Compressor with a ring body

Abstract

A compressor (20) comprises a compressor housing (30), a compressor wheel (40), an annular body (50), and an adjustment device (90, 91), wherein the annular body (50) is arranged on the upstream side (41) of the compressor wheel (40), wherein the annular body (50) has an upstream edge (51), an downstream edge (52), an inner surface (53), and an outer surface (54), wherein the inner surface (53) has a diameter increasing towards the downstream edge (52) in a first section (61) which includes the downstream edge (52), wherein the outer surface (54) has a diameter decreasing towards the downstream edge (52) in a second section (62) which includes the downstream edge (52), wherein the adjustment device (90, 91) is configured to axially adjust the annular body (50) in a region between a first end position (P1) and a second end position (P2) to move.

Description

[0001] DE 10 2017 129 884 B4 discloses an adjustable swirl generating device for a compressor, which has an axially displaceable ring body with an outer cone and with swirl-generating ribs.

[0002] DE 10 2018 110 557 A1 shows a compressor inlet with adjustable inlet geometry, which includes an axially displaceable ring body with an inner cone.

[0003] DE 10 2020 125 983 A1 shows a compressor inlet with variable geometry, comprising an axially displaceable ring body with an inner cone and an outer cone.

[0004] DE 10 2018 122 032 A1 shows an inlet device of a compressor which has an axially displaceable ring body with an inner cone and with an outer cone.

[0005] CN 1 13 574 282 B shows a centrifugal compressor with an impeller and a constriction mechanism, the constriction mechanism having a movable, ring-shaped element in the intake duct.

[0006] DE 10 2014 006 463 A1 discloses an adjustable air supply device with a flow component adjustable in an air duct, which is designed as a hollow body and has a diameter decreasing towards the outflow edge on the outer surface.

[0007] EP 2 593 643 B1 shows an exhaust gas diffuser for a gas turbine.

[0008] DE 10 2014 007 229 A1 shows an adjustable swirl generation device for compressors.

[0009] It is therefore an object of the invention to provide a new compressor with a ring body.

[0010] This problem is solved by the subject matter of claim 1.

[0011] A compressor comprises a compressor housing, a compressor wheel, an annular body, and an adjustment device, wherein the compressor wheel is arranged in the compressor housing and defines an upstream side and an outstream side in the compressor housing, wherein the annular body is arranged on the upstream side of the compressor wheel, wherein the annular body has an upstream edge, an outstream edge, an inner surface, and an outer surface, wherein the inner surface and the outer surface extend from the upstream edge to the outstream edge, wherein the inner surface has a diameter that increases towards the outstream edge in a first section which includes the outstream edge, wherein the outer surface has a diameter that decreases towards the outstream edge in a second section which includes the outstream edge, wherein the adjustment device is configured toto displace the ring body axially in a region between a first end position and a second end position, wherein in the second end position there is an external inflow cross-section between the outer shell surface and the compressor housing, which allows a fluid flow between the inflow edge and the outflow edge along the outer shell surface, and wherein in the first end position the outer shell surface and the compressor housing together form a blockage of the external inflow cross-section. The first and second sections together have resulted in very advantageous compressor characteristics. The inclusion of both sections has led to a beneficial influence on the characteristic curves, both in the first end position, where the ring body creates a fluid blockage, and in the second end position and intermediate positions, where an external fluid flow can occur.

[0012] According to a preferred embodiment, the inner lateral surface in a third section, which includes the inflow edge, has a diameter that decreases towards the outflow edge.

[0013] According to a preferred embodiment, the inner lateral surface in the first section has at least a conical shape with a first conical angle.

[0014] According to a preferred embodiment, the first cone angle lies in at least one predetermined region from a first region group, wherein the first region group comprises: - Range between 4° and 15°, - Range between 5° and 12°, and - Range between 6° and 9°.

[0015] According to a preferred embodiment, the outer lateral surface in the second section has at least a conical shape with a second conical angle.

[0016] According to a preferred embodiment, wherein the second cone angle preferably lies in at least one predetermined region from a second region group, the second region group comprising: - Range between 15° and 35°, - Range between 19° and 28°, and - Range between 21° and 26°.

[0017] According to a preferred embodiment, the first section has a first axial extension, and the ring body has a second axial extension, wherein the quotient of the first axial extension and the second axial extension lies in at least one predetermined region from a third region group, the third region group comprising: - Range between 0.20 and 0.80, - Range between 0.30 and 0.70, and - Range between 0.40 and 0.65.

[0018] According to a preferred embodiment, the second section has a third axial extension, and the ring body has a second axial extension, wherein the quotient of the third axial extension and the second axial extension lies within a predetermined region from a fourth region group, the fourth region group comprising: - Range between 0.20 and 0.70, - Range between 0.30 and 0.60, and - Range between 0.40 and 0.55.

[0019] The second section thus occupies a not insignificant portion of the outer surface area and can have an advantageous effect.

[0020] According to a preferred embodiment, ribs are arranged on the inner surface of the ring body, projecting inwards from the inner surface. At low mass flow rates, backflows with swirl occur. The ribs reduce the swirl, allowing the backflows to be carried along more effectively by the main flow.

[0021] According to a preferred embodiment, the ribs project radially inwards. This allows for a good reduction of twist.

[0022] According to a preferred embodiment, the ribs have a symmetrical airfoil profile. This means the ribs only minimally disrupt the main flow, but are effective against a swirling backflow.

[0023] According to a preferred embodiment, the ribs are designed as asymmetrical guide vanes. Particularly at low mass flow rates, such ribs can advantageously counteract a swirling backflow.

[0024] According to a preferred embodiment, the ribs have a smaller axial extent than the ring body. This reduces the influence of the ribs on the fluid flow over the ring body.

[0025] According to a preferred embodiment, the compressor has a predetermined number R of ribs, wherein the number R lies in at least one numerical range from a group of numerical ranges consisting of: - Number range between 3 and 9, - Number range between 4 and 7, and - Number range between 5 and 6.

[0026] A number of R values ​​in one of these areas has proven advantageous for the characteristic curve.

[0027] According to a preferred embodiment, the outer surface of the casing is in contact with the compressor housing in the first end position. This enables a particularly good seal.

[0028] According to a preferred embodiment, the outer surface of the ring is in contact with the compressor housing in the area of ​​the second section. The conical shape allows for an advantageous seal to be achieved by axial displacement of the ring body.

[0029] According to a preferred embodiment, the compressor housing and the second section define an annular space in the first end position, wherein the annular space is open in the axial direction towards the compressor wheel and decreases in its radial extent, at least section by section, in the axial direction away from the compressor wheel. This allows the annular space to act as an effective barrier against backflow at low mass flow rates.

[0030] According to a preferred embodiment, the adjusting device has a web via which it is connected to the ring body, the web having a symmetrical wing profile. Several webs may also be provided. Such a web design has led to improved efficiency, particularly at high mass flow rates.

[0031] Further details and advantageous embodiments of the invention will become apparent from the exemplary embodiments described below and illustrated in the drawings, which are in no way to be understood as limiting the invention, as well as from the dependent claims. It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the present invention. It shows: Fig. 1 in a longitudinal section a compressor with a ring body in a front position, Fig. 2 a longitudinal section the compressor of Fig. 1 with the ring body in a rear position, Fig. 3 in a longitudinal section the compressor of Fig. 1 in a further embodiment with a rib, Fig. 4 in a cross-section through the rib the compressor of Fig. 3, Fig. 5 in a longitudinal section the compressor of Fig. 1 in a further embodiment with a rib, Fig. 6 in a cross-section through the rib the compressor of Fig. 5, and Fig. 7 in a cross-section a web of an adjusting device.

[0032] In the following, identical or similarly functioning parts are designated with the same reference symbols and are usually described only once. The description builds upon itself across figures to avoid unnecessary repetition.

[0033] Fig. Figure 1 shows a compressor 20 with a compressor housing 30, a compressor wheel 40, a ring body 50 and an adjustment device 90, 91. Such compressors 20 are used, for example, in vehicles as turbochargers.

[0034] The compressor wheel 40 is arranged in the compressor housing 30 and defines an inlet side 41 and an outlet side 42 in the compressor housing 30.

[0035] The ring body 50 is arranged on the upstream side 41 of the compressor wheel 40.

[0036] The ring body 50 has an inflow edge 51, an outflow edge 52, an inner lateral surface 53 and an outer lateral surface 54.

[0037] The inner surface 53 and the outer surface 54 extend from the inflow edge 51 to the outflow edge (52).

[0038] The inflow edge 51 is preferably rounded and can also be referred to as a nose.

[0039] The inner surface 53 has a diameter that increases towards the outflow edge 52 in a first section 61, which includes the outflow edge 52.

[0040] The outer surface 54 has a diameter that decreases towards the outflow edge 52 in a second section 62, which includes the outflow edge 52.

[0041] The inner surface 53 has a diameter decreasing towards the outflow edge 52 in a third section 63, which includes the inflow edge 51.

[0042] The adjusting device 90, 91 is designed to axially adjust the ring body 50 in a range between a first end position P1 (cf. Fig. 2) and to move to a second end position P2. For this purpose, the bridge 91, via which the ring body 50 is connected to the adjusting device 90, is moved axially.

[0043] In the second end position P2, there is an external inflow cross-section between the outer shell surface 54 and the compressor housing 30, which allows a fluid flow 72 between the inflow edge 51 and the outflow edge 52 along the outer shell surface 54.

[0044] Additionally, the main flow 71 is shown.

[0045] Fig. Figure 2 shows the compressor 20 of Fig. 1, where the ring body 50 is in the first end position P1.

[0046] In the first end position P1, the outer surface 54 and the compressor housing 30 together form a blockage of the outer inflow cross-section. Therefore, from a fluid dynamics perspective, a continuous fluid flow 72 along the outer surface 54 is not possible.

[0047] The inner surface 53 preferably has a conical shape with a first cone angle W1, at least partially in the first section 61. In the exemplary embodiment, the advantageous cone angle W1 is 7°.

[0048] The first cone angle W1 is preferably located in at least one predefined region from a first region group, wherein the first region group comprises: - Range between 4° and 15°, - Range between 5° and 12°, and - Range between 6° and 9°.

[0049] The outer surface 54 preferably has a conical shape with a second cone angle W2, at least partially in the second section 62. In the exemplary embodiment, the advantageous cone angle W2 is 23.5°.

[0050] The second cone angle W2 is preferably located in at least one predefined region from a second region group, wherein the second region group comprises: - Range between 15° and 35°, - Range between 19° and 28°, and - Range between 21° and 26°.

[0051] The first section 61 preferably has a first axial extension 101, and the ring body 50 has a second axial extension 102, wherein the quotient of the first axial extension 101 and the second axial extension 102 lies in at least one predetermined region from a third region group, wherein the third region group comprises: - Range between 0.20 and 0.80, - Range between 0.30 and 0.70, and - Range between 0.40 and 0.65.

[0052] The first section thus occupies 20% to 80% of the total axial extent.

[0053] The second section 62 preferably has a third axial extension 103, and the ring body 50 has a second axial extension 102, wherein the quotient of the third axial extension 103 and the second axial extension 102 lies within a predetermined region of a fourth region group, the fourth region group comprising: - Range between 0.20 and 0.70, - Range between 0.30 and 0.60, and - Range between 0.40 and 0.55.

[0054] The second axial extent 102 is 17.54 mm in the exemplary embodiment. It is selected depending on the overall size of the compressor 20.

[0055] In the first end position P1, the compressor housing 30 and the second section 62 define an annular space 73, wherein the annular space 73 is open in the axial direction towards the compressor wheel 40 and decreases at least section by section in its radial extent 108 away from the compressor wheel 40 in the axial direction.

[0056] Fig. Figure 3 shows a compressor 20 accordingly Fig. 1.

[0057] Additional ribs 58 are arranged on the inner surface 53 of the ring body 50. The ribs 58 project inwards from the inner surface 53.

[0058] In the exemplary embodiment, five ribs 58 are provided. The compressor 20 preferably has a predetermined number R of ribs, wherein the number R lies in at least one numerical range from a group of numerical ranges consisting of: - Number range between 3 and 9, - Number range between 4 and 7, and - Number range between 5 and 6.

[0059] Since a shaft 42 of the compressor wheel 40 is provided in the axial area of ​​the ribs 58, the ribs 58 do not extend to the center, but have a distance from the compressor wheel 40.

[0060] Preferably, the ribs 58 project radially inwards.

[0061] The ribs 58 preferably have a smaller axial extent 104 than the ring body 50. This results in less disturbance to the flow at the ring body 50.

[0062] The outer surface 54 is preferably in contact with the compressor housing 30 in the first end position P1.

[0063] Particularly preferably, the outer surface 54 is in contact with the compressor housing 30 in the area of ​​the second section 62. This is advantageous because the diameter of the second section decreases towards the fan wheel 40, and an axial displacement of the ring body 50 thus leads to a seal against the compressor housing 30.

[0064] Fig. Figure 4 shows one of the ribs 58 of Fig. 3 in cross-section.

[0065] In the exemplary embodiment, the ribs 58 have a symmetrical wing profile.

[0066] Fig. 5 shows a compressor 20 accordingly Fig. 1

[0067] Additional ribs 59 are arranged on the inner surface 53 of the ring body 50. The ribs 58 project inwards from the inner surface 53.

[0068] Ribs 59 are designed as asymmetrical guide vanes. They have an asymmetrical airfoil profile.

[0069] Fig. Figure 6 shows a preferred profile of the bridge 91 of the adjusting device 90. Fig. 1. The Steg 91 has a symmetrical airfoil. This has proven to be very advantageous compared to an original airfoil, which was rectangular with rounded edges.

[0070] Fig.Figure 7 shows a profile of a preferred embodiment of the bridge 91, which runs between the adjusting device 90, 91 and the ring body 50.

[0071] The bridge has a symmetrical airfoil profile, and this has proven particularly advantageous for efficiency at high mass flow rates.

[0072] The following section explains the operation of the compressor described in the preceding figures.

[0073] The ring body can be freely moved back and forth between the first, closed position P1 and the second, fully open position P2 by means of the adjusting device 90, 91. The displacement preferably occurs depending on the mass flow rate.

[0074] In the open position P2 or in an intermediate position, the outer blade cross-sectional flow is influenced via the conical flow guide with angles W1 and W2 and depending on the distance from the inlet of the compressor wheel 40.

[0075] To avoid losses at the compressor cut-off limit (right side in the compressor map), it is advantageous to shift the ring body 50 so far that the entire flow cross-sectional area is uniformly supplied with air.

[0076] In the closed first position P1, the outer inflow cross-section is blocked. Here, the second section 62 allows for flow deflection of the backflow that occurs at low mass flow rates. This expands the usability of the compressor 20 at low mass flow rates or towards the surge line.

[0077] At even lower mass flow rates, the backflow from the outer second section 62 is no longer completely impeded. However, it has been shown that the backflow is deflected by the opposing main flow 71. This increases the mass flow rate to the compressor. The inner first section 61 forms a flow obstruction for the backflow. The flow obstruction is greater the further the backflow is from the compressor wheel.

[0078] The first section 61 thus additionally forms an aerodynamic flow barrier, further preventing the backflow from exiting the wheel area and resulting in an even greater expansion of the characteristic map with a surge line shifted further to the left.

[0079] The provision of ribs 58 and 59 has proven very advantageous, as it reduces the swirl of the swirling backflow at low mass flow rates. By breaking up the swirl motion, the backflow can be more easily carried along by the main flow 71. This shifts the surge line further to the left, towards lower mass flow rates.

[0080] In a fluid dynamic simulation, the surge line for a compressor without the ring body was 0.055 kg / s, for a compressor 20 with ring body 50 (position P1) it was 0.030 kg / s, and for a compressor 20 with ring body (position P1) and five fins 58 it was 0.009 kg / s. The simulation was performed at a rotational speed of 60,000 rpm. -1 carried out.

[0081] In another simulation with a rotational speed of 136,000 rpm -1The pumping limit for a compressor without the ring body was 0.160 kg / s, for a compressor 20 with ring body 50 (position P1) it was 0.065 kg / s and for a compressor 20 with ring body 50 and with five ribs 58 it was 0.042 kg / s.

[0082] The maximum efficiency in the characteristic curve, plotted against the mass flow rate, has decreased by 0.4% to 1.0% due to the inclusion of the ring body. However, this disadvantage is offset by a significantly larger operating range of the compressor 20.

[0083] Naturally, various variations and modifications are possible within the scope of the present invention.

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