DE102019101602A1 - Fluid machine - Google Patents

Abstract

Fluid flow machine, with a diffuser (12) provided downstream of an impeller (11), delimited by an inner shell (13) and an outer shell (14), with a collecting space (15) provided downstream of the diffuser (12), the diffuser ( 12) opens in the radial direction into the collecting space (15) with an orifice cross section (16), with an outlet-side end (17) of the outer shell (14) of the diffuser (12), which adjoins the collecting space (15) or into the collecting space ( 15) protrudes. The outlet-side end (17) of the outer shell (14) has a surface section (18) which faces the collecting space (15) and which extends in the radial direction in cross section. The surface section (18) of the outlet-side end (17) of the outer shell (14), which extends in the radial direction and faces the collecting space (15), goes into a surface section (20) facing the diffuser (12) with a cross-sectionally contoured surface section (19) ) of the outlet end (17) of the outer shell (14).

Description

The invention relates to a turbomachine according to the preamble of claim 1.

The basic structure of a turbocharger is known to those skilled in the art. A turbocharger has a turbine in which a first medium is expanded. Furthermore, a turbocharger has a compressor in which a second medium is compressed, using the energy obtained in the turbine when the first medium is expanded. The turbine of the turbocharger has a turbine housing and a turbine rotor. The turbocharger's compressor has a compressor housing and a compressor rotor. A bearing housing is positioned between the turbine housing of the turbine and the compressor housing of the compressor, the bearing housing being connected on the one hand to the turbine housing and on the other hand to the compressor housing. A shaft is mounted in the bearing housing, via which the turbine rotor is coupled to the compressor rotor.

From the DE 101 37 899 C1 is known as a turbine of a turbocharger designed as an axial turbine, which has a diffuser that connects to the turbine impeller and is delimited by an inner shell and an outer shell. When viewed in the flow direction of the exhaust gas, a collecting space adjoins the diffuser, the diffuser merging in the radial direction into the collecting space with an outlet cross section or opening into the collecting space. An exhaust gas flow line leads away from the collecting space. An edge is formed on an outlet-side or outlet-side end of the outer shell of the diffuser, which edge projects into or adjoins the collecting space, specifically adjacent to the cross-section of the mouth of the diffuser.

The flow from the diffuser should pass into the collecting space as undisturbed as possible. This causes difficulties in turbomachines known from practice, in particular flow separations can occur in the region of the outlet-side end of the outer shell of the diffuser, which protrudes into the collecting space or adjoins the collecting space. This is a disadvantage.

There is therefore a need for a turbomachine in which a flow can flow from a diffuser undisturbed into a collecting space adjacent to the diffuser.

Proceeding from this, the object of the invention is to create a novel flow machine. This object is achieved by a turbomachine according to claim 1.

According to the invention, the outlet-side end of the outer shell has a surface section which faces the collecting space and which extends in the radial direction in cross section. The surface section of the outlet-side end of the outer shell which extends in the radial direction and faces the collecting space merges with a surface section which is contoured in the form of a circular segment in cross section into a surface section of the outlet-side end of the outer shell which faces the diffuser.

The configuration of the turbomachine according to the invention at the outlet-side end of the outer shell of the diffuser can ensure that a flow from the diffuser can flow undisturbed into the collecting space. In particular, flow separation and turbulence can be avoided. This minimizes flow losses and increases efficiency.

Preferably, the surface section contoured in the shape of a segment merges tangentially into the surface section facing the collecting space and / or into the surface section facing the diffuser. Such a contouring of the outer shell of the diffuser at the outlet end is particularly preferred in order to minimize flow losses.

According to an advantageous development, the surface section of the outlet-side end of the outer shell of the diffuser which extends in the radial direction has a length L in the radial direction, for which the following applies: 0.1 * X≤L≤X, where X is the dimension of the mouth cross section of the diffuser in the axial direction is. According to a further advantageous development, the area segment of the outlet-side end of the outer shell of the diffuser which is contoured in the shape of a segment of a circle has a radius R for which: 0.1 * X≤R≤X, where X is the dimension of the mouth cross section of the diffuser in the axial direction. When one or preferably both of these conditions are met, the flow from the diffuser can pass into the collecting space in a particularly advantageous manner, in order to minimize flow losses.

The turbomachine is preferably an axial turbine, particularly preferably a turbocharger. The invention is particularly advantageous when used on a turbomachine designed as an axial turbine of a turbocharger.

• 1 einen schematisierten, ausschnittweisen Querschnitt durch eine erfindungsgemäße Strömungsmaschine.

Preferred developments of the invention result from the subclaims and the following description. Exemplary embodiments of the invention are explained in more detail with reference to the drawing, without being restricted to this. It shows:

• 1 a schematic, partial cross section through a turbomachine according to the invention.

1 shows a highly schematic, partial cross-section, namely meridian section, one as an axial turbine 10th an exhaust gas turbocharger designed turbomachine, an impeller 11 the axial turbine 10th axial flow and axial flow. Downstream of the turbine impeller 11 a diffuser closes 12th which is the flow in the axial turbine 10th redirected from axial to radial, with the diffuser 12th from an inner shell 13 and an outer shell 14 is limited. Seen in the flow direction of the exhaust gas, it adjoins the diffuser 12th a gathering room 15 on. Exhaust gas that flows through the diffuser 12th in the collecting room 15 enters or overflows, can via a discharge line, not shown, from the collecting space 15 be dissipated.

The diffuser 12th ends with a muzzle cross-section 16 in the collecting room 15 . As already stated, the diffuser 12th and thus the mouth cross-section 16 on the one hand from the inner shell 13 and on the other hand from the outer shell 14 limited.

At the exit end 17th of the diffuser 12th and thus at the exit end 17th the outer shell 14 has the outer shell 14 a defined contouring, namely in such a way that the outlet end 17th the outer shell 14 a surface section facing the collecting space 18th has, which is in cross section, namely in the meridian section of the 1 , extends in the radial direction, and only in the radial direction.

This, in the meridian section, extends exclusively in the radial direction, the collecting space 15 facing surface section 18th of the exit end 17th the outer shell 14 goes with a surface section contoured in the form of a circular segment in cross section or meridian section 19th into the diffuser 12th facing surface section 20 of the exit end 17th the outer shell 14 over.

It is preferably provided that the surface section contoured in the form of a segment of a circle 19th of the exit end 17th the outer shell 14 in the collecting room 15 facing surface section 18th , which extends exclusively in the radial direction in the meridian section, and in that of the diffuser 12th facing surface section 20 which is the contour of the diffuser 12th follows, in each case tangential, i.e. continuous, passes over.

The exit end 17th the outer shell 14 of the diffuser 12th borders on the collecting room 15 or at least in sections protrudes into the collecting room 15 inside.

The exit end is seen in the meridian section 17th the outer shell 14 that the diffuser 12th limited on the outside, characterized by two geometric parameters, namely by a length L of the surface section extending in the radial direction 18th and by a radius R of the surface section contoured in the shape of a segment of a circle 19th .

$$\mathrm{0,1}*\text{X}\le \text{R}\le \text{X}$$

wobei

• L die Länge des sich in Radialrichtung erstreckenden Flächenabschnitts 18 ist,
• R der Radius des kreissegmentförmig konturierten Flächenabschnitts 19 ist,
• X die Abmessung des Mündungsquerschnitts 16 des Diffusors in Axialrichtung ist.

Preferably one, particularly preferably both, of the following conditions apply: $$0.1*\text{X}\le \text{L}\le \text{X}$$

$$0.1*\text{X}\le \text{R}\le \text{X}$$

in which

• L is the length of the surface section extending in the radial direction 18th is
• R is the radius of the area segment contoured in the shape of a segment of a circle 19th is
• X the dimension of the mouth cross section 16 of the diffuser in the axial direction.

The exit end 17th the outer shell 14 of the diffuser 12th forms a bulge-like thickening, which in the meridian section of the 1 a thicker wall than an adjacent section of the outer shell 14 having.

With an outlet-side end designed in this way 17th the outer shell 14 which is the diffuser 12th in the area of the mouth cross-section 16 limited, a particularly advantageous and lossless transfer of the flow from the diffuser 12th in the itself at the diffuser 12th subsequent collection room 15 be guaranteed. The efficiency of the turbomachine can be increased by minimizing flow losses.

The invention is preferably used in an axial turbine of a turbocharger. Although the invention is used with particular preference in this application, the invention can also be used in other turbo machines with a diffuser and a collecting space adjacent to the diffuser, in which a flow starting from the diffuser in the radial direction into those adjacent to the diffuser or subsequent collection room.

Reference list

10th

Fluid machine

11

Wheel

12th

Diffuser

13

inner shell

14

outer shell

15

Gathering room

16

Mouth cross section

17th

exit end

18th

Surface section

19th

Surface section

20

Surface section

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 10137899 C1 [0003]

Claims (9)

Fluid flow machine, with a diffuser (12) provided downstream of an impeller (11), delimited by an inner shell (13) and an outer shell (14), with a collecting space (15) provided downstream of the diffuser (12), the diffuser ( 12) opens in the radial direction into the collecting space (15) with an orifice cross section (16), with an outlet-side end (17) of the outer shell (14) of the diffuser (12), which adjoins the collecting space (15) or into the collecting space ( 15) protrudes at least in sections, characterized in that the outlet-side end (17) of the outer shell (14) has a surface section (18) which faces the collecting space (15) and which extends in the radial direction in cross section, the one which extends in the radial direction Collecting space (15) facing surface section (18) of the outlet-side end (17) of the outer shell (14) with a cross-sectionally contoured surface section (19) facing the diffuser (12) Surface section (20) of the outlet-side end (17) of the outer shell (14) merges. Fluid machine after Claim 1 , characterized in that the area segment (19) contoured in the shape of a segment of a circle merges tangentially into the area section (18) facing the collecting space (15). Fluid machine after Claim 1 or 2nd , characterized in that the circular segment-shaped contoured surface section (19) merges tangentially into the surface section (20) facing the diffuser (12). Fluid machine according to one of the Claims 1 to 3rd , characterized in that the surface section (18) facing the collecting space (15) extends in cross section exclusively in the radial direction. Fluid machine according to one of the Claims 1 to 4th , characterized in that the surface section (18) extending in the radial direction has a length L in the radial direction for which: $$0.1*\text{X}\le \text{L}\le \text{X},$$

where X is the dimension of the mouth cross section (16) of the diffuser (12) in the axial direction. Fluid machine according to one of the Claims 1 to 5 , characterized in that the area segment (19) contoured in the shape of a segment of a circle has a radius R for which: $$0.1*\text{X}\le \text{R}\le \text{X},$$

where X is the dimension of the mouth cross section (16) of the diffuser (12) in the axial direction. Fluid machine according to one of the Claims 1 to 6 , characterized in that it is an axial turbine. Fluid machine after Claim 7 , characterized in that the axial turbine is a turbine of a turbocharger. Fluid machine according to one of the Claims 1 to 8th , characterized in that the respective cross section is a meridian section.

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