The specification relates to a heat exchanger and a heat exchanger plate having means for reducing thermal stress around the manifold.
Thermal stresses can be created in self-enclosed heat exchangers (i.e. stacked plate heat exchangers with integral manifolds, where the fluids are self-contained and do not require an outer housing) where manifolds for hot fluids are provided on the outer periphery of a plate stack, while central portions of the plate stack are cooled by circulation of a coolant. The hot fluid manifolds are in contact with the hot fluid and are significantly hotter than the central areas of the stack, which are in constant contact with a coolant. Consequently, there is a significant surface temperature difference at the hot gas inlet manifold between its side adjacent to the peripheral edge of the heat exchanger (outer side) and its side adjacent to the central (main) coolant passage (inner side). Such a thermal gradient in the manifold can result in high thermal stresses at the manifold. A similar issue can occur at the hot gas outlet manifold, however, it can be to a lesser extent, as the gas temperature has typically been reduced upon contact with the heat exchange coolant.
The situation described above can also create a thermal gradient across the plates which may cause thermal stresses. This issue can arise in any situation where a high temperature fluid enters a heat exchanger through uncooled manifolds provided at the outer edges of a plate stack, such as in an EGHR (exhaust gas heat recovery) cooling and charge air cooling, where a hot gas is cooled by a liquid or gaseous coolant.
Due to design constraints dictated by the valve configuration in an EGHR, and in order to maximize cooling efficiency, the exhaust inlet and outlet manifolds are located at the edges of the heat exchanger core. It will be appreciated that the portions of the stack which are in contact with the coolant will be at a considerably lower temperature than those areas of the stack which are in contact with the hot exhaust gases only (circled in FIG. 2), thereby creating a thermal gradient across the plates making up the stack. In addition, the hot exhaust gas manifold portion located close to the peripheral edges of the heat exchanger plate can be significantly hotter than the hot exhaust gas manifold portion positioned on the inner side of the plate and in contact with the coolant fluid. This can significantly affect the durability of the heat exchanger that is exposed to hot gases, such as the heat exchanger in an EGHR system.
The thermal gradient described with reference to
There is a need in the art for a heat exchanger having uniformly cooled heat exchanger plates and a base plate that can help to reduce the thermal stresses caused by the thermal gradient which results from a hot exhaust gas flowing through the heat exchanger. In addition, there is a need in the art for a means that can help to reduce and/or protect the base plate from the hot exhaust gas impinging on the base plate of a heat exchanger.
Reference will now be made, by way of example, to the accompanying drawings which show example embodiments of the present application, and in which:
Similar reference numerals may have been used in different figures to denote similar components.
The heat exchanger plate (4) has a pair of bosses (54), with one of the bosses (54) having a heat exchanger plate first fluid inlet (16) and the other boss (54) having a heat exchanger plate first fluid outlet (18). As shown in
The heat exchanger plate (4) is also provided with an embossment (34) having an aperture (36), which can be the heat exchanger plates' second fluid inlet (24) or outlet (26) and permits flow of a second fluid. The heat exchanger plate (4) shown in
The heat exchanger plate (4) has a peripheral edge portion (38) that is adapted for operatively coupling of the heat exchanger plate (4) to a second plate, such as, a second heat exchanger plate (4), deflector plate (6) (as described herein) or base plate (74). The peripheral edge portion (38) has a peripheral wall (56) and a peripheral flange (60) extending from the peripheral wall (56) to a peripheral edge (58) of the heat exchanger plate (4). As shown in
In addition, as shown in
Similarly, presence of the other channel (50) between the embossment having the second fluid outlet (26) and the peripheral edge portion (38) and having a bed (52) in a plane below the plane of the passage (32), facilitates preferential flow of the first fluid over the passage (32) to the other channel (50) prior to exiting through the first fluid outlet (18). The presence of a channel (50) can help to ensure that area between the embossments (34) having the second fluid inlet (24) and outlet (26) and the peripheral edge portion (38) receives a steady flow coolant (or first fluid), as seen in
The shape, depth, width and other aspects of the channel (50) are not particularly limited and can depend upon the particular design and application requirements. For instance, the plane in which the bed (52) of the channel (50) lies is not particularly limited, and in one embodiment, can be anywhere from being below the plane of the passage (32) of the heat exchanger plate (4) to the plane formed by the portion of the bosses (54) having the first fluid inlet/outlet (16, 18). Further, the width and shape of the channel (50) and bed (52) can be varied so long it allows sufficient fluid flow in between the peripheral edge portion (38) and the embossments (34). In the embodiment shown in the
As the bed (52) of the channel (50) lies in a plane below the plane of the heat exchanger plate passage (32), an indentation (62) can be formed between the first fluid inlet (16) and the channel (50). A similar indentation (62) can be formed between the first fluid outlet (18) and the channel (50). In addition, a step (66) can be provided between the heat exchanger plate passage (32) and the channel (50) that leads to the first fluid outlet (18) (or inlet (16)). Once the first fluid passes over the heat exchanger plate passage (32), the step (66) between the embossment (34) having the second fluid outlet (26) and the peripheral wall (56) can facilitate flow of the first fluid into the channel (50) that leads to the first fluid outlet (18). Consequently, the step (66) can help ensure that a first fluid flows into the second channel (50) before it exits through the first fluid outlet (18). Moreover, as described herein, this can help to reduce the thermal stress between second fluid outlet manifold (22) and the peripheral edge portion (38) of the heat exchanger plate (4).
The shape and position of the indentation (62) and step (66) is not particularly limited, and can depend upon the particular design or application requirements. In one embodiment, for example and without limitation, the indentation (62) and step (66) can vary from being sloped (such as a ramp) to being nearly normal to the plane of the bed (52) of the channel (50). Similarly, the position of the step (66) can vary. In the embodiment shown in
The heat exchanger plate (4) can be provided with one or more dimples (76) that can help to create a turbulent flow over the heat exchanger plate passage (32). The number and shape of the dimples is not particularly limited and can depend upon the particular design or application requirements. Further, the dimples (76) can be replaced with other means, such as, for example and without limitation, a turbulizer, which can help to create a turbulent flow and also assist with heat exchange.
When a pair of heat exchanger plates (4) are placed in a face-to-face relationship (
As shown in
By providing channels (50) having coolant flow between the second fluid inlet and outlets manifolds (20, 22), and the peripheral edge portion (38) of the heat exchanger plate (4), the second fluid inlet and outlet manifolds (20, 22) portion close to the peripheral edge portion (38) of the heat exchanger plate (4) can be cooled and can help to reduce the thermal stress, particularly, on the second fluid inlet manifold (20). In addition, this can help to limit the amount of hot exhaust gas that contacts the peripheral edge portion (38) of the heat exchanger plates (4), thereby reducing the thermal stress on the edges (58) of the heat exchanger plates (4).
Typically and as can be seen in
In one aspect, a thermally insulating gasket (72) is provided between the exhaust gas valve body (68) and the heat exchanger mounting plate (70) as shown in
In accordance with a further aspect, the specification discloses a deflector plate (6) (see
Similar to the heat exchanger plate (4), the deflector plate (6) is provided with a peripheral edge portion (46) that is adapted for operatively coupling of the deflector plate (6) to a second plate, such as a heat exchanger plate (4) or base plate (74). The base plate (74) can be similar to the base plate of a heat exchanger apparatus as shown in
In one embodiment, as disclosed herein, the deflector plate (6) is positioned near an end of the heat exchanger (2), which is distal from the opening (30) where the hot exhaust gas enters. In the embodiment shown in
In a further embodiment in accordance with the specification and as disclosed in
The position of the deflector (48) is aligned with the second fluid inlet manifold (20) to shield the base plate (74) from the hot exhaust gas. In addition, as shown in the figures, the deflector (48) extends in the same direction as the bosses having the first fluid inlet and outlet (42, 44). In one embodiment, the size and position of the deflector (48) allows the deflector to protrude towards the second fluid inlet (24) or outlet (26) of an adjacent heat exchanger plate (4). The size and shape of the deflector (48) is not particularly limited. In one embodiment, for example and without limitation, the deflector (48) is sized to nearly fill the entire area of the second fluid inlet (24) or outlet (26) of an adjacent heat exchanger plate (4). In another embodiment, in accordance with the specification, the deflector (48) has an arcuate shape as shown in the figures, with the convex portion of the deflector (48) facing the hot exhaust gas.
The point of coupling of the deflector (48) to the deflector plate (6) and the means for coupling the deflector (48) to the deflector plate (6) are also not particularly limited. In one embodiment, as shown in FIGS. 5 and 7-9, the deflector (48) is coupled to the deflector plate (6) near the deflector plate passage (40) rather than near the peripheral edge portion (46) of the deflector plate (6). In a further embodiment, the means for coupling the deflector (48) to the deflector plate (6) can vary depending upon the particular product requirements. In one embodiment, for example and without limitation, the deflector (48) is an integral part of the deflector plate (6), permitting for example the deflector to be integrally formed during the stamping of the deflector plate (6).
The material of construction of the deflector (48) and the number of deflectors (48) in the deflector plate (6) are also not particularly limited. In one embodiment, for example and without limitation, the material of construction of the deflector (48) is the same as that used for the making the deflector plate (6), particularly when the deflector (48) is an integral part of the deflector plate (6). In a particular embodiment and as shown in the figures, two deflectors (48) can be provided on the deflector plate (6). One of the deflectors (48) is aligned with the second fluid inlet manifold (20), while the second is aligned with the second fluid outlet manifold (22). Such an embodiment can help with protection of the base plate (74) from the hot exhaust gas, entering from the second fluid inlet (24) and preventing direct impingement on the base plate (74). While the second deflector (48) can help guide the hot fluid gases towards the second fluid outlet manifold (22), thereby also protecting the base plate (74) and the peripheral edge portion (38). An alternate embodiment having only a single deflector (48) positioned in line with the second fluid inlet manifold (20) are also possible, which could provide protection of the base plate (74) from the hot exhaust gas and prevent direct impingement on the base plate (74).
The presence of deflector (48) can have significant advantages in addition to the protection provided to the base plate (74). The deflector (48) can narrow the entrance of the second fluid inlet (24) to the second fluid conduit (10) closest to the deflector plate (6), thereby reducing the quantity of hot exhaust gas contacting the base plate (74). This can help to reduce the thermal stress on the base plate (74). In addition, the partial blocking of the second fluid inlet (24) to the second fluid conduit (10) closest to the deflector plate (6) can help to improve the heat flow distribution of the hot exhaust gas to the other second fluid conduits (10) in the heat exchanger. This can result in improved heat exchange efficiency between the hot exhaust gas and the coolant.
In a further embodiment, the deflector plate (6) has a depression (not shown) that is similar to the depression (64) in a base plate (74), and is positioned underneath the deflectors (48). Such an embodiment can be formed by providing a continuous plate surface from one edge of the embossment (34) to the opposing edge. In other words, the deflector plate (6) can lack the openings in the embossments (34) that can provide a passage for flow of the second fluid. In addition, the deflector plate (6) is provided with a deflector (48) that extends above such a depression. The position and presence of the depression can help to stiffen and/or further strengthen the deflector plate (6), as the deflector plate (6) is typically of the same thickness as all other plates in the stack.
In addition to the above,
In addition, in
As shown in
Embodiments of the invention are disclosed herein, which include, for example and without limitation, the following.
1. A heat exchanger plate containing:
a passage permitting fluid communication from a heat exchanger plate first fluid inlet to a heat exchanger plate first fluid outlet;
a pair of bosses, with one of the bosses having the first fluid inlet and the second boss having the first fluid outlet;
a pair of embossments, the embossments being positioned for engaging an embossment in an adjacent heat exchanger plate, when a plurality of heat exchanger plates are stacked;
a peripheral edge portion adapted for operatively coupling of the heat exchanger plate to a second plate, and wherein a plurality of face-to-face stacked heat exchanger plates form a first fluid conduit for flow of a first fluid from a heat exchanger first fluid inlet to a heat exchanger first fluid outlet; and
a channel positioned intermediate the peripheral edge portion and the embossment, and permitting fluid communication from the heat exchanger plate first fluid inlet to the passage.
2. The heat exchanger plate according to embodiment 1, wherein each embossment has an aperture permitting flow of a second fluid; and wherein a plurality of face-to-face stacked heat exchanger plates forms a second fluid conduit for flow of the second fluid from a heat exchanger second fluid inlet to a heat exchanger second fluid outlet.
3. The heat exchanger plate according to embodiment 1 or 2, wherein the channel has a bed being in a plane different from a plane defined by the passage for facilitating preferential flow of a first fluid from the heat exchanger plate first fluid inlet to the channel over flow to the passage.
4. The heat exchanger plate according to any one of embodiments 1 to 3, further containing:
an indentation from the channel to the boss having the first fluid inlet;
wherein the bed is in a plane between the plane of the passage and the plane of the boss having first fluid inlet.
5. The heat exchanger plate according to embodiment 4, further containing a step from the channel to the passage of the heat exchanger plate, the step being positioned proximate to an opposing end from the first heat exchanger inlet and outlet, and also between the peripheral edge portion and the embossments permitting second fluid flow.
6. The heat exchanger plate according to any one of embodiments 1 to 5, further containing a second channel positioned intermediate the peripheral edge portion and the embossment, and permitting fluid communication from the passage to the heat exchanger plate first fluid outlet; the channel having a bed being in a plane different from a plane defined by the passage for facilitating preferential flow of a first fluid from the passage to the second channel.
7. The heat exchanger plate according to embodiment 6, further containing a second step from the passage to the second channel of the heat exchanger plate, the second step being positioned proximate to an opposing end from the first heat exchanger inlet and outlet, and also between the peripheral edge portion and the embossments permitting second fluid flow.
8. The heat exchanger plate according to any one of embodiments 1 to 7, wherein the peripheral edge portion contains a peripheral wall and a peripheral flange extending from the wall to a peripheral edge.
9. The heat exchanger plate according to any one of embodiments 1 to 8, wherein the passage contains protrusions or dimples.
10. A heat exchanger apparatus containing:
a plurality of heat exchanger plates, the heat exchanger plates being placed in a face-to-face relationship and defining a first fluid conduit and a second fluid conduit, first fluid inlet and outlet manifolds having a first fluid inlet and first fluid outlet, respectively, and in fluid communication with the first fluid conduit, and a second fluid inlet and outlet manifolds having a second fluid inlet and a second fluid outlet, respectively, and being in fluid communication with the second fluid conduit, the plurality of heat exchanger plates permitting heat exchange between first and second fluids in the first and second fluid conduits, respectively, and
wherein
each of the plurality of heat exchanger plates containing:
a passage permitting fluid communication from a heat exchanger plate first fluid inlet to a heat exchanger plate first fluid outlet;
a pair of bosses, with one of the bosses having the first fluid inlet and the second boss having the first fluid outlet;
a pair of embossments, each embossment having an aperture permitting flow of a second fluid;
a peripheral edge portion adapted for operatively coupling of the heat exchanger plate to a second plate; and
a channel positioned intermediate the peripheral edge portion and the embossment, and permitting fluid communication from the heat exchanger plate first fluid inlet to the passage.
11. The heat exchanger apparatus according to embodiment 10, wherein the channel has a bed being in a plane different from a plane defined by the passage for facilitating preferential flow of a first fluid from the heat exchanger plate first fluid inlet to the channel over flow to the passage.
12. The heat exchanger apparatus of embodiment 10 or 11, further containing a deflector plate and a base plate, the deflector plate and the base plate being positioned distil from the second fluid inlet, and the deflector plate containing:
a deflector plate passage permitting fluid communication from a deflector plate first fluid inlet to a deflector plate first fluid outlet; the deflector plate first fluid inlet and outlet being in fluid communication with the heat exchanger plate inlet and outlet, respectively;
a pair of deflector plate bosses, with one of the bosses having a deflector plate first fluid inlet and the second boss having a deflector plate first fluid outlet;
a pair of deflector plate embossments, the embossments being positioned for engaging the base plate, and preventing contact of the second fluid from the base plate;
a deflector plate peripheral edge portion adapted for operatively coupling of the deflector plate to the base plate; and
a deflector plate channel positioned intermediate the deflector plate peripheral edge portion and the deflector plate embossment, and permitting fluid communication from the deflector plate first fluid inlet to the deflector plate passage.
13. The heat exchanger apparatus according to any one of embodiments 10 to 12, wherein the heat exchanger plate further contains:
an indentation from the channel to the boss having the first fluid inlet;
wherein the bed is in a plane between the plane of the passage and the plane of the boss having first fluid inlet.
14. The heat exchanger apparatus according to embodiment 13, wherein the heat exchanger plate further contains a step from the channel to the passage of the heat exchanger plate, the step being positioned proximate to an opposing end from the first heat exchanger inlet and outlet, and also between the peripheral edge portion and the embossments permitting second fluid flow.
15. The heat exchanger apparatus according to any one of embodiments 10 to 14, wherein the heat exchanger plate further contains a second channel positioned intermediate the peripheral edge portion and the embossment, and permitting fluid communication from the passage to the heat exchanger plate first fluid outlet; the channel having a bed being in a plane different from a plane defined by the passage for facilitating preferential flow of a first fluid from the passage to the second channel.
16. The heat exchanger apparatus according to embodiment 15, wherein the heat exchanger plate further contains a second step from the passage to the second channel of the heat exchanger plate, the second step being positioned proximate to an opposing end from the first heat exchanger inlet and outlet, and also between the peripheral edge portion and the embossments permitting second fluid flow.
17. The heat exchanger apparatus according to any one of embodiments 10 to 16, wherein the peripheral edge portion contains a peripheral wall and a peripheral flange extending from the wall to a peripheral edge.
18. The heat exchanger apparatus according to any one of embodiments 10 to 17, wherein the passage contains protrusions or dimples.
19. The heat exchanger apparatus according to any one of embodiments 10 to 18, wherein the apparatus is coupled to a valve.
20. The heat exchanger apparatus according to embodiment 19, further containing a gasket positioned between the valve and the heat apparatus.
21. A deflector plate containing:
a first boss and a second boss, both extending in a first direction from a plane of a passage, the first boss having a deflector plate first fluid inlet and the second boss having a deflector plate first fluid outlet, and the passage permitting flow of a first fluid from the deflector plate first fluid inlet to the deflector plate first fluid outlet;
a peripheral edge portion adapted for operatively coupling of the deflector plate to a second plate, and wherein a plurality of face-to-face stacked plates form a first fluid conduit for flow of the first fluid from a first fluid inlet to a first fluid outlet and a second fluid conduit for flow of a second fluid from a second fluid inlet to a second fluid outlet; and
an embossment extending in a second direction, the second direction being opposed to the first direction, and the peripheral edge of the embossment being positioned for alignment with a peripheral edge of the second fluid conduit upon stacking of the plates; and
a deflector extending from the embossment in the first direction.
22. The deflector plate according to embodiment 21, wherein the deflector has an arcuate profile and extends into the second fluid conduit upon stacking of the plates.
23. The deflector plate according to embodiment 21 or 22, wherein the deflector is coupled to the edge of the embossment and extends from proximate to the passage to the peripheral edge.
24. The deflector plate according to embodiment 21 or 22, wherein the deflector is coupled to the edge of the embossment and extends from proximate to the peripheral edge to the passage.
25. The deflector plate according to any one of embodiments 21 to 24, further containing a channel positioned intermediate the peripheral edge portion and the embossment, and permitting fluid communication from the deflector plate first fluid inlet to the passage; the channel having a bed being in a plane different from a plane defined by the passage for facilitating preferential flow of the first fluid from the deflector plate first fluid inlet to the channel over flow to the passage.
26. The deflector plate according to any one of embodiments 21 to 25, further containing an indentation from the channel to the boss having the first fluid inlet; and wherein the bed is in a plane between the plane of the passage and the plane of the boss having first fluid inlet.
27. The deflector plate according to any one of embodiments 21 to 26, further containing a step from the channel to the passage of the deflector plate, the step being positioned proximate to an opposing end from the deflector plate first fluid inlet and outlet, and also between the peripheral edge portion and the embossments.
28. The deflector plate according to any one of embodiments 21 to 27, further containing a second channel positioned intermediate the peripheral edge portion and the embossment, and permitting fluid communication from the passage to the deflector plate first fluid outlet; the channel having a bed being in a plane different from a plane defined by the passage for facilitating preferential flow of a first fluid from the passage to the second channel.
29. The deflector plate according to embodiment 28, further containing a second step from the passage to the second channel of the deflector plate, the second step being positioned proximate to an opposing end from the deflector plate inlet and outlet, and also between the peripheral edge portion and the embossments.
30. The deflector plate according to any one of embodiments 21 to 29, wherein the peripheral edge portion contains a peripheral wall and a peripheral flange extending from the wall to a peripheral edge.
31. The deflector plate according to any one of embodiments 21 to 30, wherein the passage contains protrusions or dimples.
32. A heat exchanger apparatus containing:
a plurality of heat exchanger plates and a deflector plate coupled to one another, the plurality of heat exchanger plates together with the deflector plate defining first and second fluid conduits permitting heat exchange between first and second fluids flowing in the first and second fluid conduits, respectively;
a first fluid inlet and outlet manifolds coupled to the plurality of heat exchanger plates and deflector plate for flow of the first fluid from a first fluid inlet to a first fluid outlet via the first fluid conduit;
a second fluid inlet and outlet manifolds coupled to the plurality of heat exchanger plates and deflector plate for flow of the second fluid from a second fluid inlet to a second fluid outlet via the second fluid conduit; and
a deflector coupled to the deflector plate for shielding the base plate from the second fluid, wherein
the deflector plate is positioned distal from an opening permitting entry of the second fluid flow in the second fluid inlet manifold.
33. The heat exchanger apparatus according to embodiment 32, wherein the deflector plate contains:
a first boss and a second boss, both extending in a first direction from a plane of a passage, the first boss having a deflector plate first fluid inlet and the second boss having a deflector plate first fluid outlet, and the passage permitting flow of a first fluid from the deflector plate first fluid inlet to the deflector plate first fluid outlet;
a peripheral edge portion adapted for operatively coupling of the deflector plate to the heat exchanger plate; and
an embossment extending in a second direction, the second direction being opposed to the first direction, and the peripheral edge of the embossment being positioned for alignment with a peripheral edge of the second fluid conduit upon stacking of the plates; and
the deflector extending from the embossment in the first direction.
34. The heat exchanger according to embodiment 33, wherein the deflector has an arcuate profile and extends into the second fluid conduit upon stacking of the plates.
35. The heat exchanger according to embodiment 33 or 34, wherein the deflector is coupled to the edge of the embossment and extends from proximate to the passage to the peripheral edge.
36. The heat exchanger according to embodiment 33 or 34, wherein the deflector is coupled to the edge of the embossment and extends from proximate to the peripheral edge to the passage.
37. The heat exchanger according to any one of embodiments 33 to 36, further containing a channel positioned intermediate the peripheral edge portion and the embossment, and permitting fluid communication from the first fluid inlet to the passage; the channel having a bed being in a plane different from a plane defined by the passage for facilitating preferential flow of the first fluid from the first fluid inlet to the channel over flow to the passage.
38. The heat exchanger according to any one of embodiments 33 to 37, further containing an indentation from the channel to the boss having the first fluid inlet; and wherein the bed is in a plane between the plane of the passage and the plane of the boss having first fluid inlet.
39. The heat exchanger according to any one of embodiments 33 to 38, further containing a step from the channel to the passage, the step being positioned proximate to an opposing end from the first fluid inlet and outlet, and also between the peripheral edge portion and the embossments.
40. The heat exchanger according to any one of embodiments 33 to 39, further containing a second channel positioned intermediate the peripheral edge portion and the embossment, and permitting fluid communication from the passage to the first fluid outlet; the channel having a bed being in a plane different from a plane defined by the passage for facilitating preferential flow of a first fluid from the passage to the second channel.
41. The heat exchanger according to embodiment 40, further containing a second step from the passage to the second channel, the second step being positioned proximate to an opposing end from the first fluid inlet and outlet, and also between the peripheral edge portion and the embossments.
42. The heat exchanger according to any one of embodiments 33 to 41, wherein the peripheral edge portion contains a peripheral wall and a peripheral flange extending from the wall to a peripheral edge.
43. The heat exchanger according to any one of embodiments 33 to 42, wherein the passage contains protrusions or dimples.
Certain adaptations and modifications of the described embodiments can be made. Therefore, the above discussed embodiments are considered to be illustrative and not restrictive.
This application claims the benefit of and priority to U.S. provisional application No. 61/768,324 filed Feb. 22, 2013, and having the title HEAT EXCHANGER WITH MANIFOLD COOLING AND DEFLECTOR. The content of the above patent application is hereby expressly incorporated herein by reference into the detailed description thereof.
Number | Date | Country | |
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61768324 | Feb 2013 | US |