DE102013219329B4 - Turbine arrangement for an internal combustion engine and chargeable internal combustion engine - Google Patents

Abstract

Turbine arrangement (10) for an internal combustion engine (12), having at least one fluid line (14), a turbine (16) arranged in the fluid line (14) and a bypass line (18) which is connected from the fluid line (14) upstream of the turbine (16 ) branches off and opens into the fluid line (14) downstream of the turbine (16), with a junction point (40) of the bypass line (18) extending only over an azimuthal angular range (42) of the fluid line (14) and the fluid line (14) in the direction downstream of the turbine (16) has a discontinuous opening rate in the azimuthal angle range (42) of the junction (40), characterized in that an outlet diffuser (44) is arranged downstream of the turbine (16) in the fluid line (14), the outlet diffuser (44 ) comprises a hub body (46) and the junction (40) of the bypass line (18) is in the area of the hub body (46), and wherein the hub body (46) has two profiled struts (48) which are essentially in the W Angle sector of the azimuthal angle range (42) of the fluid line (14), in which the junction point (40) is located, towards the inner wall of the fluid line (14).

Description

The invention relates to a turbine arrangement for an internal combustion engine having the features according to the preamble of claim 1. It also relates to a chargeable internal combustion engine having the features according to the preamble of claim 7.

It is common practice to arrange an outlet diffuser downstream of a turbine, in particular a turbocharger turbine, for an internal combustion engine in order to convert the kinetic energy of the outflow from the turbine into static pressure energy as much as possible. The resulting reduction in the static pressure level at the outlet of the turbine results in a corresponding increase in gas expansion in the turbine stage and thus an improvement in efficiency. However, conversion of the kinetic energy is made more difficult due to various circumstances: The flow field of the outflow from the turbine is often inhomogeneous. Turbines, in particular turbocharger turbines, also have a highly dynamic working range in which widely varying conditions of inflow and outflow to the turbine prevail. In particular, standard turbocharger turbine housings act like shock diffusers, so efficiency suffers.

One class of turbines is also operated with a bypass line, often referred to as a wastegate line, which opens downstream of the turbine. The exhaust gas mass flow that bypasses the turbine, for example due to the wastegate boost pressure control in a turbocharger turbine, must be combined with the expanded gas of the outflow behind the turbine. With the outlet housings that are commonly used, this combination causes a not inconsiderable disruptive influence on the outflow from the turbine.

In the document DE 197 08 000 A1 describes a turbocharger in a housing with a bypass of the turbine. The turbine has a spiral exhaust. An annular nozzle element is arranged downstream of the turbine as an outlet diffuser, which is fastened to the housing. The bypass includes a spiral groove passage formed around the outer peripheral surface of the nozzle member and is guided past the outer peripheral surface. As a result, a spiral flow is imposed on the exhaust gas mass flow guided through the bypass line, which has the same direction of rotation as the spiral outflow of the turbine. As a consequence, a disturbance in the outflow caused by the exhaust gas mass flow bypassing the turbine is reduced.

From the DE 31 01 131 A1 a method for improving the efficiency of an exhaust gas turbocharger is known. The bypass mass flow that is blown off is expanded with the help of an ejector nozzle and fed into the exhaust gas mass flow in such a way that the back pressure behind the turbine is reduced. For this purpose, the opening of the bypass duct into the exhaust gas duct is designed as an ejector nozzle, which introduces the bypass mass flow approximately parallel or at an acute angle of up to a maximum of approximately 30° into the exhaust gas mass flow of the turbine.

the DE 102 60 778 A1 describes an exhaust gas turbocharger for an internal combustion engine with a compressor in the intake system and an exhaust gas turbine in the exhaust system. In this case, the exhaust gas turbine has an exhaust gas collection chamber in a turbine housing, the exhaust gas of which can be fed to the turbine wheel via a turbine inlet cross section. Furthermore, an exhaust gas bypass is provided that bridges the turbine inlet cross section and connects the exhaust gas collection chamber to an outlet area of the exhaust gas turbine. The exhaust gas turbine forms a pump for a gas delivery device, with a gas delivery line assigned to the gas delivery device opening into the exhaust gas bypass.

From the DE 10 2007 017 843 A1 a turbocharger arrangement with a housing which can be connected to an internal combustion engine is known. The turbocharger arrangement has a first turbocharger and a second turbocharger, each consisting of at least one compressor and one turbine, with the two shafts of the turbochargers being arranged in a row in the longitudinal direction of one another and with the compressors each being arranged on the outside of the respective shaft and the turbines on the inside of each shaft.

Furthermore, from the DE 36 06 944 A1 an exhaust gas turbocharger with a turbine housing, which has a gas inlet and an axial gas outlet channel, is known. A bypass line connecting the gas inlet to the gas outlet channel opens into an annular recess in the wall of the gas outlet channel. A ring-shaped rotary valve is used to control the bypass quantity, which is arranged in the recess and contains a radial control opening which can be brought into or out of alignment with the mouth 12 of the bypass line 8 by rotating the rotary valve by means of an actuating linkage.

The object of the present invention is to reduce disruptive influences on the outflow from a turbine.

According to the invention, this object is achieved by a turbine arrangement for an internal combustion engine with the features according to claim 1 . Advantageous developments of the invention are characterized in the dependent claims.

A turbine arrangement according to the invention for an internal combustion engine, in particular a chargeable internal combustion engine, has at least one fluid line, a turbine arranged in the fluid line, and a bypass line which branches off from the fluid line upstream of the turbine and opens into the fluid line downstream of the turbine. A junction point of the bypass line only extends over an azimuthal angular range of the fluid line. In the direction downstream of the turbine, the fluid line has a discontinuous opening rate in the azimuthal angle range of the junction point.

With the embodiment according to the invention, a streamlined combination of the turbine outflow and the bypass flow further downstream of the turbine outlet is realized by subdividing the flow channel. The subdivision can be characterized by the turbine channel (which is asymmetrical in relation to the rotational symmetry of the turbine) with a discontinuous opening rate. In other words, the fluid line opens abruptly at or through the junction of the bypass line with the fluid line. By subdividing the fluid line and the bypass line Disturbances of the turbine outflow are reduced or prevented.The reduced flow resistance increases the efficiency and the pressure recovery is increased.

Due to the design according to the invention, the negative effect of a shock diffuser is avoided. The efficiency of the turbine is less affected. In other words, according to the invention, an increase in the performance of an outlet diffuser is made possible. This is particularly advantageous with regard to the space-related requirements with a relatively short axial overall length, especially for turbocharger turbines of internal combustion engines.

In particularly advantageous embodiments of the turbine arrangement according to the invention, the bypass line has an opening with a non-rotationally symmetrical contour at the junction point. Furthermore or alternatively, the bypass line opens into the fluid line at an acute angle in the direction downstream of the turbine. With one or more of these measures, the arrangement is given an optimized shape or position adapted to the flow problem.

The fluid line of embodiments of the turbine arrangement according to the invention can also have an internal cross section that monotonically increases in the direction downstream of the turbine, at least in the region of the junction point. The additional volume made available for the fluid facilitates the desired conversion of kinetic energy into static pressure energy.

According to the invention, the turbine arrangement for an internal combustion engine includes an outlet diffuser, which is also referred to as an outlet diffusion device: The outlet diffuser of the turbine arrangement according to the invention is arranged downstream of the turbine in the fluid line. The outlet diffuser comprises a hub body and the junction point of the bypass line is in the area of the hub body, in particular in the vicinity of the hub body, in the wall of the fluid line. A specific ratio of the hub cross-section to the area ratio coupled with it is to be designed with the aid of numerical calculations with regard to the greatest possible pressure increase that can be achieved with stable operating behavior.

According to the invention, the hub body has two profiled struts which extend essentially in the angle sector of the azimuthal angle range, more precisely one at the limits of the angle sector of the fluid line in which the junction point is located, in the direction of the inner wall of the fluid line.

Furthermore, the hub body can have an outer cross section that monotonically widens in the direction downstream of the turbine, at least in the area of the confluence point. The widening can in particular be correlated to the internal cross section of the fluid line monotonically increasing in the direction downstream of the turbine.

Due to the asymmetrical turbine channel according to the invention, the cross section of the hub body is designed to be variable perpendicular to the main flow direction (or orientation) of the fluid line in order to maintain the numerically determined geometry.

In addition or as an alternative to this, it is advantageous if the hub body has a tear-off edge on its side facing away from the turbine. In this way, the wake flow is limited. This is particularly advantageous in embodiments with a small overall axial length.

A turbine arrangement according to the invention can be used with great advantage in an internal combustion engine, more specifically in a chargeable internal combustion engine. In other words, in a turbine arrangement according to the invention for an internal combustion engine, the turbine can be part of an exhaust gas turbocharger. The exhaust gas turbocharger can in particular be a wastegate turbocharger. The increase in output achieved according to the invention can thus be used for a turbine with a highly dynamic working range.

Particularly with regard to integration that saves as much space as possible, it is advantageous if the turbine arrangement according to the invention for an internal combustion engine is accommodated in a housing part. In other words, the turbine arrangement can be integrated, in particular designed in one piece.

The turbine in the turbine arrangement according to the invention is preferably a gas turbine.

A chargeable internal combustion engine is also related to the inventive idea. A chargeable internal combustion engine according to the invention has at least one turbine arrangement with features or combinations of features according to this illustration. The embodiments in which the fluid line is part of the exhaust line of the chargeable internal combustion engine are particularly preferred.

The internal combustion engine can be part of a drive assembly of a motor vehicle, in particular a trackless land motor vehicle, for example a passenger car or a commercial vehicle.

• 1 eine schematische Darstellung einer Ausführungsform einer erfindungsgemäßen Turbinenanordnung in einer Brennkraftmaschine,
• 2 eine dreidimensionale Ansicht einer vorteilhaften Ausführungsform eines Gehäuseteils der erfindungsgemäßen Turbinenanordnung mit der Einmündungsstelle der Umgehungsleitung,
• 3 eine Ansicht der vorteilhaften Ausführungsform der 2 mit Details der Umgehungsleitung,
• 4 eine Ansicht der vorteilhaften Ausführungsform der 2 aus Richtung stromab der Turbine, und
• 5 ein Schnittbild entlang der Linie A-A der in der 4 gezeigten Ansicht.

Further advantages and advantageous embodiments and developments of the invention are presented on the basis of the following description with reference to the figures. It shows in detail:

• 1 a schematic representation of an embodiment of a turbine arrangement according to the invention in an internal combustion engine,
• 2 a three-dimensional view of an advantageous embodiment of a housing part of the turbine arrangement according to the invention with the confluence point of the bypass line,
• 3 a view of the advantageous embodiment of FIG 2 with details of the bypass line,
• 4 a view of the advantageous embodiment of FIG 2 from downstream of the turbine, and
• 5 a sectional view along the line AA in the 4 shown view.

In the 1 an embodiment of a turbine arrangement 10 according to the invention in a chargeable internal combustion engine 12 is shown schematically. The turbine arrangement 10 comprises a fluid line 14 in which a turbine 16 is arranged, and a bypass line 18 which branches off from the fluid line 14 upstream of the turbine 16 and opens into the fluid line 14 downstream of the turbine 16 . Not shown in detail in the drawing is a device for controlling the mass flow through the bypass line 18. The turbine assembly 10, together with a compressor 24 driven by the turbine 16, forms an exhaust gas turbocharger 20 of the internal combustion engine 12. It is located in a housing 22. Alternatively to the drawing In the illustration, the compressor 24 can also be accommodated in a housing 22 for the entire exhaust gas turbocharger 20 .

The compressor 24 is located in a fresh gas line 26. In certain specific embodiments, the compressor 24 can also have a bypass line. Optionally compressed fresh gas is fed via an intake manifold 28 of the fresh gas line 26 to the engine 30, here by way of example a reciprocating engine with four cylinders (symbolized by the circles). The engine 30 can be operated supercharged. Exhaust gas is discharged from the engine 30 of the internal combustion engine 12 via an exhaust line 34 , specifically first via an exhaust manifold 32 and then via the fluid line 14 . The exhaust gas drives the turbine 16 of the turbine arrangement 10 according to the invention.

The chargeable internal combustion engine 12 is in the 1 embodiment shown a drive unit of a motor vehicle.

the 2 shows a three-dimensional view of an advantageous embodiment of a housing part 38 of the turbine arrangement 10 according to the invention with the junction point 40 of the bypass line 18 in the fluid line 14 downstream of the turbine not shown in the drawing here. The junction point 40 is not arranged in a completely rotationally symmetrical manner (not a 360-degree azimuthal angle) around the main extension direction of the fluid line 14, but only extends over an azimuthal angle segment, in the azimuthal angle region 42 of the fluid line. This azimuthal angle range 42 has an angular size of less than 180 degrees, in particular less than 90 degrees, preferably less than 60 degrees. Furthermore, an outlet diffuser 44 is arranged in the housing part 38 in this embodiment. The exit diffuser 44 includes a hub body 46 which is arranged centrally in the fluid line 14 . Two struts 48 extend from the hub body 46 to the inner wall of the housing part 38. The struts 48 run approximately in the direction of the azimuthal angle of the end points of the azimuthal angle range 42 of the junction 40 of the bypass line 18.

the 3 shows details of the bypass line 18 of the advantageous embodiment of FIG 2 . In this illustration it can be seen that the bypass line 18 reaches the fluid line 14 at a feed angle 50 and opens into it in the azimuthal angle area 42 . In this embodiment, the feed angle 50 is an acute angle, in particular less than 45 degrees, preferably less than 30 degrees. In this way, strong changes in direction of the flow in the bypass line 18 are avoided.

In 4 is a view of the advantageous embodiment of FIG 2 seen from downstream of the turbine. The hub body 46 with the two struts 48 is shown in the fluid line 14 into which the bypass line 18 opens at the junction point 40 . The housing part 38 and its internal structure mentioned are mirror-symmetrical to the plane extending perpendicularly to the drawing sheet, in which the line AA lies.

the 5 is a sectional view taken along line AA of FIG 4 shown view. The fluid line 14 extends from the left part of the 5 (upstream) to the right part of the 5 (downstream) in the housing part 38 with a monotonously increasing internal cross section from a first internal cross section 52 to a second internal cross section 54. The second internal cross section 54 is significantly larger than the first internal cross section 52. It can preferably be greater than 1.5 times, preferably greater than be 1.8 times the first internal cross-section 52. This widening of the fluid line 14 takes place over a longitudinal section that is approximately twice as large as the first internal cross section 52 . The hub body 46 with the struts 48 also has a cross section, more precisely an outer cross section, that monotonically widens in the direction downstream of the turbine: It widens from a first outer cross section 56 to a second outer cross section 58. The second outer cross section 58 is reached at the tear-off edge 60.

The widening of the outer cross section of the hub body 46 takes place essentially over the same longitudinal stretch of the fluid line 14 over which its inner cross section is widened. In addition, the outer cross-section expands as the inner cross-section expands. In other words, the distance between the outer surface of the hub body 46 and the inner surface of the shell 38 remains substantially constant over the lengthwise extent of the extension.

The only exception to this according to the invention is the confluence point 40 of the bypass line 18: here the fluid line 14 has a discontinuous opening rate in the azimuthal angle range of the confluence point 40 in the direction downstream of the turbine. This discontinuity is caused by the abrupt widening at the jump path 62. The bypass line 18 opens into the fluid line 14 at an acute angle in a direction that is preferably substantially parallel to the direction in which the fluid line 14 extends.

Reference List

10

turbine arrangement

12

internal combustion engine

14

fluid line

16

turbine

18

bypass line

20

exhaust gas turbocharger

22

Housing

24

compressor

26

fresh gas line

28

intake manifold

30

engine

32

exhaust manifold

34

exhaust line

36

motor vehicle

38

housing part

40

junction point

42

azimuthal angle range

44

exit diffuser

46

hub body

48

strut

50

feeding angle

52

first internal cross-section

54

second internal cross-section

56

first external cross section

58

second external cross section

60

tear-off edge

62

jump distance

Claims (8)

Turbine arrangement (10) for an internal combustion engine (12), having at least one fluid line (14), a turbine (16) arranged in the fluid line (14) and a bypass line (18) which is connected from the fluid line (14) upstream of the turbine (16 ) branches off and opens into the fluid line (14) downstream of the turbine (16), with a junction point (40) of the bypass line (18) only extends over an azimuthal angle range (42) of the fluid line (14) and the fluid line (14) has a discontinuous opening rate in the azimuthal angle range (42) of the junction point (40) in the direction downstream of the turbine (16), characterized in that an outlet diffuser (44) is arranged downstream of the turbine (16) in the fluid line (14), wherein the outlet diffuser (44) comprises a hub body (46) and the junction point (40) of the bypass line (18) is in the region of the hub body (46), and wherein the The hub body (46) has two profiled struts (48) which extend in the direction of the inner wall of the fluid line (14) essentially in the angle sector of the azimuthal angle area (42) of the fluid line (14), in which the junction point (40) is located. Turbine arrangement (10) for an internal combustion engine (12) according to claim 1 , characterized in that the bypass line (18) at the junction point (40) has an opening with a non-rotationally symmetrical contour and/or opens into the fluid line (14) at an acute angle in the direction downstream of the turbine (16). Turbine arrangement (10) for an internal combustion engine (12) according to claim 1 or 2 , characterized in that the fluid line (14), at least in the region of the junction (40), has an internal cross section which increases monotonously in the direction downstream of the turbine. Turbine arrangement (10) for an internal combustion engine (12) according to claim 1 , characterized in that the hub body (46), at least in the area of the junction (40), has an external cross section that widens monotonously in the direction downstream of the turbine (16) and/or has a tear-off edge (60) on its side facing away from the turbine (16). Turbine arrangement (10) for an internal combustion engine (12) according to one of the preceding claims, characterized in that the turbine (16) is part of an exhaust gas turbocharger (20). Turbine arrangement (10) for an internal combustion engine (12) according to one of the preceding claims, characterized in that the turbine arrangement (10) is accommodated in a housing part (22, 38). Chargeable internal combustion engine (12), characterized by at least one turbine arrangement (10) according to one of the preceding claims. Chargeable internal combustion engine (12) according to claim 7 , characterized in that the fluid line (14) is part of the exhaust system (34) of the internal combustion engine (12).

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