Compressor stabilizer channel

Abstract

The invention relates to a stabilizer channel (10), in particular a radial compressor or an oblique compressor, having an annular stabilizer chamber (12), which surrounds a main flow channel (13) in the intake area of ​​a compressor wheel (21) and is delimited from the main flow channel (13) by an annular web (14). The annular stabilizer chamber (12) is bladeless and is connected to the main flow channel (13) via a downstream inlet channel (15) and an upstream outlet channel (16). A plurality of flow guide elements (17) are arranged in the downstream inlet channel (15). The downstream inlet channel (15) is arranged between an upstream part (142) of the annular web (14) and a downstream part (143) of the annular web 14. The invention also relates to a compressor, in particular a radial compressor or an oblique compressor, comprising a stabilizer channel (10) according to the invention, and also to a turbocharger comprising the compressor.

Description

Technical Field

[0001] The present invention relates to the field of compressors, in particular to radial compressors and oblique compressors. In particular, the present invention relates to a stabilizer channel at the compressor inlet for enhancing the mapping width and characteristic curve gradient of the compressor stage. Background Art

[0002] Exhaust gas turbochargers are used to improve the performance of internal combustion engines, especially reciprocating piston engines. Exhaust gas turbochargers usually have a radial or oblique compressor and a radial or axial turbine.

[0003] The practical operating range of radial and oblique compressors is limited to smaller mass flows by the surge boundary / flow instability: When the compressor is throttled, the angle of incidence progressively worsens until flow separation and pumping occurs. As the flow Mach number increases, the range of permissible angles of incidence, in which flow still occurs, decreases. That is, in the case of stages with high pressure ratios and / or high suction capacity, the map width tends to decrease.

[0004] As a measure for stabilizing the characteristic curve, a bypass in the form of an annular cavity can be provided in the compressor housing on the impeller profile of the compressor impeller parallel to the inlet channel. Such a bypass is also called a stabilizer chamber or a recirculator. By using a recirculator, the mass flow at the compressor impeller inlet can be artificially increased close to the surge boundary. A part of the mass flow is branched off from the compressor impeller to a side chamber (bypass). This mass flow has a high component (in the direction of rotation of the impeller - co-swirl). This co-swirl leads to a reduced operating rate of the compressor and thus to a flat characteristic curve close to the surge boundary.

[0005] In applications with pressure pulsations (e.g. caused by valve movement in supercharged internal combustion engines), a flat characteristic curve close to the surge boundary may lead to unintentional pumping. For this reason, it is required to provide a minimum pressure increase between the operating point and the surge boundary point on the operating speed curve. In the case of stages with high pressure ratios and conventional bypass / stabilizer channels, this requirement can hardly be met - due to the flat work coefficient distribution at high power and constant mass flow. Summary of the invention

[0006] The object of the present invention is to provide a stabilizer channel for a compressor, in particular a radial compressor or an oblique compressor, which is improved with respect to at least one of the disadvantages known from the prior art. The object of the present invention is also to provide an improved compressor and an improved turbocharger.

[0007] To achieve the above object, a stabilizer channel of a compressor, in particular a stabilizer channel of a radial compressor or an oblique compressor, is provided according to independent claim 1. A compressor having a stabilizer channel according to the embodiments described herein and a turbocharger having such a compressor are also provided.

[0008] Further aspects, advantages and features of the invention can be found in the dependent claims, the description and the drawings.

[0009] According to one aspect of the invention, a stabilizer channel of a compressor is provided, in particular a stabilizer channel of a radial compressor or an oblique compressor. The stabilizer channel comprises an annular stabilizer chamber which surrounds a main flow channel in an intake region of a compressor impeller and is bounded relative to the main flow channel by an annular web. The annular stabilizer chamber has no blades and is connected by a downstream inlet channel and an upstream outlet opening. A plurality of flow guide elements are arranged in the downstream inlet channel. The downstream inlet channel is arranged between an upstream portion of the annular web and a downstream portion of the annular web.

[0010] Thus, a stabilizer channel is advantageously provided, which allows an enhancement of the mapping width and characteristic curve gradient of the compressor stage. In addition, by means of a stabilizer channel according to the invention having a flow guide element in the downstream inlet channel, a stabilizer channel can be provided which is superior to conventional stabilizers known in the prior art in terms of element integration, containment properties and production costs.

[0011] According to a second aspect of the invention, a compressor, in particular a radial compressor or an oblique compressor, is provided, comprising a compressor wheel and a stabilizer channel according to one of the embodiments described herein. Thus, a compressor with an enhanced mapping width and characteristic curve gradient can advantageously be provided.

[0012] A third aspect of the invention relates to a turbocharger having a compressor according to one of the embodiments described herein, thereby advantageously providing a turbocharger that is improved over the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The invention will be explained below by means of exemplary embodiments, which are shown in the drawings and from which further advantages and modifications derive. In the drawings:

[0014] Figure 1 is a schematic diagram of a stabilizer channel of the prior art;

[0015] Figure 2 is a schematic diagram of a stabilizer channel according to an embodiment described herein;

[0016] Figure 3a and 3bis a schematic diagram of a stabilizer channel according to other embodiments described herein;

[0017] Figure 4a is a schematic diagram of a stabilizer channel according to another embodiment described herein;

[0018] Figure 4b yes Figure 4a Detailed enlargement of the image;

[0019] Figure 5 and Figure 6 is a schematic diagram of an inlet channel of a stabilizer channel according to other embodiments described herein;

[0020] Figure 7 is a schematic diagram of the structure of the flow guide element generating a counter-rotating vortex when flow passes through; and

[0021] Figure 8 is a schematic diagram of an arrangement of a flow guide element for reducing flow eddies when a flow passes through the guide element. DETAILED DESCRIPTION

[0022] Figure 1 is a schematic diagram of a stabilizer channel 10 according to the prior art. In particular, Figure 1 A section through the housing of a radial compressor, for example for compressing air in an exhaust gas turbocharger, is shown along the rotation axis 11 of the compressor impeller 21. A stabilizer chamber 12 is arranged in the compressor housing 5. The stabilizer chamber 12 is connected to the main flow channel 13 via an inlet channel 15 and an outlet opening 16. The stabilizer chamber 12 is separated from the main flow channel 13 by an annular web 14. A fixing rib 121 connecting the annular web 14 to the compressor housing is arranged in the stabilizer chamber 12.

[0023] Will refer to Figures 2 to 8 A stabilizer passage of a compressor according to the present disclosure is described. The compressor may be a radial compressor or a diagonal compressor.

[0024] According to one embodiment, which can be combined with other embodiments described herein, the stabilizer channel 10 comprises an annular stabilizer chamber 12, which surrounds a main flow channel 13 in the intake area of ​​the compressor impeller 21. In other words, the stabilizer channel 10 is usually arranged at the compressor inlet. It should be noted in this context that in the present disclosure, a "stabilizer channel" is to be understood as a channel in particular in the compressor inlet, which is configured to enhance the mapping width of the compressor stage. For example, the stabilizer channel 10 can be a recirculation channel.

[0025] The annular stabilizer chamber 12 is separated from the main flow channel 13 by an annular web 14. Figure 2As shown in the example. The annular stabilizer chamber 12 has no blades. In other words, no blades, in particular no guide vanes, are arranged in the annular stabilizer chamber 12. In particular, the annular stabilizer chamber 12 may also be without pillars. In other words, the annular stabilizer chamber 12 may be without blades and pillars, so that neither guide vanes nor pillars are present in the annular stabilizer chamber 12. In addition, the annular stabilizer chamber 12 is connected to the main flow channel 13 via a downstream inlet channel 15 and an upstream outlet opening 16. The annular stabilizer chamber 12 may be rotationally symmetrical.

[0026] like Figure 2 Schematically, a plurality of flow guide elements 17 are arranged in the downstream inlet channel 15. Typically, the plurality of flow guide elements 17 are arranged circumferentially around the central axis 11 of the main flow channel 13. In particular, the plurality of flow guide elements 17 may be arranged concentrically around the central axis 11 of the main flow channel 13. It should also be noted that the flow guide elements 17 may be formed to be flush with the inlet opening 15A on the main flow channel side of the inlet channel 15 and / or flush with the outlet opening 15B on the stabilizer chamber side of the inlet channel 15. Alternatively, as described by Figure 2 As shown in the example in FIG. 1 , the guide element 17 may be spaced apart from the inlet opening 15A on the main flow channel side of the inlet channel 15 and / or the outlet opening 15B on the stabilizer chamber side of the inlet channel. The downstream inlet channel 15 is arranged between the upstream portion 141 of the annular web 14 and the downstream portion 142 of the annular web 14.

[0027] In this disclosure, the term "inlet channel" should be understood to mean a channel that serves as a flow inlet channel into the stabilizer chamber. Figure 2 As shown in the example in FIG. 1 , the inlet passage 15 includes an inlet opening 15A on the main flow passage side and an outlet opening 15B on the stabilizer chamber side.

[0028] In the present disclosure, the terms "downstream" and "upstream" refer to the main flow in the main flow channel in the intake area of ​​the compressor impeller. For better understanding, the main flow direction 1 is marked in the figure. According to an example, Figure 2 As shown, the inlet channel 15 of the stabilizer chamber can be arranged downstream relative to the inlet edge 24 of the compressor wheel 21. The outlet opening 16 of the stabilizer chamber is usually arranged upstream of the inlet edge 24 of the compressor wheel 21.

[0029] According to one embodiment, which can be combined with other embodiments described herein, a plurality of flow guide elements 17 are configured and arranged to provide a deflection grid through which flow can flow. For example, the deflection grid can be configured and arranged to provide a deflection grid through which flow can flow substantially radially. In the present invention, the expression "substantially radially" is understood to mean that α=±45° or less than 45°, in particular α=±25° or less than 25°, relative to the radial direction r. Figure 2As shown in the example in FIG. 1 , the radial direction r extends perpendicular to the central axis 11. According to one example, "substantially radially" should be understood to mean ±10° or less than 10° relative to the radial direction r. For better understanding, Figure 5 By way of example, an inlet channel 15 is shown which is inclined at an angle α which falls within the above-mentioned definition of "substantially radial". The angle α lies in the xr plane.

[0030] like Figures 2 to 5 According to one embodiment, which can be combined with other embodiments described herein, the downstream inlet channel 15 extends substantially in a radial direction.

[0031] According to alternative embodiments that may be combined with other embodiments described herein, such as Figure 6 As shown in the example of FIG. 1 , a plurality of flow guide elements 17 are configured and arranged to provide a deflection grid through which a substantially axial flow can pass. In the present invention, the expression “substantially axially” should be understood to mean an angle range of ±45° or less than 45°, in particular ±25° or less than 25°, relative to the axial direction. Figure 2 As shown in the example in FIG. 1 , the axial direction x extends along the central axis 11. According to one example, “substantially axially” should be understood to mean that the angle range relative to the x-axis is ±10° or less than 10°. For example, the configuration of the inlet channel 15 of the stabilizer chamber and the Figure 6 The arrangement of the guide elements 17 provides a deflection grid through which a substantially axial flow can flow.

[0032] According to one embodiment that can be combined with other embodiments described herein, Figure 6 As shown in the example of FIG, the downstream inlet passage 15 comprises a substantially radially extending part 15C and a substantially axially extending part 15D. There is generally a curved transition region 15F between the substantially radially extending part 15C and the substantially axially extending part 15D.

[0033] According to one embodiment, which can be combined with other embodiments described herein, the upstream portion 141 of the annular web 14 comprises a first protrusion 18 extending substantially in the radial direction. Figure 4a , 4b and Figure 5 As shown in the example in FIG. 1 , the downstream portion 142 of the annular web 14 may also include a second protrusion 19A extending substantially in the radial direction. Alternatively, as Figure 6 As shown in the example in FIG. 1 , the downstream portion 142 of the annular web 14 may include a second protrusion 19B extending substantially in the axial direction.

[0034] According to one embodiment that can be combined with other embodiments described herein, Figure 2As shown in the example in FIG. 1 , the stabilizer channel 10 is an integral part of the compressor housing. Figure 3a As shown in the example of FIG. 1 , the stabilizer channel 10 can be integrated into an insert component 22 that can be installed in the intake area of ​​the compressor. According to other examples, such as Figure 3b As shown in the example in FIG. 1 , the stabilizer passage may be part of the inner compressor housing 20A, wherein Figure 3b 2 shows a compressor 20 having an inner compressor housing 20A and an outer compressor housing 20B.

[0035] According to one embodiment, which can be combined with other embodiments described herein, the upstream portion 141 of the annular web 14 and the downstream portion 142 of the annular web 14 are connected by a plurality of flow-guiding elements 17, for example by screw means. The screw connections can extend through the flow-guiding elements 17. The screw connections can also be produced in a different way, that is, they do not extend through the flow-guiding elements 17. Alternatively or additionally, other types of connections can also be used, such as shrinking or clamping.

[0036] According to one embodiment, which can be combined with other embodiments described herein, the plurality of flow guide elements 17 are in the form of separate elements. According to an alternative embodiment, which can be combined with other embodiments described herein, the plurality of flow guide elements 17 are integrally (integrally) formed with the upstream portion 141 of the annular web 14 and / or integrally (integrally) formed with the downstream portion 142 of the annular web 14.

[0037] According to one embodiment, which can be combined with other embodiments described herein, the downstream portion 142 of the annular web 14 has a centering shoulder 143. Alternatively or additionally, the upstream portion 141 of the annular web 14 can have a centering shoulder (not explicitly shown). The centering shoulder can be cylindrical or conical.

[0038] According to one embodiment, which can be combined with other embodiments described herein, the plurality of flow guide elements 17 each have a centering seat configured to arrange the flow guide element 17 circumferentially, in particular concentrically, in the inlet channel 15 around the central axis 11 of the main flow channel 13 .

[0039] According to one embodiment that can be combined with other embodiments described herein, at least one of the multiple guide elements 17, in particular at least half or all, is formed by a Curtis-type vane profile. In particular, at least one of the multiple guide elements 17, in particular at least half or all, can be a prismatic Curtis-type vane. Typically, the guide element 17 is in the form of a radially deflected vane. Forming a guide element from a Curtis-type vane profile, in particular a guide element in the form of a prismatic Curtis-type vane, has the advantage that it can be made relatively thick, so that a better connection of the upstream part 141 of the annular web 14 to the downstream part 142 of the annular web 14 by such a guide element is possible, for example by a threaded connection or other suitable type of connection.

[0040] According to one embodiment that can be combined with other embodiments described herein, Figure 4a and Figure 4b As shown in the example of FIG. 1 , the guide element 17 is arranged in the outflow region of the inlet channel 15 of the stabilizer chamber. The outflow region of the inlet channel 15 is to be understood as the region of the inlet channel 15 on the side of the outlet opening 15B on the stabilizer chamber side. The outflow region can, for example, extend over half of the inlet channel length L or less than half. For a better understanding, Figure 4b 1 shows by way of example an outflow region 15E of an inlet channel 15. The arrangement of the flow guide element 17 in the outflow region of the inlet channel 15 can have a favorable influence on the flow velocity and the excitation of blade vibrations.

[0041] According to one embodiment which can be combined with other embodiments described herein, the flow guide elements 17 each have an inflow-side end 17A and an outflow-side end 17B, wherein the respective outflow-side end 17B of the flow guide element 17 is inclined in the circumferential direction relative to the respective inflow-side end 17A of the flow guide element 17, such as Figure 8 As shown by the arrow in the example, between the inflow side end 17A and the outflow side end 17B, the vortex becomes smaller as the flow passes along the arrow.

[0042] Alternatively, each outflow-side end portion 17B of the flow guide element 17 may be inclined in the circumferential direction relative to each inflow-side end portion 17A of the flow guide element 17, so that a counter-swirl is generated between the inflow-side end portion 17A and the outflow-side end portion 17B. Figure 7 For better understanding, the direction of rotation of the compressor impeller is shown in Figure 2. Figure 7 and Figure 8 The rotation of the compressor wheel results in a swirling flow.

[0043] According to a second aspect of the disclosure, a compressor is provided, in particular a radial compressor or an oblique compressor, comprising a compressor impeller 21 and a stabilizer channel 10 according to one of the embodiments described herein. According to one embodiment, which can be combined with other embodiments described herein, the compressor impeller 21 comprises N1 compressor impeller blades 23 in the region of the inlet opening 15A. The number N2 of guide elements in the downstream inlet channel 15 is N2 ≥ 1.5 × N1. This is advantageous in reducing the generation of noise and vibrations during operation of the compressor.

[0044] A third aspect of the invention relates to a turbocharger having a compressor according to one of the embodiments described herein, thereby advantageously providing a turbocharger that is improved over the prior art.

[0045] Description of Reference Numerals

[0046] 1 Main flow direction

[0047] 2 Rotation direction of the compressor impeller

[0048] 5 Compressor housing

[0049] 10 Stabilizer channels

[0050] 11 Central axis / rotation axis of the compressor impeller

[0051] 12 Annular stabilizer chamber

[0052] 121 Pillar

[0053] 13 Main flow directions

[0054] 14 Annular web

[0055] 141 Upstream part of annular web

[0056] 142 Downstream portion of annular web

[0057] 143 Centering Shoulder

[0058] 15 Entrance to the stabilizer room

[0059] 15A Inlet opening on the main channel side

[0060] 15B Outlet opening on the stabilizer chamber side

[0061] 15C Substantially radially extending component

[0062] 15D Part extending substantially axially

[0063] 15E Outflow area of ​​the inlet channel

[0064] 15F Transition Area

[0065] 16 Outlet opening of the stabilizer chamber

[0066] 17. Flow guide element

[0067] 17A Inflow-side end of flow guide element

[0068] 17B Outflow-side end of flow guide element

[0069] 18 A first protrusion extending substantially in the radial direction

[0070] 19A A second protrusion extending substantially in the radial direction

[0071] 19B A second protrusion extending substantially in the axial direction

[0072] 20 Compressor

[0073] 20A Internal compressor housing

[0074] 20B External compressor housing

[0075] 21 Compressor impeller

[0076] 22 Inserting components

[0077] 23 Compressor impeller blades

[0078] 24 Inlet edge of compressor impeller

[0079] r Radial direction

[0080] x-axis direction

[0081] L Length of the inlet channel

[0082] α Angle in the xr plane to explain "substantially radial"

Claims

1. A stabilizer channel (10) of a compressor, the stabilizer channel having an annular stabilizer chamber (12) which surrounds a main flow channel (13) in the intake region of a compressor impeller (21) and is delimited relative to the main flow channel (13) by an annular web (14), wherein the annular stabilizer chamber (12) is free of blades and is connected via a downstream inlet channel (15) and an upstream outlet opening (16), wherein: A plurality of flow guide elements (17) are arranged in a downstream inlet channel (15), and wherein the downstream inlet channel (15) is arranged between an upstream portion (141) of an annular web (14) and a downstream portion (142) of the annular web (14), wherein one of the following (A) and (B) applies: (A) the upstream portion (141) of the annular web (14) includes a first protrusion (18) extending substantially in a radial direction, and the downstream portion (142) of the annular web (14) includes a second protrusion (19A) extending substantially in a radial direction; and (B) the downstream portion (142) of the annular web (14) includes a second protrusion (19B) extending substantially in an axial direction.

2. The stabilizer channel according to claim 1, wherein: The plurality of flow guide elements (17) are configured and arranged to provide a deflection grid through which flow can pass.

3. The stabilizer channel according to claim 1, wherein: The plurality of flow guide elements (17) are configured and arranged to provide a deflection grid through which a substantially radial or substantially axial flow can pass.

4. The stabilizer channel according to claim 1, wherein: The downstream inlet channel (15) extends substantially in a radial direction, or wherein the downstream inlet channel (15) comprises a substantially radially extending part (15C) and a substantially axially extending part (15D).

5. The stabilizer channel according to any one of claims 1 to 3, wherein: The plurality of flow guide elements (17) are arranged circumferentially around a central axis (11) of the main flow channel (13).

6. The stabilizer channel according to any one of claims 1 to 3, wherein: The stabilizer channel is a component of the compressor housing, or the stabilizer channel is integrated into an insert component (22) which can be installed in the intake area of ​​the compressor, or the stabilizer channel is part of an inner compressor housing (20A).

7. The stabilizer channel according to any one of claims 1 to 3, wherein: The upstream portion (141) of the annular web (14) and the downstream portion (142) of the annular web (14) are connected via the plurality of flow guide elements (17).

8. The stabilizer channel according to any one of claims 1 to 3, wherein: The plurality of flow guiding elements (17) are in the form of separate components.

9. The stabilizer channel according to any one of claims 1 to 3, wherein: The plurality of flow guide elements (17) are integrally formed with at least one of an upstream portion (141) of the annular web (14) and a downstream portion (142) of the annular web (14).

10. The stabilizer channel according to any one of claims 1 to 3, wherein: At least one of the downstream portion (142) of the annular web (14) and the upstream portion (141) of the annular web (14) has a centering shoulder (143).

11. The stabilizer channel according to any one of claims 1 to 3, wherein: The plurality of flow guide elements (17) each have a centering seat configured to arrange the flow guide element (17) in the inlet channel (15) circumferentially around a central axis (11) of the main flow channel (13).

12. The stabilizer channel according to any one of claims 1 to 3, wherein: At least one of the plurality of flow guide elements (17) is formed of at least one of a Curtis-type blade profile and a prismatic blade profile.

13. The stabilizer channel according to any one of claims 1 to 3, wherein: At least half of the plurality of flow guide elements (17) are formed of at least one of a Curtiss-type blade profile and a prismatic blade profile.

14. The stabilizer channel according to any one of claims 1 to 3, wherein: The plurality of flow guide elements (17) are arranged in an outflow region (15E) of an inlet channel (15) of the stabilizer chamber.

15. The stabilizer channel according to any one of claims 1 to 3, wherein: The flow guide elements (17) each have an inflow side end (17A) and an outflow side end (17B), wherein the outflow side end of the flow guide element (17) is inclined in the circumferential direction relative to the inflow side end (17A) of the flow guide element (17) so as to reduce vortex or generate counter-vortex when flow passes through them.

16. The stabilizer channel according to any one of claims 1 to 3, wherein: The compressor is a radial compressor or an oblique compressor.

17. A stabilizer channel according to any one of claims 1 to 3, wherein: The plurality of flow guide elements (17) are arranged circumferentially and concentrically around a central axis (11) of the main flow channel (13).

18. A stabilizer channel according to any one of claims 1 to 3, wherein: The upstream portion (141) of the annular web (14) and the downstream portion (142) of the annular web (14) are threadedly connected via the plurality of flow guide elements (17).

19. A stabilizer channel according to any one of claims 1 to 3, wherein: At least one of the downstream portion (142) of the annular web (14) and the upstream portion (141) of the annular web (14) has a cylindrical or conical centering shoulder (143).

20. A stabilizer channel according to any one of claims 1 to 3, wherein: The plurality of flow guide elements (17) each have a centering seat configured to arrange the flow guide element (17) in the inlet channel (15) circumferentially and concentrically around a central axis (11) of the main flow channel (13).

21. A stabilizer channel according to any one of claims 1 to 3, wherein: The inlet passage (15) serves as a flow inlet passage into the annular stabilizer chamber (12).

22. A stabilizer channel according to any one of claims 1 to 3, wherein: At least one of the plurality of flow guide elements (17) is formed by a Curtis-type blade.

23. A stabilizer channel according to any one of claims 1 to 3, wherein: At least half of the plurality of flow guide elements (17) are formed by Curtis-type blades.

24. A compressor (20) having a compressor impeller (21) and a stabilizer duct (10) according to any one of claims 1 to 23.

25. The compressor according to claim 24, wherein: In the region of an inlet opening (15A) of the inlet channel (15), the compressor wheel (21) comprises N1 compressor wheel blades (23) and N2 flow guide elements (17), N2 ≥ 1.5N1.

26. The compressor of claim 24, wherein: The compressor is a radial compressor or an oblique compressor.

27. A turbocharger having a compressor (20) according to any one of claims 24 to 26.

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