JP4306739B2 - Refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus having an ejector.

  Hereinafter, a conventional refrigeration cycle apparatus having an ejector will be described. In the refrigeration cycle apparatus, the ejector is arranged downstream of the radiator, and a nozzle that ejects the refrigerant guided from the radiator as a driving fluid at high speed, a mixing unit that mixes the refrigerant ejected from the nozzle and the suction fluid, The diffuser is configured to diffuse the mixed refrigerant. By increasing the suction pressure of the compressor due to the boosting action of the ejector, the number of rotations of the compressor can be reduced and the apparatus can be downsized. Moreover, compared with the expansion valve used until now, there exists an advantage that a part of effective energy wasted by the expansion valve can be recovered, and the efficiency of the refrigeration cycle can be increased. However, when the refrigerant introduced to the nozzle inlet is a supercooled liquid refrigerant, it flows out from the nozzle in the form of large droplets or a liquid film and cannot be mixed well with the suction fluid at the mixing section, effectively increasing the pressure increasing action. Couldn't get.

  On the other hand, there is a refrigeration cycle apparatus configured to flow into a nozzle in a gas-liquid two-phase state (see, for example, Patent Document 1). This includes a heating means disposed at a portion between the radiator and the ejector, and the heating means heats the supercooled liquid phase refrigerant, thereby increasing the enthalpy of the supercooled liquid phase refrigerant by a predetermined amount. It is configured. Moreover, it was the structure which controls the opening degree and ventilation volume of a nozzle so that the high pressure refrigerant | coolant which flowed out from the heat radiator may flow into a nozzle in a gas-liquid two-phase state.

JP 2006-17444 (page 7-8, FIG. 1)

For example, in a configuration in which a gas-liquid two-phase refrigerant obtained by increasing the enthalpy of the supercooled liquid-phase refrigerant by a predetermined amount with a heater or the like is caused to flow into the ejector and easily boil at the nozzle throat, the droplet after passing through the throat However, the bubble size of the boiled refrigerant was about several mm in diameter. At this size, miniaturization was not yet sufficient, and the bubbles were likely to stick together to form large bubbles. For this reason, since it ejected as a driving fluid of a large droplet from the nozzle, there was a problem that the mixing performance with the suction fluid was poor and the ejector performance could not be improved so much.
Moreover, in the structure provided with other heat sources, such as a heater, in order to make it flow into a nozzle in a gas-liquid two-phase state, there existed a subject that power consumption increased in order to use another heat source.
Further, in the configuration in which the heat exchange amount in the radiator is controlled to flow into the nozzle in the gas-liquid two-phase state, there is a problem that it is not easy to control the gas-liquid two-phase state.

  The present invention has been made to solve the above-described problems, and has an object to promote mixing of a driving fluid and a suction fluid in an ejector, to improve ejector efficiency, and to obtain an efficient refrigeration cycle apparatus. And

The refrigeration cycle apparatus according to the present invention includes a compressor that puts the refrigerant in a high-pressure state, a heat-dissipation-side heat exchanger that dissipates heat of the high-pressure refrigerant from the compressor, and heat dissipation from the heat-dissipation-side heat exchanger. Bubble generation means that uses a refrigerant containing fine bubbles as a later refrigerant, and suction from the suction portion by a driving fluid that flows out of the nozzle portion at a high speed by reducing the pressure of the refrigerant containing fine bubbles generated by the bubble generation means. An ejector that sucks a fluid, mixes the driving fluid and the suction fluid in a mixing unit, and then expands in the diffuser unit and flows out in a low pressure state, and evaporation side heat exchange that evaporates the low-pressure refrigerant from the ejector comprising a vessel, wherein the bubble generating means, the compressor or at least partially the gas refrigerant inlet flowing the outgoing heat of the gas refrigerant among the refrigerant flowing from the radiator side heat exchanger A liquid refrigerant inflow portion into which a refrigerant containing a large amount of liquid out of the refrigerant flowing out of the exchanger flows, and the gas refrigerant is caused to flow from the gas refrigerant inflow portion into the liquid refrigerant flowing in from the liquid refrigerant inflow portion. It is configured to generate bubbles .

According to the refrigeration cycle apparatus according to the present invention, the refrigerant having a fine fine bubbles by the ejector of the drive fluid, since mixing with the aspiration fluid and ejecting fine droplets from the nozzle portion of the ejector, and the gas The contact area of the liquid increases and mixing is promoted. For this reason, it is possible to improve the ejector efficiency and to provide an efficient refrigeration cycle apparatus as a whole.

Embodiment 1 FIG.
Hereinafter, the refrigeration cycle apparatus according to Embodiment 1 of the present invention will be described. FIG. 1 is a refrigeration cycle apparatus according to Embodiment 1 of the present invention, and is a configuration diagram showing a circuit configuration of an air conditioner that cools a room, for example. As shown in the figure, the refrigeration cycle apparatus according to the present embodiment includes an outdoor unit 100, an indoor unit 101, a two-phase extension pipe 71 connecting the outdoor unit 100 and the indoor unit 101, and a gas extension pipe 72. . The refrigerant circuit in the outdoor unit 100 includes a compressor 1 that brings the refrigerant into a high pressure state, a heat release side heat exchanger 2 that dissipates heat from the high pressure state refrigerant from the compressor 1, and a heat release from the heat release side heat exchanger 2. For example, a fine bubble generating device 3 for generating bubbles of about several hundred μm or less, and a pipe for connecting them. Further, a pipe between the compressor 1 and the heat radiation side heat exchanger 2 and the fine bubble generating device 3 are connected by a bypass pipe 9, and one end side of the bypass pipe 9 is a discharge part of the compressor 1 and a heat radiation side heat exchanger. The other end side is connected to the gas refrigerant inflow portion of the fine bubble generating device 3.

  The refrigerant circuit in the indoor unit 101 includes an ejector 4 that sucks and mixes suction fluid from a suction portion by a driving fluid and mixes it to flow out in a low-pressure state, a gas-liquid separator 5, for example, a throttle device 6 as a refrigerant flow rate adjusting means, and a low-pressure state An evaporation side heat exchanger 7 that evaporates the refrigerant, an auxiliary heat exchanger 13 that is provided on the suction side of the compressor 1 and converts the sucked refrigerant into a gas refrigerant state with an appropriate superheat degree, and a pipe for connecting them. It is configured. The liquid phase part of the gas-liquid separator 5 is connected to the expansion device 6 and further connected to the suction part of the ejector 4 via the evaporation side heat exchanger 7. On the other hand, the gas phase part of the gas-liquid separator 5 is connected to the suction side of the compressor 1 via the auxiliary heat exchanger 13, and auxiliary heat exchange is performed even when the gas separation efficiency of the gas-liquid separator 5 becomes low. The gas refrigerant is reliably sucked into the compressor 1 by absorbing heat with the compressor 13 and gasifying it. For example, R404A, which is an HFC-based mixed refrigerant, is sealed inside the pipe as a refrigerant.

  The heat radiation side heat exchanger 2, the evaporation side heat exchanger 7, and the auxiliary heat exchanger 13 are, for example, plate fin tube type heat exchangers composed of plate fins and pipes, and air is supplied to the outer surface of the heat exchanger. An outdoor blower 11 that blows air, an indoor blower 12, and an auxiliary heat exchanger blower 14 are provided.

The first temperature detection means 21 is provided between the expansion device 6 and the evaporation side heat exchanger 7, and the second temperature detection means 22 is provided between the evaporation side heat exchanger 7 and the ejector 4, so that the heat radiation side heat exchanger is provided. 3 and the fine bubble generating device 3 are provided with a third temperature detecting means 23, and a pressure sensor 24 is provided between the compressor 1 and the heat radiation side heat exchanger 2, and these detected values are control means, for example, control It is taken into the device 31.
In the figure, thin dotted arrows indicate the directions of input signals for sending information detected by the detection means 21, 22, 23, 24 to the control device 31, and thick dotted arrows indicate that the control device 31 has the respective devices 1, 3, 6 Indicates the direction of the control signal sent to. Moreover, the solid line arrow has shown the flow direction of the refrigerant | coolant in a circuit.

  Next, the configuration of the fine bubble generating device 3 and the ejector 4 which are bubble generating means will be described in detail.

FIG. 2 is an explanatory view showing an example of the structure of the fine bubble generator 3. The fine bubble generating device 3 according to the present embodiment has a Venturi structure, and further includes, for example, a needle portion 51 as resistance adjusting means for adjusting the flow resistance. As shown in the figure, the fine bubble generating device 3 includes a needle portion 51, a gas refrigerant inflow portion 52, a decompression portion 53, a divergent portion 54, and a throat portion 55, and the liquid refrigerant inflow portion 3a is used as the heat radiation side heat exchanger 2. The gas refrigerant inflow portion 52 is connected to the bypass pipe 9, and the refrigerant outlet portion 3 c is connected to the nozzle inlet portion of the ejector 4. The internal liquid refrigerant channel has a channel cross-sectional area that decreases from the liquid refrigerant inlet 3a toward the throat 55, and is disconnected from the throat 55 toward the outlet 3c of the microbubble generator 3. The gas refrigerant inflow part 52 is provided in the vicinity of the throat part 55. The flow path cross-sectional area in the fine bubble generating device 3 can be increased or decreased by displacing the needle portion 51 left and right as viewed in the drawing by the motor 56. That is, the control unit 31 sends a control signal to the motor 56 to adjust the flow resistance, whereby the refrigerant state can be controlled. For example, in the case where the refrigerant state of the suction portion of the compressor 1 is controlled by the microbubble generator 3, when the inverter compressor whose rotation speed can be changed during the operation is used as the compressor 1, the operating condition changes Correspondingly, optimum operation can be performed, so that it can be applied to a refrigeration cycle apparatus used in a wide flow range. Moreover, if the refrigerant | coolant state of the inlet_port | entrance part of the fine bubble generator 3 is controlled by the needle part 51, the fine bubble whose diameter is several hundred micrometers or less can be generated uniformly.
As illustrated in detail in circles in the figure, the gas refrigerant flow path intersects the liquid refrigerant flow path, and the angle θ formed by the gas refrigerant insertion direction and the liquid refrigerant flow direction intersects each other. Thus, for example, it is provided to be 90 degrees or more and 180 degrees or less.

  In the microbubble generator 3, since the liquid refrigerant flow flowing from the liquid refrigerant inflow portion 3a and the gas refrigerant flow inserted from the gas refrigerant inflow portion 52 flow so as to intersect, the gas refrigerant flow is sheared by the liquid refrigerant flow. It becomes a fine bubble, becomes a homogeneous fine bubble flow, and flows out from the refrigerant | coolant exit part 3c. Here, since θ is set to be, for example, 90 degrees or more and 180 degrees or less, the gas refrigerant is inserted in the direction in which the gas refrigerant collides with the flow of the liquid refrigerant. It becomes easy to be sheared by the refrigerant, and the bubbles become finer bubbles.

FIG. 3 is an explanatory view showing the cylindrical ejector 4, FIG. 3 (a) shows a cross-sectional configuration along the axis of the ejector 3, and FIG. 3 (b) shows positions X1 to X6 in FIG. 3 (a). It is a graph which shows the pressure P corresponding to each position. 3B, the horizontal axis indicates the position of the ejector 3, and the vertical axis indicates the pressure P. In FIG.
The ejector 4 used in the present embodiment includes a suction unit 42, a nozzle unit 43, a mixing unit 44, and a diffuser unit 45. The nozzle unit 43 further includes a decompression unit 43a, a divergent unit 43b, and a throat unit 43c. . The throat portion 43 c is a portion having the smallest opening area in the nozzle portion 43. The inlet part of the nozzle part 43 is connected to the refrigerant outlet part 3c of the fine bubble generating device 3, the suction part 42 is connected to the outlet part of the evaporation side heat exchanger 7, and the outlet part of the diffuser part 45 is connected to the gas-liquid separator 5. Connect to the entrance of the.

  The driving fluid flowing in from the arrow A is decompressed by the decompression unit 43a, flows through the throat part 43c and the divergent part 43b, and flows through the flow path following the nozzle outlet part 43d. The ejector 3 has, for example, a fixed throttle configuration in which the area ratio (hereinafter referred to as expansion ratio) of the nozzle throat portion 43c and the nozzle outlet portion 43d is constant, and the liquid refrigerant R3 having the pressure P1 (position X1) flowing in from the direction of the arrow A. , And the pressure is reduced by the pressure reducing portion 43a, and the throat portion 43c (position X2) becomes a high speed of sound speed. Furthermore, it expands in the divergent part 43b, becomes supersonic, is depressurized to the pressure P3 (position X3), and is ejected from the nozzle outlet part 43d as a driving fluid. At this time, the refrigerant R9 in the gas-liquid two-phase state or gas state flowing in from the direction of the arrow B is sucked, and the mixed gas-liquid two-phase refrigerant R5 recovers the pressure in the mixing unit 44 (position X4-position X5), Further, the pressure rises to the pressure P2 (position X6) by the diffuser portion 45 and flows out as the refrigerant R6.

Next, the operation of the refrigeration cycle apparatus will be described with reference to FIGS. FIG. 4 is a pressure-enthalpy diagram relating to the refrigeration cycle apparatus according to the present embodiment, where the horizontal axis indicates enthalpy (kJ / kg) and the vertical axis indicates pressure (pascal).
The high-temperature and high-pressure gas refrigerant R1 discharged from the compressor 1 dissipates heat to the air mainly by the heat-radiating side heat exchanger 2, and the refrigerant itself condenses and liquefies to become liquid refrigerant R21. The other part of the gas refrigerant R1 flows into the bypass pipe 9, is depressurized by the pipe resistance, enters the state of R22, and is bypassed to the gas refrigerant inflow portion 52 of the fine bubble generating device 3.

  The liquid refrigerant R21 radiated by the heat radiation side heat exchanger 2 flows into the liquid refrigerant inflow portion 3a of the fine bubble generating device 3, and passes through the bypass pipe 9 between the compressor 1 and the heat radiation side heat exchanger 2 inlet to gas. It mixes with gas refrigerant R22 inserted from refrigerant inflow part 52, and will be in state R3. At this time, the inserted gas refrigerant R22 is divided into bubbles having a diameter of about several hundreds μm by a shearing force with the liquid refrigerant R21 to form a homogeneous fine bubble flow. And it becomes a refrigerant | coolant of state R3, flows out of the outdoor unit 100, flows into the ejector 4 in the indoor unit 101 through the two-phase extension piping 71. The operation of the fine bubble generator 3 will be described in detail later.

  The refrigerant in the state R3 that has flowed into the ejector 4 is decompressed by the nozzle portion 43 to become the state R4, sucks the suction fluid, mixes it in the mixing portion 44 (state R5), passes through the diffuser portion 45, and passes through the diffuser portion 45 (b). As shown in FIG. 4, the pressure is increased to P2 to be in state R6.

  The refrigerant in the state R6 that has passed through the diffuser portion 45 flows into the gas-liquid separator 5 and is separated into the liquid refrigerant in the state R7 and the gas refrigerant in the state R10. The gas refrigerant in the state R10 absorbs heat in the auxiliary heat exchanger 13 and reliably becomes a gas refrigerant and flows into the suction side of the compressor 1. On the other hand, the liquid refrigerant in the state R7 is depressurized by the expansion device 6 (state R8), absorbs heat from the air by the evaporation side heat exchanger 7, and evaporates and vaporizes itself to become a gas refrigerant in the state R9 and is sucked by the ejector 3. The evaporation side heat exchanger 7 absorbs heat from room air to cool the room.

Hereinafter, the operation in the vicinity of the fine bubble generating device 3 and the ejector 4 will be described in more detail. In general, the ejector 4 has a step of decompressing and expanding the high-pressure refrigerant, sucking the low-pressure gas refrigerant and converting the expansion energy into pressure energy, and the suction pressure of the compressor 1 is reduced as compared with the step of decompressing with the expansion valve. It is an effective device for the refrigeration cycle apparatus because it can be recovered and a part of the heat energy wasted in the process of depressurizing the high-pressure refrigerant in the expansion valve.
FIG. 5 is an explanatory diagram for explaining the operation of the fine bubble generating device 3 and the ejector 4. The fine bubble generating apparatus 3 according to the present embodiment is configured by a Venturi tube, that is, a nozzle having a shape of rapid reduction-rapid expansion, and a gas refrigerant inflow portion 52 around the throat portion 55 where the flow path cross-sectional area is minimized. Is provided. For example, the diameter of the throat 55 is about 3 mm, the diameter of the refrigerant outlet 3 c is about 8 mm, the inclination angle of the divergent portion 54 is about 4 to 8 degrees, and the area ratio of the refrigerant outlet 3 c to the throat 55 is 7 It consisted of about ~ 8.
In addition, the dimension of each part of the microbubble generator 3 is an example, and is not limited to said numerical value. However, the cross-sectional area of the throat 55 of the microbubble generator 3 is configured to be larger than the cross-sectional area of the throat 43c of the ejector 4, and the decompression action in the refrigeration cycle is mainly operated by the ejector 4.

  In the microbubble generator 3, the liquid refrigerant flowing from the liquid refrigerant inflow portion 3 a is decompressed and accelerated by the decompression portion 53, and is sheared so as to tear off the gas refrigerant inserted in the direction intersecting from the gas refrigerant inflow portion 52. , Bubbles of several hundred μm are generated. In addition to this, the channel cross-sectional area is suddenly reduced-expanded by the venturi pipe, so that a sudden pressure rise is applied to the generated bubbles at the divergent portion 54, and the bubbles suddenly increase as the divergent portion 54 moves. It disintegrates and is further refined into a fine and substantially uniform size. Further, the fine bubbles generated by the rapid collapse exist almost uniformly in the space of the divergent portion 54 and flow out from the refrigerant outlet portion 3c.

  FIG. 6 is an explanatory diagram for explaining the size of bubbles at the refrigerant outlet portion 3c, and the uniform and fine bubble flow (a), that is, the fine bubble generator 3 according to the present embodiment finely bubbles the refrigerant. A state in which the gas-liquid two-phase refrigerant is caused to flow into the ejector 4 by heating a normal bubble flow (b), for example, a refrigerant that flows out of the heat radiation side heat exchanger 2. FIG. 6 is an explanatory view schematically showing the inside of the pipe in the AA cross section of the refrigerant outlet portion 3c of the fine bubble generating device 3 of FIG. 5 and the BB cross section of the nozzle divergent portion 43b of the ejector 4. In addition, in the case of a normal bubble flow, since it does not have the fine bubble generator 3, the cross section AA of FIG. 6 (b) is the state of the refrigerant | coolant in the nozzle inlet part of the ejector 4. FIG. As shown in FIG. 6 (b) AA cross section, a normal gas-liquid two-phase refrigerant has a bubble flow of about several millimeters. As shown in the A-A cross section, uniform fine bubbles of several hundred μm or less flow almost uniformly without being biased to the space in the pipe. That is, it flows into the ejector 4 as a uniform homogeneous fine bubble flow.

  As shown in FIG. 5, the refrigerant flowing into the nozzle portion 43 is a uniform homogeneous fine bubble flow, and is depressurized in a state where bubbles are dispersed in the refrigerant liquid from the ejector decompression portion 43a to the throat portion 43c. When bubbles grow, the formation of a liquid film is prevented and droplet nuclei are generated. Thereafter, as shown in the BB cross section of FIG. 6A, the droplet nucleus becomes a fine droplet state in the divergent portion 43b, and is ejected from the nozzle outlet portion 43d. By ejecting fine liquid droplets from the nozzle outlet portion 43d, the refrigerant in the ejector mixing portion 44 becomes a homogeneous state in which the gas-liquid speed difference is reduced, and the contact area between the driving fluid and the gas refrigerant as the suction fluid is increased. As a result, the driving fluid and the suction fluid are well mixed.

  On the other hand, the normal bubble flow of FIG.6 (b) is shown as a comparative example. In a normal bubble flow, bubbles of about several millimeters as shown in the AA cross section of FIG. 6B flow as the driving fluid of the ejector 4, so that the bubbles are destroyed when the pressure is reduced by the ejector pressure reducing portion 43a. Bubbles stick to each other, and a liquid film is formed on the wall surface of the pipe as shown in the BB cross section of FIG. That is, the refrigerant liquid that spreads out from the nozzle portion 43 with a diameter substantially equal to the nozzle diameter is ejected. For this reason, even if the gas refrigerant is sucked from the periphery of the jet flow, the contact area is not so large, and therefore, it is not mixed well.

In the present embodiment, by flowing the homogeneous microbubble flow into the ejector 4, the liquid film is easily broken when the refrigerant is decompressed by the decompression unit 43a, and fine droplets are ejected from the nozzle unit outlet 43d. Gas-liquid mixing is promoted in the mixing unit 44, 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.
Further, since the droplets of the driving fluid and the gas refrigerant of the suction fluid are mixed well by being ejected in a fine droplet state from the nozzle portion 43, the gas refrigerant R9 from the evaporation side heat exchanger 7 can be easily sucked. Thus, the suction flow rate increases. As the flow rate of the suction fluid increases, the ejector pressure increase amount (P3-P1 in FIG. 3) increases.

FIG. 7 shows the calculation result of the ejector mixing efficiency with respect to the diameter of the droplet ejected from the nozzle portion 43. The horizontal axis in FIG. 7 is the diameter of the liquid droplets ejected from the nozzle part 43, and the vertical axis is the ejector mixing efficiency (%). Since the ejector mixing efficiency (%) is defined as the energy conversion efficiency when the velocity energy ejected from the nozzle is converted into the boosted energy, the ejector mixing efficiency (%) = (pressurized energy / velocity energy). ) X100. As shown in the figure, when the diameter of the droplet ejected from the nozzle portion 43 is reduced from 100 μm to 10 μm, double boosting energy can be obtained even with the same velocity energy, and the ejector mixing efficiency is doubled. .
However, the droplet diameter shown on the horizontal axis is ejected from the nozzle portion 43 and is different from the bubble diameter generated by the fine bubble generating device 3. The microbubble generator 3 according to the present embodiment is provided, and the refrigerant that has been bubbled to about several hundreds μm as the driving fluid of the ejector 4 is allowed to flow into the decompression unit 43a to be further decompressed and expanded. It is considered that the droplet diameter ejected from the nozzle portion 43 is 100 μm or less because it is further destroyed by adding a rise. The smaller the bubble diameter generated by the fine bubble generating device 3, the smaller the droplets ejected from the nozzle portion 43. Therefore, it is preferable that the fine bubble generating device 3 generates bubbles with a small diameter as much as possible.

According to the simulation result in the case where the microbubble generator 3 having the configuration of the present embodiment is provided and bubbles of several hundred μm or less are generated, the refrigeration cycle apparatus in which the high pressure Pd is 2.0 MPa and the low pressure Ps is 0.4 MPa. , The pressure increase is increased from 0.03 MPa to 0.05 MPa by reducing the diameter of the droplets ejected from the nozzle portion 43, and the ejector mixing efficiency is improved to about twice that of the prior art. The result shows that the COP efficiency is improved by 5% compared to the prior art. Here, the conventional apparatus is a bubble flow in a normal gas-liquid two-phase state.
For example, in the refrigeration cycle apparatus having the configuration shown in FIG. 1, the suction pressure of the compressor 1 can be increased from about 0.4 MPa to about 0.45 MPa by using the fine bubble generating device 3 and the ejector 4. In the case of a refrigeration cycle apparatus that does not include the fine bubble generating device 3, the pressure is about 0.43 MPa. By providing the fine bubble generating device 3, the suction pressure becomes high and high-efficiency operation is possible.

  In order to generate bubbles having a diameter of several hundred μm or less with the fine bubble generating device 3 according to the present embodiment, the void ratio α (the volume flow ratio of the gas refrigerant to the liquid refrigerant) is preferably about 40% at the maximum. . When the void ratio α is 40% or less, the dryness of the inlet of the ejector 4 is 0 or more and 0.2 or less. Therefore, in other words, if the pipe diameter or pipe length of the bypass pipe 9 is set so that the dryness of the inlet of the ejector 4 is 0 or more and 0.2 or less, the void ratio α is 40% or less. In addition, bubbles having a diameter of several hundred μm or less can be generated by the fine bubble generator 3.

  FIG. 8 shows, as a comparative example, a refrigeration cycle apparatus having a configuration in which the refrigerant flowing out from the heat radiation side heat exchanger 2 is used as the driving fluid for the ejector 4, and the refrigerant circulation is operated only in the refrigerant state at the nozzle inlet of the ejector 4. Other conditions, such as quantity, show the change in cycle efficiency (COP) when operating as the same. When the degree of supercooling is large, that is, when it flows in a liquid state, the cycle efficiency (COP) is high, and the efficiency gradually decreases as the degree of dryness increases. With respect to the degree of supercooling and the degree of dryness, it is a monotonous change that a high cycle efficiency (COP) can be obtained if the degree of supercooling is high.

FIG. 9 is a graph showing the efficiency of the ejector unit (hereinafter referred to as ejector unit efficiency) according to the refrigeration cycle apparatus according to the present embodiment, the horizontal axis represents the dryness of the driving fluid at the inlet of the ejector 4, and the vertical axis Shows the efficiency of the ejector alone. The ejector single unit efficiency μe is expressed by the following formula 1 from the balance between the recovery power and the ejector pressurization work.
μe = (GexΔP) / (GnxΔHxρe) Equation 1
here,
Ge: Flow rate of suction fluid (suction flow rate)
ΔP: pressure increase, P2-P3 in FIG.
Gn: Flow rate of refrigerant flowing out from the ejector 4
△ H: Difference in enthalpy between the inlet and outlet of ejector 4,
In FIG. 4, the enthalpy difference between state R3 and state R4
ρe: Gas density, which is obtained from the temperature and pressure of the ejector suction part.

FIG. 9 shows the configuration shown in FIG. 1. The bypass pipe 9 connected to the microbubble generator 3 is appropriately changed in diameter so that the refrigerant state at the nozzle inlet of the ejector 4 is different, and the refrigerant circulation amount is changed. The other conditions show the change in the ejector unit efficiency when operating under the same conditions. The horizontal axis shows the dryness, and the vertical axis shows the ejector efficiency.
As shown in FIG. 1, in the configuration provided with the fine bubble generating device 3 and using the fine bubbles as the driving fluid of the ejector 4, the ejector single unit efficiency decreases as the degree of supercooling increases from zero. On the other hand, when the dryness is about 0.1, the ejector single unit efficiency is the highest, and when it is larger than 0.1, the efficiency is slightly reduced, but there is not much change.
From FIG. 9, it can be seen that the dryness of the driving fluid flowing into the ejector 4 is preferably 0 or more. When the degree of dryness is smaller than 0 (the degree of supercooling is greater), the refrigerant is considered to flow out into the mixing unit 44 as a liquid film flow at the nozzle unit 43. For this reason, the pressure increase amount is small without being well mixed with the suction fluid in the mixing unit 44, and the suction amount of the suction fluid is also small. Therefore, Ge and ΔP in Formula 1 are reduced, and the ejector unit efficiency μe is reduced.

FIG. 10 shows the configuration shown in FIG. 1, by appropriately changing the pipe diameter of the bypass pipe 9 connected to the fine bubble generating device 3, and operating so that the refrigerant state at the nozzle inlet of the ejector 4 is different. The other conditions indicate the change in cycle efficiency (COP) when operating under the same conditions. The horizontal axis shows dryness, and the vertical axis shows cycle efficiency.
In the configuration in which the fine bubble generating device 3 is provided and the fine bubbles are used as the driving fluid of the ejector 4, the cycle efficiency decreases as the degree of supercooling increases from 0 as shown in the figure. On the other hand, when the dryness is about 0.1, the cycle efficiency is the highest, and when it is greater than 0.2, the cycle efficiency is reduced. That is, the dryness of the drive fluid of the ejector 4 is preferably 0 or more and 0.2 or less. When the degree of dryness is smaller than 0, that is, when the degree of supercooling is larger than 0, it is considered that the efficiency of the ejector itself is lowered as shown in FIG. Further, when the dryness is larger than 0.2, the state R3 moves to a state where the enthalpy is larger in the pressure-enthalpy diagram shown in FIG. 4, and the system efficiency is lowered.

  Thus, the refrigeration cycle apparatus is configured by setting the pipe diameter size and pipe length of the bypass pipe 9 so that the dryness of the refrigerant flowing into the ejector 4 as the driving fluid is 0 or more and 0.2 or less. The system efficiency (COP) is improved. Here, the dryness of the refrigerant flowing into the ejector 4 as the driving fluid is configured to be not less than 0 and not more than 0.2. This is confirmed in advance by performing a preliminary operation. The dryness of the refrigerant flowing into the ejector 4 as the driving fluid is determined by the pressure value on the high pressure side of the refrigeration cycle (the detected value of the pressure sensor 24), the bypass pipe 9 of the refrigerant flowing out from the compressor 1, and the heat radiation side heat exchanger 2. It can be obtained by calculating the flow rate ratio.

By the way, when the fine bubble generator 3 is not provided, the gas-liquid two-phase refrigerant flowing in the pipe is a large bubble. For this reason, pressure loss and noise are generated in the two-phase extension pipe 71 on the upstream side of the ejector. However, in the present invention, the flow state downstream of the fine bubble generator 3 is changed to a microbubble flow by the fine bubble generator 3. There is little pressure loss, and there is an effect that noise can be reduced.
In the above description, the liquid refrigerant is caused to flow from the liquid refrigerant inflow portion 3a of the microbubble generator 3. However, depending on the operating condition, the liquid refrigerant containing the gas refrigerant to some extent may flow from the liquid refrigerant inflow portion 3a. By letting a refrigerant containing a large amount of liquid out of the refrigerant flowing out from the heat radiation side heat exchanger 2 from the liquid refrigerant inflow portion 3a, the gas refrigerant flowing in from the gas refrigerant inflow portion 52 intersects with the fine gas bubbles. Since it can generate | occur | produce, there exists an effect similar to the above.

  FIG. 11 is a flowchart showing an example of a control process by the control means 31 according to the present embodiment. The operation of the control means 31 will be described below based on this flowchart. The control means 31 is specifically composed of a microcomputer, and based on the detection values of the respective parts measured by the detection means 21, 22, 23, 24, the rotational speed of the compressor 1 and the needle of the fine bubble generating device 3 The throttle opening of the part 51 and the decompression means 6, for example, the throttle opening of the electronic expansion valve are determined, and a control signal is transmitted to each actuator.

  When the temperature of the first temperature detecting means 21 is TH1, the rotational speed of the compressor 1 is controlled so that TH1 becomes the target evaporation temperature ETm. Further, when the temperature of the second temperature detecting means 22 is TH2, and the difference TH2-TH1 between TH2 and TH1 is the outlet superheat degree SH of the evaporation side heat exchanger 7, the expansion device 6 is adjusted so that SH becomes the target superheat degree SHm. Control the throttle opening. Further, the temperature of the third temperature detecting means 23 is TH3, the pressure of the pressure sensor 24 is P24, and the saturated liquid temperature Ts obtained from P24, the difference Ts−TH3 between Ts and TH3, is the subcooling at the outlet side of the heat radiating side heat exchanger 2. Calculated as degree SC. Then, the throttle opening degree of the needle portion 51 of the fine bubble generating device 3 is controlled so that the supercooling degree SC becomes the target supercooling degree SCm.

  Specifically, first, in STEP 1, the throttle opening of the needle 51 of the microbubble generator 3 is initialized, in STEP 2 the throttle opening of the expansion device 6 and in STEP 3 the rotation speed of the compressor 1 is initialized. In STEP4, if | TH1-ETm |> ε3, the process returns to STEP3 to change the rotational speed of the compressor 1. That is, when TH1> ETm, the rotational speed of the compressor 1 is increased, and when TH1 <ETm, the rotational speed of the compressor 1 is decreased. As a result of changing the rotational speed of the compressor 1, the evaporation temperature TH1 is measured and judged in STEP4. If | TH1-ETm | <ε3, the process proceeds to STEP5, and the rotational speed of the compressor 1 is determined.

  In STEP6, if | SH-SHm |> ε2, the process returns to STEP2, and the opening degree of the expansion device 6 is changed. That is, when SH> SHm, the aperture device 6 is opened, and when SH <SHm, the aperture device 6 is closed. As a result of changing the opening degree of the expansion device 6, the degree of superheat SH is measured and determined in STEP6. If | SH-SHm | <ε2, the expansion opening amount of the expansion device 6 is determined in STEP7.

  In STEP 8, if | SC-SCm |> ε1, the process returns to STEP 1 to change the throttle opening of the needle portion 51 of the fine bubble generating device 3. That is, when SC> SCm, the needle portion 51 of the fine bubble generating device 3 is opened, and when SC <SCm, the needle portion 51 of the fine bubble generating device 3 is closed. As a result of changing the throttle opening of the needle portion 51, the degree of supercooling SC is measured and judged in STEP8. If | SC-SCm | <ε1, the throttle opening of the needle portion 51 of the microbubble generator 3 is determined in STEP9. Is determined and the control ends. As an example of each target value, for example, when the refrigeration cycle apparatus performs indoor cooling, the target evaporation ETm is −30 ° C. to 10 ° C., the target superheat degree SHm is 5 ° C. to 15 ° C., and the target subcool degree SCm is It is set in the range of 5 to 20 ° C.

  The number of revolutions of the compressor 1 is controlled with the highest priority for the purpose of ensuring the function of the refrigeration cycle apparatus because it determines the flow rate of refrigerant circulating through the refrigeration cycle apparatus, that is, the refrigeration capacity. The throttle opening of the decompression means 6 is prioritized because it determines the efficiency of the evaporation side heat exchanger 7, that is, the efficiency of the refrigeration cycle apparatus by controlling the degree of outlet superheat of the evaporation side heat exchanger 7. The The throttle opening of the microbubble generator 3 is the lowest priority because it controls the degree of outlet supercooling of the heat-radiating heat exchanger 2 and maximizes the operating efficiency. Here, ε1, ε2, and ε3 are allowable errors in operation control.

As shown in FIG. 11, the control means 31 is operated so that the evaporation temperature, the outlet superheat degree of the evaporation side heat exchanger 7, and the outlet subcooling degree of the heat radiation side heat exchanger 2 become optimum target values, The refrigeration cycle apparatus can be efficiently operated according to the usage situation. That is, by controlling the evaporation temperature of the evaporation side heat exchanger 7, it is possible to operate without waste according to the load of the object to be cooled. Further, by controlling the degree of superheat at the outlet of the evaporation side heat exchanger 7, it is possible to prevent the liquid from returning to the compressor 1 and to improve the reliability of the compressor 1. Further, by controlling the degree of supercooling of the liquid refrigerant inlet 3a of the fine bubble generating device 3, fine bubbles can be uniformly generated in the fine bubble generating device 3, and the cycle efficiency (COP) of the refrigeration cycle device can be improved. ) Can be raised.
However, the present invention is not limited to the control process shown in FIG. For example, the suction side superheat degree of the compressor 1 may be controlled by resistance adjusting means provided in the fine bubble generating device 3 or the ejector 4, for example, a needle portion. In this case, it is not necessary to control the degree of supercooling on the inflow side of the fine bubble generating device 3, or the amount of heat exchange is controlled by the rotational speed of the blower of the heat radiation side heat exchanger 2, so that You may comprise so that a supercooling degree may be controlled.

  Here, in order to make the gas refrigerant into bubbles by shearing the gas refrigerant into fine bubbles in the fine bubble generating device 3, the gas refrigerant is sheared into the liquid refrigerant by providing θ to be, for example, 90 degrees or more and 180 degrees or less. Although it becomes an easy structure, it is not restricted to this. The size of the generated bubbles is also affected by the diameter of the pipe into which the gas refrigerant is inserted, here the diameter of the bypass pipe 9, the flow rate of the liquid refrigerant, the volume flow rate ratio of the gas refrigerant, and the like. If these conditions are set appropriately, if the angle θ is inserted so that the gas refrigerant intersects the flow direction of the liquid refrigerant, the inserted gas refrigerant is easily cut by the liquid refrigerant. , Some fine bubbles are generated.

  Moreover, the position of the gas refrigerant inflow part 52 of the microbubble generator 3 is shown in FIG. The microbubble generator 3 uses a Venturi tube having a decompression section 53, a throat section 55, and a divergent section 54 as the main flow path, and a configuration in which a gas refrigerant is inserted into the throat section 55 having the smallest cross-sectional area (FIG. )), A configuration in which the gas refrigerant is inserted upstream of the throat 55 (FIG. 12B), and a configuration in which the gas refrigerant is inserted downstream of the throat 55 (FIG. 12C). . In either case, the liquid refrigerant shears the gas refrigerant into fine bubbles of several hundred μm. Further, in the divergent portion 54 between the throat portion 55 and the outlet portion 3c, a sudden pressure increase is applied, and the bubbles are further finely collapsed. If the gas refrigerant inflow portion 52 is provided at least in the vicinity of the throat 55 and the gas refrigerant is allowed to flow in, the position where the gas refrigerant inflow portion 52 is provided can generate fine bubbles.

  Moreover, although the gas refrigerant inflow part 52 of the fine bubble generator 3 is made into one place in FIG. 2, it is not restricted to this. Two or more locations may be provided. If a plurality of gas refrigerant inflow portions 52 having a reduced diameter are provided, the gas refrigerant can be sheared more efficiently and fine bubbles can be generated. When providing the several gas refrigerant inflow part 52, it is good to provide with good balance on the periphery in the cross section of the microbubble generator 3. FIG.

The microbubble generator 3 according to the present embodiment has a micro-level configuration that combines both the mechanism of generating bubbles using shear flow and the mechanism of micronization using the collapse phenomenon of bubbles. Those that generate fine bubbles are shown.
On the other hand, the structure provided with either one mechanism may be sufficient. For example, what uses a shear flow may be a configuration in which the gas refrigerant flows into the portion that accelerates the liquid refrigerant and the accelerated liquid refrigerant from the crossing direction. The size of bubbles generated by shearing the gas refrigerant with the liquid refrigerant is affected by the pipe diameter of the gas refrigerant, the inflow speed of the gas refrigerant, the speed of the liquid refrigerant, and the like. If the pipe diameter of the gas refrigerant is, for example, several hundred μm, the generated bubbles can be expected to be several hundred μm or less. In order to generate fine bubbles by shearing, it is preferable that the liquid refrigerant has a high speed. Further, it is preferable that the speed of the gas refrigerant is low, and it is preferable that the pipe diameter of the gas refrigerant is small. Further, even in a cylindrical configuration with a uniform cross-sectional area, the gas refrigerant can be bubbled by the shearing force of the liquid refrigerant by appropriately configuring the cross-sectional areas of the liquid refrigerant channel and the gas refrigerant channel.

  On the contrary, the configuration of the venturi tube, that is, the configuration in which fine bubbles are generated by the collapse phenomenon of the bubbles of the gas refrigerant contained in the liquid refrigerant by rapid contraction and rapid expansion, without the mechanism for generating the bubbles by shearing. Good. For example, when the gas refrigerant is inserted in the flow direction of the liquid refrigerant, the gas refrigerant may be inserted in the same direction, not in the intersecting direction. That is, in the case where the microbubble generator 3 does not have the needle portion 51, a gas refrigerant inflow portion may be provided along the flow path of the liquid refrigerant. In practice, the inlet of the gas refrigerant inlet may be configured to open upstream of the throat 55 and near the center of the liquid refrigerant flow path. A shearing force acts to some extent between the gas refrigerant inserted from the inlet of the gas refrigerant inflow portion and the liquid refrigerant flowing therearound, and the refrigerant contains fine bubbles of about several tens of millimeters. Then, after the refrigerant containing bubbles is decompressed and expanded by the decompression unit 53, the bubbles are collapsed by suddenly pressurizing by the divergent part 54, whereby fine bubbles of about several hundred μm can be generated.

  Further, in the present embodiment, since a fixed ejector having a constant expansion ratio is used, compared to an expansion ratio change type variable throttle ejector that varies the cross-sectional area of the throat using a needle portion or the like, it depends on the operating state. No overexpansion or underexpansion occurs. For example, loss due to shock waves can occur when overexpanded, but this can be prevented, so that the droplets ejected from the nozzle can be made as fine as possible, and mixing can be promoted to maintain high ejector efficiency. Can do.

When a variable aperture ejector is used as the ejector 3, a fine bubble generator 3 that does not have the needle portion 51 may be used. In this case, in the control process shown in FIG. 11, the degree of subcooling at the outlet of the heat radiation side heat exchanger 2 may be controlled by the throttle means of the ejector 3.
Moreover, although the needle part 51 is provided as an example of the resistance adjustment means which can adjust flow path resistance by increasing / decreasing a flow-path cross-sectional area, it is not restricted to a needle part. For example, a door that can open and close the refrigerant flow path is provided in the refrigerant flow path. For example, when the door is set up vertically, the flow resistance becomes maximum, and the door is laid to be parallel to the refrigerant flow path. Resistance adjusting means such as sometimes making the flow path resistance minimum may be used.

  Further, the configuration of the indoor unit 101 is not limited to that shown in FIG. 1 and may be any configuration. For example, an evaporation side heat exchanger is provided on the outlet side of the ejector 4, and a gas-liquid separator is provided on the downstream side thereof, and the liquid phase part of the gas / liquid separator is connected to the suction part of the ejector 4. The configuration may be such that the portion is connected to the suction side of the compressor. A plurality of evaporation side heat exchangers may be provided.

  As described above, according to the present embodiment, the compressor 1 that brings the refrigerant into a high-pressure state, the heat-dissipation-side heat exchanger 2 that dissipates the heat of the high-pressure refrigerant from the compressor 1, and the heat-dissipation-side heat exchange. The bubble generating means 3 which uses the refrigerant after heat dissipation from the vessel 2 as a refrigerant containing fine bubbles, and the drive which depressurizes the refrigerant containing fine bubbles generated by the bubble generating means 3 and flows out from the nozzle portion 43 at a high speed. The suction fluid is sucked from the suction portion 42 by the fluid, the drive fluid and the suction fluid are mixed by the mixing portion 44, then expanded by the diffuser portion 45 and discharged in a low pressure state, and the low pressure state from the ejector 4 By providing the evaporation side heat exchanger 7 that evaporates the refrigerant, the refrigerant containing fine bubbles of several μm to several 100 μm generated by the bubble generating means 3 is used as the driving fluid for the ejector 4. Gas-liquid at Mixing can be promoted to improve the ejector efficiency, and a more efficient refrigeration cycle apparatus can be obtained.

  In addition, the bubble generating means 3 includes a refrigerant flowing out from the gas refrigerant inflow portion 52 and the heat radiating side heat exchanger 2 into which at least a part of the gas refrigerant out of the refrigerant flowing out from the compressor 1 or the heat radiating side heat exchanger 2 flows. Liquid refrigerant inflow portion 3a for injecting a refrigerant containing a large amount of the liquid, and by causing the gas refrigerant to flow from the gas refrigerant inflow portion 52 into the liquid refrigerant flowing in from the liquid refrigerant inflow portion 3a, bubbles are generated. With this configuration, it is possible to generate fine bubbles by the bubble generating means 3 using the liquid refrigerant and the gas refrigerant on the high pressure side, and to use the refrigerant containing these fine bubbles as a driving fluid for the ejector 4. Thus, gas-liquid mixing in the ejector 4 can be promoted to improve the ejector efficiency, and a more efficient refrigeration cycle apparatus can be obtained.

  Further, a bypass pipe 9 having one end connected to a pipe between the discharge part of the compressor 1 and the inlet part of the heat radiation side heat exchanger 2 and the other end connected to the gas refrigerant inflow part 52 of the bubble generating means 3. A part of the gas refrigerant discharged from the compressor 1 passes through the bypass pipe 9 and flows into the gas refrigerant inflow portion 52, and causes the refrigerant flowing out from the heat radiation side heat exchanger 2 to flow into the liquid refrigerant inflow portion 3a. Thus, it is possible to generate fine bubbles by the bubble generating means 3 using a liquid refrigerant and a gas refrigerant on the high pressure side with a relatively simple configuration in which the bypass pipe 9 is provided, and the refrigerant containing these fine bubbles is ejected. By using the driving fluid 4, gas-liquid mixing in the ejector 4 can be promoted, the ejector efficiency can be improved, and a more efficient refrigeration cycle apparatus can be obtained.

  Further, the bubble generating means 3 is configured such that the gas refrigerant flow channel flowing in from the gas refrigerant flow inlet portion 3a intersects the liquid refrigerant flow channel flowing in from the liquid refrigerant flow inlet portion 52, and flows in from the liquid refrigerant flow inlet portion 3a. The liquid refrigerant flow to be generated intersects the gas refrigerant flow flowing in from the gas refrigerant inflow portion 52 to generate bubbles, thereby generating fine bubbles in the bubble generating means 3 using the liquid refrigerant and gas refrigerant on the high-pressure side, By using the refrigerant containing fine bubbles as a driving fluid of the ejector 4, gas-liquid mixing in the ejector 4 can be promoted to improve the ejector efficiency, and a more efficient refrigeration cycle apparatus can be obtained. .

  Further, the liquid refrigerant flow path of the bubble generating means 3 has a flow path cross-sectional area that decreases from the liquid refrigerant inlet part 3 a toward the throat part 55, and flows from the throat part 55 toward the outlet 3 c of the bubble generating means 3. The cross-sectional area is configured to increase, and the gas refrigerant inflow portion 52 is provided in the vicinity of the throat 55, so that fine bubbles are generated by the bubble generating means 3 using the liquid refrigerant and the gas refrigerant on the high pressure side. By using a refrigerant containing fine bubbles as the driving fluid of the ejector 4, gas-liquid mixing in the ejector 4 can be promoted to improve the ejector efficiency, and a more efficient refrigeration cycle apparatus can be obtained.

  Further, the bubble generating means 3 or the ejector 4 has a resistance adjusting means 51 that can adjust the flow resistance of the refrigerant, so that the state of the liquid refrigerant flowing into the bubble generating means 3 and the state of the refrigerant sucked into the compressor 1 can be controlled. There is an effect that the efficiency of the refrigeration cycle apparatus can be improved.

  Further, by controlling the supercooling degree of the refrigerant at the liquid refrigerant inlet portion 3a of the bubble generating means 3 to be a preset target supercooling degree by the resistance adjusting means 51, stable fine bubbles are generated. It is possible to improve the efficiency of the refrigeration cycle apparatus.

In addition, since the dryness of the refrigerant flowing into the ejector 4 as the driving fluid is 0 or more and 0.2 or less, fine droplets can be ejected from the nozzle portion 43 of the ejector 4. The gas-liquid mixing in 4 can be promoted, the ejector efficiency can be improved, and a more efficient refrigeration cycle apparatus can be obtained.
In particular, in the present embodiment, the length or diameter of the pipe connected in advance to the gas refrigerant inflow portion 52 is configured so that the dryness of the refrigerant flowing into the ejector 4 as the driving fluid becomes 0 or more and 0.2 or less. As a result, the ejector efficiency and the refrigeration cycle efficiency can be improved.

  Further, the auxiliary heat exchanger 13 connected to the suction side of the compressor 1 is provided, so that the refrigerant state sucked into the compressor 1 can be reliably changed to a gas refrigerant, and the liquid refrigerant is sucked into the compressor 1. There is an effect that it is possible to obtain a highly reliable refrigeration cycle apparatus by preventing it from being performed.

  As the refrigeration cycle device has been improved in performance, there is little room for further improvement in performance. In particular, it is difficult to further improve the performance of devices having a small temperature difference between the refrigerant and air in the evaporation side heat exchanger, such as room air conditioners and refrigerators. Under such circumstances, the ejector 4 is a useful device that can increase the suction pressure of the compressor 1 without being restricted by the temperature difference of the evaporation side heat exchanger 7 and can realize a high-performance refrigeration cycle apparatus. is there. In the present embodiment, the efficiency of the refrigeration cycle apparatus is improved by using the ejector 4 and further improving the efficiency of the ejector 4 as a driving fluid for the ejector 4 using a refrigerant containing fine bubbles of several μm to several 100 μm. it can.

Embodiment 2. FIG.
Hereinafter, a refrigeration cycle apparatus according to Embodiment 2 of the present invention will be described. FIG. 13 is a refrigeration cycle apparatus according to Embodiment 2 of the present invention, for example, a configuration diagram showing a circuit configuration of an air conditioner that cools a room. The same reference numerals as those in FIG. 1 denote the same or corresponding parts, and the description thereof is omitted here. The configuration of the fine bubble generating device 3 is the same as that in FIG. 2, and the configuration of the ejector 4 is the same as that in FIG.

Ejector The refrigerant circuit in the outdoor unit 100 in the refrigeration cycle apparatus according to the present embodiment includes a compressor 1, a heat radiation side heat exchanger 2, a gas-liquid separator 8, and a fine bubble generator having a function of adjusting flow resistance. 3 and a pipe for connecting them, the liquid phase part of the gas-liquid separator 8 is connected to the liquid refrigerant inflow part 3a of the fine bubble generator 3, and the gas phase part is connected to the fine bubble generator by the pipe 10 3 is connected to the gas refrigerant inflow portion 52.
In the first embodiment, the gas refrigerant on the upstream side of the heat radiation side heat exchanger 2 is caused to flow into the gas refrigerant inflow portion 52. However, in this embodiment, the outlet portion of the heat radiation side heat exchanger 2 and the fine bubble generating device 3 are used. The gas-liquid separator connected between the inlet part of this is provided. Then, the refrigerant flows out from the heat-dissipation side heat exchanger 2 in a gas-liquid two-phase state and is separated into a gas refrigerant and a liquid refrigerant by the gas-liquid separator 8, and the gas refrigerant in the gas phase portion flows into the gas refrigerant inflow portion 52. I am letting.

Hereinafter, the operation of the refrigeration cycle apparatus will be described with reference to FIGS. 13 and 14. FIG. 14 is a pressure-enthalpy diagram relating to the refrigeration cycle apparatus according to the present embodiment, in which the horizontal axis indicates enthalpy (kJ / kg) and the vertical axis indicates pressure (pascal).
The high-temperature and high-pressure gas refrigerant R1 discharged from the compressor 1 dissipates heat to the air in the heat radiation side heat exchanger 2 and condenses and liquefies itself, and becomes a gas-liquid two-phase refrigerant R2 and flows into the gas-liquid separator 8. In the gas-liquid separator 8, the gas-liquid two-phase refrigerant is separated into the gas refrigerant R2G and the liquid refrigerant R2L, the gas refrigerant R2G is depressurized by the pipe resistance to become the gas refrigerant R3G, and the liquid refrigerant R2L is depressurized by the microbubble generator 3 The pressure is reduced at the portion 53 to become the liquid refrigerant R3L. The liquid refrigerant is introduced from the liquid refrigerant inflow portion 3a of the microbubble generator 3 and the flow passage cross-sectional area is reduced by the decompression portion 53, thereby increasing the speed of the liquid refrigerant. When the gas refrigerant R3G flows from the gas refrigerant inflow part 52 so as to intersect the refrigerant flow of the liquid refrigerant in the vicinity of the throat 55, the gas refrigerant is sheared by the liquid refrigerant. That is, when the gas refrigerant R3G and the liquid refrigerant R3L are mixed again in the fine bubble generating device 3, the inserted gas refrigerant R2G becomes fine bubbles by the shearing force with the liquid refrigerant R2L. Furthermore, when the pressure rises at the divergent portion 54, the bubbles collapse, and a microbubble flow having a size of about several hundred μm is almost uniform and is present almost uniformly without being biased in the flow path. The refrigerant R3 containing the substantially uniform fine bubbles almost uniformly flows into the ejector 4. Since the driving operation after flowing into the ejector 4 is the same as that of the first embodiment, detailed description thereof is omitted.

  Since the configuration and operation of the microbubble generator 3 and the ejector 4 are the same as those in the first embodiment, detailed description thereof is omitted here. Also in the present embodiment, the fine bubble generating device 3 is provided upstream of the ejector 4, and the refrigerant circulating in the refrigeration cycle device is caused to flow into the fine bubble generating device 3 with the gas refrigerant and the liquid refrigerant flowing on the high pressure side, A refrigerant containing fine bubbles of several hundreds of μm or less is obtained by a shearing force when the liquid refrigerant flow and the gas refrigerant flow are crossed, or by a bubble collapse phenomenon when a sudden pressure increase is applied after expansion under reduced pressure. Since the droplets of the driving fluid in the ejector 4 become fine, the area in contact with the suction fluid in the gas state increases, and the mixing of the driving fluid and the suction fluid is promoted in the mixing portion, so that the amount of pressure increase can be increased. Further, it is easy to suck the gas refrigerant R4 from the evaporation side heat exchanger 7, and the flow rate of the suction fluid increases. For this reason, ejector efficiency and refrigeration cycle efficiency can be improved.

  Also, in this embodiment, fine bubbles are generated by utilizing both the shearing force when the liquid refrigerant flow and the gas refrigerant flow are crossed and the bubble collapse phenomenon when a sudden pressure increase is applied after decompression expansion. However, fine bubbles may be generated by at least one of the mechanisms.

  Since the control process by the control means 31 is the same as that of Embodiment 1, detailed description is abbreviate | omitted here. However, in the first embodiment, the target value SCm of the outlet side subcooling degree of the heat radiation side heat exchanger 2 is set to 5 to 20 ° C. However, in this embodiment, the two-phase state is set in the gas-liquid separator 8. Therefore, the supercooling degree target value SCm is set to 0 to 5 ° C. Here, SCm = 5 ° C. is because a non-equilibrium that becomes a two-phase state occurs even when the degree of supercooling is 5 ° C.

  Here, the pipe diameter and the pipe length of the pipe 10 connecting the gas phase part of the gas-liquid separator 8 and the gas refrigerant inflow part 52 of the fine bubble generating device 3 are the dryness of the refrigerant flowing into the ejector 4 as the driving fluid. Is set to be 0 or more and 0.2 or less. Therefore, as in the first embodiment, fine droplets can be ejected from the nozzle portion 43 of the ejector 4, gas-liquid mixing in the ejector 4 can be promoted, the ejector efficiency can be improved, and the cycle efficiency (COP) ) Can be obtained. In practice, an appropriate pipe 10 is used, and it may be confirmed in advance by a preliminary operation that the dryness of the refrigerant flowing into the ejector 4 as the driving fluid is 0 or more and 0.2 or less.

  FIG. 15 is a configuration diagram showing a circuit configuration of another refrigeration cycle apparatus of the present embodiment. As shown in the figure, heating means 15 is provided upstream of the gas-liquid separator 8 to heat the refrigerant flowing between the heat-radiation side heat exchanger 2 and the gas-liquid separator 8. For example, even if the refrigerant is in a liquid single-phase state at the outlet of the heat radiation side heat exchanger 2, the enthalpy is increased by heating by the heating means 15 such as a heater, and the refrigerant is reliably supplied at the inlet of the gas-liquid separator 8. Can be in a gas-liquid two-phase state. After that, the gas-liquid separator 8 separates the gas and liquid, and the micro-bubble generator 3 generates a homogeneous micro-bubble flow as the drive fluid for the ejector as in the configuration of FIG.

  In this way, by providing the heating means 15 for heating the refrigerant between the heat-radiating side heat exchanger 2 and the gas-liquid separator 8, the refrigerant flowing into the gas-liquid separator 8 is surely made into a two-phase refrigerant. Can do. As a result, a fine bubble can be reliably generated by the fine bubble generator 3, and the refrigeration cycle apparatus that can improve ejector efficiency and cycle efficiency can be obtained.

Moreover, the gas-liquid separator 8 in this Embodiment can utilize what is equipped with the refrigerating-cycle apparatus normally as a liquid reservoir which temporarily stores an excess refrigerant | coolant.
In the present embodiment, as in the first embodiment, the configuration of the indoor unit 101 is not limited to FIGS. 13 and 15, and may be configured in any manner.

  As described above, according to the present embodiment, the gas-liquid separator 8 is provided which is connected between the outlet portion of the heat radiation side heat exchanger 2 and the inlet portion of the bubble generating means 3. Is connected to the gas refrigerant inflow portion 52 of the bubble generating means 3, and the liquid phase portion of the gas-liquid separator 8 is connected to the liquid refrigerant inflow portion 3 a of the bubble generating means 3. And the gas refrigerant can be used to generate fine bubbles in the bubble generating means 3, and the refrigerant containing the fine bubbles is used as a driving fluid for the ejector 4 to promote gas-liquid mixing in the ejector 4. Ejector efficiency can be improved, and a more efficient refrigeration cycle apparatus can be obtained.

Embodiment 3 FIG.
In Embodiments 1 and 2, a configuration is provided in which one evaporation side heat exchanger 7 in the indoor unit 101 is provided, but the present invention is not limited to this. In Embodiment 3 of the present invention, a refrigeration cycle apparatus provided with a plurality of, for example, two evaporation side heat exchangers 7a and 7b will be described. The indoor unit 100 is similar in configuration and effect to the first embodiment or the second embodiment, and the description thereof is omitted here.
FIG. 16 is a configuration diagram illustrating a circuit configuration of the indoor unit 101 of the refrigeration cycle apparatus according to Embodiment 3 of the present invention. In the figure, two evaporation side heat exchangers 7a and 7b exchange heat with indoor air blown by indoor fans 12a and 12b, respectively. Refrigerant flow rate adjusting means, for example, expansion devices 6a and 6b are provided upstream of the evaporation side heat exchangers 7a and 7b, respectively, to adjust the flow rate of the liquid refrigerant flowing into the evaporation side heat exchangers 7a and 7b. The evaporation side heat exchangers 7a and 7b are installed, for example, in separate rooms and cool the respective rooms. An example of the expansion devices 6a and 6b is an electronic expansion valve. For example, when it is not necessary to operate one of the evaporation side heat exchangers 7a or 7b, the expansion device 6a or 6b may be closed. In the figure, control signal lines from the control means to the expansion devices 6a and 6b, temperature detection means installed around the respective evaporation side heat exchangers 7a and 7b, and input signal lines from the detection means are omitted. It was.

  In some cases, such as when the refrigeration cycle apparatus is a showcase or a refrigerator, the evaporation temperature may be set to a plurality of different temperatures. For example, when cooling to a plurality of different temperatures, such as a refrigeration evaporation side heat exchanger 7a having a low evaporation temperature of about −20 ° C. and a refrigeration evaporation side heat exchanger 7b having a high evaporation temperature of about 5 ° C. The evaporation side heat exchangers 7a and 7b having different evaporation temperatures are connected in parallel. As decompression means, for example, a capillary tube 16 is connected between the suction part of the ejector 4 and the evaporation side heat exchanger 7b.

  That is, the refrigerant circuit in the indoor unit 101 includes the ejector 4, the gas-liquid separator 5, the expansion device 6a, the expansion device 6b, the evaporation side heat exchanger 7a, the evaporation side heat exchanger 7b, the capillary tube 16, and the auxiliary heat exchanger. 13 and a pipe for connecting them, and the pipe connected to the liquid phase part of the gas-liquid separator 5 is branched into two, one of which is an ejector through the expansion device 6a and the evaporation side heat exchanger 7a 4 is connected to the suction part 42 of the ejector 4 through the expansion device 6b, the evaporation side heat exchanger 7b and the capillary tube 16, and the gas phase part of the gas-liquid separator 5 is connected to the auxiliary heat. It connects to the suction side of the compressor 1 via the exchanger 13.

  The refrigerant that has passed through the ejector 4 flows into the gas-liquid separator 5 and is separated into liquid refrigerant and gas refrigerant. The gas refrigerant is reliably converted into gas refrigerant by the auxiliary heat exchanger 13 and flows into the suction side of the compressor 1. A part of the liquid refrigerant of the gas-liquid separator 5 is decompressed by the expansion device 6 a, absorbs heat from the air by the evaporation side heat exchanger 7 a, evaporates and vaporizes itself, becomes a gas refrigerant, and is sucked by the ejector 4. . Similarly, the other part of the liquid refrigerant of the gas-liquid separator 5 is decompressed by the expansion device 6b, absorbs heat from the air by the evaporation side heat exchanger 7b, and evaporates and vaporizes itself to become a gas refrigerant. The pressure is reduced at 16 and sucked by the ejector 4. The evaporation side heat exchangers 7a and 7b absorb heat from the room air to cool the room, and the evaporation side heat exchangers 7a and 7b can set two different temperatures.

  Here, the capillary tube 16 is configured to equalize the pressure of the refrigerant flowing out from the plurality of evaporation side heat exchangers 7a and 7b and cause the ejector 4 to suck the gas refrigerant when the gas refrigerant flows into the suction portion 42 of the ejector 4. . Since the refrigerant pressure on the side where the evaporating temperature is set higher is higher than the refrigerant pressure on the side where the evaporating temperature is set low, the capillary tube 16 is connected to the outlet of the evaporation side heat exchanger 7b where the evaporating temperature is set high. And reducing the pressure so that the refrigerant pressure at the outlets of the evaporation side heat exchangers 7a and 7b becomes equal. The capillary tube 16 may be other decompression means such as an open / close expansion valve or an electronic expansion valve.

  When there are a plurality of refrigerant pipes sucked into the ejector 4 and the refrigerant pressure in each pipe is not uniform, the refrigerant may flow backward depending on the pressure difference. On the other hand, in this embodiment, since the pressure reducing means 16 is provided so as to equalize the pressures of the plurality of refrigerants sucked by the ejector 4, a reverse flow occurs in the ejector 4, or one suction part to another suction part. And a highly reliable refrigeration cycle apparatus can be obtained.

  Moreover, the other structural example of the indoor unit 101 of the structure which has the several evaporation side heat exchangers 7a and 7b is shown in FIG. FIG. 17 is a configuration diagram showing a circuit configuration of the indoor unit 101 of the refrigeration cycle apparatus according to the present embodiment. In the figure, ejectors 4a and 4b are connected to the two evaporation side heat exchangers 7a and 7b, respectively.

  That is, the refrigerant circuit in the indoor unit 101 includes the ejector 4a, the ejector 4b, the gas-liquid separator 5, the expansion device 6a, the expansion device 6b, the evaporation side heat exchanger 7a, the evaporation side heat exchanger 7b, the capillary tube 16, and the auxiliary unit. It is comprised with the heat exchanger 13 and piping for connecting them. Then, the connecting pipe from the outdoor unit 100 is branched into two at the branching section 18, one of which is the suction section 42 of the ejector 4a via the ejector 4a, the gas-liquid separator 5, the expansion device 6a, and the evaporation side heat exchanger 7a. Connected to. The other is connected to the suction part 42 of the ejector 4b via the ejector 4b, the gas-liquid separator 5, the expansion device 6b, the evaporation side heat exchanger 7b, and the capillary tube 16, and the gas-phase part of the gas-liquid separator 5 is The auxiliary heat exchanger 13 is connected to the suction side of the compressor 1.

  The fine bubble generator 3 in the outdoor unit 100 generates a uniform and homogeneous fine bubble refrigerant and circulates to the indoor unit 101 through a two-phase extension pipe 71. And the refrigerant | coolant is branched into two by the branch part 18 in the indoor unit 101, and is made to flow in into the nozzle part 43 as a drive fluid of ejectors 4a and 4b. The refrigerant that has passed through the ejectors 4a and 4b flows into the gas-liquid separator 5 and is separated into liquid refrigerant and gas refrigerant. The gas refrigerant is reliably converted into gas refrigerant by the auxiliary heat exchanger 13 and flows into the suction side of the compressor 1. A part of the liquid refrigerant of the gas-liquid separator 5 is decompressed by the expansion device 6 a, absorbs heat from the air by the evaporation side heat exchanger 7 a, evaporates and vaporizes itself to become a gas refrigerant, and is sucked by the ejector 3. . Similarly, the other part of the liquid refrigerant of the gas-liquid separator 5 is decompressed by the expansion device 6b, absorbs heat from the air by the evaporation side heat exchanger 7b, and evaporates and vaporizes itself to become a gas refrigerant. Is aspirated. The evaporation side heat exchangers 7a and 7b absorb heat from the room air to cool the room, and the evaporation side heat exchangers 7a and 7b can set two different temperatures.

  In the configuration of FIG. 16, the gas refrigerant is sucked into the single ejector 4 from the two evaporation side heat exchangers 7a and 7b. In this case, there is an effect that the number of ejectors 4 is one and the entire apparatus can be reduced in size, but there is a possibility that the two suction fluids may not be sucked well depending on the refrigerant state, for example, the balance of pressure value and flow rate. . On the other hand, in the configuration of FIG. 17, the gas refrigerant that has flowed out of one evaporation side heat exchanger 7b is sucked into one ejector 4a and the other ejector 4b is sucked into one ejector 4a. is there. In this case, the number of ejectors 4 is two, and the entire apparatus becomes slightly larger. However, even if there is a change in the balance of the refrigerant states of the two suction fluids, for example, the pressure value and the flow rate, the suction is successful and stable operation is achieved. There is an effect that is possible.

  In FIGS. 16 and 17, the two evaporation side heat exchangers 7 a and 7 b are provided, but the number is not limited to two. A plurality of three or more may be used, which is effective when cooling to a plurality of different temperatures. Further, it is not necessary to set different evaporation temperatures, and a plurality of evaporation side heat exchangers may be operated at the same evaporation temperature. It is effective when cooling multiple rooms or places. When operating at the same evaporation temperature, the refrigerant pressure is the same, and it is not necessary to provide the capillary 16 as a decompression means between the suction part 42 of the ejector 4 and the evaporation side heat exchanger 7.

  As described above, according to the present embodiment, as in the first embodiment, the compressor 1 that brings the refrigerant into a high-pressure state, and the heat-dissipation side heat exchanger that radiates the heat of the high-pressure refrigerant from the compressor 1. 2, the bubble generating means 3 that uses the refrigerant after heat dissipation from the heat radiation side heat exchanger 2 as a refrigerant containing fine bubbles, and the refrigerant containing fine bubbles generated by the bubble generating means 3 is decompressed at a high speed. The ejector 4 that sucks the suction fluid from the suction portion 42 by the driving fluid flowing out from the nozzle portion 43, mixes the driving fluid and the suction fluid in the mixing portion 44, expands in the diffuser portion 45, and flows out in a low pressure state; By providing the evaporation side heat exchanger 7 for evaporating the low-pressure refrigerant from the ejector 4, the refrigerant containing fine bubbles of several μm to several hundred μm generated by the bubble generating means 3 is driven by the ejector 4. By using fluid The gas-liquid mixing in the ejector 4 can be promoted, the ejector efficiency can be improved, and a more efficient refrigeration cycle apparatus can be obtained.

  Further, at least two evaporation side heat exchangers 7a and 7b, an ejector 4 for sucking refrigerant flowing out from each of the evaporation side heat exchangers 7a and 7b by the suction part 42, and evaporation side heat exchangers 7a and 7b Provided in at least one of the plurality of refrigerant flow rate adjusting means 6a, 6b for adjusting the flow rate of the refrigerant flowing in and between the evaporation side heat exchangers 7a, 7b and the ejector 4, and a plurality of evaporation side heat exchanges And the decompression means 16 for equalizing the pressure of the refrigerant sucked into the ejector 4 from the chambers 7a and 7b, thereby providing an evaporation side heat exchanger 7a that can be operated at a plurality of different evaporation temperatures using an efficient ejector. 7b, which is advantageous in that a refrigeration cycle apparatus with good cycle efficiency can be obtained.

  In addition, it includes at least two ejectors 4a and 4b for sucking the refrigerant flowing out from at least two evaporation side heat exchangers 7a and 7b, respectively, and branches the refrigerant containing fine bubbles generated by the bubble generating means 3. By providing the branch portions that flow into the plurality of ejectors 4a and 4b, the evaporation side heat exchangers 7a and 7b that use an efficient ejector, can be stably operated, have high reliability, and can be operated at a plurality of different evaporation temperatures. There is an effect that a refrigeration cycle apparatus having a high cycle efficiency is provided.

  In FIGS. 1, 13, 15, 16, and 17 of the first to third embodiments, the auxiliary heat exchanger 13 is provided on the suction side of the compressor 1 so that the compressor 1 can The refrigerant is sucked in to prevent liquid back and improve the reliability of the refrigeration cycle apparatus. For example, the auxiliary heat exchanger 13 is not necessarily provided when the gas-liquid separator 5 is operated in a state where the gas phase portion is always present. A configuration in which the gas phase portion of the gas-liquid separator 5 is connected to the suction side of the compressor 1 may be employed.

Embodiment 4 FIG.
In the fourth embodiment of the present invention, another embodiment of the fine bubble generating device 3 will be described. FIG. 18 is an explanatory diagram showing the configuration of the microbubble generator 3 according to Embodiment 4 of the present invention, and FIG. 18 (a) shows the position of the liquid refrigerant inflow portion 3a in the cross section perpendicular to the liquid refrigerant flow path. FIG. 18B is an explanatory view showing a cross-sectional configuration of the fine bubble generating device 3. In the figure, solid arrows indicate the flow of the liquid refrigerant, and white arrows indicate the flow direction of the refrigerant containing fine bubbles.
The shape of the inner wall surface of the decompression unit 53 of the microbubble generator 3 forms a part of a conical shape. The liquid refrigerant inflow portion 3a is provided at a position deviated from the conical shaft, and the liquid refrigerant flows into a position off the conical shaft. Here, the liquid refrigerant inflow portion 3a is provided at an eccentric position, thereby constituting a swirling means for swirling the liquid refrigerant flowing into the fine bubble generating device 3.

  The liquid refrigerant flowing in from the liquid refrigerant inflow part 3a flows into the decompression part 53, but turns into a swirl flow while being decompressed along the conical inner wall surface, and flows at an increased speed. By causing the gas refrigerant to flow into the swirling flow of the liquid refrigerant at a high speed from the gas refrigerant inflow portion 52, the gas refrigerant is torn off by the shearing force due to the gas-liquid speed difference. The diameter of the inlet of the gas refrigerant inflow portion 52 is set to several mm, for example, and sheared with a liquid refrigerant which is a high-speed swirling flow, thereby generating uniform fine bubbles having a diameter of several hundreds of microns or less. Can be made. The gas refrigerant inflow portion 52 is provided, for example, on the side wall of the tube near the throat 55, and the gas refrigerant flows in from the direction intersecting the liquid refrigerant flow path.

  By making the liquid refrigerant a swirl flow, it is smoothly accelerated by the inner wall surface of the decompression section 53, and a shearing force effectively acts on the gas refrigerant flowing from the gas refrigerant inflow section 52. Further, when flowing through the divergent portion 54 through the throat portion 55, a sudden pressure increase is applied and the air bubbles collide with the flow passage wall surface, thereby further miniaturizing the bubbles. In the configuration shown in FIG. 18, the throat 55 and the divergent part 54 are also swirled to some extent, easily collide with the wall surface of the flow path, promote miniaturization, and disturb the generated fine bubbles. There can be uniformly fine bubbles in the inside. Fine bubbles of almost uniform size are generated uniformly on average in the space, and this is used as the drive fluid of the ejector 4, thereby improving the mixing efficiency of the drive fluid and the suction fluid in the ejector 4, and the ejector efficiency. In addition, the cycle efficiency of the refrigeration cycle apparatus can be improved.

  FIG. 19 is an explanatory view showing another configuration example of the fine bubble generating device 3 according to the present embodiment, in which a part of the decompression unit 53 is cut away. In this configuration, the gas refrigerant inflow portion 52 is provided so as to flow in the direction of the central axis of the conical shape constituting the inner wall surface of the decompression portion 53 instead of the pipe side wall. The liquid refrigerant inflow portions 3a are provided at a plurality of, for example, two locations at positions deviated from the central axis. Here, the liquid refrigerant inflow portion 3a is provided at an eccentric position, and the flow path between the pipe outer wall of the gas refrigerant inflow portion 52 and the inner wall of the decompression portion 53 serves as a guide that guides the swirling flow. The swirling means is configured to swirl the liquid refrigerant flowing into the swirling flow.

  As in FIG. 18, by making the liquid refrigerant swirl, it is smoothly accelerated on the inner wall surface of the decompression unit 53, and a shearing force effectively acts on the gas refrigerant flowing from the gas refrigerant inflow part 52. For this reason, fine bubbles are stably generated, and the fine bubbles are disturbed by the swirling flow. With this almost uniform size, fine bubbles that are present homogeneously in the space on average are stably generated and used as the driving fluid of the ejector 4, so that the mixing efficiency of the driving fluid and the suction fluid is ejected by the ejector 4. And the cycle efficiency of the ejector efficiency and the refrigeration cycle apparatus can be improved.

The configuration of FIG. 19 is a configuration that causes a swirling flow of the liquid refrigerant flowing from the liquid refrigerant inflow portion 3a, and the central portion of the shaft is a portion where the liquid refrigerant does not flow so much. By using this portion, the gas refrigerant inflow portion 52 is provided, and the liquid refrigerant flowing from the liquid refrigerant inflow portion 3a can be smoothly swirled by the pipe outer wall constituting the gas refrigerant inflow portion 52.
In addition, in such a structure, the needle part 51 cannot be provided in the fine bubble generator 3. In this case, if the ejector 4 is provided with a resistance adjusting means capable of adjusting the flow resistance of the needle portion or the like, the circulation amount of the refrigerant and the superheat degree of the suction side refrigerant of the compressor 1 can be controlled. it can.

  18 and 19, the liquid refrigerant is swirled and the gas refrigerant is allowed to flow without swirling. However, the present invention is not limited to this, and both the gas refrigerant and the liquid refrigerant may be swirled. When both the gas refrigerant and the liquid refrigerant are swirled, if the counterflow is such that the swirling directions of the gas refrigerant and the liquid refrigerant are reversed, the gas refrigerant is easily sheared, and fine bubbles can be generated reliably.

  As described above, the bubble generating means 3 in the present embodiment has the swirling means that turns at least one of the refrigerant flow in the liquid refrigerant flow path and the gas refrigerant flow path into a swirl flow. And more fine bubbles can be generated. Here, the swiveling means is, for example, a position where the liquid refrigerant inflow portion 3a is eccentric with respect to the refrigerant flow path. In the above, since the bubble generating means 3 is constituted by a Venturi tube, the inner wall surface of the liquid refrigerant channel has a conical shape. However, the liquid refrigerant inflow portion 3a is eccentric from the center of the cylindrical shape. Even if provided, a swirl flow can be formed. Further, the flow path may be formed by, for example, a guide so that the liquid refrigerant swirls and flows.

In the first to fourth embodiments, the configuration in which the needle portion 51 is provided as the resistance adjusting means for adjusting the flow resistance in the fine bubble generating device 3 and the ejector 4 is used as the fixed throttle is shown. A configuration in which resistance adjusting means is provided in at least one of the bubble generating device 3 or the ejector 4 or a configuration in which both the fine bubble generating device 3 and the ejector 4 are fixed throttles, and resistance adjusting means such as an expansion valve is added to the refrigerant circuit may be used. .
However, as shown in the first embodiment, if the fine bubble generating device 3 is provided with a needle portion as resistance adjusting means, the degree of supercooling on the inlet side of the fine bubble generating device 3 as in STEPs 8 and 9 of FIG. Can be controlled to a preset target degree of superheat, and fine bubbles can be generated satisfactorily.
Further, as described above, by using the ejector 4 as a fixed throttle, the expansion ratio in the ejector 4 can be made constant, and there is an effect that a good ejector efficiency can be obtained stably.

In the first to fourth embodiments, the bubble generating means is configured to generate bubbles using the shearing force of the liquid refrigerant and the gas refrigerant, or the shape of the rapid reduction / expansion is used in the configuration of the Venturi tube. Then, the structure in which the bubbles are refined by the bubble collapse phenomenon has been described in detail. As another configuration example of the fine bubble generating device 3, a configuration other than using a shearing force or a bubble collapse phenomenon is possible.
For example, when a refrigerant in a high-pressure two-phase state flowing out from the heat-dissipation side heat exchanger 2 is passed through a porous body, for example, a sintered metal body having porosity, about several hundred μm when passing through the holes constituting the porous body. The structure which generates the bubble of the diameter of may be sufficient.
In addition, a high-pressure two-phase refrigerant flowing out of the heat radiation side heat exchanger 2 is once stored in a predetermined container, and ultrasonic vibration is applied to the storage part, so-called microbubbles having a diameter of about several hundreds μm due to the vibration. May be generated. The vibration frequency at this time is a frequency higher than about several tens of khz, and sufficiently fine bubbles can be generated.
Moreover, although a bubble can be generated by shearing force, bubble collapse phenomenon, a porous body, vibration, etc., it is good also as a structure which combined these two or more. For example, vibration may be applied to a configuration including a porous body.

Embodiment 5 FIG.
FIG. 20 is an explanatory view showing a cross section of the ejector and the bubble generating means according to Embodiment 5 of the present invention, and FIG. 21 is a block diagram showing an example of a circuit configuration when this ejector is incorporated in a refrigeration cycle apparatus. . In the figure, the same reference numerals as those in FIG. 1 or FIG. 13 denote the same or corresponding parts, and the description thereof is omitted here. This embodiment is characterized in that the fine bubble generating device and the ejector are integrated, and the ejector 17 includes a bubble generating means. Similarly to FIG. 3, the ejector 17 includes a suction part 62, a nozzle part 63, a mixing part 64, and a diffuser part (not shown). That is, in the ejector 17, the refrigerant containing fine bubbles is decompressed, the suction fluid is sucked from the suction portion 62 by the driving fluid flowing out from the nozzle portion 63 at a high speed, and the driving fluid and the suction fluid are mixed by the mixing portion 64. After that, it is expanded in the diffuser section, slightly boosted and discharged in a low pressure state. The suction part 62 is connected to the outlet of the evaporation side heat exchanger 7 and sucks the low-pressure refrigerant having high dryness flowing out from the evaporation side heat exchanger 7 by the driving fluid flowing out from the nozzle part 63. The ejector 17 is configured to generate fine bubbles at the nozzle portion 63.

  The nozzle inlet portion 63d is connected to the liquid phase portion of the gas-liquid separator 8, and a high-pressure liquid refrigerant flows in. The nozzle part 63 has a decompression part 63a, a divergent part 63b, and a throat part 63c. The decompression part 63a includes a gas refrigerant inflow part 52 connected to the gas phase part of the gas-liquid separator 8, and a high-pressure gas refrigerant. Flows in. The liquid refrigerant flowing from the nozzle inlet portion 63d has a flow velocity increased at the decompression portion 63a, and the gas refrigerant flowing from the gas refrigerant inflow portion 52 becomes a fine bubble having a diameter of about several hundreds μm due to the shearing force with the high-speed liquid refrigerant. . In the vicinity of the throat 63c, the bubble expands due to the decompression, and the bubble rapidly collapses as it moves in the divergent portion 63b, and the bubble becomes finer at once and flows out from the nozzle portion 63 as a fine droplet. . Since this becomes the driving fluid of the ejector 17, the contact area with the suction fluid is increased in the mixing unit 64, and the mixture is homogeneously mixed. As the driving fluid and the suction fluid are efficiently and uniformly mixed in the mixing unit 64, the suction amount of the suction fluid increases and the pressure increase amount of the ejector 17 increases. Further, the change from the pressure energy to the velocity energy at the decompression unit 63a of the ejector 4 further approaches the isothermal change, and the heat energy can be recovered. For this reason, the cycle efficiency of the refrigeration cycle apparatus can be improved.

  In the configuration of the present embodiment, the decompression unit 53 and the throat portion 55 of the fine bubble generating device 3 in the first and second embodiments are integrated with the decompression unit 43a and the throat portion 43c of the ejector 4. For example, in this configuration, by integrating the fine bubble generating device 3 and the ejector 4 shown in FIGS. 2 and 3, the size can be reduced, and the entire refrigeration cycle device can be reduced in size.

  The configuration of the refrigeration cycle apparatus equipped with the ejector 17 is not limited to that shown in FIG. 21. For example, the ejector 17 and the gas-liquid separator 8 may be disposed in the outdoor unit 100. In this case, the number of connecting pipes between the indoor unit 100 and the outdoor unit 101 increases, but the indoor unit 101 can be downsized. Further, as shown in FIG. 1, a part of the gas refrigerant on the outlet side of the compressor 1 is allowed to flow into the gas refrigerant inflow portion 52, and the refrigerant at the outlet of the heat radiation side heat exchanger 2 is allowed to flow into the nozzle inlet portion 63d. Any configuration may be used.

  In FIG. 20, the needle portion is not provided, but the nozzle portion 63 is provided with, for example, the needle portion shown in FIG. 2 as resistance adjusting means that can increase or decrease the cross-sectional area. You may comprise so that it may adjust. In the configuration of the refrigeration cycle apparatus in FIG. 21, the ejector 17 has a needle portion, and the control means 31 moves the position of the needle portion back and forth to control the flow path cross-sectional area. .

  Further, as shown in the fourth embodiment, the liquid refrigerant flowing from the nozzle inlet portion 63d is swirled, or the gas refrigerant flowing from the gas refrigerant inflow portion 52 is swirled, and the shearing force of the liquid refrigerant on the gas refrigerant. May be easy to act.

In addition, as the fine bubble generating device, a configuration in which vibration is applied to the refrigerant with ultrasonic waves or a configuration in which a porous sintered metal is allowed to pass may be configured integrally with the ejector. It is only necessary that fine bubbles are generated on the upstream side of the throat portion 63c of the nozzle portion 63 of the ejector 17. More specifically, for example, when the ultrasonic bubble vibration is configured as the fine bubble generating device, if the ultrasonic vibration is applied to the needle portion or the nozzle portion, which is a component of the ejector, it can be integrated and miniaturized. In the case of generating fine bubbles by a porous body, for example, a sintered metal having porosity is provided at the nozzle inlet portion 63d of the ejector, and the high-pressure two-phase refrigerant flowing from the nozzle inlet portion 63d passes through the sintered metal. If it is configured to flow through the pressure reducing portion 63a of the nozzle, it can be integrated and miniaturized.
Moreover, although a bubble can be generated by shearing force, bubble collapse phenomenon, a porous body, vibration, etc., it is good also as a structure which combined these two or more. For example, vibration may be applied to a configuration including a porous body.

As described above, in the present embodiment, bubble generating means is provided in the nozzle portion 63 of the ejector 17, the refrigerant containing fine bubbles is generated in the nozzle portion 63, and fine droplets are generated in the mixing portion 64 of the ejector 17. Therefore, mixing in the mixing unit 64 can be promoted, an efficient ejector can be obtained, and the entire refrigeration cycle apparatus can be downsized.
In particular, the liquid refrigerant inflow portion 63d and the gas refrigerant inflow portion 52 of the bubble generating means are provided in the nozzle portion 63 of the ejector 17, and the bubble generating means and the ejector are integrated to generate gas refrigerant bubbles in the nozzle portion 63, thereby mixing the mixing portion. It can be realized with a simple structure of ejecting to 64.

  In the first to fifth embodiments, the heat radiation side heat exchanger 2 and the evaporation side heat exchanger 7 are not limited to the above, but water or brine such as a double pipe or a plate heat exchanger is used as a heating source or A liquid-liquid heat exchanger as a cooling source may be used.

  In the first to fifth embodiments, the circuit configuration has been described as an example of the refrigeration cycle apparatus as FIGS. 1 and 13, but is not limited thereto. If the ejector 4 is used as the decompression means of the refrigeration cycle apparatus, the same effects as those of the above-described embodiment can be obtained. The present invention can be applied to any refrigeration cycle apparatus as long as the bubble generating means 3 is provided on the upstream side of the ejector 4 or in the nozzle portion so that the fine bubbles generated by the bubble generating means 3 are allowed to flow as the driving fluid of the ejector 4. The system efficiency of the refrigeration cycle apparatus can be improved.

  In Embodiments 1 to 5, the refrigerant is not limited to R404A. In a refrigeration cycle apparatus with a high pressure and a refrigeration cycle apparatus with a low low pressure, the enthalpy that can be recovered is large, so the effect of using the ejector described in the first to fifth embodiments is great. Therefore, the refrigerant is not limited to the above. For example, R410A, R407C, R134a, R32 of CFCs (HFC system and HCFC system) that are used at low temperatures such as chillers, refrigerators, and unit coolers, It can also be applied to HC refrigerants such as R290. Carbon dioxide (CO2) refrigerant may be used, but in this case, the effect of each embodiment of the present invention can be obtained when the operation is performed not to exceed the critical point on the high pressure side.

1 is a configuration diagram illustrating a circuit configuration of a refrigeration cycle apparatus according to Embodiment 1. FIG. It is explanatory drawing which shows an example of the structure of the fine bubble generator which concerns on Embodiment 1. FIG. It is explanatory drawing which shows the ejector which concerns on Embodiment 1, FIG. 3 (a) shows the cross-sectional structure along the axis | shaft of an ejector, FIG.3 (b) shows each position of the position X1-X6 of Fig.3 (a). It is a graph which shows the pressure P corresponding to. It is a pressure-enthalpy diagram which concerns on the refrigerating-cycle apparatus by Embodiment 1, an enthalpy is shown on a horizontal axis and a pressure is shown on a vertical axis | shaft. It is explanatory drawing explaining operation | movement of the microbubble generator which concerns on Embodiment 1, and an ejector. FIG. 4 is an explanatory diagram for explaining the size of bubbles in the first embodiment. 6 is a graph illustrating a relationship between a droplet diameter ejected from a nozzle portion and ejector mixing efficiency according to the first embodiment. It is a graph which shows the cycle efficiency with respect to a dryness as a comparative example which concerns on Embodiment 1. FIG. 4 is a graph illustrating the efficiency of a single ejector with respect to the dryness according to the first embodiment. 4 is a graph showing ejector cycle efficiency with respect to dryness according to the first embodiment. 3 is a flowchart illustrating an example of a control process by a control unit according to the first embodiment. FIG. 10 is an explanatory diagram illustrating a modification of the gas refrigerant inflow portion of the fine bubble generating device according to the first embodiment. 6 is a configuration diagram illustrating a circuit configuration of a refrigeration cycle apparatus according to Embodiment 2. FIG. It is a pressure-enthalpy diagram which concerns on the refrigerating-cycle apparatus by Embodiment 2, a horizontal axis shows enthalpy and a vertical axis | shaft shows a pressure. It is a block diagram which shows the circuit structure of the other refrigeration cycle apparatus which concerns on Embodiment 2. FIG. 6 is a configuration diagram illustrating a circuit configuration of an indoor unit of a refrigeration cycle apparatus according to Embodiment 3. FIG. It is a block diagram which shows the circuit structure of the indoor unit 101 of the other refrigeration cycle apparatus which concerns on Embodiment 3. FIG. It is explanatory drawing which shows the structure of the fine bubble generator which concerns on Embodiment 4, FIG. 18 (a) is explanatory drawing which shows the position of a liquid refrigerant inflow part, FIG.18 (b) shows the cross-sectional structure of a fine bubble generator. It is explanatory drawing shown. It is explanatory drawing which shows the other structural example of the fine bubble generator which concerns on Embodiment 4. FIG. It is explanatory drawing which shows the cross section of the ejector which concerns on Embodiment 5. FIG. It is a block diagram which shows an example of a circuit structure when the ejector which concerns on Embodiment 5 is integrated in the refrigerating-cycle apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Heat radiation side heat exchanger 3 Bubble generating means 3a Liquid refrigerant inflow portion 4, 4a, 4b Ejector 5 Gas-liquid separator 6, 6a, 6b Refrigerant flow rate adjusting means 7, 7a, 7b Evaporation side heat exchanger 8 Air Liquid separator 9 Bypass pipe 13 Auxiliary heat exchanger 15 Heater 17 Ejector 21, 22, 23 Temperature detecting means 24 Pressure detecting means 31 Control means 42 Suction part 43 Nozzle part 43a Depressurizing part 43b Wide part 43c Throat part 44 Mixing part 45 Diffuser Unit 51 resistance adjusting means 52 gas refrigerant inflow part 53 pressure reducing part 54 divergent part 55 throat part 62 suction part 63 nozzle part 63a pressure reducing part 63b divergent part 63c throat part 63d nozzle inlet part 64 mixing part

Claims (14)

A compressor that brings the refrigerant into a high-pressure state, a heat-dissipation side heat exchanger that dissipates the heat of the high-pressure state refrigerant from the compressor, and the heat-radiated refrigerant from the heat-dissipation side heat exchanger contains fine bubbles The bubble generating means as a refrigerant, and the suction fluid is sucked from the suction portion by the driving fluid flowing out from the nozzle portion at a high speed by decompressing the refrigerant containing the fine bubbles generated by the bubble generating means, and the mixing portion An air discharger that mixes the driving fluid and the suction fluid and then expands in the diffuser section and flows out in a low-pressure state; and an evaporation side heat exchanger that evaporates the low-pressure refrigerant from the ejector. The means includes a gas refrigerant inflow portion into which at least a part of the gas refrigerant out of the refrigerant flowing out of the compressor or the heat dissipation side heat exchanger flows, and a liquid of the refrigerant flowing out of the heat dissipation side heat exchanger. And a liquid refrigerant inlet portion in which the refrigerant state flowing rich, that said by introducing the gas refrigerant from the gas refrigerant inlet portion to the liquid refrigerant flowing from the liquid refrigerant inlet portion adapted to generate a bubble A characteristic refrigeration cycle apparatus. One end side is connected to a pipe between the discharge part of the compressor and the inlet part of the heat radiation side heat exchanger, and the other end side is provided with a bypass pipe connecting to the gas refrigerant inflow part of the bubble generating means, A part of the gas refrigerant discharged from the compressor flows into the gas refrigerant inflow portion through the bypass pipe, and the refrigerant that flows out of the heat radiation side heat exchanger flows into the liquid refrigerant inflow portion. The refrigeration cycle apparatus according to claim 1 . A gas-liquid separator connected between an outlet portion of the heat radiation side heat exchanger and an inlet portion of the bubble generating means, and the gas refrigerant inflow of the gas phase portion of the gas-liquid separator and the bubble generating means part connect, refrigeration cycle apparatus according to claim 1, wherein the connecting the liquid refrigerant inlet portion of the air bubble generating means with a liquid phase portion of the gas-liquid separator. The bubble generating means is configured such that a gas refrigerant channel flowing from the gas refrigerant inflow portion intersects a liquid refrigerant channel flowing from the liquid refrigerant inflow portion, and a liquid flowing from the liquid refrigerant inflow portion. refrigeration cycle apparatus according to any one of claims 1 to 3 refrigerant flow by intersecting the gas refrigerant flow flowing from the gas refrigerant inlet portion, characterized in that generating bubbles. The angle formed between the gas refrigerant flow path and the liquid refrigerant flow path is 90 degrees or more and 180 degrees or less so that the gas refrigerant flows in a direction in which the liquid refrigerant collides with the liquid refrigerant flow. The refrigeration cycle apparatus according to claim 4. The liquid refrigerant flow path of the bubble generating means has a reduced cross-sectional area from the liquid refrigerant inlet portion toward the throat and an increased cross-sectional area from the throat portion toward the outlet of the bubble generating means. configured to, refrigeration cycle apparatus according to any one of claims 1 to 5, characterized in that a said gas coolant inlet in the vicinity of the throat. The said bubble generation means has a turning means which makes a swirl flow the at least one refrigerant flow of the liquid refrigerant flow path and the refrigerant flow of the gas refrigerant flow path. The refrigeration cycle apparatus according to any one of the above. The refrigeration cycle apparatus according to any one of claims 2 to 7, wherein the bubble generating means or the ejector includes a resistance adjusting means capable of adjusting a flow resistance of the refrigerant. 9. The refrigeration cycle apparatus according to claim 8, wherein the resistance adjustment unit controls the supercooling degree of the refrigerant at the liquid refrigerant inlet portion of the bubble generating unit to be a preset target supercooling degree. . 2. The bubble generating means is provided in the nozzle portion of the ejector, a refrigerant containing fine bubbles is generated at the nozzle portion, and fine droplets are ejected to the mixing portion of the ejector. The refrigeration cycle apparatus according to any one of claims 9 to 9. 10. The refrigeration cycle apparatus according to claim 1, wherein the refrigerant flowing into the ejector as a driving fluid has a dryness of 0 or more and 0.2 or less. At least two of the evaporation side heat exchangers, the ejector that sucks the refrigerant flowing out from each of the evaporation side heat exchangers by the suction part, and the flow rate of the refrigerant flowing into the evaporation side heat exchanger are adjusted respectively. Pressure of the refrigerant that is provided in at least one of a plurality of refrigerant flow rate adjusting means and a pipe between the evaporation side heat exchanger and the ejector, and is sucked into the ejector from the plurality of evaporation side heat exchangers The refrigeration cycle apparatus according to any one of claims 1 to 11, further comprising a decompression unit that equalizes the pressure. At least two ejectors for sucking the refrigerant flowing out from at least two of the evaporation side heat exchangers are provided, and the refrigerant containing fine bubbles generated by the bubble generating means is branched to flow into the plurality of ejectors. 13. A refrigeration cycle apparatus according to claim 12, further comprising a branch portion. The refrigeration cycle apparatus according to any one of claims 1 to 13, further comprising an auxiliary heat exchanger connected to the suction side of the compressor.

Images