Exhaust-gas heat exchanger

Patent metadata

Field	Value
Publication number	US-9394813-B2
Application number	US-201314371455-A
Country	US
Kind code	B2
Filing date	Aug 26, 2013
Priority date	Aug 28, 2012
Publication date	Jul 19, 2016
Grant date	Jul 19, 2016

Abstract

An exhaust-gas heat exchanger for an exhaust system for cooling an exhaust-gas flow, having an inner pipe and an outer pipe, wherein the two pipes are indirectly or directly welded to one another in sealing fashion at the inlet side, a jacket pipe is arranged around the outside of the outer pipe and an annular gap for coolant is arranged between the outer pipe and the jacket pipe, and the inner pipe has an axial flow cross section (A 2 ) at the end as viewed in the flow direction (S) and has a perforation (P 2 ), which forms a radial flow cross section, in a direction at right angles to a flow direction (S). Between the inner pipe and the outer pipe there is formed an exhaust-gas duct for the exhaust-gas flow, wherein an intermediate pipe which is mounted in displaceable and/or rotatable fashion on the inner pipe is provided with a perforation (P 4 ) by which the axial flow cross section (A 2 ) of the inner pipe can be at least partially closed off.

First claim

What is claimed is:

1. An exhaust-gas heat exchanger for an exhaust system for cooling an exhaust-gas flow comprising: an inner pipe and an outer pipe, wherein
a) the two pipes are indirectly or directly welded to one another in sealing fashion at an inlet side,
b) between the inner pipe and the outer pipe there is formed an exhaust-gas duct for the exhaust-gas flow,
c) a jacket pipe is arranged around an outside of the outer pipe and an annular gap for coolant is arranged between the outer pipe and the jacket pipe,
d) the inner pipe has a perforation (P 2 ) with a radial flow cross section in a direction at right angles to a flow direction (S) and an opening with an axial flow cross section (A 2 ) at an end of the inner pipe as viewed in the flow direction (S),
e) an intermediate pipe with a perforation (P 4 ) is provided on the inner pipe such that it can be displaced or rotated, and the intermediate pipe perforation (P 4 ) forms a radial flow cross section that is equivalent to the inner pipe perforation (P 2 ) radial flow cross section,
f) the intermediate pipe can at least partly close off the perforation (P 2 ) of the inner pipe and alter the radial flow cross section, and
g) wherein an adjustable device is provided for at least partly closing off the opening and altering the axial flow cross section (A 2 ), wherein the adjustable device and the intermediate pipe are configured as a subassembly, and a switching element is provided, by which the intermediate pipe and the adjustable device can only be moved at the same time.

2. The exhaust-gas heat exchanger according to claim 1 , wherein the axial flow cross section (A 2 ) of the opening and the radial flow cross section of the perforation (P 2 ) of the inner pipe can be changed at the same time.

3. The exhaust-gas heat exchanger according to claim 1 , wherein the perforation (P 4 ) of the intermediate pipe at least partly overlaps with the perforation (P 2 ) of the inner pipe.

4. The exhaust-gas heat exchanger according to claim 1 , wherein the intermediate pipe can rotate about a center axis (M) and/or shift in the direction of the center axis (M).

5. The exhaust-gas heat exchanger according to claim 1 , wherein the radial flow cross section as the sum of the areas of all holes forming the perforation (P 2 ) of the inner pipe corresponds at least to a value of 1.2 times the axial flow cross section (A 2 ) of the inner pipe.

6. The exhaust-gas heat exchanger according to claim 1 , wherein the switching element is controlled actively or passively by an exhaust-gas back pressure created by the exhaust-gas flow or by an actuator.

7. The exhaust-gas heat exchanger according to claim 1 , wherein the perforation (P 4 ) of the intermediate pipe at least partly overlaps with the perforation (P 2 ) of the inner pipe and/or the two radial flow cross sections are identical.

8. The exhaust-gas heat exchanger according to claim 7 , wherein the intermediate pipe can rotate about a center axis (M) and/or shift in the direction of the center axis (M).

9. The exhaust-gas heat exchanger according to claim 8 , wherein the device and the intermediate pipe are configured as a subassembly, and a switching element is provided, by which the intermediate pipe and the device can be moved at the same time.

10. The exhaust-gas heat exchanger according to claim 9 , wherein the radial flow cross section as the sum of the areas of all holes forming the perforation (P 2 ) of the inner pipe corresponds at least to a valve of 1.2 times the axial flow cross section (A 2 ) of the inner pipe.

11. The exhaust-gas heat exchanger according to claim 10 , wherein the switching element can be controlled actively or passively by an exhaust-gas back pressure created by the exhaust-gas flow or by an actuator.

12. The exhaust-gas heat exchanger according to claim 1 , wherein the two radial flow cross sections are identical.

13. A method for regulating an exhaust-gas flow in an exhaust- gas heat exchanger in an exhaust system, wherein the exhaust-gas heat exchanger has an inner pipe and an intermediate pipe mounted on the inner pipe, the inner pipe and the intermediate pipe each have a perforation (P 2 , P 4 ) with a radial flow cross section in a radial direction of a center axis (M), comprising the steps of;
mounting the intermediate pipe so that it can rotate or move relative to the inner pipe,
regulating the quantity of the exhaust-gas flow that flows in the radial direction through the perforation (P 2 ) of the inner pipe in the direction of an exhaust-gas duct by moving the intermediate pipe, and
regulating the quantity of the exhaust-gas flow which flows in the axial direction through an opening of the inner pipe arranged downstream from the perforation (P 2 ) in a flow direction (S) by only moving an adjustment device, wherein the intermediate pipe and the adjustment device are mechanically coupled and moved at the same time.

Assignees

• Tenneco Gmbh

Inventors

• Geminn Markus
• Steigert Andreas
• Roth Margit
• Womann Marcel
• Jochem Alexander

Classifications

• F01N2470/24

  Concentric tubes or tubes being concentric to housing, e.g. telescopically assembled · CPC title

• F02M26/00

  Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems · CPC title

• F01N2240/36

  an exhaust flap · CPC title

• F02M26/26

  characterised by details of the bypass valve · CPC title

• F28D7/103

  consisting of more than two coaxial conduits or modules of more than two coaxial conduits · CPC title