JP2020045803A - Ejector - Google Patents

Abstract

To provide an ejector capable of suppressing a reduction in the ejector efficiency by restricting the occurrence of a swirl in a joint part where a drive flow discharged from a nozzle and a suction flow are joined.SOLUTION: At a joint part 22 of a body 20, an inner peripheral tapered face 20a is provided whose inner diameter is gradually smaller toward the downstream. In the joint part 22, there is a fixed guide member 30. The guide member 30 has a conical pipe 31 forming an inside conical flow path L10 whose inner diameter is gradually smaller toward the downstream using the shaft center of a nozzle 10 as a central axis C to form an outside conical flow path L20 between the outer peripheral face of the conical pipe 31 and the inner peripheral tapered face 20a of the body 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ejector capable of suppressing generation of a vortex at a junction where a driving flow and a suction flow discharged from a nozzle merge, thereby suppressing a decrease in ejector efficiency.

  For example, some circuits for circulating a refrigerant include an ejector. The ejector has a nozzle from which the driving flow is ejected from the opening at the distal end, and a main body portion arranged so as to surround the periphery of the nozzle and provided with a junction with the driving flow at a position on the extension of the opening at the distal end of the nozzle, And a suction conduit connected to open inside the main body. In this ejector, when the refrigerant is ejected as a drive flow from the opening at the tip of the nozzle, the refrigerant is sucked into the inside of the main body as a suction flow through a suction pipe, and the suction flow is merged with the drive flow at the merging portion, and is transmitted to the downstream diffuser. (See, for example, Patent Document 1).

JP 2002-22295 A

  By the way, the driving flow discharged from the nozzle merges with the suction flow at the merging portion and flows into the mixing portion. However, due to the inclination or deviation of the flow channel axis or the spread of the jet, a part of the flow is near the mixing portion inlet. A vortex that collides with the wall surface of the junction and flows backward along the wall surface of the junction generates vortex loss (see FIG. 5). Further, the suction flow generally flows in from the side surface of the main body because the nozzle for discharging the driving flow is disposed in a hollow portion having no main body. For this reason, a flow (secondary flow) occurs not only in a plane passing through the flow path axis of the driving flow but also in a plane orthogonal to the flow path axis, and vortex loss occurs (see FIG. 6). As a result, there is a problem that a loss occurs due to the generation of the vortex in the mixing section, and the ejector efficiency is reduced.

  The present invention has been made in view of the above, and provides an ejector capable of suppressing generation of a vortex at a junction where a driving flow discharged from a nozzle and a suction flow merge with each other, thereby suppressing a decrease in ejector efficiency. The purpose is to do.

  In order to solve the above-described problem and achieve the object, an ejector according to the present invention includes a nozzle from which a driving flow is injected from an opening at a tip, and an ejector that is disposed so as to surround a periphery of the nozzle. A main body portion provided with a joining portion with the driving flow at a portion that is an extension of the main body portion, and the suction flow is injected into the main body portion through the suction inflow port by ejecting the driving flow from the tip opening of the nozzle. An ejector that sucks, merges the driving flow and the suction flow at the merging section, and leads out to a downstream mixing section that mixes the merged driving stream and the suction flow, wherein the ejector is downstream to the merging section of the main body. An inner peripheral taper surface that gradually reduces the inner diameter is provided, and has a guide member fixed in the merging portion.The guide member has a central axis about the axis of the nozzle, and has a gradually decreasing inner diameter toward the downstream. Is small It has a conical tube forming the inner conical flow path comprising, and forming an outer conical flow path between the outer surface and the inner peripheral tapered surface of the body portion of the conical tube.

  The ejector according to the present invention is characterized in that, in the above invention, the guide member is arranged separately from the nozzle and a downstream end face of the junction.

  The ejector according to the present invention is characterized in that, in the above invention, the upstream opening of the conical tube is provided downstream of the tip opening of the nozzle.

  The ejector according to the present invention is characterized in that, in the above invention, the diameter of the upstream opening of the conical tube is larger than the diameter of the tip opening of the nozzle.

  The ejector according to the present invention is characterized in that, in the above invention, the diameter of the downstream opening of the conical tube is smaller than the diameter of the downstream opening of the junction.

  Further, in the ejector according to the present invention, in the above invention, the guide member includes an outer conical flow path between the outer peripheral tapered surface of the conical tube and the inner peripheral tapered surface of the main body, which is formed into a plurality of flow paths. It has a dividing wall for dividing.

  The ejector according to the present invention is characterized in that, in the above invention, the dividing wall is formed radially with respect to the central axis.

  In the ejector according to the present invention, in the above invention, the divided wall has an outer peripheral tapered surface at a portion in contact with the inner peripheral tapered surface.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of the vortex in the junction which joins the drive flow and the suction flow discharged from the nozzle can be suppressed, and the fall of ejector efficiency can be suppressed.

FIG. 1 is a sectional side view of an ejector according to an embodiment of the present invention. FIG. 2 is a sectional view taken along line AA of the ejector shown in FIG. FIG. 3 is a perspective view showing the configuration of the guide member shown in FIG. FIG. 4 is a diagram illustrating the relationship between the opening diameters of the nozzle, the guide member, and the mixing unit, and the flows of the driving flow and the suction flow. FIG. 5 is a diagram showing a configuration of a conventional ejector and a flow of a driving flow and a suction flow in a merging section. FIG. 6 is a sectional view taken along line BB of the ejector shown in FIG.

  Hereinafter, preferred embodiments of an ejector according to the present invention will be described in detail with reference to the accompanying drawings.

  1 and 2 show a main part of an ejector according to an embodiment of the present invention. The ejector exemplified here is applied to a refrigerant circulation circuit, which is not shown in the drawing, and performs suction of the refrigerant flowing through the second refrigerant path by using the refrigerant flowing through the first refrigerant path as a driving flow. The apparatus includes a nozzle 10, a main body 20, and a guide member 30. FIG. 3 is a perspective view showing the configuration of the guide member 30.

  The nozzle 10 has a cylindrical shape having a refrigerant passage 11 at the center. The tip of the nozzle 10 has a tapered shape in which the outer diameter gradually decreases toward the tip (right side in FIG. 1), and the inner diameter of the internal refrigerant passage 11 also decreases gradually toward the tip. It is. Although not explicitly shown in the drawing, a first refrigerant path is connected to a base end of the refrigerant path 11 of the nozzle 10.

  The main body 20 has a columnar shape with a hollow center and a circular cross section. In the hollow part of the main body part 20, a suction passage part 21, a merging part 22, and a mixing part 23 are provided. The suction passage portion 21 is a portion having a uniform inner diameter that is larger than the outer diameter of the nozzle 10, and is provided at a base end portion of the main body portion 20. The joining portion 22 is a portion that is continuous with the tip of the suction passage portion 21 and is formed in a tapered shape so that the inner diameter gradually decreases from the tip of the nozzle 10 toward the tip. The mixing section 23 is a section that is continuous with the tip of the junction section 22 and has a uniform inner diameter. Further, a diffuser section (boost section) 24 whose inner diameter gradually increases toward the distal end is connected to the distal end of the mixing section 23.

  A guide member 30 is provided at the junction 22. An inner peripheral tapered surface 20a whose inner diameter gradually decreases toward the downstream side is provided at the junction 22 of the main body 20. The guide member 30 is disposed inside the junction 22 and separated from the upstream end surface SA of the junction 22 and the downstream end surface SB of the junction 22, with the axis of the nozzle 10 as the central axis C, and directed downstream. A plurality of flows radially with respect to the central axis C are formed in a conical pipe 31 whose inner diameter gradually decreases and an outer conical flow path L20 between an outer tapered surface 31a of the conical tube 31 and an inner tapered surface 20a of the main body 20. And a dividing wall 32 for dividing into roads. Note that the upstream end surface SA is a hollow portion of the main body 20, and is a plane that passes through the tip of the nozzle 10 and is orthogonal to the axis (center axis C) of the nozzle 10. Further, the downstream end face SB is an upstream open end face of the mixing section 23. In FIGS. 1 to 3, since the four divided walls 32 are provided, the outer conical flow path L <b> 20 is divided into four around the circumference of the conical tube 31. The inside of the conical tube 31 forms an inner conical flow path L10.

  The guide member 30 is provided in the junction 22 with the outer tapered surface 32a of the dividing wall 32 and the inner peripheral tapered surface 20a of the main body 20 in contact with each other.

  As shown in FIG. 4, the upstream opening diameter d2 of the inner conical flow path L10 of the guide member 30 is formed to be larger than the tip opening diameter d1 of the nozzle 10. Further, the downstream opening diameter d3 of the inner conical flow path L10 of the guide member 30 is formed smaller than the upstream opening diameter d4 of the mixing section 23. The upstream opening diameter d2 is larger than the downstream opening diameter d3.

  Therefore, both the inner conical flow path L10 and the outer conical flow path L20 have a flow path cross-sectional area that decreases toward the downstream side. Since the upstream opening diameter d2 of the inner conical flow path L10 of the guide member 30 is formed larger than the tip opening diameter d1 of the nozzle 10, the driving flow flows through the inner conical flow path L10 and the outer conical flow The suction flow flows through the path L20. Further, the suction flow flowing through the outer conical flow path L20 is rectified in the direction of the central axis C by the dividing wall 32.

  In the conventional ejector, as shown in FIG. 5, the guide member 30 is not provided at the merging section 22, so that the jet of the driving flow discharged from the nozzle 10 has a part of the flow near the inlet of the mixing section 23. The vortex F11 collides with the peripheral tapered surface 20a and flows backward along the inner peripheral tapered surface 20a, and vortex loss occurs. When the suction flow flows in from the side surface of the main body 20, a vortex F12 due to the flow (secondary flow) is also generated in a plane orthogonal to the central axis C as shown in FIG. .

  On the other hand, in the present embodiment, as shown in FIG. 4, since the jet of the driving flow discharged from the nozzle 10 is introduced into the inner conical flow path L10, the jet flow is generated by the inner wall surface of the inner conical flow path L10. Vortex loss due to the generation of the vortex F11 can be suppressed.

  Further, since the outer conical flow path L20 is divided in the circumferential direction by the dividing wall 32, the suction flow passing through the outer conical flow path L20 is rectified in the direction of the central axis C. Vortex loss due to generation can be suppressed.

  Further, since the suction flow flows through the outer conical flow path L20, an increase in pressure loss of the suction flow can be suppressed.

  In the present embodiment, a decrease in ejector efficiency can be suppressed by these actions.

  In the above-described embodiment, the ejector is applied to the refrigerant circulation circuit, and the ejector that suctions the refrigerant flowing through the second refrigerant path using the refrigerant flowing through the first refrigerant path as a driving flow is exemplified. It is also possible to apply the present invention to a circuit in which another fluid is used as a driving flow and a suction flow. In this case, the fluid may be gas or liquid, or may be a gas-liquid two-phase mixed fluid of liquid and gas.

  Further, the shapes of the conical tube 31, the inner conical flow path L10, and the outer conical flow path L20 need not be a perfect conical shape, but are a part of the conical shape as described in the embodiment described in this specification. Not only includes a truncated cone shape, but also a conical shape with irregularities and voids in the wall surface, a shape in which multiple cones with different apical angles are joined in the middle, a tip with a gradually different apex angle Shapes that are rounded toward the direction are also included. Further, other pyramid shapes such as a polygonal pyramid may be appropriately used according to the purpose. In the above-described embodiment, the guide member 30 has the four divided walls 32. However, the present invention is not limited to this, and the number of the divided walls 32 may be three or more. Alternatively, the dividing wall 32 may be attached to the inner peripheral tapered surface 20a, and the outer peripheral surface of the conical tube 31 may be connected to the inner tapered surface of the dividing wall 32.

  In addition, each configuration illustrated in the above-described embodiment and modified examples is a schematic function, and does not necessarily need to be physically configured as illustrated. In other words, the form of distribution / integration of each device and component is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed / integrated in arbitrary units according to various usage situations. Can be configured.

DESCRIPTION OF SYMBOLS 10 Nozzle 11 Refrigerant passage 20 Main part 20a Inner peripheral taper surface 21 Suction passage part 22 Merging part 23 Mixing part 24 Diffuser part 30 Guide member 31 Conical tube 31a Outer peripheral taper surface 32 Dividing wall 32a Outer taper surface C Central axis d1 Tip opening diameter d2 Upstream opening diameter d3 Downstream opening diameter d4 Upstream opening diameter F11, F12 Vortex L10 Inner conical flow path L20 Outer conical flow path SA Upstream end face SB Downstream end face

Claims (8)

A nozzle from which a driving flow is jetted from an opening at the tip,
A main body portion disposed so as to surround the periphery of the nozzle, and provided with a joining portion with the driving flow at a portion on an extension of a tip opening of the nozzle,
A suction flow is sucked into the main body through a suction inflow port by injecting a driving flow from a tip opening of the nozzle, and the driving flow and the suction flow are merged at the merging portion, and the merged driving flow is provided. Ejecting to a downstream mixing unit for mixing the suction flow and the suction flow,
The merging portion of the main body portion is provided with an inner peripheral tapered surface whose inner diameter gradually decreases toward the downstream,
Having a guide member fixed in the junction,
The guide member has a conical tube that forms an inner conical flow path with the inner axis being the central axis of the nozzle and having a gradually decreasing inner diameter toward the downstream,
An ejector, wherein an outer conical flow path is formed between an outer peripheral surface of the conical tube and the inner peripheral tapered surface of the main body.   2. The ejector according to claim 1, wherein the guide member is disposed separately from the nozzle and a downstream end surface of the junction. 3.   The ejector according to claim 1, wherein an upstream opening of the conical tube is provided downstream of a tip opening of the nozzle.   The ejector according to any one of claims 1 to 3, wherein the diameter of the upstream opening of the conical tube is larger than the diameter of the tip opening of the nozzle.   The ejector according to any one of claims 1 to 4, wherein a diameter of a downstream opening of the conical tube is smaller than a diameter of a downstream opening of the junction.   The said guide member has a dividing wall which divides the outer conical flow path between the outer peripheral taper surface of the said conical pipe and the said inner peripheral taper surface of the said main-body part into several flow paths, The Claim 1 characterized by the above-mentioned. The ejector according to any one of claims 1 to 5, wherein   The ejector according to claim 6, wherein the dividing wall is formed radially with respect to the central axis.   The ejector according to claim 6, wherein the divided wall has an outer peripheral tapered surface at a portion that contacts the inner peripheral tapered surface.

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