Exhaust gas heat exchanger

Patent metadata

Field	Value
Publication number	US-11655745-B2
Application number	US-201816755559-A
Country	US
Kind code	B2
Filing date	Oct 9, 2018
Priority date	Oct 12, 2017
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

An exhaust gas heat exchanger may include a tube bundle and a housing through which a coolant is flowable. The tube bundle may include a plurality of exhaust gas-conducting tubes held in a first tube base and a second tube base. The housing may enclose the tube bundle and may have face ends delimited by the first tube base and the second tube base. The housing may include a coolant inlet arranged in a region of the second tube base and a coolant outlet arranged in a region of the first tube base such that the coolant flows in counter flow relative to the exhaust gas. A plurality of coolant bypass passages may be arranged between the tube bundle and the housing. At least a subset of the plurality of coolant bypass passages may be at least partly blocked by an inlay structured and arranged to steer a coolant flow.

First claim

The invention claimed is:

1. An exhaust gas heat exchanger, comprising:
a tube bundle including a plurality of parallel exhaust gas-conducting tubes, which on an inlet side are held in a first tube base and on an outlet side are held in a second tube base;
a housing through which a coolant is flowable, the housing enclosing the tube bundle and having face ends delimited by the first tube base and the second tube base, the housing including a coolant inlet and a coolant outlet;
the tube bundle having a stepped outer circumference and the housing having a round cross section such that between the tube bundle and the housing a plurality of coolant bypass passages are arranged;
the coolant inlet arranged in a region of the second tube base and the coolant outlet arranged in a region of the first tube base such that the coolant in the housing flows in counter flow relative to the exhaust gas in the plurality of tubes;
wherein at least a subset of the plurality of coolant bypass passages are at least partly blocked by an inlay structured and arranged to steer a coolant flow in a direction of the first tube base and between the plurality of tubes to cool the plurality of tubes; and
wherein the inlay has a C-shaped cross section.

2. The exhaust gas heat exchanger according to claim 1 , wherein the inlay is at least one of welded, soldered, and screwed to the housing.

3. The exhaust gas heat exchanger according to claim 1 , wherein one of:
the inlay is a deep-drawn sheet metal inlay having a wall thickness of 0.3 mm to 0.8 mm;
the inlay is a metallic casted inlay; and
the inlay is a plastic injection moulded inlay.

4. The exhaust gas heat exchanger according to claim 1 , wherein an axial length of the inlay amounts to at least 33% of an axial length of the plurality of tubes.

5. The exhaust gas heat exchanger according to claim 1 , wherein the inlay is arranged such that:
the subset of coolant bypass passages at least partially blocked by the inlay are arranged in a region of the coolant outlet;
at least a second subset of coolant bypass passages of the plurality of coolant bypass passages disposed opposite the subset of coolant bypass passages are open; and
the first tube base is overflowed by the coolant transversely to an exhaust gas flow direction.

6. The exhaust gas heat exchanger according to claim 1 , wherein the housing is a sheet metal housing having a wall thickness of 1.0 mm to 1.5 mm.

7. The exhaust gas heat exchanger according to claim 1 , wherein:
the inlay surrounds the tube bundle in a positively locked manner; and
a distance between the inlay and the tube bundle corresponds to a distance between two tubes of the plurality of tubes of the tube bundle.

8. The exhaust gas heat exchanger according to claim 1 , wherein the plurality of tubes are structured as a plurality of flat tubes.

9. The exhaust gas heat exchanger according to claim 1 , wherein the inlay is disposed in the housing such that a distance between the inlay and the second tube base is equal to ⅔ of an axial length of the plurality of tubes.

10. The exhaust gas heat exchanger according to claim 1 , wherein the inlay includes a middle part and two collars arranged on a longitudinal end side.

11. The exhaust gas heat exchanger according to claim 10 , wherein:
the two collars of the inlay are structured complementarily to an inner circumference of the housing; and
the inlay lies flat against the housing via the two collars.

12. The exhaust gas heat exchanger according to claim 1 , wherein the inlay includes a middle portion and two collars, the two collars disposed on opposing longitudinal ends of the middle portion.

13. The exhaust gas heat exchanger according to claim 12 , wherein the inlay includes a plurality of bevels projecting from the middle portion.

14. The exhaust gas heat exchanger according to claim 13 , wherein the plurality of bevels protrude from the middle portion toward the tube bundle and extend along the middle portion from one of the two collars to the other of the two collars.

15. The exhaust gas heat exchanger according to claim 14 , wherein the plurality of bevels are structured and arranged in a complimentary manner to at least a portion of the stepped outer circumference of the tube bundle such that the inlay engages the tube bundle in a positively locked manner via the plurality of bevels.

16. An exhaust gas heat exchanger, comprising:
a cylindrical housing through which a coolant is flowable, the housing including a coolant inlet and a coolant outlet;
a first tube base disposed in a region of the coolant outlet and delimiting a first face end of the housing;
a second tube base disposed in a region of the coolant inlet and delimiting a second face end of the housing;
a tube bundle including a plurality of parallel exhaust gas-conducting tubes disposed within the housing, an inlet side of the plurality of tubes coupled to the first tube base and an outlet side of the plurality of tubes coupled to the second tube base such that the coolant and the exhaust gas flow through the housing in opposite directions;
the tube bundle having a stepped outer circumference such that a plurality of coolant bypass passages are defined between the tube bundle and the housing;
an inlay structured and arranged to at least partly block at least a subset of the plurality of coolant bypass passages such that a coolant flow is directed toward the first tube base and between the plurality of tubes; and
wherein the inlay has a C-shaped cross section.

17. The exhaust gas heat exchanger according to claim 16 , further comprising two diffusers connected to opposing longitudinal ends of the housing, wherein at least a portion of each of the two diffusers is disposed within the housing.

18. The exhaust gas heat exchanger according to claim 16 , wherein the inlay includes a middle portion and two collars, the two collars disposed on opposing longitudinal ends of the middle portion.

19. The exhaust gas heat exchanger according to claim 18 , wherein the inlay further includes a plurality of bevels that protrude from the middle portion toward the tube bundle and extend along the middle portion from one of the two collars to the other of the two collars.

20. An exhaust gas heat exchanger, comprising:
a housing through which a coolant is flowable, the housing including a coolant inlet and a coolant outlet;
a first tube base disposed in a region of the coolant outlet and delimiting a first face end of the housing;
a second tube base disposed in a region of the coolant inlet and delimiting a second face end of the housing;
a tube bundle including a plurality of parallel exhaust gas-conducting tubes disposed within the housing, an inlet side of the plurality of tubes coupled to the first tube base and an outlet side of the plurality of tubes coupled to the second tube base such that the coolant and the exhaust gas flow through the housing in opposite directions;
the tube bundle having a stepped outer circumference such that a plurality of coolant bypass passages are defined between the tube bundle and the housing;
an inlay structured and arranged to at least partly block at least a subset of the plurality of coolant bypass passages such that a coolant flow is directed toward the first tube base and between the plurality of tubes;
wherein the plurality of tubes are structured as a plurality of rectangular tubes and are disposed spaced apart from one another; and
wherein a distance between the inlay and the tube bundle is equal to

Assignees

• Mahle Int Gmbh

Inventors

• Geskes Peter
• Müller Harald
• Schwaderer Daniel
• Stadelhofer Dirk

Classifications

• F28F9/026

  with static flow control means, e.g. with means for uniformly distributing heat exchange media into conduits · CPC title

• F02M26/32

  Liquid-cooled heat exchangers · CPC title

• F28D7/1684 Primary

  the conduits having a non-circular cross-section · CPC title

• F28D21/0003

  the heat being recuperated from exhaust gases (F28D21/0014 takes precedence) · CPC title

• F01N2240/02

  a heat exchanger · CPC title