EP1416123B1 - Vortex inlet vanes - Google Patents

Abstract

The compressor assembly, for a turbocharger at an internal combustion motor, has an inserted spin unit (7) fitted into the housing (3) and/or the air intake (6) and in front of the running wheel (5), to generate a spiral flow towards the wheel. The spin unit is inserted at the junction between the housing and the air intake, with a mounting flange (12) to secure it radially within the housing or the air intake, and fix it axially between the air intake and the housing. An elastic seal (8) is between the air intake and/or the spin unit and the housing.

Description

The invention relates according to the preamble of claim 1, a swirl generating device for swirling flow of an impeller of a compressor or a (centrifugal) pump with a housing and a suction line.

With regard to an increase in performance and / or to improve the efficiency and also the exhaust gas quality, it is known to apply internal combustion engines with compressed air; In this context, for example, exhaust-driven turbocharger have proven.

The operation of such compressor is often due to the better dynamic properties near the surge limit in the compressor map, but this acoustic disadvantages in the form of very disturbing hissing noise, possibly the instability leads to longer-term operation in this area even damage to the compressor wheel. Furthermore, the operation in the area of the surge limit is particularly lossy, resulting in a very poor efficiency. Also related with (centrifugal) pumps in general, the problems described.

One way to remedy this situation is exhaust gas turbochargers in controlled operation, with a distinction between turbine and compressor-side control. In the context of a compressor-side control, upstream air grids can be used for the compressor impeller.

For example, a compressor inlet arranged at the compressor inlet influences the direction of flow of the air in such a way that in the critical map area there is a reduction in the entry shock losses at the turbine wheel. It is thus achieved an advantageous shift of the surge line in the direction of smaller mass flows.

To name in this context is the DE 42 12 880 A1 , which discloses an adjustable guide grid, whose vanes comprise a pivotable vane member. According to the DE 42 12 880 A1 the compressor is preceded by a vane ring, which comprises a housing and divided vanes. This relatively complex constructed Leitgitter must be included in terms of a coordinated design of the adjacent components in the design of the overall system, which is why it is not possible to easily integrate the guide grid in an existing compressor system. The vane ring housing is also insufficiently decoupled from the compressor housing, so that the acoustic behavior is problematic. In addition, production, installation and maintenance of the arrangement due to the large number of items associated with a very large effort.

Furthermore, the DE 2 060 271 A1 to call, which a method for the automatic adjustment of the entrance swirl with compressors of Exhaust gas turbochargers and a nozzle described. The axial flow-through distributor is arranged in the suction pipe of the compressor and is inserted up to an axial stop in an area with extended inner diameter, the nozzle and the compressor housing are in positive contact with each other. Disadvantageously, on the one hand for accommodating the diffuser a particularly adapted, dimensionally accurate, structural design of the compressor housing is necessary, on the other hand, flow-induced vibrations of the diffuser can continue unimpeded into the compressor housing.

The object of the invention is to provide an acoustically optimized, working with a good efficiency swirl generating device, which is very simple and so is particularly inexpensive to manufacture and assemble and which can be integrated in a simple way without significant changes of adjacent components in an existing system.

The object is achieved with a swirl generating device having the features of claim 1, wherein according to the underlying idea, a vorschiebbarer in the neck-like inlet of the housing and / or in the suction line, the impeller upstream swirl generator is provided, the housing suction side for connection is formed like a nozzle with the suction line and the swirl generator in the connecting region between the suction line and the housing is arranged and the swirl generator comprises a mounting flange both for radial fixing within the suction line or the housing, as well as for axial fixing between the suction line and housing.

According to the invention, the fastening flange has a lip radially on the outside as an assembly aid and for the seal.

Particularly preferred embodiments and developments of the invention are the subject of the dependent claims.

According to a particularly preferred embodiment, for the acoustic decoupling of the suction line and / or the Oral / generator from the housing means - such as an elastic seal between the suction line and / or swirl generator on the one hand and housing on the other.

Conveniently, the swirl generator includes a mounting flange for both radial fixation within the charge air suction or the compressor housing, wherein the radially outer edge of the flange rests on the inside of the charge air suction or the compressor housing, as well as for axial fixation between charge air suction and compressor housing, the charge air suction with the inlet nozzle end having the compressor housing corresponding axial-directional paragraph.

It is very expedient for the swirl generator to have an annular, radially outer region which optionally simultaneously forms the aforementioned fastening flange, with inner guide vanes, and the guide vanes are arranged rigidly, the vanes being adjustable and / or deformable according to a particularly preferred embodiment, so that an adjustment can be made according to the mass throughput.

As a very advantageous embodiment of the vanes of the swirl generator is viewed from an elastically deformable plastic.

The swirl generator is flowed through axially in accordance with a preferred embodiment of a flow medium, while extending the vanes of the swirl generator, starting from a fixed leading edge, which is connected to the annular, radially outer region in the flow direction and thereby have a curvature in the radial direction, so that a flow twist can be generated.

Expediently, the guide vanes of the swirl generator cover regions of a total of 20-30%, in particular of about 25%, of the area flowed on, in a state which is not or little flowed through. "Angeströmte surface" of the swirl generator is present in the sense of an axial projection to understand.

According to a preferred embodiment, the swirl generator comprises four guide vanes which, in a state which is not or slightly flowed through, each cover an area of the surface which has flowed over an angle of 35-45 °, in particular of approximately 40 °.

It is considered particularly advantageous if the guide vanes of the swirl generator are deformable depending on the mass flow of the flow medium.

With increasing mass flow, according to a preferred embodiment of the invention, the vanes of the swirl generator are deformed against their radial curvature, so that a smaller flow swirl is generated. Accordingly, the curvatures of the vanes of the swirl generator covered, circular segment-like areas of the surface flowed reduce with increasing mass flow.

Conveniently, in the upper and maximum operating range of the compressor or the pump, a maximum deformation of the vanes of the swirl generator is established. For example, in the upper and maximum operating region of the compressor or the pump, the guide vanes of the swirl generator cover circular-segment-like regions of a total of 4% -14%, in particular of approximately 9%, of the area flowed on due to the curvature.

According to a preferred embodiment of the swirl generator with four guide vanes, these cover in the upper and maximum operating region of the compressor or the pump in each case over an angle of 1 - 11 °, in particular of approximately 6 °, extending, circular-segment-like area of the surface.

Figur 1

einen Meridianschnitt durch einen Verdichter mit einer Drallerzeugungseinrichtung,

Figur 2

einen Drallerzeuger in unterschiedlichen Ansichten,

Figur 3

ein Diagramm zur Verformung der Drallerzeugerflügel abhängig vom Massenstrom sowie

Figur 4

die Verformung der Drallerzeugerflügel bei unterschiedlichen Massenströmen.

Hereinafter, a particularly preferred embodiment of the invention with reference to figures will be explained in more detail, showing schematically and by way of example

FIG. 1

a meridian section through a compressor with a swirl generating device,

FIG. 2

a swirl generator in different views,

FIG. 3

a diagram for the deformation of the swirler blades depending on the mass flow as well

FIG. 4

the deformation of the swirler blades at different mass flows.

In FIG. 1 is a radial compressor 1 of an exhaust gas turbocharger not shown here an internal combustion engine with a suction-side swirl generating device 2 shown. The compressor comprises an impeller 5, which is arranged in a housing 3 and has impeller blades, which is driven by means of an exhaust gas turbine via a shaft. It is sucked in accordance with the direction of arrow A charge air via a charge air suction 6 and conveyed through a diffuser channel 17 and a spiral channel 4 in a charge air pressure line; if necessary, the charge air is admixed with recirculated exhaust gas.

In order to achieve a spin-loaded, directed flow of the impeller blades, a swirl generator 7 is provided as an insertion part in the inflow. The swirl generator 7 has a cylindrical, pipe-section-shaped main body 11 with inner vanes 18 and is inserted into the charge air line 6, so that the outside of the main body 11 rests against the pipe inside the charge air line 6. To fix the swirl generator 7, in particular in the axial direction, this comprises a flange 12, the charge air line side surface rests against a shoulder 13 of the charge air line 6, whereas the compressor-side surface of the flange 12 is in communication with the end face of a seal 8. The diameter of the flange 12 corresponds approximately to the inner diameter of the flared end 15 of the charge air line 6, so that a determination in the radial direction is given.

The compressor housing 3 is formed on the charge air inlet pipe side, wherein the end portion 10 of the nozzle 16 on the outside has a reduced diameter, on which the rubber-elastic seal 8 is pushed. The seal 8 stands in the direction of the flange 12 of the swirl generator 7 via the end 14 of the nozzle 16, so that the swirl generator 7 is decoupled from the compressor housing 3. On the outside, the seal 8 circumferential lamellae 9, which allow easy sliding of the charge air line 6, but prevent inadvertent release of the compound; In addition, the flange 12 is held with a certain bias in the axial direction.

According to the present embodiment, the swirl generator 7 comprises four to nine blades 18, whose outlet angle can be selected according to the charge air mass flow between 15 ° and 75 °. Preference is given to an odd number of blades 18, which reduces the risk of resonance formation on the compressor wheel blades. As one shown in the figure rigid design of the swirl generating device always represents a compromise between acoustic and full load behavior of the compressor, the blades 18 of the swirl generator 7 are preferably adjustable or deformable depending on the mass flow rate, with an adjustment or deformation is effected by the gas force itself expediently.

The swirl generator 7 is made of a plastic such as glass-fiber reinforced polyamide, where appropriate - especially if a backflow of hot charge air from the compressor can not be effectively prevented - a metal version is preferred. Due to the high temperatures occurring in the charge air compression, the compressor housing 3 is made of cast aluminum; the charge air intake manifold is made of glass fiber reinforced polyamide.

In the present FIG. 1 the swirl generator 7 is shown with blades 18 without a central web, according to another embodiment, however, an embodiment with central central web is considered appropriate.

FIG. 2 shows a four-leaf swirl generator in different views. The swirl generator 200 is made in one piece by injection molding from a relatively soft thermoplastic material with a hardness of about 45 Shore D, so that the wings 202 have the required flexibility. The regions which require greater stability - such as the annular, radially outer region 204, the leading edges 206 of the wings 202 and the central region 208 - are structurally designed in particular by means of saponification ribs or material reinforcements.

Clearly visible in the view 210 from below in conjunction with the 3D view 212, as the wings 202 extending from the leading edges 206 in the flow direction marked a, and thereby have a curvature in the radial direction for swirl generation. In the present case, the flow a is placed in a right-handed twist, wherein the direction of the wing curvature of course from the direction of rotation of the downstream in the flow of the pump or compressor impeller (see. FIG. 1 , Para. 5) depends.

The wings 202 are axially straight at their radially inner side in the central region 208 over approximately half its length, so that in each case a free, particularly deformable wing end 216 remains. On the outside, the wing curvature from the wing tip 216 can continue into the region of the leading edge 202, since the wings 202 are not fixed axially straight here.

In the lateral view 214, the leading edges 206 and the wings 202 extending in the direction of flow a can be seen. In mounting position, the swirl generator is in the area between suction line and pump or compressor housing (see. FIG. 1 ) are fixed by means of the annular, radially outer region 204, so that the region 204 projecting in the axial direction, such as leading edges 206 and wings 202, for receiving in the intake manifold or in the intake manifold have a reduced diameter. With regard to a favorable flow profile, the central region 208 is conically formed on the inflow side, the vane edges 218 are retracted in the flow direction a to a smaller diameter, the terminations are rounded.

As an assembly aid and to ensure a radially biased seal in the suction line or in the pump or compressor housing, the annular, radially outer region 204 of the swirl generator 200 has on the outside a lip 220. The lip has a slightly larger diameter than the clear diameter of the insertion area, so the swirl generator 200 can only be pushed forward with the leading edges 206.

The curvature of the guide vanes 202 causes a swirling action of the flow flowing in the direction a. On the one hand, the swirl generation depends on the curvature of the guide vanes 202, on the other hand, the Leitschaufelkrümmung depends on the mass flow. The relationship is with the diagram 300 in FIG FIG. 3 shown for different temperatures. On the ordinate the mass flow is normalized, on the abscissa the deflection of the guide vanes 202 in mm. All three curves 302 for -20 ° C, 304 for 23 ° C and 306 for 65 ° C show the increasing with increasing mass flow deformation of the vanes 202 of the swirl generator 200, this is associated with a correspondingly decreasing swirl generation. The higher the temperature of the flow medium, the softer the vanes 202 of the swirl generator 200, which is expressed in the steeper rise of the deformation curves 304 and 306. Due to the structural design of the swirl generator 200 in particular the curve 304 in the range 0.6 to 0.8 of the normalized air mass flow shows a clear plateau. Despite the relatively high air mass flow, a certain amount of swirl generation is achieved in this area, which only drops sharply when the air mass flow increases even further.

Significantly determines the swirl generation in addition to the design of the wings of the flown, with increasing mass flow decreasing wing area corresponding to the projection in the flow direction. FIG. 4 shows the flowed surface of a four-blade swirl generator at a temperature of the flow medium of 23 ° C for different mass flows. At 20% of the rated power mass flow, the blades of the swirl generator according to a) each cover circular sector-shaped regions 402 of approximately 37 °. With increasing mass flow, the wings cover due to the elastic deformation a decreasing portion of the flowed surface, so that the blades of the swirl generator, as shown at b) cover at 40% of the rated power mass flow each circular sector-shaped areas 404 of about 30 °. With c), the deformation is shown at 60% of the rated power mass flow, wherein the blades of the swirl generator respectively cover sector-shaped areas 406 of about 20 °, according to d) 80% of the rated power mass flow each sector-shaped areas 408 of about 17 ° are covered. According to e) results in the rated power mass flow maximum deformation of the blades of the swirl generator, wherein the wings each cover sector-shaped areas 410 of about 7 ° and thus a minimum swirl generation is achieved.

Claims (15)

1. A Vortex generation device for vortex-loaded flow onto an impeller of a compressor or a pump with a housing and a suction line, wherein

   - a vortex generator (7) which can be introduced into the housing (3) and/or into the suction line (6) and is arranged in front of the impeller (5), is provided,

   - the housing (3) is configured in the manner of a connecting piece on the suction side for connection to the suction line (6), and the vortex generator (7) is introduced in the connection region between the suction line (6) and housing (3) and

   - the vortex generator (7) comprises a fastening flange (12, 204) both for radial fixing within the suction line (6) or the housing (3), and also for axial fixing between the suction line (6) and housing (3),

   characterised in that
   the fastening flange (12, 204) of the vortex generator (7, 200) has a lip (220) radially on the outside as an assembly aid and for sealing.
2. A Vortex generation device according to claim 1, characterised in that an elastic seal (8) is provided between the suction line (6) and/or vortex generator (7), on the one hand, and the housing (3), on the other hand.
3. A Vortex generation device according to any one of the preceding claims, characterised in that the vortex generator (7, 200) has an annular, radially outer region (204) with inner guide blades (18, 202).
4. A Vortex generation device according to any one of the preceding claims, characterised in that the guide blades (18, 202) of the vortex generator (7, 200) are rigidly arranged.
5. A Vortex generation device according to any one of the preceding claims, characterised in that the guide blades (18, 202) of the vortex generator (7, 200) can be adjusted and/or deformed.
6. A Vortex generation device according to any one of the preceding claims, characterised in that the guide blades (18, 202) of the vortex generator (7, 200) consist of an elastically deformable plastics material.
7. A Vortex generation device according to any one of the preceding claims, wherein a flow medium axially flows through the vortex generator, characterised in that the guide blades (18, 202) of the vortex generator (7, 200) extend in the flow direction and have a curvature in the radial direction, so a flow vortex can be generated.
8. A Vortex generation device according to any one of the preceding claims, characterised in that the guide blades (18, 202) of the vortex generator (7, 200) in the state without or a slight through-flow, cover regions of a total of 20 to 30%, in particular of about 25%, of the area onto which there is a flow.
9. A Vortex generation device according to any one of the preceding claims, characterised in that the vortex generator (7, 200) comprises four guide blades (18, 202), which in the state without or a slight through-flow, in each case cover a segment of a circle-like region of the area onto which there is a flow extending over an angle of 35° to 45°, in particular about 40°.
10. A Vortex generation device according to any one of the preceding claims, characterised in that the guide blades (18, 202) of the vortex generator (7, 200) can be deformed as a function of the mass flow of the flow medium.
11. A Vortex generation device according to any one of the preceding claims, characterised in that with an increasing mass flow, the guide blades (18, 202) of the vortex generator (7, 200) are deformed counter to their radial curvature, so a small flow vortex is generated.
12. A Vortex generation device according to any one of the preceding claims, characterised in that the segment of a circle-like regions (402, 404, 406, 408) of the area onto which there is a flow covered due to curvature by the guide blades (18, 202) of the vortex generator (7, 200) are reduced with the increasing mass flow.
13. A Vortex generation device according to any one of the preceding claims, characterised in that in the upper and maximum operating range of the compressor or the pump, a maximum deformation of the guide blades (18, 202) of the vortex generator (7, 200) is adjusted.
14. A Vortex generation device according to any one of the preceding claims, characterised in that in the upper and maximum operating range of the compressor or the pump, the guide blades (18, 202) of the vortex generator (7, 200), due to curvature, cover segment of a circle-like regions of a total of 4 to 14%, in particular about 9%, of the area onto which there is a flow.
15. A Vortex generation device according to claim 9, characterised in that the four guide blades (202) of the vortex generator (7, 200), in the upper and maximum operating range of the compressor or the pump, in each case cover a segment of a circle-like region of the area onto which there is a flow, extending over an angle of 1° to 11°, in particular about 6°.

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