Exhaust gas recirculation cooler for an internal combustion engine

Abstract

An exhaust gas recirculation cooler may include a housing having a coolant inlet opening into an inlet region and a coolant outlet, and a plurality of cooling tubes arranged in the housing next to one another to form a tube row, each cooling tube connecting an exhaust gas inlet and outlet. At least two tube rows with one arranged on top of another and spaced from each other may form a tube block. Exhaust gas may be flowable through an inside of each cooling tube, and a coolant flow may be able to be circulated outside of the cooling tubes within the housing and flowable through an annular space enclosing the tube block in a circumferential direction. A flow guide arrangement for guiding the coolant in the interior of the tube block may be arranged in the housing lying against at least portions of one of the tube rows.

Claims

1. An exhaust gas recirculation cooler for an internal combustion engine, comprising: a housing having a coolant inlet opening into an inlet region in the housing, and a coolant outlet; and a plurality of cooling tubes arranged in the housing next to one another to form a tube row, each of the plurality of cooling tubes connecting an exhaust gas inlet and an exhaust gas outlet; wherein the tube row includes at least two tube rows with one arranged on top of another and spaced from each other to form a tube block; wherein exhaust gas is flowable through an inside of each of the plurality of cooling tubes, and a coolant flow is able to be circulated outside of the cooling tubes within the housing and is flowable through an annular space enclosing the tube block in a circumferential direction; wherein a flow guide arrangement for guiding the coolant in the interior of the tube block is arranged in the housing lying against at least portions of one of the at least two tube rows; and wherein the flow guide arrangement includes a flow guide structure arranged in at least a portion of the inlet region of the housing and engaging the tube block, and the flow guide structure includes a wire element.

2. The exhaust gas recirculation cooler according to claim 1, wherein the flow guide structure engages about at least one of the tube rows on a side facing the annular space at least in certain areas.

3. The exhaust gas recirculation cooler according to claim 1, wherein the flow guide structure includes at least one fixing region for fixing the flow guide structure on a respective one of the tube rows, and at least one flow guide region for guiding the coolant between adjacent tube rows.

4. The exhaust gas recirculation cooler according to claim 3, wherein at least one of the fixing region and the flow guide region of the flow guide structure is clamped in between the adjacent tube rows.

5. The exhaust gas recirculation cooler according to claim 3, wherein the flow guide region diverts the coolant flowing in from the coolant inlet to the exhaust gas inlet.

6. The exhaust gas recirculation cooler according to claim 3, wherein the fixing region and the flow guide region are integrally formed on the wire element.

7. The exhaust gas recirculation cooler according to claim 1, wherein the wire element is one of an injection molded part, an injection molding, or a wire formed part.

8. The exhaust gas recirculation cooler according to claim 1, wherein the flow guide arrangement includes a ring structure arranged in the annular space about the tube block, the ring structure separating the inlet region within the annular space from the coolant outlet in a fluid-tight manner at least in certain areas.

9. The exhaust gas recirculation cooler according to claim 8, wherein the ring structure includes at least one passage opening through which the coolant is flowable from the inlet region within the annular space to the coolant outlet.

10. The exhaust gas recirculation cooler according to claim 8, wherein the ring structure is fixed on at least one of the tube block and the housing in at least one of a resilient manner and a preloaded manner.

11. The exhaust gas recirculation cooler according to claim 1, wherein the housing includes a circulation space that encloses the tube block in the inlet region in the circumferential direction.

12. The exhaust gas recirculation cooler according to claim 8, wherein the flow guide arrangement includes the ring structure and the flow guide structure, wherein the flow guide structure is integrally formed on the ring structure.

13. The exhaust gas recirculation cooler according to claim 8, wherein the flow guide arrangement includes the ring structure and the flow guide structure, wherein the ring structure engages about the flow guide structure arranged on the tube block.

14. An exhaust gas recirculation cooler for an internal combustion engine, comprising: a housing having a coolant inlet opening into an inlet region in the housing, and a coolant outlet; a plurality of cooling tubes arranged in the housing next to one another to form a tube row, each of the plurality of cooling tubes connecting an exhaust gas inlet and an exhaust gas outlet; wherein the tube row includes at least two tube rows with one arranged on top of another and spaced from each other to form a tube block; and wherein exhaust gas is flowable through an inside of each of the plurality of cooling tubes, and a coolant flow is able to be circulated outside of the plurality of cooling tubes within the housing and is flowable through an annular space enclosing the tube block in a circumferential direction; wherein a flow guide arrangement for guiding the coolant in the interior of the tube block is arranged in the housing lying against at least portions of one of the at least two tube rows; and wherein the flow guide arrangement includes a wire element and a ring structure arranged in the annular space about the tube block, the ring structure separating the inlet region within the annular space from the coolant outlet in a fluid-tight manner at least in certain areas.

15. The exhaust gas recirculation cooler according to claim 14, wherein the ring structure includes at least one passage opening through which the coolant is flowable from the inlet region within the annular space to the coolant outlet.

16. The exhaust gas recirculation cooler according to claim 14, wherein the ring structure is fixed on at least one of the tube block and the housing in at least one of a resilient manner and a preloaded manner.

17. The exhaust gas recirculation cooler according to claim 14, wherein the flow guide arrangement includes the ring structure and at least one flow guide structure, wherein the at least one flow guide structure is integrally formed on the ring structure.

18. The exhaust gas recirculation cooler according to claim 14, wherein the flow guide arrangement includes the ring structure and at least one flow guide structure, wherein the ring structure engages about the at least one flow guide structure arranged on the tube block.

19. An exhaust gas recirculation cooler, comprising: a housing having a coolant inlet and a coolant outlet; and a plurality of cooling tubes arranged in the housing with at least two tube rows forming a tube block and connecting an exhaust gas inlet and an exhaust gas outlet, wherein exhaust gas is flowable through an inside of the plurality of cooling tubes, and a coolant flow is able to be circulated outside of the plurality of cooling tubes and is flowable through an annular space enclosing the tube block in a circumferential direction, wherein a flow guide arrangement for guiding the coolant in the interior of the tube block is arranged in the housing, and wherein the flow guide arrangement includes a wire element arranged in at least a portion of the inlet region of the housing and engaging the tube block.

20. The exhaust gas recirculation cooler of claim 19, wherein the wire element is one of an injection molded part, an injection molding, or a wire formed part.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) It shows, in each case schematically

(2) FIG. 1 a part sectional view of an exhaust gas recirculation cooler according to the invention;

(3) FIG. 2 a part sectional view of an exhaust gas recirculation cooler with a circulation space;

(4) FIG. 3 a view of a flow guide arrangement that is arranged on a tube block;

(5) FIG. 4 a plan view of a flow guide arrangement which is arranged on a tube block;

(6) FIG. 5 a view of a flow guide structure;

(7) FIG. 6 a view of a plurality of flow guide structures which are arranged to form a flow guide arrangement;

(8) FIG. 7 a view of an exhaust gas recirculation cooler with a ring structure;

(9) FIG. 8 a view of an exhaust gas recirculation cooler with a ring structure and with a plurality of flow guide structures.

DETAILED DESCRIPTION

(10) FIG. 1 shows a part sectional view of an exhaust gas recirculation cooler 1 according to the invention. The exhaust gas recirculation cooler 1 comprises a housing 2 in which a plurality of cooling tubes 3 are arranged in columns next to one another to form a tube row 4 and at least two tube rows 4 on top of one another and spaced from one another to form a tube block 5. The respective cooling tube 3 can be flowed through by exhaust gas on the inside and gas-guidingly connects an exhaust gas inlet 6 to an exhaust gas outlet 7. The individual cooling tubes 3 are connected in a fluid-tight manner on the exhaust gas inlet 6 with an exhaust gas inlet base 6a and on the exhaust gas outlet 7 with an exhaust gas outlet base 7a. On the outside, the coolant flow can circulate about the respective cooling tube 3 within the housing 2, for the purpose of which the housing 2 comprises a coolant inlet 9 which opens into the housing 2 in an inlet region 8 and a coolant outlet 10. The exhaust gas recirculation cooler 1 also comprises an annular space 11 enclosing the tube block 5 in the circumferential direction, which can be flowed through by the coolant. According to the invention, the exhaust gas recirculation cooler 1 comprises a flow guide arrangement 12 for guiding the coolant in the interior of the tube block 5, which is arranged in the housing 2 lying against at least one of the tube rows 3 at least in certain areas. In this exemplary embodiment, the flow guide arrangement 12 has a ring structure 13 which is arranged about the tube block 5 in the annular space 11. The ring structure 13 separates in a fluid-tight manner the inlet region 8 within the annular space 11 from the coolant outlet 10, so that a draining of the coolant about the tube block 5 from the inlet region 8 is prevented and the heat transfer in the inlet region 8 is improved. To further improve the heat transfer between the exhaust gas and the coolant, the housing 2 comprises a circulation space 14 which encloses the tube block 5 in the inlet region 8 in the circumferential direction.

(11) FIG. 2 shows a part sectional view of the exhaust gas recirculation cooler 1 with the circulation space 14. For the sake of clarity, the middle cooling tubes 3 in the tube row 4 are shown in dashed lines. In the circulation space 14, the coolant is dammed up prior to it being guided to the exhaust gas inlet 6 and the tube block in the inlet region 8 is cooled longer. From the circulation space 14, the coolant can subsequently be guided into the tube block 5as indicated by arrows. In this way, an even exposure of the tube block 5 to the coolant can be achieved and consequently the heat transfer between the coolant and the exhaust gas in the inlet region 8 increased.

(12) FIG. 3 shows a view and FIG. 4 a plan view of the flow guide arrangement 12 which is arranged on the tube block 5. The flow guide arrangement 12 comprises two flow guide structures 15 which in this exemplary embodiment are via elements. The flow guide structures 15 can be arranged in certain areas in the inlet region 8 of the housing 2 and from the annular space 11 engage in the tube block 5. The flow guide structures 15 each have a fixing region 17 for fixing the respective flow guide structure 15 on the respective tube row 4 and a flow guide region 18 for guiding the coolant between the adjacent tube rows 4. The fixing region 17 engages about the respective tube row 4 and clampingly fixes the flow guide structure 15 on the tube block 5.

(13) In order to increase the heat transfer between the coolant and the exhaust gas, the flow guide region 18 diverts the coolant flowing in from the coolant inlet 9 to the exhaust gas inlet 6. The flow region 18 of the respective flow guide structure 15 to this end comprises two guiding channels 19 which substantially extend in a transverse direction 20 to a longitudinal direction 21 of the tube block 5. The respective guiding channel 19 hasas is visible in FIG. 4an angle to the transverse direction 20 and can divert the coolant to the exhaust gas inlet 6 and to the exhaust gas inlet base 6a. The angle of the guiding channel 19 to the transverse direction 20 or to the longitudinal direction 21 of the tube block 5 and the length of the guiding channel 19 can be adapted in order to influence the flow pattern of the coolant in the tube block 5. By diverting the coolant, the flow guide structure 15 delays a draining of the coolant from the inlet region 8 so that the heat transfer between the coolant and the exhaust gas can be increased.

(14) In FIG. 5, a single wire element 16 of the flow guide structure 15 and in FIG. 6 a total of four wire elements 16 of the flow guide structure 15 to the flow guide structure 12 are arranged. Here, the respective wire element 16 can for example be an injection moulded part and injection moulding or a wire formed part. The fixing region 17 and the flow guide region 18 are integrally formed on the wire element 16. Accordingly, the wire element 16 can be produced cost-effectively. The fixing region 17 of the wire element 16 is formed meander-like and makes possible a force-fit fixing of the wire element 16 on the tube row 4. The flow guide region 18 of the wire element 16 comprises two guiding channels 19 through which guiding the coolant in each case between the adjacent tube rows 4 is made possible. The flow pattern of the coolant in the tube block 5 can be advantageously influenced by changing the length and the width of the guiding channel 19 and the angle to the transverse direction 20.

(15) FIG. 7 shows a view of the exhaust gas recirculation cooler 1 with the ring structure 13 of the flow guide arrangement 12. Here, the ring structure 13 is arranged in the annular space 11 about the tube block 5 and fluid-inhibitingly separates the inlet region 8 within the annular space 11 from the coolant outlet 10. Accordingly, a draining of the coolant about the tube block 5 from the inlet region 8 is advantageously inhibited and the heat transfer in the inlet region 8 improved. In order to prevent damming-up of the coolant and thus an overheating in the inlet region 8, the ring structure 13 comprises at least one passage opening 22. The passage opening 22 is arranged in an angled region 23 of the ring structure 13 and makes possible a draining of the coolant from the inlet region 8 within the annular space 11. In order to influence the draining of the coolant from the inlet region 8, the ring structure 13 can comprise a plurality of passage openings 22 which differ in the size and in the position.

(16) In FIG. 8, a view of the exhaust gas recirculation cooler 1 with the flow guide arrangement 12 is shown, which comprises the ring structure 13 and the flow guide structures 15. The ring structure 13 engages about the flow guide structures 15 arranged on the tube block 5, as a result of which an additional fixing of the flow guide structure 15 in the tube block 5 is made possible.

(17) The flow guide arrangement 12 can be arranged in the tube block 5 for example even during the production of the exhaust gas recirculation cooler 1. Dependent on the dimensions of the exhaust gas recirculation cooler 1, the flow guide arrangement 12 can also be suitably adapted. By way of the flow guide arrangement 12, the heat transfer in the exhaust gas recirculation cooler 1 according to the invention is improved and because of this a mechanical failure of the exhaust gas recirculation cooler 1 as a consequence of an overheating advantageously prevented and also the efficiency of the exhaust gas recirculation cooler 1 increased.