is a block diagram of the ejector which concerns on Embodiment 1, (b) is a figure which shows the pressure change inside an ejector. 2 is a ph diagram of the refrigeration cycle apparatus according to Embodiment 1. FIG. (A) is explanatory drawing of the structure and effect | action of the nozzle part of the ejector which concern on Embodiment 2, (b) is a schematic block diagram of an ejector. It is a refrigerant circuit diagram of a conventional refrigeration cycle apparatus of a two-stage throttle system. It is explanatory drawing of a structure and effect | action of the nozzle of the conventional ejector.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Heat radiation side heat exchanger, 3rd expansion valve, 4th 2nd expansion valve, 5, 5A ejector, 6 Gas-liquid separator, 7 3rd expansion valve, 8 Load side 1st heat exchanger, 9 Load side second heat exchanger, 10 bypass pipe, 11 outdoor fan, 12 indoor first fan, 13 indoor second fan, 20 control device, 21 first temperature detector, 22 second temperature detector, 50 nozzle part, 50a Inner nozzle part, 50b Outer nozzle part, 50c Flow path between inner nozzle part and outer nozzle part, 51 Ejector mixing part, 52 Diffuser part, 53 Ejector suction part, 54 Tapering, 55 Throat part, 56 Divergent part , 57 Gas-liquid mixing section, 100 outdoor unit, 101 indoor unit, 102, 103 connection piping.

Claims (12)

  1. An ejector comprising: a nozzle portion including a tapered portion, a throat portion, and a divergent portion, and a gas-liquid mixing portion that mixes liquid refrigerant and gas refrigerant as a driving flow upstream of the tapered portion.   An inner nozzle portion and an outer nozzle portion having a tapered portion, a throat portion, and a divergent portion are provided. The inner nozzle portion is disposed with its tip facing the throat portion of the outer nozzle portion, and is driven by the inner nozzle portion. An ejector characterized in that a liquid refrigerant is supplied as a flow and a gas refrigerant is supplied to a flow path between the inner nozzle portion and the outer nozzle portion.   3. The ejector according to claim 1, wherein a first variable throttle device is provided in the liquid refrigerant supply path, and a second variable throttle device is provided in the gas refrigerant supply path. In a refrigeration cycle apparatus comprising at least a compressor, a condenser, an ejector, a gas-liquid separator, and an evaporator to constitute a refrigeration cycle,
The nozzle part of the ejector comprises a tapered part, a throat part, and a divergent part, and a gas-liquid mixing part that mixes liquid refrigerant from the condenser and gas refrigerant from the compressor as a driving flow upstream of the tapered part A refrigeration cycle apparatus comprising: In a refrigeration cycle apparatus comprising at least a compressor, a condenser, an ejector, a gas-liquid separator, and an evaporator to constitute a refrigeration cycle,
The ejector includes an inner nozzle portion and an outer nozzle portion having a tapered portion, a throat portion, and a divergent portion, and the inner nozzle portion is disposed with its tip facing the throat portion of the outer nozzle portion, A liquid refrigerant is supplied from the condenser as a driving flow to the nozzle part, and a gas refrigerant is bypassed and supplied from the compressor to an annular flow path between the inner nozzle part and the outer nozzle part. Refrigeration cycle equipment.   6. The refrigeration cycle apparatus according to claim 4, wherein a first variable throttle device is provided in the liquid refrigerant supply path, and a second variable throttle device is provided in the gas refrigerant supply path.   The refrigeration cycle apparatus according to claim 4 or 6, wherein a pipe connecting the compressor and the condenser and the gas-liquid mixing unit are connected by a bypass pipe provided with the second variable throttle device. .   The refrigeration cycle apparatus according to claim 5 or 6, wherein a pipe connecting the compressor and the condenser and the annular flow path are connected by a bypass pipe provided with the second variable throttle device.   The refrigeration cycle apparatus according to any one of claims 4 to 8, further comprising a third variable throttle device between the gas-liquid separator and the evaporator.   The refrigeration cycle apparatus according to any one of claims 4 to 9, further comprising an auxiliary evaporator between the gas-liquid separator and the compressor.   Controlling the degree of opening of one or both of the first variable throttle device and the second variable throttle device so that the dryness of the refrigerant at the inlet of the nozzle of the ejector falls within a range of 0 to 0.4. The refrigeration cycle apparatus according to any one of claims 4 to 10, wherein: CO _2, R404a, R410A, R32, isobutane, refrigeration cycle apparatus according to any one of claims 4 to 11, characterized by using any one of propane as a refrigerant.

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