Heat exchanger with plate projections

Abstract

A plate heat exchanger including first and second sets of heat exchanger plates. The second set plates are alternately stacked with the first set plates to form flow channels therebetween. The first set plates have first projections protruding in one direction from the plane of the plates and second projections protruding in the opposite direction from the plane of the plate. The second set plates have third projections protruding in the one direction from the plane of the second set plates. The first projections are connected to adjacent second set plates and the second projections protrude into the space between at least two of the third projections. The second projections may be spaced from and not connected to the second set plates, with the height of the third projections from the second set plates being greater than the height of the first and second projections from opposite sides of the first set plates.

Description

CROSS REFERENCE TO RELATED APPLICATION(S)

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

TECHNICAL FIELD

The present invention relates to a plate heat exchanger, and more particularly a plate heat exchanger having at least two types of heat exchanger plates stacked to form flow channels between them with projections protruding from the plane of the plate connected to the adjacent heat exchanger plate.

BACKGROUND OF THE INVENTION AND TECHNICAL PROBLEMS POSED BY THE PRIOR ART

Plate heat exchangers having projections from the plates are known, for example, from FIG. 8 of EP 742 418 B1 (prescribed there as oil coolers). They are also known from numerous other publications for other types of applications, including DE 100 34 343C2, DE 201 19 565 U1 and U.S. Pat. No. 4,781,248.

Internal inserts, as opposed to projections formed in the plates themselves, are also often used with plate heat exchangers. However, such inserts often can cause difficult to remove residues to remain in the flow channels, including, for example, fine metallic chips that form during production of the internal inserts. If such residues reach the oil loop, for example, they can lead to failure of the system. Despite this, however, better heat exchange efficiency can often be achieved with internal inserts over heat exchangers in which the plate bottoms are shaped. In addition, internal inserts often enjoy advantages over the mentioned shapes with respect to strength of the plate heat exchanger (especially its resistance to high internal pressures) since the inserts may be metallically connected over a relatively large area to the opposite plate bottoms of the heat exchanger plates.

The present invention is directed toward overcoming one or more of the problems set forth above.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, a plate heat exchanger is provided including first and second sets of heat exchanger plates. The plates of the second set are alternately stacked with the plates of the first set of plates to form flow channels therebetween. The first set of heat exchanger plates have first projections protruding in one direction from the plane of the plates and second projections protruding in the opposite direction from the plane of the plate. The second set of heat exchanger plates have third projections protruding in the one direction from the plane of the plates of the second set. The first projections are connected to the adjacent heat exchanger plate of the second set and the second projections narrow the flow channel by protruding into the space between at least two of the third projections.

In one form of this aspect of the present invention, the first projections are connected to adjacent heat exchanger plates by solder.

In another form of this aspect of the present invention, the first and second projections have an identical form. In an alternate form of this aspect of the present invention, the first and second projections have different configurations from one another.

In still another form of this aspect of the present invention, the number, configuration and arrangement of the first and second projections are selected to optimize heat exchanger strength and heat exchange efficiency.

In yet another form of this aspect of the present invention, the plates of both sets are trough-like with a protruding edge and inserted one in the other to connect on the edge.

According to another form of this aspect of the present invention, the second projections are spaced from and not connected to the plates of the second set of plates.

According to yet another form of this aspect of the present invention, the second protrusions are connected to the adjacent heat exchanger plate of the first set.

According to still another form of this aspect of the present invention, the first projections lie against the plane of the adjacent plate of the second set of heat exchanger plates.

According to another form of this aspect of the present invention, the first and second projections have the same height (h), in opposite directions, from the plate from which they protrude. According to an alternate form, the first projections have a first height in one direction from the plate, and the second projections have a second height in the opposite direction from the plate, and the first and second heights are different.

According to yet another form of this aspect of the present invention, height (H) of the third projections from the second set plates is greater than the height (h) of the first and second projections from opposite sides of the first set plates.

According to still another form of this aspect of the present invention, all of the plates of the first and second sets have at least four openings forming four channels through the stacked plates, two of the channels serving for feed or discharge of oil and the other two for feed or discharge of a coolant. In further forms, annular deformations are provided around the openings for selectively defining and blocking passages between the plate opening channels and the flow channels formed between the plates, and/or deflecting deformations are provided only partially around the plate openings of at least two of the plate opening channels to deflect the oil and/or coolant.

According to yet another form of this aspect of the present invention, the flow channels in which the first projections protrude are provided for coolant and the other flow channels into which the second projections protrude are provided for oil.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a plate heat exchanger according to the present invention;

FIG. 2 is one type of heat exchanger plate according to the present invention, as viewed from above;

FIG. 3 is detail A from FIG. 2;

FIG. 4 is detail similar to FIG. 3 for differently configured projections;

FIG. 5 is the heat exchanger plate of FIG. 2 as seen from below;

FIG. 6 is detail B from FIG. 5;

FIG. 7 is a cross-section through stacked plates of a plate heat exchanger according to the present invention;

FIG. 8 is a cross-section through another location of the plate heat exchanger;

FIG. 9 is a cross-section along line 9-9 of FIG. 7;

FIG. 10 is an enlarged cross-section of stacked plates of a heat exchanger according to the present invention;

FIG. 11 is an enlarged cross-section similar to FIG. 10 but of a different plate configuration;

FIG. 12 is a perspective view from above of a heat exchanger plate of the type shown in FIG. 11; and

FIG. 13 is a cut out portion of FIG. 1, showing the passages as formed through the stacked plates.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a housingless plate heat exchanger 20 incorporating the present invention as may be used, for example, for cooling and/or temperature control of transmission oil by means of the engine coolant in a vehicle.

The heat exchanger 20 includes stacked heat exchanger plates 22, 24 having four openings 26-29 that form four channels 30-33 in the plate heat exchanger, which serve to supply or discharge oil and coolant.

The elements of the plate heat exchanger may advantageously be made from aluminum sheet having an expedient solder coating, and the heat exchanger plates 22, 24 may be advantageously produced from aluminum sheet with a sheet thickness of about 0.3 mm by means of suitable sheet deformation methods.

The heat exchanger plates 22, 24 are designed trough-like with a continuous raised edge 36 therearound, with the stacked plates 22, 24 sealed around the raised edges 36 and the plate heat exchanger 20 sealed on the top by a cover plate 38 and on the bottom by a base plate 40. The connections for the two heat exchange media may be provided in the base plate 40, which may also function to fasten the plate heat exchanger to another element (e.g., by holes 41). Knobs 42 may also be provided on the base plate 40 to assist in positioning the stack of heat exchanger plates 22, 24 on base plate 40.

The cover plate 38 is illustrated in FIG. 1 with cut away corners 44 to show the four channels 30-33, which are covered by the cover plate 38. Depending on the requirements of the system with which the heat exchanger 20 is used, the connections for both media that participate in heat exchange can also occur through the cover plate 38, or other connection configurations can also be used with the present invention as will be understood by those skilled in the art.

FIGS. 2 and 5 show one of the heat exchanger plates 22. The other heat exchanger plate 24 is shown in FIG. 12. Both heat exchanger plates 22, 24 have an annular deformation 50 at the four openings 26-29. In accordance with the present invention, the two types of heat exchanger plates 22, 24 differ with respect to the shapes or projections or protrusions from the plane 52 of the plate bottom 54.

Heat exchanger plate 22 is of special significance here. It has first projections 50 and second projections 62 that protrude in the opposite direction from the plane of the plate 52. Roughly square or rectangular second projections 62 extend upward from the plane of the plate 52 in FIG. 2 and roughly circular first projections 60 can be seen, which protrude downward from the plane of the plate 52 or from the plate bottom 54. Since FIG. 5 shows a heat exchanger plate 22 of the same type, but viewed from the bottom, the direction of the projections 60, 62 is opposite of that described in FIG. 2 accordingly. This also applies for FIG. 6, which only shows an enlarged cut-out B from FIG. 5.

The rectangular projections 62 have a gradation 68, which is readily apparent from the enlarged depiction in FIG. 11. The gradation 68 increases the rigidity, increases the surface, and therefore contributes to increased heat exchange efficiency. As further shown in FIGS. 7, 8 and 11, the projections 62 constrict flow channels 72. The configuration of the individual projections 60, 62 and that of projections 76 on the other heat exchanger plates 24 (see FIGS. 7-8 and 10-12) may be selected according to the particular design purpose by one skilled in the art. For example, a variant is shown in FIG. 4 in which all the first and second projections 60, 62 are circular. The projections 76 on the heat exchanger plates 24 all point in one direction (i.e., downward in the orientation of FIGS. 7 and 8). The height H of the projections 76 as illustrated is advantageously greater than the height h of the projections 60 or 62. The heights H, h determine the spacing between the plate bottoms 54 and the height of the flow channels 72 and 78 whereby, in the illustrated embodiment, one set of flow channels 72 (e.g., for oil) have a greater height H than the height h of the other flow channels 78 (e.g., for coolant). It should be appreciated, therefore, that selection of the height of the projections may readily allow different size flow channels 72, 78 for easy adaptation of the present invention for different applications and heat exchange media.

In the depicted practical examples, the height h of the projections 60 and 62 is identical, but it should be appreciated that this is not essential to the present invention. The height h of the projections 62 in an undepicted practical example could be identical to the height H of the projections 76, in which case the projections 62 would lie against the heat exchanger plate 24 and could be connected to it.

Positioning of the individual projections 60, 62 in the illustrated embodiment may advantageously be in different alternating rows 80, 82 viewed in the longitudinal direction 84 of the plate 22. For example, as illustrated, rows 80 that are formed only from square projections 62 and alternating rows 82 include alternating circular projections 60 and square projections 62. The rows 80, 82 may advantageously be arranged as mirror images of each other relative to the center 86 of the heat exchanger plate 22. It should be understood, however, that a different sequence and arrangement of projections 60 and 62 could also be chosen within the scope of the present invention, with optimization of the arrangement occurring by achievement of minimal pressure loss with simultaneously high heat exchange efficiency. It should further be understood that the form of the projections 60, 62 and 76 (e.g., round or oval, square or rectangular, elongated arc-like, with or without gradation 68, or with more than one gradation 68) can also be varied from those shown in the Figures within the scope of the present invention.

A number of circular projections 60 may be concentrated in the plate bottom 54 in the region 90 between openings 26, 27 and 28, 29, as illustrated in FIG. 2, which circular projections 60 are connected to the plate bottoms 54 of adjacent heat exchanger plates 24 to provide particularly high internal pressure stability in the region 90 between the openings 26-29. It should be understood, however, that the projections 60 could also be advantageously connected to projections (not shown) in the plate bottom 54 of an adjacent heat exchanger plate 24.

The described two types of trough-like heat exchanger plates 22, 24 are stacked one in the other alternately so that the flow channels 72 for oil and flow channels 78 for coolant are produced between the heat exchanger plates 22 and 24 (see FIGS. 7 and 8). The oil flow channels 72 are hydraulically connected to an oil inlet channel 30 and an oil outlet channel 33 and the coolant flow channels 78 are accordingly connected to the other (coolant) inlet channel 31 and the other (coolant) outlet channel 32.

The arrows in FIGS. 9, 10 and 11 represent possible flow directions of the two media, with the dashed arrows showing the coolant and the solid arrows showing the oil. It should be appreciated that the projections 62 protrude into a space 92 between two projections 76 and produce turbulence 94 there (see FIG. 11).

FIG. 9 shows a horizontal section through a part of an oil flow channel 72 of an alternate embodiment having a different arrangement of projections 60, 62, 76. The cut passes through the projections 62 of one heat exchanger plate 22 and through the projections 76 on the other heat exchanger plate 24 (the projections 60 on the heat exchanger plate 22 appear uncut and represent a circular ring or ellipse). Turbulence 94 for the flowing oil is produced in the regions around the projections 62, and the oil can flow linearly 96 between the projections 76 and 62. The spacings 98 may advantageously be chosen as small as possible so that the oil undergoes the most efficient possible heat exchange with the coolant. As is apparent in FIG. 2, the spacing 98 can also be entirely omitted so that effective swirling (turbulence 94) of the oil occurs.

A top view of the second type of heat exchanger plate 24 is shown in FIG. 12, wherein the projections 76 are regularly arranged and protrude downward from the plane of the plate 52 of the heat exchanger plate 24. The arrangement of projections 60, 62 and 76 of both heat exchanger plates 22 and 24 should ideally be adapted to each other in order to guarantee optimal functioning of the heat exchanger.

As can be seen from FIGS. 2 and 12, both types of heat exchanger plates 22, 24 have a partial deformation 50 at the openings 26 and 29 and an oppositely-directed annular deformation 100. Such annular deformations 100 are also situated on the other openings 27 and 28. Passages 102 between the supply and discharge channels 30-33 and the flow channels 72, 78 are suitably located around the channels 30-33, with the partial deformations 50 serving to produce flow deflection in those corner areas of the plate heat exchanger to help ensure that the entire surface of the heat exchanger plates participate in heat exchange. This type of deformation of the heat exchanger plate on the edge of the openings was already described in the still unpublished application DE 103 48 803.0, the disclosure of which is hereby incorporated by reference. With the present application, however, only two of the four openings 26, 29 are provided with the partial deformations 50. Other configuration possibilities of the partial deformation 50 can be found in DE 103 48 803.0.

In accordance with the present invention, a plate heat exchanger 20 may be adapted to provide suitable strength and heat exchange efficiency for a stipulated application without having to provide internal inserts in the flow channels. As a result, good results can be achieved both in terms of internal pressure stability and heat exchange efficiency, without the contamination drawbacks potentially present when internal inserts are used.

By appropriate positioning and configuration of the projections 60, 62, 76, internal pressure stability may be achieved by the connected projections 60, 76 and improved heat exchange efficiency may be achieved by the projections 60, 62, 76 as well (with the projections increasing the heat-exchanging surfaces and increasing the flow rate of the medium by constricting the channel so that the mentioned improvement in heat exchange efficiency is achieved). The increase in surface available for heat exchange is achieved, for example, in the flow channel 72 by the projections 62.

Further, it should be appreciated that the elimination of inserts/turbulence plates according to the present invention allows the heat exchanger 20 to be produced more favorably in an automated process. Only two different types of heat exchanger plates need be stacked, one on the other, to provide for simplification and cost reduction in manufacturing.

Still other aspects, objects, and advantages of the present invention can be obtained from a study of the specification, the drawings, and the appended claims. It should be understood, however, that the present invention could be used in alternate forms where less than all of the objects and advantages of the present invention and preferred embodiment as described above would be obtained.

Claims

1. A plate heat exchanger, comprising:

a first set of heat exchanger plates having first projections protruding in one direction from the plane of said plates and second projections protruding in the opposite direction from the plane of the plate; and

a second set of heat exchanger plates having third projections protruding in said one direction from the plane of said plates of said second set, said plates of said second set being alternately stacked with said plates of said first set of plates to form flow channels therebetween;

wherein said first projections are connected to the adjacent heat exchanger plate of the second set and said second projections narrow the flow channel by protruding into the space between at least two of said third projections.

2. The plate heat exchanger of claim 1, wherein said first projections are connected to adjacent heat exchanger plates by solder.

3. The plate heat exchanger of claim 1, wherein said first and second projections have an identical form.

4. The plate heat exchanger of claim 1, wherein said first and second projections have different configurations from one another.

5. The plate heat exchanger of claim 1, wherein the number, configuration and arrangement of said first and second projections are selected to optimize heat exchanger strength and heat exchange efficiency.

6. The plate heat exchanger of claim 1, wherein said plates of both sets are trough-like with a protruding edge and inserted one in the other to connect on said edge.

7. The plate heat exchanger of claim 1, wherein said second projections are spaced from and not connected to said plates of said second set of plates.

8. The plate heat exchanger of claim 1, wherein said second protrusions are connected to the adjacent heat exchanger plate of the first set.

9. The plate heat exchanger of claim 1, wherein said first projections lie against the plane of the adjacent plate of the second set of heat exchanger plates.

10. The plate heat exchanger of claim 1, wherein said first and second projections have the same height (h), in opposite directions, from the plate from which they protrude.

11. The plate heat exchanger of claim 1, wherein said first projections have a first height in one direction from the plate, and said second projections have a second height in the opposite direction from the plate, and said first and second heights are different.

12. The plate heat exchanger of claim 1, wherein the height (H) of the third projections from the second set plates is greater than the height (h) of the first and second projections from opposite sides of the first set plates.

13. The device of claim 1, wherein all of the plates of said first and second sets have at least four openings forming four channels through said stacked plates, two of said channels serving for feed or discharge of oil and the other two for feed or discharge of a coolant.

14. The device of claim 13, further comprising annular deformations around said openings for selectively defining and blocking passages between said plate opening channels and said flow channels formed between said plates.

15. The device of claim 13, further comprising deflecting deformations only partially around said plate openings of at least two of said plate opening channels to deflect the oil and/or coolant.

16. The plate heat exchanger of claim 1, wherein said flow channels in which said first projections protrude are provided for coolant and the other flow channels into which said second projections protrude are provided for oil.