Component of an exhaust gas system and method for exhaust gas after-treatment

1. A component of an exhaust gas system of an internal combustion engine, comprising:

at least one housing with a single inlet for an exhaust gas at a first axial end of the housing and a single outlet for the exhaust gas at a second axial end of the housing opposite the first axial end of the housing;

an annular heat exchanger arranged in the housing and through which the exhaust gas can flow from the inlet in an axial direction and along a first flow path; and

an annular catalyst body, arranged downstream of the annular heat exchanger and arranged radially inside the annular heat exchanger and through which the exhaust gas can flow at least in a radial direction,

wherein downstream of the annular catalyst body, the exhaust gas flows through the annular heat exchanger in the radial direction and along a second flow path.

2. The component as claimed in claim 1 , wherein an annular outflow channel surrounds the annular heat exchanger outwardly in the radial direction so that the exhaust gas enters the annular outflow channel downstream of the second flow path and leaves the housing via the outlet.

3. The component as claimed in claim 1 , wherein the housing extends in the axial direction between the inlet, which is arranged on a first end face of the housing, and the outlet, which is arranged on a second end face of the housing.

4. The component as claimed in claim 1 , further comprising:

a deflection zone arranged downstream of the first flow path and configured to deflect the exhaust gas in an opposing axial direction; and

a central channel extending in the axial direction is arranged inside the annular catalyst body in the radial direction, and the exhaust gas leaving the deflection zone enters the central channel and from the central channel enters the annular catalyst body.

5. The component as claimed in claim 4 , further comprising:

a feed device for a reaction medium arranged one of upstream of the first flow path or in the deflection zone.

6. The component as claimed in claim 4 , wherein the deflection zone is a dome-shaped element.

7. The component as claimed in claim 1 ,

wherein the annular catalyst body comprises a plurality of flow channels for through-conduction of the exhaust gas,

wherein the plurality of flow channels extend at least in the radial direction and in the axial direction.

8. The component as claimed in claim 1 , wherein along the first flow path, surfaces of the annular heat exchanger contacting the exhaust gas have a structured surface, which is therefore larger than a flat surface.

9. The component as claimed in claim 8 , wherein along the second flow path, the surfaces of the annular heat exchanger contacting the exhaust gas have a structured surface which is therefore larger than a flat surface.

10. The component as claimed in claim 1 , wherein a heat exchange medium flows through the annular heat exchanger only in the axial direction.

11. The component as claimed in claim 1 , wherein at least one component downstream of the annular catalyst body has a catalytic coating on:

surfaces of the annular heat exchanger along the second flow path; and

an annular outflow channel which surrounds the annular heat exchanger outwardly in the radial direction, so that the exhaust gas enters the annular outflow channel downstream of the second flow path and leaves the housing via an outlet.

12. The component as claimed in claim 1 , wherein the inlet comprises a conical portion configured to guide the exhaust gas to the annular heat exchanger.

13. The component as claimed in claim 12 , wherein a base of the conical portion is arranged at a radially inner portion of the annular heat exchanger.

14. A method for exhaust gas after-treatment for an internal combustion engine, comprising:

a. entry of an exhaust gas into a single inlet at a first axial end of a housing of a component of an exhaust gas system;

b. guiding the exhaust gas in an axial direction and along a first flow path through an annular heat exchanger;

c. deflecting the exhaust gas into a central channel arranged in a radial direction inside the annular heat exchanger and extends in the axial direction;

d. deflecting the exhaust gas from the central channel in a radial direction;

e. entry of the exhaust gas into an annular catalyst body with through-flow at least in a radial direction, so that, downstream of the annular catalyst body, the exhaust gas flows through the annular heat exchanger in the radial direction and along a second flow path; and

f. exiting of the exhaust gas from a single exit at a second axial end of a housing opposite the first axial end of the housing.

15. The method as claimed in claim 14 ,

wherein an annular outflow channel surrounds the annular heat exchanger outwardly in the radial direction; and

the exhaust gas enters the annular outflow channel downstream of the second flow path and is conducted in the axial direction towards an outlet of the housing of the component.

16. A motor vehicle comprising:

at least an internal combustion engine; and

an exhaust gas system with a component comprising:

at least one housing with a single inlet for an exhaust gas at a first axial end of the housing and a single outlet for the exhaust gas at a second axial end of the housing opposite the first axial end of the housing;

an annular heat exchanger arranged in the housing and through which the exhaust gas can flow from the inlet in an axial direction and along a first flow path; and

an annular catalyst body, arranged downstream of the annular heat exchanger and arranged radially inside the annular heat exchanger and through which the exhaust gas can flow at least in a radial direction,

wherein downstream of the annular catalyst body, the exhaust gas flows through the annular heat exchanger in the radial direction and along a second flow path.