HEAT EXCHANGER HAVING AN INTERNAL BYPASS
The present invention provides an exhaust recirculation cooler for transferring heat between engine exhaust and a coolant. The cooler can include a housing having a first end and a second end spaced from the first end, a heat transfer region extending through the housing and including a plurality of tubes positioned along a flow path for the coolant, and an internal bypass extending through the housing between the first end and the second end adjacent to the heat transfer region. Together, at least one of the plurality of tubes and the internal bypass provide an exhaust flow path through the cooler.
The present invention relates to heat exchangers and, more particularly, to an exhaust gas waste heat recovery system and a method of operating the same.
SUMMARYIn some embodiments, the present invention provides an exhaust recirculation cooler for transferring heat between engine exhaust and a coolant. The cooler can include a housing having a first end and a second end spaced from the first end, a heat transfer region extending through the housing and including a plurality of tubes positioned along a flow path for the coolant, and an internal bypass extending through the housing between the first end and the second end adjacent to the heat transfer region. Together, at least one of the plurality of tubes and the internal bypass can provide an exhaust flow path through the cooler.
The present invention also provides an exhaust recirculation cooler including a housing having a first end and a second end spaced from the first end and at least partially enclosing a heat transfer region, and a primary exhaust flow path including two passes extending through the housing between the first and second ends in counter flow directions. At least a portion of the primary exhaust flow path can have heat-transfer augmentations and can extend through the heat transfer region wherein heat is transferred from exhaust traveling through the primary exhaust flow path to a coolant flow path. The cooler can also include a secondary exhaust flow path extending through the housing between the first end and the second end and being substantially free from heat transfer augmentations.
In addition, the present invention provides a method of operating an exhaust recirculation cooler including a housing at least partially defining a heat transfer region. The method can include the act of directing engine exhaust through the housing between first and second ends of the housing around the heat transfer region and back through the heat transfer region.
The present invention also provides a method of operating an exhaust recirculation cooler including a housing having a first end and a second end and at least partially defining a heat transfer region. The method can include the acts of directing engine exhaust along two passes through the heat transfer region in counter flow directions, transferring heat from the engine exhaust traveling through the heat transfer region to coolant traveling through the heat transfer region, and directing engine exhaust from the first end of the housing toward the second end of the housing through an internal bypass in the housing and around the heat transfer region.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
Also, it is to be understood that phraseology and terminology used herein with reference to device or element orientation (such as, for example, terms like “central,” “upper,” “lower,” “front,” “rear,” and the like) are only used to simplify description of the present invention, and do not alone indicate or imply that the device or element referred to must have a particular orientation. In addition, terms such as “first,” “second,” and “third” are used herein for purposes of description and are not intended to indicate or imply relative importance or significance.
As shown in
In some embodiments such as the illustrated embodiment of
The heat exchanger 10 can also or alternatively include a first header 40 positioned between the first end 14 of the housing 12 and the first collection tank 28 and a second header 42 positioned between the second end 16 of the housing 12 and the second collection tank 30. In some such embodiments, the first header 40 can at least partially enclose a fluid reservoir of the first collection tank 28 and the second header 42 can at least partially enclose a fluid reservoir of the second collection tank 30. In other embodiments, the heat exchanger 10 can include a single header 40 and/or a single collection tank 28 located at one of the first and second ends 14, 16 or at another location on the heat exchanger 10.
In some embodiments, the first and second headers 40, 42 can be substantially similarly configured and can be substantially similarly sized. For example, in the illustrated embodiment of
As shown in
The heat exchanger core 54 can also include a number of baffles 58 (e.g., six in the illustrated embodiment of
As shown in FIGS. 2 and 4-9, the heat exchanger core 54 can also or alternatively include a heat transfer region 60. The heat transfer region 60 can include one or more of the tubes 56, and each of the tubes 56 in the heat transfer region 60 can include surface augmentations 62 for increasing heat transfer between the first working fluid traveling along the first flow path 24 and a second working fluid (e.g., exhaust gas, water, engine coolant, CO2, an organic refrigerant, R12, R245fa, air, and the like) traveling along a second flow path (represented by arrows 64 in
In some embodiments, such as the illustrated embodiments of
The tube or tubes 56 of the bypass 66 can also or alternatively be positioned along the flow path 24 of the first working fluid. In some embodiments, the tube or tubes 56 of the bypass 66 can be at least partially insulated and/or can have a thicker outer wall than the tube or tubes 56 of the heat exchange region 60 to prevent and/or reduce the transfer of heat between the first working fluid traveling along the first flow path 24 and the second working fluid traveling through the bypass 66 along the second flow path 64. Alternatively or in addition, the bypass 66 can be configured such that the second working fluid travels at a greater velocity through the tube or tubes 56 of the bypass 66 than the tubes 56 of the heat transfer region 60. For example, as shown in
The heat exchanger 10 can also include a valve 70 supported adjacent to a flow-directing wall 74 downstream from the second header 42 for controlling the flow of the second working fluid. In some embodiments such as the illustrated embodiment of
During operation, the heat exchanger 10 can transfer heat from the second working fluid to the first working fluid. Alternatively, while reference is made herein to transferring heat between two working fluids, in some embodiments of the present invention, the heat exchanger 10 can operate to transfer heat between three or more fluids. In other embodiments, the heat exchanger 10 can operate as a recuperator and can transfer heat from a high temperature location of a heating circuit to a low temperature location of the same heating circuit. In some such embodiments, the heat exchanger 10 can transfer heat from a working fluid traveling through a first portion of the heat transfer circuit to the same working fluid traveling through a second portion of the heat transfer circuit.
With reference to
Once the second working fluid is downstream from the second header 42 and/or once the second working fluid enters the second collection tank 30, the valve 70 selectively directs the second working fluid into the heat transfer region 60 or away from the heat exchanger 10. More specifically, when the valve 70 is moved toward the second position (shown in
When the valve 70 is moved toward the first position (shown in
With reference to
In the illustrated embodiment of
In the illustrated embodiment of
As shown in
While reference is made herein to an embodiment in which a collection tank 128 is secured to one end (i.e., the first end 114) of the housing 112 and a mounting flange 143 is secured to an opposite end (i.e., the second end 116) of the housing 112, in other embodiments, mounting flanges 143 can be secured to both the first and second ends 114, 116 of the housing 112, or alternatively, a collection tank 128 can be secured to the second end 116 of the housing 112 and a mounting flange 143 can be secured to the first end 114 of the housing 112. As shown in FIGS. 10 and 12-14, a valve 170 can be supported adjacent to a flow-directing wall 174 downstream from the mounting flange 143 for controlling the flow of the second working fluid.
With reference to
Once the second working fluid is downstream from the second header 142 and/or the mounting flange 143, the valve 170 selectively directs the second working fluid into the heat transfer region 160 or away from the heat exchanger 110. More specifically, when the valve 170 is moved toward a second position, the valve 170 and the wall 174 prevent the second working fluid from entering the heat transfer region 160 through the second opening 146 in the mounting flange 143 and direct the second working fluid outwardly away from the heat exchanger 110 and along the secondary pathway (not shown).
When the valve 170 is moved toward the first position, the valve 170 and the wall 174 prevent the second working fluid from exiting the heat exchanger 110 and direct the second working fluid toward the second opening 146 in the mounting flange 143 and into the heat transfer region 160 along the primary pathway 164A. As shown in
With reference to
The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes are possible.
Claims
1. An exhaust recirculation cooler for transferring heat between engine exhaust and a coolant, the heat exchanger comprising:
- a housing having a first end and a second end spaced from the first end;
- a heat transfer region extending through the housing and including a plurality of tubes positioned along a flow path for the coolant; and
- an internal bypass extending through the housing between the first end and the second end adjacent to the heat transfer region, together, at least one of the plurality of tubes and the internal bypass providing an exhaust flow path through the cooler.
2. The exhaust recirculation cooler of claim 1, wherein the coolant is directed across a wall of the bypass.
3. The exhaust recirculation cooler of claim 1, wherein the exhaust flow path is a first exhaust flow path, and further comprising a second exhaust flow path extending through an other of the plurality of tubes, and a valve located adjacent to the second end of the housing and being moveable relative to the housing to selectively direct the exhaust through the first and second exhaust flow paths.
4. The exhaust recirculation cooler of claim 1, further comprising a header secured to an end of the plurality of tubes and defining an inlet to the heat transfer region, an outlet to the heat transfer region and one of an inlet and an outlet to the bypass.
5. The exhaust recirculation cooler of claim 1, wherein the exhaust flow path includes two passes extending through the housing between the first and second ends in counter flow directions.
6. The exhaust recirculation cooler of claim 1, wherein the exhaust flow path is a first exhaust flow path, and further comprising a second exhaust flow path extending through an other of the plurality of tubes, and a valve located adjacent to an outlet of the bypass and being moveable relative to the housing to selectively direct the exhaust from the first exhaust flow path through the second exhaust flow path and away from the cooler.
7. An exhaust recirculation cooler comprising:
- a housing having a first end and a second end spaced from the first end and at least partially enclosing a heat transfer region;
- a primary exhaust flow path including two passes extending through the housing between the first and second ends in counter flow directions, at least a portion of the primary exhaust flow path having heat-transfer augmentations and extending through the heat transfer region wherein heat is transferred from exhaust traveling through the primary exhaust flow path to a coolant flow path; and
- a secondary exhaust flow path extending through the housing between the first end and the second end and being substantially free from heat transfer augmentations.
8. The exhaust recirculation cooler of claim 7, wherein the heat transfer region includes a plurality of tubes, and further comprising an internal bypass extending through the housing between the first end and the second end adjacent to the heat transfer region.
9. The exhaust recirculation cooler of claim 8, wherein the primary exhaust flow path extends through at least one of the plurality of tubes.
10. The exhaust recirculation cooler of claim 8, wherein the coolant flow path is directed across a wall of the bypass.
11. The heat exhaust recirculation cooler of claim 7, further comprising a heat exchanger core including a plurality of tubes supported in the housing and extending through the heat transfer region, the primary exhaust flow path extending through at least one of the plurality of tubes, and wherein the secondary exhaust flow path extends through an other of the plurality of tubes.
12. The heat exhaust recirculation cooler of claim 7, further comprising a header supported at one end of the housing and at least partially defining an inlet to each of the primary and secondary exhaust flow paths.
13. The exhaust recirculation cooler of claim 7, further comprising a valve located adjacent to the second end of the housing and being moveable relative to the housing to selectively direct the exhaust through the primary and secondary exhaust flow paths.
14. The exhaust recirculation cooler of claim 7, further comprising a header secured to one of the first end and the second end of the housing and defining an inlet to the primary exhaust flow path, an outlet to the primary exhaust flow path, and one of an inlet and an outlet to the secondary exhaust flow path.
15. A method of operating an exhaust recirculation cooler including a housing at least partially defining a heat transfer region, the method comprising the act of:
- directing engine exhaust through the housing between first and second ends of the housing around the heat transfer region and back through the heat transfer region.
16. The method of claim 15, further comprising moving a valve relative to the housing to adjust the exhaust flow through the housing.
17. The method of claim 16, wherein moving the valve includes moving the valve from a first position, in which the valve directs the engine exhaust from a bypass extending through the housing between the second end and the first end into the heat transfer region, and a second position, in which the valve directs the engine exhaust from the bypass away from the heat transfer region.
18. The method of claim 15, wherein the heat exchanger includes a header supported in the housing, and wherein directing the engine exhaust through the housing includes directing the exhaust through an inlet of an exhaust flow path defined in the header and directing the engine exhaust through an outlet of the exhaust flow path defined in the header.
19. The method of claim 15, wherein directing the engine exhaust around the heat transfer region includes directing the exhaust through an internal bypass extending through the housing.
20. The method of claim 19, wherein the heat exchanger includes a header supported in the housing, and wherein directing the engine exhaust through the internal bypass includes directing the engine exhaust through an outlet of the internal bypass defined in the header and through an inlet of an exhaust flow path defined in the header.
21. The method of claim 15, wherein directing the engine exhaust through the housing includes directing the engine through two passes extending through the housing between the first and second ends in counter flow directions.
22. A method of operating an exhaust recirculation cooler including a housing having a first end and a second end and at least partially defining a heat transfer region, the method comprising the acts of:
- directing engine exhaust along two passes through the heat transfer region in counter flow directions;
- transferring heat from the engine exhaust traveling through the heat transfer region to coolant traveling through the heat transfer region; and
- directing engine exhaust from the first end of the housing toward the second end of the housing through an internal bypass in the housing and around the heat transfer region.
23. The method of claim 22, further comprising moving a valve relative to the housing to adjust the flow of engine exhaust through the housing.
24. The method of claim 23, wherein moving the valve includes moving the valve from a first position, in which the valve directs the engine exhaust from the bypass into the heat transfer region, and a second position, in which the valve directs the engine exhaust from the bypass away from the heat transfer region.
25. The method of claim 24, wherein the heat exchanger includes a header supported in the housing, and wherein directing the engine exhaust through the internal bypass includes directing the engine exhaust through an outlet of the internal bypass defined in the header and through an inlet of an exhaust flow path defined in the header.
Type: Application
Filed: Aug 30, 2007
Publication Date: Mar 5, 2009
Inventor: Catherine R. Braun (Milwaukee, WI)
Application Number: 11/848,052
International Classification: F28F 27/02 (20060101); F28F 9/00 (20060101);