EXHAUST GAS SYSTEM UNIT

Abstract

The disclosure relates to an exhaust gas sub-system for an internal combustion engine, having a catalytic converter with an inlet section for introducing an exhaust gas flow into the outer housing and having a feed line for secondary gas, the feed line having an inflow element at the end, which opens at the inlet section, the outer housing has an inlet opening for exhaust gas, an external heating element for heating the secondary gas and for generating hot gas being provided in the feed line upstream of the inflow element, at least one inflow opening in the outer housing being assigned to the inflow element, via which hot gas can be fed into the inlet section.

Claims

1. An exhaust gas sub-system for an internal combustion engine, comprising: a catalytic converter housing with an inlet section and with an inlet opening for introducing an exhaust gas flow into the catalytic converter housing and, for secondary gas, a feed line that is free of an exhaust gas flow, the feed line comprising an inflow element at its end, by means of which the secondary gas is fed to the exhaust gas flow, wherein the inflow element is placed upstream of the catalytic converter housing, wherein a heating element for heating the secondary gas is provided in the feed line upstream of the inflow element, wherein at least one inflow opening at the inlet section is correlated to the inflow element via which the heated secondary gas can be fed to the exhaust gas flow starting from the feed line, wherein the inflow element together with an outer side of the inlet section delimits a collection chamber from which the secondary gas can be guided into the inlet section via the inflow opening, wherein each inflow opening comprises an opening cross-section and an opening axis, wherein opening axes of adjacent inflow openings are inclined at an angle ? to one another and thereby comprising different incident angles towards an exhaust gas main flow center axis.

2. The exhaust gas sub-system according to claim 1, wherein the inflow element is positioned at the inlet section and/or that the inflow opening is provided in the inlet section.

3. The exhaust gas sub-system according to claim 1, wherein all inflow openings comprise the same opening cross-section, or that at least a first part of 30% to 70% of the inflow openings comprise a larger opening cross-section than a second part of 70% to 30% of the inflow openings.

4. The exhaust gas sub-system according to claim 1, wherein the inlet section comprises at least one or more recesses, at least one inflow opening being provided in each recess.

5. The exhaust gas sub-system according to claim 3, wherein the opening axes are inclined at an angle ? to one another within a recess.

6. The exhaust gas sub-system according to claim 5, wherein the angle ? fulfils the following condition: 20?<=?<=170? or 70?<=?<=90?.

7. The exhaust gas sub-system according to claim 3, wherein the opening axes of adjacent inflow openings and/or opening axes within a recess are inclined at different angles ?1, ?2 towards an exhaust gas main flow center axis, wherein 70?<=?1<=90? and 20?<=?2<=40?.

8. The exhaust gas sub-system according to claim 1, wherein at least two rows of inflow openings and/or two rows of recesses are provided, each comprising at least one inflow opening per recess, the rows extending in a circumferential direction U with respect to the exhaust gas main flow center axis and being arranged next to one another.

9. The exhaust gas sub-system according to claim 8, wherein within at least one row, the angle ? varies between two inflow openings and/or the angle ?1, ?2 varies.

10. The exhaust gas sub-system according to claim 8, wherein between adjacent rows, the angle ? varies and/or the angle ?1, ?2 varies.

11. The exhaust gas sub-system according to claim 1, wherein the inflow element encloses the inlet section with respect to the circumferential direction U of the exhaust gas main flow center axis at an angle ?, wherein 50?<=?<=360?.

12. The exhaust gas sub-system according to claim 1, wherein that the secondary gas can be heated electrically via the heating element or by means of a combustor of the heating element.

13. The exhaust gas sub-system according to claim 1, wherein a control unit is provided for actively controlling the heating element, by means of which the temperature and/or the mass flow of the secondary gas can be adjusted.

14. The exhaust gas system comprising an exhaust sub-system according claim 1.

15. A method for operating an exhaust gas system according to claim 14, wherein the secondary gas is heated by means of the heating element so that the temperature of a catalytic converter is regulated.

Description

DRAWINGS

[0028] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0029] Further advantages and details of the disclosure are explained in the claims and in the description and shown in the figures. It shows:

[0030] FIG. 1 a schematic representation of the exhaust gas sub-system;

[0031] FIG. 2a a schematic representation of the inlet section with inflow openings;

[0032] FIG. 2b a further embodiment with respect to FIG. 2a;

[0033] FIG. 3 a schematic sketch of the inlet section as seen from the front;

[0034] FIG. 4 a schematic sketch of a motor vehicle exhaust system.

[0035] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

[0036] Example embodiments will now be described more fully with reference to the accompanying drawings.

[0037] An exhaust gas sub-system 1 shown in FIG. 1 is part of a comprehensive exhaust gas system 4 according to FIG. 4 for complete cleaning and aftertreatment of an exhaust gas flow 4.3 or of a main exhaust gas flow of an internal combustion engine 4.6. Downstream of the exhaust gas sub-system 1 described further below, the exhaust gas system 4 comprises a catalytic converter housing 2 with an exhaust gas catalytic converter not shown in further detail and a particulate filter 4.1 and, further downstream, an exhaust gas silencer 4.2. The exhaust gas sub-system 1 is connected to a manifold 4.5 of the combustion engine 4.6. The respective components are flow-coupled to each other via exhaust pipes 4.4.

[0038] The exhaust gas sub-system 1 comprises an exhaust gas-carrying inlet section 3, which is coupled upstream to the catalytic converter housing 2 for the purpose of supplying exhaust gas. Opposite the catalytic converter housing 2, the inlet section 3 is fed with the exhaust gas flow 4.3 of the combustion engine 4.6 via an exhaust pipe that is not shown in further detail. The exhaust gas entering upstream of the inlet section 3 is routed to the catalytic converter housing 2 via the inlet section 3. The inlet section 3 comprises a conical basic shape so that its flow cross-section increases from an inlet opening 3.2 to the catalytic converter housing 2.

[0039] The inlet section 3 is coupled to an inflow element 5.1, which according to FIG. 1 is designed as a half-shell channel, which is placed on an outer side 3.4 of the inlet section 3 in the circumferential direction U, as shown in FIG. 3. Together with the inlet section 3 or the outer side 3.4 of its housing wall 3.3, the inflow element 5.1 forms a collection chamber 5.4, which is supplied with heated secondary gas 5.3 via a supply line 5 and a heating element connected thereto at an upstream position. The heated secondary gas 5.3 flows into the inlet section 3 via the collection chamber 5.4 and corresponding inflow openings 5.2 within the inlet section 3 or within a housing wall 3.3 of the inlet section 3 and is mixed there with the exhaust gas flow 4.3 or is mixed into the exhaust gas flow 4.3. The housing wall 3.3 comprises several inlet openings 5.2. According to FIG. 2a, the inlet openings 5.2 are each arranged as a hole and distributed in the circumference of the inlet section 3 or in the circumferential direction U. The opening cross-section Q is round. Alternatively, it can be oval. Since no flow guide elements are provided at the inlet openings 5.2, the opening cross-section Q is free of guide elements. According to FIG. 2a, two rows 5a, 5b of inflow openings 5.2 are provided. According to the embodiment of FIG. 2b, two rows 3a, 3b of recesses 3.1 are provided, with two inflow openings 5.2 each being arranged within a recess 3.1 of the housing wall 3.3.

[0040] In the sectional view according to the embodiment of FIG. 1, the respective recess 3.1 is shown with the two inflow openings 5.2 contained therein.

[0041] The respective inflow opening 5.2 comprises an opening axis 5.5 that is aligned normal to the surrounding housing wall 3.3. According to the embodiment of FIG. 1, two inflow openings 5.2 are provided in the respective recess 3.1 whose opening axis 5.5 is set or inclined at an angle ? to each other. According to the embodiment of FIG. 1, lower half, a first flow axis is radially aligned and forms an angle ?1 of approximately 90? with an exhaust gas main flow axis 2.1. The other opening axis forms an angle ?2 of approximately 30? with the main exhaust gas flow axis 2.1. This means that a part of the hot gas is supplied in a radial direction and another part of the exhaust gas is supplied with a corresponding axial directional component. The angle ?1 can also be less than 90?. This would be accompanied by a directional component that is directed into the opposite direction of the main exhaust gas direction.

[0042] The collection chamber 5.4 is supplied via a feed line from an active, separate and external heating element 6 comprising a combustion chamber or combustor 6.1, into which secondary gas 5.3 flows for the purpose of heating and which, when heated, is released to the collection chamber 5.4, and thus to and into the inlet section 3. Alternatively, the secondary gas 5.3 can be heated electrically. Moreover, a control unit 7 is provided, which regulates the active heating element 6 and adjusts the temperature and mass flow of the secondary gas 5.3.

[0043] In the embodiment of FIG. 3, the inlet section 3 is shown in a front view. The inflow element 5.1 extends over an angle ? having approximately 200?. The inflow element 5.1 is also supplied via a supply line 5 with a secondary gas 5.3 that was heated in the heating element 6, in this case with ambient air.

[0044] According to FIG. 4, the exhaust system 4 of a motor vehicle comprises an internal combustion engine 4.6 comprising a manifold 4.5. The exhaust gas flow 4.3 is directed through the exhaust pipe 4.4 and fed to the inlet section 3. The inflow element 5.1 is provided at the inlet section 3, through which the secondary gas 5.3, heated by the heating element 6, is fed into the exhaust gas flow 3 and mixed with the exhaust gas flow 3. In particular, the heating element 6 is not part of the exhaust system 4 and is therefore to be regarded as external. Further downstream, there is provided a catalytic converter housing 2 with a catalytic converter 2.2, to which a particulate filter 4.1 is connected. An exhaust silencer 4.2 is provided at the end of the exhaust pipe 4.4.

[0045] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.