JP2005233121A - Variable flow rate nozzle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable flow rate nozzle capable of reducing drop of nozzle efficiency when a valve means reduces nozzle opening in a variable flow rate nozzle capable of adjusting flow rate of fluid passing therethrough by displacing the valve means in a nozzle axial direction. <P>SOLUTION: A main nozzle 17 and a sub nozzle 20 including restriction parts 17b, 20e reducing passage section of high pressure refrigerant flowing to an fluid jet ports 17a, 20d are arranged to conform to axial lines, diameter of a sub jet opening 20d of the sub nozzle 20 is formed smaller than diameter of the jet port 17a of the main nozzle 17. The sub nozzle 20 is displaced in an axial direction R to change distance between an external taper part 20f of the sub nozzle 20 and the restriction part 17b of the nozzle 17. Consequently, flow rate of refrigerant is adjusted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a variable flow rate nozzle capable of reducing the pressure of a fluid and adjusting the flow rate of the fluid passing therethrough, and is applied to an ejector that is a momentum transporting pump that transports fluid by the entrainment action of a working fluid ejected from the nozzle at a high speed. It is effective.

  Conventionally, as a nozzle in an ejector used as a refrigerant decompression unit and a refrigerant circulation unit in a refrigeration cycle, a nozzle using a flow rate variable nozzle capable of adjusting a flow rate of a passing refrigerant is known in Patent Document 1. The applicant previously proposed a patent application (hereinafter referred to as a prior application example) of Japanese Patent Application No. 2002-31260 using a needle valve having a tapered tip as a valve means for adjusting the refrigerant flow rate. doing.

  In the ejector 50 of the conventional example described in Patent Document 1 in FIG. 21, the refrigerant having a high pressure in the compressor flows into the high-pressure space 18 through the inflow port 51. Thereafter, the passage area of the high-pressure refrigerant is reduced by the throttle portion 52a of the nozzle 52, whereby the pressure energy is converted into velocity energy, accelerates, and is ejected from the ejection port 52b. Due to the entraining action of the jetted high-speed refrigerant flow, the vapor-phase refrigerant evaporated by the evaporator is sucked from the vapor-phase refrigerant inlet 53.

  Further, in the conventional example, the valve means 54a, 54b for increasing / decreasing the passage area is displaced in the nozzle axial direction (left-right direction in FIG. 21) R, thereby opening the nozzle 52 (the passage area through which the refrigerant can pass). Can be changed. That is, the flow rate of the refrigerant passing through the nozzle 52 can be increased or decreased. Similarly, in the ejector 55 of the prior application example of FIG. 22, the needle valve 19 having the tapered shape 19 a at the tip is displaced in the axial direction R (left and right direction in FIG. 22) R, and the flow rate of the refrigerant passing through the nozzle 52 is changed. It can be increased or decreased.

According to these, when the compressor rotates at a high speed, that is, when there is a large amount of refrigerant flowing into the ejectors 50 and 55, the opening degree of the nozzle 52 can be increased and the amount of refrigerant passing through the nozzle 52 can be increased. Therefore, since the amount of refrigerant flowing through the nozzle 52, in other words, the evaporator on the downstream side of the refrigerant flow of the ejectors 50 and 55 increases, the amount of refrigerant flowing through the cycle is particularly large compared to the case where the flow rate of refrigerant passing through the nozzle 52 cannot be increased or decreased. The refrigeration (cooling) capacity at the time can be improved.
JP-A-5-31421

  However, in the conventional example (prior application example), the valve means 54 a and 54 b (needle valve 19) change the flow passage cross-sectional area of the throat B having the smallest flow passage area of the refrigerant in the nozzle 52. More specifically, in the ejector 50 (55) of the conventional example (prior application example), when the valve means 54a and 54b (needle valve 19) are displaced in the axial direction R of the nozzle 52, the inner wall surface of the nozzle 52 in the throat B. And the distance from the outer wall surface of the valve means 54a, 54b (needle valve 19). That is, the substantial channel cross-sectional area in the axial direction R of the nozzle 52 changes.

  Therefore, when the opening of the nozzle 52 is reduced, that is, the refrigerant passage cross-sectional area at the throat B is reduced, the passage cross-sectional area at the downstream side of the refrigerant flow from the throat B is compared with the passage cross-sectional area of the throat B. Will increase rapidly. As a result, there is a problem that a loss due to rapid expansion occurs and the nozzle efficiency decreases.

  The reduction in nozzle efficiency means that the pressure energy of the refrigerant is not sufficiently converted into velocity energy at the nozzle 52. Therefore, the gas phase refrigerant evaporated by the evaporator cannot be sucked, and the refrigeration cycle does not operate normally.

  In the “problem to be solved by the invention”, the parentheses indicate the case of the prior application example.

  In view of the above points, the present invention provides a variable flow nozzle capable of adjusting the flow rate of fluid passing therethrough by displacing the valve means in the axial direction of the nozzle. For the purpose of mitigation.

In order to achieve the above object, according to the first aspect of the present invention, in the variable flow rate nozzle, a plurality of throttle portions (17b, 20e) for reducing the passage area of the high-pressure side fluid flowing to the fluid ejection port (17a, 20d) are provided. Nozzles (17, 20),
The plurality of nozzles (17, 20) are arranged such that the axes of the plurality of nozzles (17, 20) coincide with each other, and at least one nozzle (20) among the plurality of nozzles (17, 20) is By displacing in the axial direction (R) of the axial line, the passage area of the high-pressure side fluid can be increased or decreased.

  According to this, since the axes of the plurality of nozzles (17, 20) are arranged so as to coincide with each other, the passage area of the fluid in which at least one nozzle (20) that can be displaced in the axial direction (R) of the axis is increased or decreased is This is smaller than the case where the passage area of the fluid is increased or decreased by one valve means (needle valve) as in the prior application example of FIG.

  Therefore, if the flow passage cross-sectional area of the fluid ejected from the ejection ports (17a, 20d) (corresponding to the throat portion in FIG. 22) is the same, the book has a small fluid passage area where one nozzle (20) increases or decreases. In the invention, the degree of expansion of the cross-sectional area of the fluid becomes small particularly at a small opening. Therefore, the energy loss (decrease in nozzle efficiency) accompanying the expansion of the passage area can be reduced.

Moreover, in invention of Claim 2, it is an ejector using the flow volume variable nozzle of Claim 1,
A needle valve (19) that increases or decreases the opening degree of the nozzle (20) located on the most upstream side of the flow of the high-pressure side fluid among the plurality of nozzles (17, 20) by being displaced in the axial direction (R); , A space having a high-pressure space (18) into which the high-pressure side fluid flows from the inflow port (10a) and a second inflow port (21a) into which the low-pressure side fluid flows, and the fluid jet ports (17a, 20d) inside And a suction space (22) in which the low-pressure side fluid is sucked from the second inlet (21a) by the entrainment action of the high-pressure side fluid ejected from the fluid jet ports (17a, 20d) at a high speed. It is arranged in the fluid flow downstream part, the mixing part (23) in which the high-pressure side fluid and the low-pressure side fluid mix, the fluid flow downstream part from the mixing part (23), and the fluid flow in the downstream direction Gradually increase fluid passage area And go diffuser portion an ejector that includes a (24) are characterized.

  Accordingly, the variable flow rate nozzle having the effect described in claim 1 can be used as a component of the ejector. In addition, the following effects can be exhibited as an ejector. The fluid can be depressurized by reducing the fluid passage with the throttle portions (17a, 20d). Also, a momentum transport type pump action that sucks and transports the low-pressure side fluid from the second inlet (21a) of the suction space (22) by the entrainment action of the working fluid ejected from the fluid jet outlet (17a, 20d) at high speed. Can be demonstrated. Furthermore, the pressure of the fluid can be increased by the diffuser portion (24) in which the passage area of the fluid increases.

  Moreover, in the ejector according to claim 2, the displacement amount of the at least one nozzle (20) and the needle valve (19) that can be displaced in the axial direction (R) is controlled as 1 in the ejector according to claim 2. Two displacement means (25, 40) may be used.

In the invention described in claim 4, in the ejector, in the ejector, the high pressure space (18) into which the high pressure side fluid flows from the inflow port (10a), and the low pressure space (10c) in which the internal pressure is lower than that of the high pressure space (18). A plurality of nozzles (17, 20) having throttle portions (17b, 20e) for reducing the passage area of the high-pressure fluid flowing from the high-pressure space (18) to the fluid jets (17a, 20d), and a plurality of nozzles ( 17, 20), a load means (41) for applying a load toward at least one nozzle (20) toward the fluid ejection port (17 a, 20 d), and an axial direction (R of the plurality of nozzles (17, 20)) ), The needle valve (19) for increasing or decreasing the opening degree of the nozzle (20) located on the most upstream side of the flow of the high-pressure side fluid among the plurality of nozzles (17, 20), and the low-pressure side fluid Inflow A space having an inflow port (21a), in which the fluid outlets (17a, 20d) are arranged, and the second inflow port is generated by the entrainment action of the high-pressure side fluid ejected from the fluid outlets (17a, 20d) at a high speed. A suction space (22) from which the low-pressure side fluid is sucked from (21a),
The plurality of nozzles (17, 20) are arranged so that the axes of the plurality of nozzles (17, 20) coincide with each other, and at least one nozzle (20) is at least 1 by the load of the load means (41). An ejector characterized in that one nozzle (20) closes a variable fluid passage, and at least one of the nozzles (20) is disposed in a high pressure space (18) and the other is disposed in a low pressure space (10c).

  According to this, when the pressure in the high pressure space (18) suddenly rises, the pressure difference between the high pressure space (18) and the low pressure space (10c) causes the load means (41) to move to at least one nozzle (20). It becomes larger than the applied load. Thereby, at least one nozzle (20) receives a force in the direction of opening the fluid passage. Therefore, the fluid having an abnormally high pressure in the high-pressure space (18) can be ejected into the suction space (22) and the pressure in the high-pressure space (18) can be reduced, thereby preventing parts from being damaged due to the abnormal high pressure. it can.

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

(First embodiment)
In the present embodiment, the ejector according to the present invention is applied to a refrigeration cycle of a vehicle air conditioner, and FIG. 1 is a schematic diagram of the refrigeration cycle according to the present embodiment. In FIG. 1, 11 is a compressor 11 that sucks and compresses refrigerant. The refrigerant that has become a high pressure state by the compressor 11 flows into the radiator 12. In the radiator 12, the refrigerant radiates heat to the outdoor air, in other words, the refrigerant is cooled by the outdoor air.

  The cooled refrigerant flows into the ejector 13. The ejector 13 converts the pressure energy of the refrigerant flowing out of the radiator 12 into velocity energy, thereby sucking the gas phase refrigerant evaporated in the evaporator 16 described later and converting the expansion energy of the refrigerant into pressure energy. The suction pressure of the compressor 11 is increased. Details of the ejector 13 will be described later.

  The refrigerant that has flowed out of the ejector 13 flows into the gas-liquid separator 14. In the gas-liquid separator 14, the refrigerant that has flowed is separated into a gas-phase refrigerant and a liquid-phase refrigerant and stored, and the separated gas-phase refrigerant is sucked into the compressor 11 and compressed again. The liquid refrigerant thus drawn is sucked to the evaporator 16 side.

  The evaporator 16 exhibits cooling capability by heat-exchanging the liquid-phase refrigerant with the air blown into the room and evaporating. The first decompressor 15 disposed between the gas-liquid separator 14 and the evaporator 16 is a throttle (decompression) means for decompressing the liquid-phase refrigerant sucked from the gas-liquid separator 14 to the evaporator 16 side. The pressure in the evaporator 16 (evaporation pressure) is reliably reduced by the first decompressor 15.

  Next, the overall structure of the ejector 13 according to the present invention will be described with reference to FIG. 2. The refrigerant upstream body 10 of the ejector 13 has a high-pressure space 18 inside the upstream body 10 after passing through the radiator 12 described above. An inlet 10a into which the high-pressure refrigerant flows and a main nozzle portion 17 are formed. The main nozzle portion 17 is provided with an ejection port 17a from which a refrigerant is ejected.

  Further, a tapered constricted portion 17b is formed in a portion between the high-pressure space 18 and the jet port 17a so that the passage area of the high-pressure refrigerant decreases from the high-pressure space 18 toward the jet port 17a. The throttle portion 17b is axisymmetric with respect to the central axis.

  Further, a needle valve 19 that adjusts the flow rate of the refrigerant passing through the main nozzle portion 17 by being displaced in the axial direction R of the main nozzle portion 17 is disposed in the upstream body 10. The needle valve 19 is a substantially needle-shaped rod-like member, and a tapered portion 19a whose cross section decreases toward the jet outlet side end 19b is formed at a site on the jet outlet direction R1 side. On the other hand, a screw portion 26 is disposed at a site on the side in the direction R2 opposite to the jet port. The threaded portion 26 is fixed integrally with the needle valve 19, and a thread is formed on the outer peripheral surface. The screw portion 26 is fitted into a concave screw portion formed in the rotor 25a of the stepping motor 25 that is a displacement means of the needle valve 19. In addition, the sub nozzle 20 arrange | positioned in the jet nozzle side site | part of the needle valve 19 is mentioned later.

  By the way, in the refrigerant | coolant downstream body 21 of the ejector 13, in the state which combined the upstream body 10 and the downstream body 21, the suction space 22 in which the jet nozzle 17a is located is formed. The downstream body 21 is provided with a gas-phase refrigerant inlet 21 a through which the gas-phase refrigerant evaporated by the evaporator 16 flows into the suction space 22. In the downstream body 21, a mixing portion 23 having a substantially constant cross section is formed on the downstream side of the refrigerant flow in the suction space 22, and further on the downstream side of the refrigerant flow in the mixing portion 23. A diffuser portion 24 is formed in which the passage sectional area gradually increases in the lateral direction.

  Next, the details of the sub-nozzle 20 will be described with reference to FIGS. 3 and 4. The sub-nozzle 20 is located in the internal space of the main nozzle portion 17 in the high-pressure space 18 described above. The sub nozzle 20 includes a sub nozzle body 20a having a space 20b therein. The sub-nozzle body portion 20a includes a sub-inlet 20c through which high-pressure refrigerant flows from the high-pressure space 18 into the internal space 20b, a sub-outlet 20d through which high-pressure refrigerant is ejected from the internal space 20b, and high-pressure refrigerant from the internal space 20b. A tapered sub-throttle portion 20e is formed in which the passage area is reduced as it flows to the ejection port 20d. In addition, an outer tapered portion 20 f corresponding to the throttle portion 17 b of the main nozzle portion 17 is formed in a portion of the outer peripheral portion of the sub nozzle main body portion 20 a on the jet nozzle 17 a side of the main nozzle portion 17.

  Note that the outer peripheral surface of the sub-nozzle main body portion 20a and the portion orthogonal to the sub-inlet port 20c is shaped to fit with the inner surface of the nozzle portion 17 with a small gap, and the axis of the sub-nozzle 20 Reliably matches the axis R of the nozzle portion 17. Further, since the outer surface of the sub nozzle body 20a and the inner surface of the nozzle portion 17 have a minute gap, the sub nozzle 20 can naturally be displaced (slid) in the nozzle axial direction R.

  By the way, the needle valve 19 described above is arranged in the sub nozzle inner space 20b. The taper portion 19 a of the needle valve 19 has a shape corresponding to the sub throttle portion 20 e of the sub nozzle 20. Further, the needle valve 19 is formed with two stepped portions, that is, a spout-side stepped portion 19e and a stepped portion 19f opposite to the spout. A bottom portion 20g of the sub nozzle 20 is disposed so as to be slidable in the axial direction R between the stepped portions 19e and 19f.

  Next, more detailed shapes of the jet port 17a of the main nozzle portion 17, the sub jet port 20d of the sub nozzle 20, and the tapered portion 19a of the needle valve 19 will be described with reference to FIG. The taper portion 19a of the needle valve 19 is formed with a taper angle of θ1, and the sub-throttle portion 20e of the sub nozzle 20 corresponding to the taper portion 19a is formed with a taper angle of θ2. Further, the outer tapered portion 20f of the sub nozzle 20 is formed with a taper angle of θ3, and the throttle portion 17b of the main nozzle portion 17 corresponding to the outer tapered portion 20f is formed with a taper angle of θ4.

  In the present embodiment, the magnitude relationship is θ1 <θ2 <θ3 <θ4, and θ2−θ1 <θ4−θ3. Furthermore, the magnitude relationship among the diameter φD1 of the jet nozzle 17a of the main nozzle portion 17, the maximum diameter φD2 of the tapered portion 19a of the needle valve 19 and the diameter φD3 of the sub jet nozzle 20d is φD3 <φD2 <φD1. The tapered portion 19a of the needle valve 19, the sub-throttle portion 20e of the sub-nozzle 20, the outer tapered portion 20f, the throttling portion 17b of the main nozzle portion 17, the spout 17a, and the sub-spout 20d are arranged so that their central axes coincide. Has been.

  Next, the operation of the present embodiment in the above configuration will be described. When the compressor 11 is started, the gas-phase refrigerant is sucked into the compressor 11 from the gas-liquid separator 14, and the compressed refrigerant is discharged to the radiator 12. The Then, the refrigerant cooled by the radiator 12 flows into the high-pressure space 18 from the inlet 10 a of the ejector 13.

  Here, an operation in which the needle valve 19 changes the main nozzle portion 17 from the fully closed state to the fully open state will be described with reference to FIGS. 8 and 3, 6, and 7. When the step motor 25 receives the control signal and rotates the rotor 25a, the screw portion 26 converts the rotational force of the rotor 25a into a linear displacement force in the nozzle axial direction R, and the needle valve 19 is displaced.

  When the needle valve 19 is displaced in the direction R2 opposite to the ejection port from the fully closed state of the main nozzle portion 17 in FIG. 3, the distance between the sub-throttle portion 20e of the sub-nozzle 20 and the taper portion 19a of the needle valve 19 gradually increases. . That is, the refrigerant flow rate (= nozzle opening degree) passing through the nozzle portion 19b increases (point a → point b in FIG. 8). Point b is a state where the taper portion 19a fully opens the sub nozzle 20 (FIG. 6).

  Further, when the needle valve 19 is displaced in the direction R2 opposite to the ejection port, the stepped portion 19f opposite to the ejection port of the needle valve 19 is displaced in contact with the bottom 20g of the sub nozzle 20, so that the sub nozzle 20 is also displaced in the opposite direction R2. To do. At this time, the refrigerant flows in the space 18a → the outlet 17a between the high pressure space 18 → the main nozzle portion 17 and the sub nozzle 20 in addition to the flow of the high pressure space 18 → the sub inlet 20c → the sub outlet 20d. That is, since the distance between the outer tapered portion 20f of the sub nozzle 20 and the throttle portion 17b of the main nozzle portion 17 gradually increases, the amount of refrigerant blown from the jet outlet 17a through the space 18a (= nozzle opening). Degrees) (in FIG. 8, point b → point d).

  At this time, naturally, the opening degree of the sub nozzle 20 is fully open (point b → point f). The point c → the point e shows the opening degree of the throttle part 17b of the main nozzle part 17 by the outer tapered part 20f of the sub nozzle 20 alone. The amount of refrigerant passing through the main nozzle 17 (= nozzle opening) is the sum of the points c → e and b → f in FIG. 8, that is, the point b → d. Point d is a state where the outer tapered portion 20f fully opens the nozzle portion 17 (FIG. 7). The bottom 20g of the sub-nozzle 20 always receives a force in the left direction (R1 direction) in the figure due to the pressure of the refrigerant.

  By the way, the refrigerant in the high-pressure space 18 flows toward the jet port 17a when the opening of the nozzle portion 17 is not fully closed (opening 0%) due to the displacement of the needle valve 19 (arrow A in FIGS. 6 and 7). ). At this time, the refrigerant is decompressed and expanded by restricting the passage area by the restricting portion 17b or the sub restricting portion 20e. In other words, the pressure energy is converted to velocity energy.

  Then, the refrigerant that has passed through the throttle portion 17b or the sub-throttle portion 20e is jetted from the jet port 17a to the suction space 22 at a high speed. At this time, the refrigerant that has become a gas phase in the evaporator 16 is sucked from the gas phase refrigerant inlet 21a by the high-speed jet flow. The refrigerant jetted from the jet port 17a and the vapor phase refrigerant sucked from the gas phase refrigerant inlet port 21a flow to the diffuser part 24 while being mixed in the mixing part 23. Then, the dynamic pressure of the refrigerant is converted into a static pressure by the diffuser unit 24 and returns to the gas-liquid separator 14. On the other hand, since the refrigerant in the evaporator 16 is sucked by the ejector 13, the liquid-phase refrigerant flows from the gas-liquid separator 14 into the evaporator 16, and the refrigerant that flows in absorbs heat from the air blown into the room and evaporates. To do.

  Next, the functions and effects of the first embodiment are listed. (1) The sub-nozzle 20 and the needle valve 19 increase / decrease the opening degree of the outlet 17a of the main nozzle 17, so that the respective valve means 19, 20 increase / decrease. The passage area can be reduced. Therefore, in particular, the degree of expansion of the refrigerant flow area in the vicinity of the minimum opening of each of the valve means 19 and 20 can be reduced, and the reduction in nozzle efficiency can be reduced.

  More specifically, as shown in FIG. 8, the needle valve 19 increases or decreases the opening degree of the nozzle 17a of the nozzle 17 from 0% to a predetermined opening degree, and the sub nozzle 20 increases or decreases from the predetermined opening degree to 100%. Considering the case of the needle valve 19 as an example, the needle valve 19 opens and closes the sub outlet 20d of the sub nozzle 20 as shown in FIG.

  For comparison, it is assumed that the diameter of the throat B in the prior application example of FIG. 22 is the same φD1 as the jet outlet 17a of the main nozzle 17 of the present embodiment, and the diameter of the jet of refrigerant is the same as the jet outlet diameter. Assume. When the refrigerant of the prior application example has the minimum opening of the needle valve 19 (the distance between the taper portion 19a and the sub-throttle portion 20e is Δd), the refrigerant flow path cross-sectional area is Δd (exactly from Δd). The calculated area is expanded from φD1 (area calculated by φD1, hereinafter the same). On the other hand, in this embodiment, the flow path cross-sectional area of the refrigerant increases from Δd to φD3. At this time, since the dimensional relationship is φD3 <φD1, in this embodiment, the degree of expansion of the refrigerant flow area in the vicinity of the minimum opening can be reduced as compared with the prior application example, and the reduction in nozzle efficiency is reduced. be able to.

  (2) Since the taper angle θ2 of the needle valve 19 that opens and closes the sub-jet 20d of the sub-nozzle 20 is reduced, the nozzle opening degree can be controlled more precisely.

  The needle valve 19 of the present embodiment opens and closes the sub-jet 20d having a diameter of φD3. Therefore, when the amount of displacement by which the needle valve 19 can be displaced in the axial direction R is constant, the axial direction is larger than in the case where the single nozzle valve 19 opens and closes the outlet 17a of the main nozzle 17 as in the prior application example. The rate of increase / decrease in the passage area of the refrigerant with respect to the displacement of R can be reduced. That is, the taper angle θ1 of the needle valve 19 can be reduced to control the nozzle opening more precisely. Thereby, hunting of the needle valve 19 (control vibration generated by control near the boundary) can be prevented.

  Further, as in this embodiment, the taper angle θ1 of the needle valve 19, the sub-throttle portion taper angle θ2, the outer taper angle θ3 of the sub-nozzle 20, and the throttling portion taper angle θ4 of the main nozzle 17 are set to θ2-θ1 <θ4-θ3. Then, the increase / decrease of the passage area of the refrigerant per displacement can be reduced in the portion close to the fully closed state and increased in the portion close to the fully open state.

  (3) Moreover, since the jet nozzle 17a of the main nozzle 17 can be made larger than the maximum diameter φD2 of the tapered portion 19a of the needle valve 19, the flow rate of the refrigerant at the maximum opening degree can be increased.

  In order to make the throat B open at 0% only by the tapered portion 19a of the needle valve 19 as in the prior application example of FIG. 22, the maximum diameter of the tapered portion 19a must be smaller than the diameter of the throat B. Don't be. That is, the diameter of the throat B is limited by the maximum diameter of the tapered portion 19a.

  However, in this embodiment, since the two valve means 19 and 20 open and close the spout 17a (diameter φD1) of the main nozzle 17, the needle valve 19 has a sub spout 20d (diameter) of the sub-nozzle 20 having a diameter smaller than φD1. φD3) may be opened and closed. For this purpose, the maximum diameter φD2 of the tapered portion 19a of the needle valve 19 may be made larger than φD3.

  On the other hand, since the opening degree of the spout 17a is adjusted by the outer tapered portion 20f of the sub nozzle 20, the diameter φD1 of the spout 17a may be smaller than the maximum diameter of the outer tapered portion 20f. Generally, since the maximum diameter of the outer tapered portion 20f is larger than the maximum diameter of the needle tapered portion 19a, the diameter φD1 of the ejection port 17a can be made larger than the maximum diameter φD2 of the needle tapered portion 19a. Therefore, the flow rate of the refrigerant when the nozzle 17 is fully opened can be increased, and the refrigeration capacity of the refrigeration cycle can be improved.

  (4) The needle valve 19 is provided with a spout-side stepped portion 19e and a spout-side opposite stepped portion 19f, and the bottom portion 20g of the sub-nozzle 20 is slidably disposed in the axial direction R between these portions. Therefore, the needle valve 19 and the sub nozzle 20 can be displaced by one displacement means (motor 25).

  More specifically, when the needle valve 19 is closed in the state shown in FIG. 6 and the needle valve 19 is opened, and the needle valve 19 is further displaced in the left (R2) direction in the drawing, the bottom 20g of the sub nozzle 20 is ejected. The sub nozzle 20 is displaced together with the needle valve 19 in contact with the side stepped portion 19e (region C in FIG. 8). Therefore, the needle valve 19 and the sub nozzle 20 can be displaced by one displacement means (motor 25).

(Second Embodiment)
Although the example which applied the ejector which concerns on this invention to the refrigerating cycle of a vehicle air conditioner was shown in 1st Embodiment, the ejector which concerns on this invention is applied to the heat pump cycle for hot water supply in this embodiment. In the present embodiment, carbon dioxide (CO2) is used as the refrigerant, and this is a supercritical cycle in which the refrigerant pressure on the high pressure side is equal to or higher than the critical pressure of the refrigerant.

  FIG. 10 shows the heat pump cycle of the present embodiment, and a water refrigerant heat exchanger 31 that heats the water in the water circulation path 30 by the heat of the refrigerant is arranged instead of the radiator in the first embodiment. The water heated by the water refrigerant heat exchanger 31 to become hot water is sent to the tank 33 by the water pump 32 disposed in the water circulation path 30.

  The tank 33 is configured so that cold water before heating and hot water after heating flow in and stored in the water / refrigerant heat exchanger 31, and the hot water is supplied to a user or the like as hot water. On the other hand, the cold water is sent to the water refrigerant heat exchanger 31 by the water pump 32 and heated as described above.

  In addition, since the ejector 13 of this embodiment has the same structure as 1st Embodiment, naturally the effect (1)-(4) of 1st Embodiment can be exhibited.

  By the way, in the hot water supply heat pump cycle, the cycle balance changes as shown in FIG. 11 depending on the temperature of the water flowing into the water-refrigerant heat exchanger 31. When the inflow water temperature is high as shown in FIG. 11B, the density of the refrigerant flowing into the nozzle 17 is reduced and the enthalpy difference Q contributing to the heating of water is reduced. Therefore, in order to ensure the heating capacity necessary for heating the water, a larger amount of refrigerant must be flowed, and a large area of the refrigerant passage (the jet port 17a at the opening degree of 100%) is required.

  On the other hand, since the density of the refrigerant flowing into the nozzle 17 is large and the refrigerant flow rate is small as shown in FIG. 11A in winter and the like, a small refrigerant passage area (a state where the opening of the nozzle 17 is small) is required. Furthermore, if the change rate of the refrigerant passage area with respect to the movement of the needle valve 19 in the axial direction R is large, hunting of the cycle is caused. Therefore, in winter when the refrigerant passage area is small, more precise control of the refrigerant passage area is required. Become. When these are summarized, the required characteristics as shown by the solid line in FIG. 12 are obtained.

  This required characteristic coincides with the effect (1) (see FIG. 8) of the nozzle 17 of the present embodiment. That is, the nozzle 17 of the present embodiment satisfies the above-described required characteristics. In other words, the heat pump cycle can be optimally operated. Note that the variable nozzle 52 of the prior application example cannot satisfy the requirements because it exhibits the characteristics shown by the dotted line in FIG.

(Third embodiment)
In the present embodiment, in the ejector 13 having substantially the same configuration as that of the first and second embodiments, a protruding portion 20h is disposed at an end portion in the direction R2 opposite to the jet port of the main body portion 20a of the sub nozzle 20. The projecting portion 20 h comes into contact with the stepped portion 10 b of the upstream body 10. In more detail using FIG. 13, the sub-nozzle body 20a is always in the right direction R1 in the figure due to the dynamic pressure of the high-pressure refrigerant flowing around it and the low pressure acting on the outer surface of the end of the sub-nozzle 20 on the jet outlet side. In order to receive force, it moves to the direction which obstruct | occludes the jet nozzle 17a.

  However, in the present embodiment, the displacement in the right direction R1 in the figure stops at the point where the protruding portion 20h contacts the stepped portion 10b of the upstream body 10. At this time, since there is a gap between the outer tapered portion 20f of the sub nozzle 20 and the throttle portion 17b of the nozzle 17, the ejection port 17a is not fully closed.

   FIG. 14 shows the relationship between the displacement amount of the needle valve and the opening of the nozzle, and there is a gap (nozzle opening) between the outer tapered portion 20f of the sub-nozzle 20 and the throttle portion 17b of the nozzle 17. If the opening is smaller than the minimum required opening, it can be seen that the required flow rate can be controlled.

  By the way, in order to fully close the jet nozzle 17a, it is necessary to process the sub-nozzle 20, the main nozzle 17 and the like with high accuracy, which causes a cost increase during mass production. However, in this embodiment, since the ejection port 17a does not need to be fully closed, the processing accuracy is loosened, and the cost of the sub nozzle 20, the main nozzle 17, and the like can be reduced.

  In addition, also in 3rd Embodiment, the effect of (1)-(4) of 1st Embodiment can be exhibited.

(Fourth embodiment)
In the above-described first to third embodiments, the example in which the stepping motor 25 is used as the displacement means for displacing the needle valve 19 is shown. However, in this embodiment, the linear solenoid 40 is used as the displacement means as shown in FIG. I use it. For example, in a car air conditioner using CO2 as a refrigerant and using a belt-driven compressor, the rotational speed of the belt-driven compressor varies depending on the engine rotational speed, and therefore a linear solenoid 40 having better response than the stepping motor 25 is required. There is a case. In the present embodiment, the needle valve 19 that adjusts the opening of the sub nozzle 20 d of the sub nozzle 20 is controlled by the electromagnetic force of the linear solenoid 40.

  FIG. 15 shows an overall configuration diagram of the present embodiment. In this embodiment, a linear solenoid 40 is arranged as a displacement means of the needle valve 19 in place of the stepping motor 25 of the first to third embodiments, and the main nozzle 17 and the like have substantially the same configuration as that of the first embodiment. is there. The linear solenoid 40 includes a coil 40a, a yoke 40b, a plunger 40c, a magnetic flux leakage portion 40d, a cap 40e, and a coil spring 40f, and the needle valve 19 is press-fitted into the plunger 40c.

  Next, in this embodiment, when the nozzle 17 is fully closed and only the needle valve 19 is controlled, the balance of the force applied to the needle valve 19 is shown in FIG. On the plunger 40c, the elastic force Fk by the coil spring 40f always acts in the right direction in the figure. Since only the elastic force Fk acts on the needle valve 19 when the cycle is stopped, the needle valve 19 is displaced in the right direction until the sub outlet 20d and the outlet 17a are fully closed.

  When the cycle starts and a current flows through the coil 40a, an electromagnetic force Fs is generated in the plunger 40c in the left direction in the figure. Since the elastic force Fk is set to be small, Fs> Fk is immediately established, and the plunger 40c, that is, the needle valve 19 is displaced leftward, so that the sub-injection port 20d is opened and the refrigerant flows. When the refrigerant begins to flow, a pressure difference is generated before and after the nozzle 17a of the nozzle 17. When the pressure on the high pressure side is PH and the pressure on the low pressure side is PL, a force Fp due to a pressure difference (PH-PL) acts on the needle valve 19 in the right direction in the figure. The electromagnetic force Fs of the linear solenoid 40 is controlled so that these balances Fs = Fp + Fk are established. The operation of the nozzle 17 is the same as in the first embodiment.

  Next, the function and effect of this embodiment will be described. Since the needle valve 19 is displaced by the linear solenoid 40, the needle valve 19 can be controlled with a faster response than the stepping motor 25. Furthermore, since the opening degree of the jet outlet 17a is controlled by the needle valve 19 and the sub nozzle 20 as in this embodiment, the electromagnetic force required for the displacement can be reduced.

  As shown in FIG. 16, the necessary electromagnetic force Fs in the present plan is Fs = (PH−PL) · S + Fk. Here, S indicates the opening area of the sub-jet 20 d of the sub-nozzle 20. On the other hand, the necessary electromagnetic force Fs ′ when adjusting the opening of the jet nozzle (throat B in the prior application example) with one needle valve 19 as in the prior application example is Fs ′ = (PH−PL) · S '+ Fk. Here, S ′ is the area of the throat portion B of the prior application example, and in order to make the explanation easy, in order to make the refrigerant passage area when the opening degree of the nozzle 100% coincide, Assume that it is the same as the area.

  In the present embodiment, the nozzle opening degree can be controlled only by the needle valve 19 at a low flow rate, but when the variable control of the throat B (jet 17a) is performed only by the needle valve 19 as in the prior application example. Must be designed to have a throat B (jet 17a) area that can accommodate the required maximum flow rate. Supplementally, the characteristic of the refrigerant flow rate in the car air conditioner is that the flow rate range is wide. Since a large refrigerant flow rate is required under the cool-down condition as compared with the flow rate under the general traveling condition, the area of the throat B (jet port 17a) needs to be increased in order to flow a large flow rate.

  Therefore, S <S ′. That is, Fs <Fs ′, and the required electromagnetic force Fs of the present embodiment is smaller than the required electromagnetic force Fs ′ of the prior application example. Thereby, in this embodiment, the needle valve 19 can be displaced by the smaller linear solenoid 40, and the electric power consumed by the solenoid 40 can also be reduced. Note that the comparison is made on the assumption that the difference between the high-pressure side refrigerant pressure PH and the low-pressure refrigerant pressure PL is the same.

  Moreover, also in this embodiment, the effect of (1)-(4) of 1st Embodiment can be exhibited.

(Fifth embodiment)
As shown in FIGS. 17, 18, and 19, the sub-nozzle 20 of this embodiment differs from the sub-nozzle 20 in the first to fourth embodiments described above in that the sub-coil spring 41 disposed in the sub-nozzle bottom outer space 10 c is the sub-nozzle 20. Usually, it is pressed against the throttle portion 17b of the main nozzle 17 by the applied force Fsk. Further, the main body portion 20a of the sub nozzle 20 separates the high pressure space 18 from the sub nozzle low portion outer space 10c. The main body 20a is provided with an inlet 20i through which high-pressure refrigerant flows into the internal space 20b of the sub nozzle 20.

  The needle valve 19 is located in the high-pressure space 18, the sub-nozzle bottom outer space 10c, and the space 43 where the plunger is located. And between the high pressure space 18 and the sub nozzle bottom part outer space 10c, it arrange | positions so that a slide is possible in the hole formed in the sub nozzle main-body part 10a. Further, between the sub-nozzle bottom outer space 10 c and the plunger space 43, it is slidably disposed in a hole formed in the upstream body 10. An O-ring 44 is disposed in the hole to further improve the sealing performance between the sub-nozzle bottom outer space 10c and the plunger space 43.

  Further, in the present embodiment, the passage 45 that connects the high-pressure space 18 and the plunger space 43 in order to make the pressure applied to the needle valve 19 substantially constant between the jet side end 19b and the jet side opposite end 19c. Is formed.

  By the way, although the component structure of the refrigerant | coolant flow downstream from the jet nozzle 17a is a structure substantially the same as 1st-4th embodiment, the suction space 21 and the sub nozzle bottom part outer space 10c are connected to the ejector 13 of this embodiment. A communicating path 42 is disposed.

  Next, the operation and effect of the present embodiment will be described. When the cycle is operating normally, the sub nozzle 20 is pressed against the nozzle 17 by the sub coil spring 41. Then, the solenoid valve 40 displaces the needle valve 19 in the axial direction R to adjust the opening of the sub-jet 20d.

  On the other hand, when the heat load of the evaporator 16 suddenly increases, the compressor 11 becomes abnormally high in order to increase the refrigerant circulation amount, so that the refrigerant path on the high-pressure side becomes abnormally high in pressure. May be damaged. Further, when the flow rate of the high-pressure refrigerant is abnormally increased when the opening degree of the needle valve 19 is small, the high-pressure side refrigerant may become abnormally high.

  However, in the present embodiment, when the pressure PH in the high pressure space 18 suddenly increases, the force Fsk applied to the sub nozzle 20 in the right direction in the drawing as shown in FIG. The difference (PH-PL) between the applied force and the pressure PH of the high-pressure space 18 and the pressure PL of the sub-nozzle bottom outer space 10c becomes larger. Accordingly, the sub-nozzle 20 is displaced leftward in the figure to open the jet port 17a.

  At this time, the refrigerant in the high-pressure space 18 passes through the space 18a between the main nozzle portion 17 and the sub-nozzle 20 from the sub-inlet 20c and is ejected from the ejection port 17a. That is, the sub nozzle 20 can be used as a relief valve at the time of abnormally high pressure. Thereby, it is possible to reliably avoid an abnormal increase in the high-pressure side pressure.

(Other embodiments)
In the fifth embodiment described above, an example in which the suction space 21 and the sub nozzle bottom outer space 10c are simply communicated with each other through the communication path 42 is shown. However, a pressure adjusting means, for example, an electromagnetic valve or the like is disposed in the communication path 42. The pressure in the bottom outer space 10c may be adjusted.

  In the first to fifth embodiments described above, the example in which the main nozzle 17 is integrally formed with the upstream body 10 has been shown. However, the main nozzle 17 is formed separately, and then the upstream body 10 and It may be fixed integrally.

  In the above-described first to fifth embodiments, two nozzles 17 and 20 are shown, but two or more nozzles 17 and 20 may be provided.

  In the first to fifth embodiments described above, the throttling portions 17b and 20e of the nozzles 17 and 20 have been shown as examples of straight lines in the cross section represented by FIG. It may be a curve that approaches asymptotic lines. The taper angle at this time is an angle between a tangent line of a curve and an axis line in a certain cross section. Similarly, the shape of the tapered portion 19a of the needle valve 19 may be a curved line. At this time, the taper angle θ1 is the same as in the case of the throttle portion.

  Moreover, the ejector of this invention is applicable also to cycles other than the refrigerating cycle and heat pump cycle which were shown to the above-mentioned 1st-5th embodiment. Furthermore, the nozzle of the present invention can be disposed in a flow path other than the above-described embodiment, for example, a simple cylindrical tube.

  In the first to fifth embodiments described above, various refrigerants such as carbon dioxide CO2 and alternative chlorofluorocarbon HFC134a can be used.

  In the first to fifth embodiments, the main nozzle 17 is a tapered nozzle. However, the main nozzle 17 may be a divergent nozzle.

  Further, the magnitude relationship between the diameters φD1 and φD3 of the jet nozzles described in the first to fifth embodiments is merely an example, and the passage amount of the refrigerant is increased or decreased by the displacement of the sub nozzle 20 and the needle valve 19. Therefore, the size relationship of the spout is not limited to this.

It is a schematic diagram which shows the refrigerating cycle of 1st Embodiment which applied the ejector of this invention to the vehicle air conditioner. It is sectional drawing which shows the whole structure of the ejector which concerns on 1st Embodiment. It is sectional drawing to which the nozzle part of the ejector of FIG. 2 was expanded, Comprising: The nozzle part has shown the state fully closed. It is a figure which shows the AA cross section of FIG. 2 and FIG. It is sectional drawing which shows the jet nozzle vicinity of a nozzle part among the ejectors which concern on 1st Embodiment. It is sectional drawing to which the nozzle part of the ejector of FIG. 2 was expanded, and the state which the needle valve is fully opened is shown. It is sectional drawing to which the nozzle part of the ejector of FIG. 2 was expanded, Comprising: The state in which the nozzle part is fully opened is shown. It is a figure which shows the relationship between the displacement amount of a needle valve and the nozzle opening degree in the ejector which concerns on 1st Embodiment. It is a figure which shows the relationship between the nozzle opening degree and nozzle efficiency in the ejector which concerns on 1st Embodiment, and a prior application example. It is a schematic diagram which shows the heat pump cycle of 2nd Embodiment which applied the ejector of this invention to the water heater. It is a pressure-enthalpy diagram in the heat pump cycle of the second embodiment, and shows (a) when the water temperature flowing into the water refrigerant heat exchanger is low, and (b) when the water temperature flowing into the water refrigerant heat exchanger is high. Yes. It is the figure which showed the characteristic of the relationship between the needle valve displacement amount which the heat pump cycle of 2nd Embodiment requires, and a nozzle opening degree. It is sectional drawing which shows the nozzle part of the ejector which concerns on 3rd Embodiment. It is a figure which shows the relationship between the displacement amount of a needle valve, and the nozzle opening degree in the ejector which concerns on 3rd Embodiment. It is sectional drawing which shows the whole structure of the ejector which concerns on 4th Embodiment. It is sectional drawing which shows the force added to the nozzle part of the ejector which concerns on 4th Embodiment. It is sectional drawing which shows the whole structure of the ejector which concerns on 5th Embodiment. It is sectional drawing to which the nozzle part of the ejector which concerns on 5th Embodiment was expanded, Comprising: The nozzle part shows the state fully closed. It is a figure which shows the DD cross section of FIG. It is sectional drawing which shows the force added to the nozzle part of the ejector which concerns on 5th Embodiment. It is sectional drawing which shows the ejector which concerns on patent document 1 (conventional example). It is the figure which expanded the nozzle part among the ejectors concerning a prior application example.

Explanation of symbols

10a ... Inlet, 10c ... Sub nozzle bottom outer space (low pressure space),
17 ... main nozzle part (nozzle), 17a ... fluid outlet, 17b ... throttle part,
18 ... High pressure space, 19 ... Needle valve, 20 ... Sub nozzle,
20d: Sub outlet (fluid outlet), 20e ... Sub throttle part (squeezing part),
21a ... Gas phase refrigerant inlet (second inlet), 22 ... Suction space, 23 ... Mixing section,
24 ... Diffuser part, 25 ... Stepping motor (displacement means),
40 ... Linear solenoid (displacement means), 41 ... Sub coil spring (load means),
R: Nozzle axial direction.

Claims (4)

A plurality of nozzles (17, 20) having throttle portions (17b, 20e) for reducing the passage area of the high-pressure side fluid flowing to the fluid ejection ports (17a, 20d);
The plurality of nozzles (17, 20) are arranged such that the axes of the plurality of nozzles (17, 20) coincide with each other,
Among the plurality of nozzles (17, 20), at least one nozzle (20) can be increased or decreased by displacing in the axial direction (R) of the axial line. A variable flow rate nozzle characterized by An ejector using the flow rate variable nozzle according to claim 1,
A needle valve that increases or decreases the opening degree of the nozzle (20) located on the most upstream side of the flow of the high-pressure side fluid among the plurality of nozzles (17, 20) by displacing in the axial direction (R). 19)
A high-pressure space (18) into which the high-pressure side fluid flows from the inflow port (10a);
A space having a second inlet (21a) into which a low-pressure side fluid flows, wherein the fluid outlets (17a, 20d) are disposed therein, and the fluid outlets (17a, 20d) are ejected at a high speed. A suction space (22) through which the low-pressure side fluid is sucked from the second inflow port (21a) by the entrainment action of the high-pressure side fluid;
A mixing section (23) disposed in a downstream portion of the fluid flow with respect to the suction space (22) to mix the high-pressure side fluid and the low-pressure side fluid;
An ejector comprising: a diffuser portion (24) disposed in a downstream portion of the fluid flow with respect to the mixing portion (23) and gradually increasing a passage area of the fluid toward the downstream side of the fluid flow. The displacement amount of the at least one nozzle (20) and the needle valve (19) that can be displaced in the axial direction (R) is controlled by one displacement means (25, 40). The ejector according to claim 2. A high-pressure space (18) into which the high-pressure side fluid flows from the inflow port (10a);
A low pressure space (10c) having an internal pressure lower than that of the high pressure space (18);
A plurality of nozzles (17, 20) having throttle portions (17b, 20e) for reducing the passage area of the high-pressure fluid flowing from the high-pressure space (18) to the fluid ejection ports (17a, 20d);
A load means (41) for applying a load toward at least one nozzle (20) of the plurality of nozzles (17, 20) toward the fluid ejection port (17a, 20d);
By displacing in the axial direction (R) of the plurality of nozzles (17, 20), the nozzle (20) located on the most upstream side of the flow of the high-pressure side fluid among the plurality of nozzles (17, 20). A needle valve (19) to increase or decrease the opening of
A space having a second inlet (21a) into which a low-pressure side fluid flows, wherein the fluid outlets (17a, 20d) are disposed therein, and the fluid outlets (17a, 20d) are ejected at a high speed. A suction space (22) through which the low-pressure side fluid is sucked from the second inlet (21a) by the entrainment action of the high-pressure side fluid;
The plurality of nozzles (17, 20) are arranged such that the axes of the plurality of nozzles (17, 20) coincide with each other,
Due to the load of the load means (41), the at least one nozzle (20) closes a fluid passage through which the at least one nozzle (20) can be varied;
One of the at least one nozzle (20) is disposed in the high-pressure space (18), and the other is disposed in the low-pressure space (10c).

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