Stacked plate heat exchanger with top and bottom manifolds

A heat exchanger has a core comprised of at least one core section defined by a plate stack comprising a plurality of core plates, each core plate having a plurality of spaced apart, raised openings surrounded by a flat area. The raised openings of adjacent plates are sealed together to define a plurality of tubular structures. Top and bottom manifolds are sealed to the top and bottom of the core, with continuous top and bottom end plates providing structurally rigid connections between multiple core sections of the heat exchanger. The heat exchanger may have numerous configurations, including stepped core, curved core, angled core, and/or a core having multiple sections of the same or different length, while minimizing the number of unique parts and/or parts of complex shape.

FIELD OF THE INVENTION

The invention generally relates to an improved construction of heat exchangers for heating and/or cooling liquids, and particularly to heat exchangers for use in vehicle systems which are easily adaptable to various configurations, inexpensive to manufacture, reliable, and which use a minimum number of unique parts.

BACKGROUND OF THE INVENTION

Heat exchangers for vehicle systems must be lightweight, strong, reliable, inexpensive to manufacture, and must fit within confined spaces. For example, so-called “in-tank” heat exchangers for heating and/or cooling various liquids within a vehicle system must fit within the confines of a reservoir for the liquid being heated or cooled, while maximizing heat exchange with the liquid within the reservoir. Examples of liquids which may be heated and/or cooled by in-tank heat exchangers include engine oil, transmission oil, axle oil, power steering fluid, and liquid fuel.

As an example, in-tank heat exchangers for heating and/or cooling engine oil are typically located inside an oil pan which is bolted to the underside of an engine block. Oil pans typically have a shallow region and a deeper sump. In order to maximize heat transfer within this space, the heat exchanger may require a shape which is non-planar and/or non-rectangular. Manufacturing such a heat exchanger with a conventional tube and fin construction, with or without header tanks, can be expensive and difficult, at least partly due to the number of unique components required. Furthermore, the conventional tube-and-fin construction tends to be application specific and is difficult to adapt to different types and shapes of oil pans.

There remains a need for an improved construction of heat exchangers for vehicle systems which are easily adapted to various configurations, inexpensive to manufacture, reliable, and which use a minimum number of unique parts, without sacrificing simplicity, manufacturability and reliability.

SUMMARY OF THE INVENTION

In one aspect, there is provided a heat exchanger comprising a core, a top manifold and a bottom manifold. The core has a height, a length, and a top and a bottom between which the height is defined. The core comprises at least one core section having a top, a bottom and a length.

Each core section comprises:(i) a plate stack comprising a plurality of core plates, wherein the plate stack has a top and a bottom, and wherein each of the core plates comprises a generally flat plate having a plurality of spaced apart, raised openings provided along its length, and a flat area surrounding said plurality of raised openings, wherein the raised openings of adjacent core plates in said plate stack are sealed together to define a plurality of tubular structures extending between the top and the bottom of the plate stack;(ii) a top plate sealed to the top of the plate stack, the top plate having one or more openings communicating with the plurality of tubular structures; and(iii) a bottom plate sealed to the bottom of the plate stack, the bottom plate having one or more openings communicating with the plurality of tubular structures.

The top manifold is provided on and sealed to the top of the core, and comprises:(i) at least one top manifold tank section having an interior defining a top manifold tank space, wherein the top manifold tank space of each said top manifold tank section is in flow communication with at least one of the tubular structures of one of the at least one core sections; and(ii) a top manifold end plate provided on the top manifold tank section and at least partly sealing the top manifold tank space, wherein the top manifold end plate extends throughout the length of the core at the top thereof.

The bottom manifold is provided on and sealed to the bottom of the core, and comprises:(i) at least one bottom manifold tank section having an interior defining a bottom manifold tank space, wherein the bottom manifold tank space of each said bottom manifold tank is in flow communication with at least one of the tubular structures of one of the at least one core sections; and(ii) a bottom manifold end plate provided on the bottom manifold tank section and at least partly sealing the bottom manifold tank space, wherein the bottom manifold end plate extends throughout the length of the core at the bottom thereof.

DETAILED DESCRIPTION

A heat exchanger10according to a first embodiment is now described below with reference toFIGS. 1 to 6.

Heat exchanger10comprises a core12having a height, a length, and a top14and a bottom16between which the height is defined. Heat exchanger10further comprises a top manifold18provided on and sealed to the top14of core12, and a bottom manifold20provided on and sealed to the bottom16of core12.

Although terms such as “top” and “bottom”, “above”, “below”, “height”, “length”, “width”, etc. are used throughout the description and claims, these terms are used for convenience only. It should not be inferred that the use of any of these terms requires any of the heat exchangers described herein to have a specific orientation in use.

The core12of heat exchanger10consists of a single core section22comprising a plate stack24, a top plate26and a bottom plate28. In the present embodiment, the terms “core12” and “core section22” are used synonymously. Also, the core section22is sometimes referred to herein as the “first core section22”, particularly in embodiments having a core12comprised of multiple core sections22.

The plate stack24comprises a plurality of core plates30, the plate stack24having a top and a bottom32,34.FIGS. 3 and 4illustrate a type of core plate30which may be used in heat exchanger10, and which may also be used in any of the other embodiments described herein. Each of the core plates30comprises a generally flat plate having a plurality of spaced apart, raised openings36provided along its length, and a flat area38surrounding the plurality of raised openings36. Within plate stack24, the raised openings36of adjacent core plates30are sealed together to define a plurality of tubular structures40extending between the top and bottom32,34of plate stack24. As can be seen fromFIGS. 1 and 2, the plate stack24formed by core plates30is similar in structure to a tube-and-fin core structure, with the tubular structures40corresponding to cylindrical tubes, and the surrounding flat areas38corresponding to fins. Also, in the present embodiment, the top plate26and bottom plate28are identical to core plates30.

FIGS. 3 and 4illustrate the specific structure of core plates30, withFIG. 3illustrating a single core plate30in isolation, andFIG. 4showing how the plates30are stacked. As shown in these drawings, each of the raised openings36has a flat top sealing surface42, and the flat areas38of the core plates30define an opposite flat bottom sealing surface44. The core plates30are joined together with the flat top sealing surfaces42of the core plates30joined to the flat top sealing surfaces42of an adjacent core plate30, and with the flat bottom sealing surface44of each core plate30joined to the flat bottom sealing surface44of an adjacent core plate30. Accordingly, when the core plates30are joined together to form a stack as shown inFIGS. 1 and 2, the plate stack24consists of alternating layers of paired flat areas38and paired openings36.

As can been seen fromFIGS. 3 and 4, the core plates30of heat exchanger10are rectangular, having a pair of straight, parallel side edges and a pair of straight, parallel ends. Furthermore, the core plates30making up the plate stack24are identical to one another.

The top and bottom plates26,28of plate stack24each have one or more openings36sealed to and communicating with the plurality of tubular structures40. As mentioned above, the top and bottom plates26,28of heat exchanger10are identical to one another and to the core plates30. The top and bottom plates26,28are oriented such that their flat bottom sealing surfaces44provide sealing flanges for sealing to one of the adjacent manifolds18,20.

The top manifold18comprises a top manifold tank section46having a hollow interior defining a top manifold tank space48, wherein the top manifold tank space48is in flow communication with at least one of the tubular structures40of the core12/core section22. In the present embodiment, the top manifold18comprises a single tank section46which communicates with all of the tubular structures40.

As shown in the close-up ofFIG. 5and the exploded view ofFIG. 6, the top manifold18further comprises a top manifold end plate50which is provided on the top manifold tank section46and sealed thereto so as to partly close and seal the top manifold tank space48. As shown, the top manifold end plate50extends throughout the length of the core12at the top14thereof.

Similarly, the bottom manifold comprises a bottom manifold tank section52having an interior defining a bottom manifold tank space54which is in flow communication with at least one of the tubular structures40of core12/core section22. In the present embodiment, the bottom manifold tank space54is in flow communication with all of the tubular structures40.

The bottom manifold20further comprises a bottom manifold end plate56provided on the bottom manifold tank section52and partly sealing the bottom manifold tank space54, wherein the bottom manifold end plate56extends throughout the length of the core12at the bottom16thereof.

It can be seen from the drawings that the top and bottom manifold end plates50,56are structural in nature and are typically thicker than core plates30. These manifold end plates50,56are flat plates, defining the top and bottom of heat exchanger10. Furthermore, each of the manifold end plates50,56in the present embodiment includes a fluid inlet or outlet opening58,60with inlet or outlet fittings62,64being sealingly connected to the manifold end plates50,56for the purpose of connecting the inlet and outlet openings58,60to other components of a coolant circulation system (not shown).

The tubular structures40define a plurality of fluid flow channels, which in the present embodiment extend throughout the height of core12and which are adapted to permit fluid flow in the same direction, i.e. from the inlet58and inlet fitting62, through the top manifold18, through the tubular structures40to the bottom manifold20, and out through the fluid outlet60and outlet fitting64. The path followed by fluid flowing through heat exchanger10is indicated by the arrows inFIG. 2.

Each of the manifold tank sections46,52of heat exchanger10has an identical construction, and the components thereof are identified by identical reference numerals. As best seen inFIG. 6, the top manifold tank section46comprises a pair of stamped plates66which in the present embodiment are identical to one another. It will be appreciated that the bottom manifold tank section52will have a similar or identical construction. Each of the stamped plates66comprises a flat peripheral edge portion68surrounding a central raised portion70with a flat top sealing surface72, the flat top sealing surface72surrounding at least one opening74provided in the central raised portion70. In heat exchanger10there are five separate openings74in the flat top sealing surface72, corresponding to the number of tubular structures40, however, it will be appreciated that this is not essential. To form the manifold tank section46or52, the flat top sealing surfaces72of a pair of stamped plates66are sealingly joined together to form a tank section46,52.

The flat peripheral edge portion68of each stamped plate66provides a flat bottom sealing surface76which is opposed to the flat top sealing surface72of the central raised portion70. The manifold end plates50,56each have flat surfaces which are sealingly joined to one of the flat bottom sealing surfaces76of the manifold tank section46,52. In the present embodiment, the other flat bottom sealing surface76of each manifold tank section46,52is sealingly joined to the flat top sealing surface42or44of the top or bottom plate26or28. As in heat exchanger10, the top and bottom plates26,28of heat exchanger78may be identical to one another and to the core plates30, and are oriented such that their flat bottom sealing surfaces44provide sealing flanges for sealing to one of the adjacent manifolds18,20. Constructing the top and bottom manifold tank sections46,52as described above helps to simplify construction by avoiding the need to form deep drawn header tanks of complex shape. The raised portions70of stamped plates66are relatively shallow and can be formed with simple tooling, even in embodiments where the manifold tank sections46,52are non-linear.

A heat exchanger78according to a second embodiment is now described below with reference toFIGS. 7-10. Heat exchanger78includes a number of elements which are similar or identical to the elements of heat exchanger10described above. In the following description, like reference numerals are used to identify like elements, and the above description of like elements of heat exchanger10applies equally to the elements of heat exchanger78, unless otherwise indicated.

Like heat exchanger10, heat exchanger78includes a core12having a top14and a bottom16, a top manifold18and bottom manifold20. Unlike heat exchanger10, the flow path followed by the fluid passing through heat exchanger78is U-shaped, and therefore the fluid inlet and outlet58,60and the inlet and outlet fittings62,64are provided on one of the manifolds18or20. In the illustrated embodiment, the fittings62,64and inlet and outlet58,60are provided on the top manifold18, however they may be instead be provided on the bottom manifold20. Heat exchangers having this U-shaped flow configuration are commonly referred to as “two-pass” heat exchangers.

It can be seen that the core12of heat exchanger78is generally rectangular, but is non-planar. In the present embodiment, the core12comprises a core section22, and the core section22comprises a first portion80and a second portion82, both of which are rectangular and planar. As in the first embodiment, the terms “core12” and “core section22” are used synonymously in the description of the second embodiment.

However, the first and second portions80,82of core section22are non-planar in relation to one another, and are arranged in a “stepped” configuration, defined herein as a configuration in which the first and second portions of a core section22are both rectangular and planar, but are located in different planes which are parallel to one another. In addition, the first and second portions80,82in the stepped configuration may have overlapping ends, as shown inFIG. 7. This stepped configuration is particularly useful where heat exchanger78must be enclosed in an irregularly shaped space, such as the interior of an oil pan. The stepped configuration of heat exchanger78permits one portion80or82of the core section22to be received in a shallow portion of the oil pan, while the other portion80or82may be received in the sump of the oil pan.

The stepped core12of heat exchanger78may be constructed from a single plate stack24or from two separate plate stacks24. For example, the entire core12and core section22may comprise a single plate stack24in which each of the core plates30has a stepped shape, with edges following the configuration of the stepped core12. In this case, the first and second portions80,82of the core section22each form part of the same plate stack24, and the core plates30in the plate stack24may be identical to one another.

Alternatively, the first portion80of the core section22may comprise a first plate stack24, and the second portion82may comprise a second plate stack24. In this case, the first and second plate stacks24are separate from one another, each comprising a stack of core plates30. In this variation, which is consistent with the embodiment shown inFIGS. 7 to 10, the core plates30making up each of the plate stacks24of the first and second portions80,82may have a simple rectangular shape, and may optionally be identical to one another, thereby minimizing the amount of special tooling needed to construct the heat exchanger78.

In order to provide the two-pass configuration, the top manifold18of heat exchanger78(best seen in the exploded view ofFIG. 8A) comprises first and second manifold tank sections, both identified by reference numeral46, so as to create two separate top manifold tank spaces48. The first manifold tank section46of top manifold18communicates with all of the tubular structures40of the first portion80of core section22, whereas the second manifold tank section46of the top manifold18communicates with all of the tubular structures40of the second portion82of core section22. As with the core plates30, the top manifold tank sections46may optionally be joined together, or may be separate from one another. According to this configuration, one of the top manifold tank spaces48will comprise an inlet manifold space and the other top manifold tank space48will comprise an outlet manifold space, each communicating with an inlet or outlet opening58,60and an inlet or outlet fitting62,64.

The bottom manifold20of heat exchanger78(best seen in the exploded view ofFIG. 8B) includes a single manifold tank section52which communicates with all of the tubular structures40of the core section22. Therefore, the bottom manifold20provides a manifold tank space54in which the fluid received from the tubular structures40of the first portion80changes direction and enters the tubular structures40of the second portion82.

Therefore, as shown inFIG. 8A, the top manifold end plate50has a fluid inlet opening58in flow communication with the first manifold tank section46of the top manifold18, and a fluid outlet opening60in flow communication with the second manifold tank section46of the top manifold18. In contrast, the bottom manifold end plate56, shown inFIG. 8B, is free of openings.

FIGS. 9 and 10illustrate a type of core plate30which may be used in heat exchanger78, and which may also be used in any of the other embodiments described herein. As in the core plates shown inFIGS. 3 and 4, the core plates30ofFIGS. 9 and 10each comprise a generally flat plate having a plurality of spaced apart, raised openings36provided along its length, and having a flat area38surrounding the plurality of raised openings36. In order to form the plurality of tubular structures40, the core plates30are stacked and the raised openings36of adjacent core plates30in the plate stack24are sealed together to define the tubular structures40.

Core plates30ofFIGS. 9 and 10differ from those shown inFIGS. 3 and 4in that the core plates30of each plate stack24are joined together with the raised openings36facing in the same direction. To provide sealing, the raised openings36have sloped side walls84such that the raised openings36of adjacent plates30nest with one another, as shown inFIG. 10. In this type of core plate30, the sealing together of the raised openings36is provided between the sloped side walls84of adjacent openings36. The raised openings36in the core plates30ofFIGS. 9 and 10may be formed by simply piercing the core plate30with a punch, rather than by stamping the core plate30. The use of piercing to form raised openings36can result in less thinning of the material of core plate30in the vicinity of opening36, as compared to a stamping operation, particularly at the ends of the core plate30. In addition, the use of pierced openings36with nestable, sloped sidewalls permits some adjustment of the spacing between adjacent core plates30, simply by increasing or decreasing the amount of nesting. The use of piercing to form raised openings36results in openings36having a frusto-conical shape, without a flat top surface.

Each of the core plates30shown inFIGS. 9 and 10may further comprises at least one raised protrusion86extending from the same side of plate30as raised openings36and having a height which is substantially the same as a desired spacing between the flat areas38of adjacent core plates30. Each of the raised protrusions86is provided between an adjacent pair of raised openings36. Thus, when the plates are stacked as inFIG. 10, a top88of each protrusion86will contact the flat area38of an adjacent core plate36, thereby providing a stop, and ensuring consistent spacing between adjacent core plates. To improve contact with the flat areas38of the core plates30, the tops88of protrusions86may be flat. In the present embodiment, the protrusions86are in the form of circular, flat-topped dimples provided between each pair of raised openings36. However, it will be appreciated that the shape, spacing and number of protrusions86may vary from that shown inFIGS. 9 and 10. It will also be appreciated that protrusions86are not necessarily provided in all embodiments, and that it may be desired to provide core plates30without protrusions, for example, where it is desired to use the degree of nesting of openings36(in case of the core plate30ofFIGS. 9 and 10) to provide some variability in the spacing between adjacent core plates30.

The core plates30ofFIGS. 9 and 10include another feature which helps to minimize the number of unique parts used to construct heat exchanger78. In this regard, each of the core plates30ofFIGS. 9 and 10has a central longitudinal axis A (shown inFIG. 9) along which the centers of the raised openings36are aligned. However, the centers of the raised protrusions86are offset relative to the central longitudinal axis A. Thus, when a plurality of identical core plates30ofFIGS. 9 and 10are assembled into a core stack, the plates30are rotated by180degrees such that the raised protrusions86in adjacent plates30will be axially offset relative to one another, and will not become nested. The offset of protrusions86is best seen inFIG. 8A, which shows top plates26, being identical to core plates30, and including centrally located raised openings36and offset protrusions86. The offset of the protrusions86is sufficient to ensure that at least a portion of the top88of each raised protrusion86will be in contact with the flat area38of an adjacent core plate30, thereby providing the desired spacing between the core plates30.

In order to facilitate assembly of the plate stacks24, the core plates30ofFIGS. 9 and 10may have visual indicators to distinguish one end of the core plate30from the other. In this regard,FIGS. 9 and 10show that each core plate30is formed with a pair of opposed ends90,92, wherein end92is formed with cutoff corners94. It can be seen inFIG. 10that the ends90,92alternate with one another in adjacent core plates30of the plate stack24, and that the raised protrusions86are out of alignment with one another.

The top and bottom manifolds18,20of heat exchanger78also have a somewhat different structure from the top and bottom manifolds18,20of heat exchanger10described above. According to the present embodiment, the top and bottom manifolds18,20include top and bottom manifold end plates50,56which are in the form of flat plates extending along the length of core12/core section22. Both the top and bottom manifold end plates50,56have a stepped configuration such that they follow the stepped shape of the core12and extend throughout the length of core12, thereby providing structural rigidity to heat exchanger78. This is particularly important where the first and second portions80,82of the core section22comprise separate plate stacks24.

In heat exchanger78, the construction of each top manifold tank section46may be consistent with that of heat exchanger10described above, comprising stamped plates66. Each of the first and second manifold tank sections46may comprise a single pair of stamped plates66having a stepped shape similar to that of manifold end plates50,56, or may comprise two separate stamped plates66as shown inFIG. 8A, each having a similar or identical shape to each other and to the stamped plates66of heat exchanger10described above.

As shown inFIG. 8A, the top manifold18of heat exchanger78further comprises a top stack end plate96having one face joined to the flat area38of the top plate26(identical to core plate30and with like elements identified with like reference numerals) of the first and second portions80,82of the first core section22, and an opposite face joined to the top manifold tank section46. Similarly, as shown inFIG. 8B, the bottom manifold20of heat exchanger78further comprises a bottom stack end plate98having a first face joined to the flat area38of the bottom plate28(identical to core plate30and with like elements identified with like reference numerals) of core section22and an opposite second face joined to the bottom manifold tank section52. In the present embodiment, the top and bottom stack end plates96,98are flat and planar, and have a peripheral shape which is substantially identical to that of the top and bottom manifold end plates50,56. Furthermore, the thicknesses of the top and bottom stack end plates96,98may be the same as the thicknesses of the top and bottom manifold end plates50,56, such that the top and bottom stack end plates96,98also provide structural rigidity to the core12of heat exchanger78.

The top stack end plate96is further provided with at least one opening100through which flow communication is provided between one or more of the tubular structures40of the core12and one of the manifold tank spaces48of the top manifold18. In the present embodiment, the top stack end plate96includes a plurality of openings100consisting of simple holes equal in number to, and aligned with, the tubular structures40of core12, and the raised openings36of top plates26and core plates30.

The bottom stack end plate98is provided with at least one opening101through which flow communication is provided between one or more of the tubular structures40of the core12and one of the manifold tank space54of the bottom manifold20. In the present embodiment, the bottom stack end plate98includes a plurality of openings101equal in number and aligning with the tubular structures40of core12, and with the raised openings36of bottom plates28and core plates30. In the present embodiment, using core plates30as shown inFIGS. 9 and 10, the openings101in the bottom stack end plate98are in the form of raised openings which face in the same direction as the raised openings36of the bottom plates28, thereby providing a degree of nesting so as to assist in sealing plates28and98together. As such, the bottom stack end plate98may have a thickness less than that of the top stack end plate96which is formed with openings100in the form of simple holes. However, in embodiments using the plates30shown inFIGS. 3 and 4, the openings100,101in both the top and bottom stack end plates96,98may be simple holes, in which case the top and bottom stack end plates96,98may be identical to one another.

A heat exchanger102in accordance with a third embodiment is now described with reference toFIGS. 11-15. Heat exchanger102includes a number of elements which are similar or identical to the elements of heat exchangers10and78described above. In the following description, like reference numerals are used to identify like elements, and the above description of like elements of heat exchangers10and78applies equally to the elements of heat exchanger102, unless otherwise indicated.

The heat exchanger102according to the third embodiment includes a core12having a top14and a bottom16, a top manifold18and a bottom manifold20. The core12comprises a core section22which is comprised of a first portion80and a second portion82. In the present embodiment, the first and second portions80,82of core12and first core section22are non-planar in relation to one another. Each of the first and second portions80,82of the first core section22are rectangular and planar, and are angled relative to one another so as to provide the core12/core section22with an angled configuration, wherein an included angle between the first and second portions80,82of core12is greater than90degrees, i.e. about150degrees. As in the embodiments described above, the terms “core12” and “core section22” are used synonymously in the description of the third embodiment.

In heat exchanger102, the first portion80of core section22comprises a first plate stack24and the second portion82of the core section22comprises a second plate stack24. As can be seen from the drawings, the first and second plate stacks24are separate from one another, each comprising a stack of core plates30which are rectangular in shape, and may comprise the core plates shown inFIGS. 3-4or inFIGS. 9-10. The core plates30of the two plate stacks24may be identical to one another.

The heat exchanger102is similar to heat exchanger78in that it has a two-pass configuration, wherein the top manifold18has a pair of top manifold tank sections46, one of the top manifold tank sections46being in flow communication with the tubular structures40of the first portion80of core section22, while the other top manifold tank section46is in flow communication with all of the tubular structures in the second portion82of core section22. The bottom manifold20, on the other hand, includes a single manifold tank section52which communicates with all of the tubular structures40of the first core section22. The bottom manifold tank section52may therefore be comprised of a pair of stamped plates66which follow the shape of the core12and the manifold end plates50,56. Aside from the angled orientation and shapes of the manifolds18,20of heat exchanger102, it will be appreciated that will otherwise be structurally similar to the top and bottom manifolds18,20illustrated inFIGS. 8A and 8B.

Rather than providing two separate plate stacks24of identical configuration, it will be appreciated that the first and second portions80,82of the first core section22may form part of the same plate stack24such that the core plates30have edges which follow the angled configuration of the first core section22, and are of generally the same shape as the top and bottom manifold end plates50,56. In this configuration, all of the core plates30comprising the single plate stack24may be identical to one another.

It will be appreciated that the angle between the first and second portions80,82of first core section22in heat exchanger102may be altered from that shown inFIGS. 11-15by merely changing the shapes of the plates making up the manifolds18,20. The included angle between the first and second portions80,82of first core section22can thus be varied from less than or equal to 90 degrees to greater than 90 degrees, or vice versa.

A heat exchanger104according to a fourth embodiment is now described below with reference toFIGS. 16-19. Heat exchanger104comprises a core12having a top14and a bottom16, a top manifold18and a bottom manifold20. The core12comprises a first core section22which is non-planar, and in which the first portion80and the second portion82are non-planar in relation to one another. According to this embodiment, the first core section22is curved, such that the plate stack24includes a plurality of core plates30having curved edges. As in the first to third embodiments, the terms “core12” and “first core section22” are used synonymously in the description of the fourth embodiment. Aside from the curved orientation and shapes of the manifolds18,20of heat exchanger104, it will be appreciated that will otherwise be structurally similar to the top and bottom manifolds18,20illustrated inFIGS. 8A and 8B.

A heat exchanger106according to a fifth embodiment is now described below with reference toFIGS. 20-23. Heat exchanger106includes a number of elements which are similar or identical to the elements of heat exchangers10,78and102described above. In the following description, like reference numerals are used to identify like elements, and the above description of like elements of heat exchangers10,78and102applies equally to the elements of heat exchanger106, unless otherwise indicated.

Heat exchanger106comprises a core12having a top14and a bottom16, a top manifold18and a bottom manifold20. The core12of heat exchanger106is generally L-shaped, so as to permit the heat exchanger106to be inserted into an irregularly shaped fluid reservoir.

To provide this L-shape, the heat exchanger106is comprised of a first core section22and a second core section108. The second core section108is provided below the first core section22, with the top manifold18being provided on top of the first core section22and the bottom manifold20being provided on the bottom of the second core section108. The L-shape of the core is provided by constructing one of the core sections22or108to be longer than the other core section22or108. In the present embodiment, the first core section22is longer than the second core section108, and the top manifold18is also longer than the bottom manifold20.

Each of the first and second core sections22,108of heat exchanger106are rectangular and planar, and the first and second core sections22,108are co-planar in relation to one another. The core sections22,108each comprise a plate stack24comprising a plurality of core plates30, and the top and bottom plates26,28of each core section are identical to the core plates30.

In the present case, the core plates30making up each plate stack24are comprised of a stack of plates30in accordance withFIGS. 9 and 10, in which the raised openings36of adjacent plates nest with one another and raised protrusions86are provided between the raised openings36. As can be seen from the front elevation ofFIG. 21, the first core section22is comprised of core plates30having a total of eight raised openings36so as to form eight tubular structures40extending throughout the height of the first core section22. The second core section108, on the other hand, is comprised of a plate stack24made up of core plates30having a total of five raised openings36, forming five tubular structures40extending throughout the height of the second core section108.

In the present embodiment, where the heat exchanger106is formed from two core sections22,108, the top manifold18and bottom manifold20are provided on different manifold sections. Heat exchanger108further comprises a third manifold, referred to herein as an intermediate manifold110, which is provided between the first and second core sections22,108, and is sealed to the bottom of the first core section22and the top of the second core section108. As with the top and bottom manifolds18,20, the intermediate manifold110comprises at least one intermediate manifold tank section112having an interior defining an intermediate manifold tank space114. The intermediate manifold tank space of each tank section is in flow communication with at least one of the tubular structures40of at least one of the core sections22,108.

In the illustrated embodiment, both the top manifold18and the intermediate manifold110are structurally similar to one another, and each have two manifold tank sections46or112having a structure as described above. A first top manifold tank section46and top manifold tank space48(on right hand side ofFIG. 21) communicate with the four tubular structures40on the right side of heat exchanger106(also referred to herein as a first subset of tubular structures) as shown inFIG. 21, and the second top manifold tank section46and tank space48(on the left hand side ofFIG. 21) are in flow communication with the four tubular structures40of first core section22on the left side ofFIG. 21(also referred to herein as the second subset of tubular structures. Similarly, a first intermediate manifold tank section112and corresponding tank space114(on the right hand side ofFIG. 21) are in flow communication with the first subset of tubular structures40of the first core section22, and the second intermediate manifold tank section112and corresponding tank space114(on the left hand side ofFIG. 21) are in flow communication with the second subset of tubular structures40of the first core section22.

Further, it can be seen fromFIG. 21that the first manifold tank section112of intermediate manifold110is in communication with a first subset of the tubular structures40of the second core section108. In this embodiment, the first subset of tubular structures40in second core section108corresponds to the tubular structure40at the right end of second core section108inFIG. 21. Therefore, all of the fluid flowing through the four right-hand tubular structures40of core section22is collected in the first manifold section112of the intermediate manifold110, and flows into the tubular structure40at the right end of second core section108.

The second manifold tank section112of the intermediate manifold110communicates with a second subset of tubular structures40of the second core section108, corresponding to the four tubular structures40on the left side of second core section108. Therefore, the second subset of tubular structures40of the first core section22is in flow communication with the second subset of tubular structures of the second core section108through the second manifold tank section112of intermediate manifold110.

In terms of overall structure, the top manifold18of heat exchanger106is similar to that shown inFIG. 8A, relating to heat exchanger78. In this regard, the top manifold18of heat exchanger106has a top manifold end plate50which is shown inFIG. 20A, having an overall rectangular shape and including fluid inlet and outlet openings58,60. The top manifold tank section46is comprised of stamped plates66, as shown inFIG. 20A. However, rather than being separate plates66as inFIG. 8A, adjacent stamped plates66inFIG. 20Aare joined together end-to-end and are identified as66A and66B. The top manifold of heat exchanger106also includes a top stack end plate96which is structurally similar to that shown inFIG. 8A, having openings100in the form of simple holes and with a thickness greater than that of the core plates30.

In order to provide the L-shaped core12of heat exchanger106with structural rigidity, the intermediate manifold110further comprises an intermediate manifold support plate116(shown inFIG. 20A) which partly seals the intermediate manifold tank space114of both the first and second manifold tank sections112. As shown, the intermediate manifold support plate116extends throughout the length of the intermediate manifold110, having four openings100(the first four openings from the left end of plate116) which permit flow communication between the second subset of tubular structures40of the first core section22and the second subset of tubular structures40of the second core section108. The support plate116also includes an opening100(the far right opening100in plate116) which provides flow communication between the first subset of tubular structures40of the first core section22and the first subset of tubular structures40of the second core section108.

The intermediate manifold110further comprises an intermediate manifold end plate118which may also be a structural member, and which may have the same shape as the intermediate manifold support plate116. In this embodiment, the end plate118is structurally similar to the bottom stack end plate98shown inFIG. 8B, having raised openings101to mate with raised openings of bottom plates28of core section22. End plate118may instead be provided with openings100in the form of simple holes where the core plates30and bottom plates28have the structure shown inFIGS. 3 and 4.

The bottom manifold20of heat exchanger106is shorter than the top and intermediate manifolds, and includes a single manifold tank section52and corresponding tank space54, so as to permit the fluid to change direction, as shown inFIG. 21. Aside from having a different shape from the bottom manifold20of heat exchanger78, the bottom manifold20of heat exchanger106may be otherwise structurally similar or identical to the bottom manifold20shown inFIG. 8B.

The top manifold end plate50has a fluid inlet opening58in flow communication with the first manifold tank section46of the top manifold18, and a fluid outlet opening in flow communication with the second manifold tank section46of the top manifold18. According to this configuration, the heat exchanger106comprises a first plurality of fluid flow passages which are defined by the first subsets of tubular structures40of the first and second core sections22,108, the first plurality of fluid flow passages being adapted to permit fluid flow in the same direction from the fluid inlet opening58to the bottom manifold20, wherein the fluid flow path through heat exchanger106is indicated by arrows inFIG. 21. A second plurality of fluid flow passages is defined by the second subsets of tubular structures40of the first and second core sections22,108, the second plurality of fluid flow passages being adapted to permit fluid flow in the same direction (i.e. the upward direction inFIG. 21) from the bottom manifold20to the fluid outlet opening60.

A heat exchanger120according to a sixth embodiment is now described below with reference toFIGS. 24-27. Heat exchanger120includes a number of elements which are similar or identical to the elements of heat exchangers10,78,102and106described above. In the following description, like reference numerals are used to identify like elements, and the above description of like elements of heat exchangers10,78,102and106applies equally to the elements of heat exchanger120, unless otherwise indicated.

Heat exchanger120is similar to heat exchanger106described above in that the core has a L-shape and the overall flow configuration through heat exchanger120is U-shaped. As with heat exchanger106, the heat exchanger120comprises a first core section22which is provided on top of a second core section108. The most significant difference between heat exchangers106and120is that the first core section22of heat exchanger120is non-planar, and comprises a first portion80and a second portion82. In the illustrated embodiment, the second portion82of the first core section22and the second core section108lie in a common plane, whereas the first portion80of the first core section22lies in a different plane. More specifically, the first core section22has a stepped configuration, with the first and second portions80,82of the first core section22being parallel and having overlapping ends, and with the top manifold end plate50and intermediate manifold support plate116having edges which follow the stepped configuration of the first core section22. The plate stacks24comprising the first and second core sections22,108of heat exchanger120are as described above with reference toFIGS. 3-4 and 9-10, and in the present embodiment comprise core plates30as shown inFIGS. 9 and 10. The first and second portions80,82of the first core section22may either comprise separate plate stacks24, or the first and second portions80,82of the first core section22may comprise a single plate stack24, as described above. Where the first and second portions80,82of the first core section22are comprised of separate plate stacks24, one or both of them may be identical to one another and/or to the core plates30of the second core section108.

Although the invention has been described in connection with certain embodiments, it is not limited thereto. Rather, the invention includes all embodiments which may fall within the scope of the following claims.