GB2607094A

GB2607094A - Heat exchanger

Info

Publication number: GB2607094A
Application number: GB2107652.6A
Authority: GB
Inventors: Dillingham Chris
Original assignee: Denso Marston Ltd
Current assignee: Denso Marston Ltd
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2022-11-30
Anticipated expiration: 2041-05-28
Also published as: GB2607094B; GB202107652D0

Abstract

A heat exchanger comprises a stack of plates 12A, 12B, a cold fluid inlet (20, Fig.1), a cold fluid outlet (22, Fig.1), a hot fluid inlet (24, Fig.1) and a hot fluid outlet (26, Fig.1). A plurality of cold fluid flow paths 16 and hot fluid flow paths 18 are defined between the plates, with alternating cold and hot fluid flow paths. Each plate comprises a first face (28, Fig 3A), a second face (30, Fig.3A), and a plurality of apertures (32, 34, Fig 3A). In one arrangement, each plate 12A cooperates with a superjacent plate 12B for creating a plurality of seals around each aperture. In another arrangement, the apertures define first apertures (32, Fig.3A) and second apertures (34, Fig.3B). Each plate comprises first and second annular projections (36, 28 Fig.3A), extending from the first face by a first distance d1, d2 respectively, and each surrounding a corresponding one of the first and second apertures. The first distance is greater than the second distance. The first annular projections on a first plate co-operate with the second annular projections of a superjacent plate for creating a seal therebetween. The heat exchanger may be a water cooled oil cooler.

Description

Heat Exchanger

FIELD OF THE INVENTION

The present invention relates to a heat exchanger.

BACKGROUND OF THE INVENTION

Heat exchangers are a type of apparatus configured for transferring heat from one fluid to another fluid. A common type of heat exchanger is a stacked plate type heat exchanger including a plurality of plates which are arranged in a stack, and which define a plurality of flow paths therebetween. The flow paths alternate between cold fluid flow paths configured to convey cold fluid, and hot fluid flow paths configured to convey hot fluid. Each flow path is isolated from adjacent flow paths via seals (e.g. brazed joints).

A water cooled oil cooler is a type of heat exchanger which is used to cool oil (e.g. engine oil), where the cooling medium is water-based (e.g. a 50:50 water/glycol mix). Often, water cooled oil coolers are stacked plate type heat exchangers in which hot oil flows through the hot fluid flow paths, while water-based coolant flows through the cold fluid flow paths. Such heat exchangers rely on the seals between adjacent flow paths to prevent contamination of fluids which could lead to damage of the heat exchanger and/or interconnected components. For example, in an automotive application a leak of water-based coolant in a cold fluid path into an adjacent hot fluid path would contaminate engine oil passing through said hot fluid path, which would affect lubrication of the engine.

The present invention seeks to overcome, or at least mitigate, one or more problems of

the prior art.

SUMMARY OF THE INVENTION

According to a first aspect of the invention a heat exchanger is provided, the heat exchanger comprising: a plurality of plates arranged in a stack, one plate on top of another, wherein the plurality of plates are spaced apart from one another; a plurality of cold fluid flow paths and a plurality of hot fluid flow paths defined between the plurality of plates, in which said plurality of cold fluid flow paths are interspersed between said plurality of hot fluid flow paths; a cold fluid inlet for input of cold fluid to said plurality of cold fluid flow paths and a cold fluid outlet for expulsion of cold fluid from said plurality of cold fluid flow paths; and a hot fluid inlet for input of hot fluid to said plurality of hot fluid flow paths and a hot fluid outlet for expulsion of hot fluid from said plurality of hot fluid flow paths; wherein each plate comprises a first face, a second face, a group of first apertures extending through the plate from the first face to the second face, and a group of second apertures extending through the plate from the first face to the second face; wherein each plate comprises a group of first annular projections, each surrounding a respective aperture of the group of first apertures, and wherein each of the first annular projections projects from said first face by a first distance; wherein each plate comprises a group of second annular projections, each surrounding a respective aperture of the group of second apertures, wherein each of the second annular projections projects from said first face by a second distance; wherein the first distance is greater than the second distance; and wherein the plates are configured such that the group of first annular projections on a first plate co-operate with the group of second annular projections of a superjacent plate for creating a seal between each first annular projection and a respective second annular projection.

It will be understood that each of the first annular projections defines a passageway for connecting two cold fluid flow paths together or for connecting two hot fluid flow paths together via a respective first aperture. In this way, a single cold fluid inlet/outlet pair can facilitate a flow of cold fluid through each of the plurality of cold fluid flow paths, and a single hot fluid inlet/outlet pair can facilitate a flow of hot fluid through each of the hot fluid flow paths.

Having first annular projections which co-operate with second annular projections of a superjacent plate has been found to facilitate effective sealing therebetween, which inhibits contamination between hot fluid and cold fluid in the respective flow paths.

In exemplary embodiments, said stack of plates comprises: a group of first plates in which said first and second apertures are arranged in a first array; and a group of second plates in which said first and second apertures are arranged in a second array different to the first array; wherein the first and second arrays are configured to facilitate sealing co-operation between the first and second annular projections surrounding the respective apertures when said first plates are interspersed between said second plates.

Put another way, each first aperture of the first array is aligned with a second aperture of the second array and each second aperture of the first array is aligned with a first aperture of the second array, so that the respective first and second annular projections are arranged to facilitate sealing co-operation therebetween.

Such a configuration allows the plates of the stack to be spaced apart without a need for any intermediate components such as spacing bars.

In exemplary embodiments, each first annular projection on a first plate is configured to extend into a second annular projection of a superjacent plate in the stack, such that the seal is at least partly located beyond the first face of said superjacent plate.

Having a seal at least partly located beyond the first face of a superjacent plate offers an alternative or additional seal location to a typical arrangement in which an annular projection of a first plate forms a seal with the second face of a superjacent plate radially outboard of an aperture in said superjacent plate.

In exemplary embodiments, each of the first annular projections comprises an outer radial surface and each of the second annular projections comprises an inner radial surface, and wherein a seal is created between the outer radial surface of a first annular projection of a first plate and the inner radial surface of a respective second annular projection of a superjacent plate.

It will be understood that said outer radial surfaces each define a seal surface of the first annular projections and said inner radial surfaces each define a seal surface of the second annular projections of a superjacent plate.

It will also be understood that, in exemplary embodiments, said seal surfaces project from their respective apertures, so that at least part of the seal is formed outboard of the first faces of the respective plates.

In exemplary embodiments, the outer radial surface of each first annular projection extends in the direction of (e.g. is angled or curved towards) a centre of a respective first aperture, and the inner radial surface of each second annular projection extends in the direction of (e.g. is angled or curved towards) a centre of a respective second aperture.

Such a configuration has been found to improve seal performance as the angled or curved inner radial surfaces of the second annular projections slide down the angled or curved outer radial surfaces of the first annular projections when the plates are compressed together during assembly. Improved seal performance inhibits contamination between hot fluid and cold fluid in the respective flow paths.

In exemplary embodiments, said first face defines a substantially planar surface, wherein the outer radial surface of each first annular projection is arranged at a first angle with respect to said planar surface of the first face, and the inner radial surface of each second annular projection is arranged at a second angle with respect to said planar surface of the first face, wherein said first angle is greater than said second angle; optionally, wherein said first angle is in the range of 2 to 10 degrees greater than the second angle; optionally, wherein said first angle is in the range of 5 to 85 degrees; optionally, wherein said first angle is in the range of 20 to 40 degrees; optionally, wherein said first angle is approximately 30 degrees; optionally, wherein said second angle is in the range of 3 to 83 degrees; optionally, wherein said second angle is in the range of 18 to 38 degrees; optionally, wherein said second angle is approximately 27 degrees.

Having such a first angle greater than such a second angle has been found to facilitate a sliding contact between said outer radial surface and said inner radial surface which improves seal performance and inhibits contamination between hot fluid and cold fluid in the respective flow paths.

A difference of 2 to 10 degrees between the first and second angles has been found to be optimal for creating a good seal between said first and second projections.

In exemplary embodiments, said first face and said second face each define a substantially planar surface, wherein each of the first annular projections comprises an annular shoulder, and wherein the plates are configured such that the second face of a first plate is located on said annular shoulders of a subjacent plate in the stack; optionally, wherein each annular shoulder is parallel to said planar surfaces of said first and second faces.

In exemplary embodiments, the plates are configured such that the second face of a first plate co-operates with the annular shoulders of a subjacent plate for creating a second seal between each annular shoulder and a portion of said second face radially outboard of a respective second aperture of said first plate.

Having second seals between said annular shoulders and the second faces of adjacent plates provides a redundant seal (e.g. as a back-up seal in case said first seal is compromised). Such a redundant seal inhibits contamination between hot fluid and cold fluid in the respective flow paths, even in the presence of manufacturing flaws or damage which affects the first seal.

In exemplary embodiments, each annular shoulder is spaced apart from the planar surface of said first face by a third distance in the range of 1 to lOmm; optionally, wherein said annular shoulder is spaced apart from said planar surface of said first face by a third distance in the range of 2 to 4 mm; optionally, wherein said annular shoulder is spaced apart from said planar surface of said first face by a third distance of 3mm.

Such a third distance defines a spacing between adjacent plates and thus a height of the respective cold or hot fluid flow paths. Such a range of third distances have been found to be particularly suitable for heat exchangers suitable for use in automotive applications.

In exemplary embodiments, each of said first annular projections comprises an inner radial profile and an outer radial profile, wherein said inner radial profile of each first annular projection conforms substantially to the shape of the outer radial profile of said first annular projection; and/or wherein each of said second annular projections comprises an inner radial profile and an outer radial profile, wherein the inner radial profile of each second annular projection conforms substantially to the shape of the outer radial profile of said second annular projection.

Having inner and outer radial profiles which conform to substantially the same shape allows plates with an identical array of projections to nest closely together for storage prior to assembly. In addition, such a configuration provides a simple way of forming said first and second projections (e.g. by pressing sheet metal).

Furthermore, when said inner and outer radial profiles extend in the direction of (e.g. are angled or curved towards) a centre of a respective aperture, this shape has been found to effectively guide a portion of fluid away from the respective aperture and into an associated hot or cold fluid path.

According to a second aspect of the invention a heat exchanger is provided, the heat exchanger comprising: a plurality of plates arranged in a stack, one plate on top of another, wherein the plurality of plates are spaced apart from one another; a plurality of cold fluid flow paths and a plurality of hot fluid flow paths defined between the plurality of plates, in which said plurality of cold fluid flow paths are interspersed between said plurality of hot fluid flow paths; a cold fluid inlet for input of cold fluid to said plurality of cold fluid flow paths and a cold fluid outlet for expulsion of cold fluid from said plurality of cold fluid flow paths; and a hot fluid inlet for input of hot fluid to said plurality of hot fluid flow paths and a hot fluid outlet for expulsion of hot fluid from said plurality of hot fluid flow paths; wherein each plate comprises a first face, a second face, and a plurality of apertures; and wherein the plates are configured such that each plate co-operates with a superjacent plate for creating a plurality of seals around each aperture in the stack.

Having a plurality of seals provided around each aperture provides redundant seals (e.g. back-up seals in case a first seal is compromised). Such redundant seals inhibits contamination between hot fluid and cold fluid in the respective flow paths, even in the presence of manufacturing flaws or damage which affects another of the seals.

In exemplary embodiments, said plurality of apertures comprises a group of first apertures and a group of second apertures, wherein each plate further comprises a group of first annular projections each surrounding a respective first aperture, wherein each first annular projection projects from said first face and comprises a plurality of seal surfaces for cooperating with a superjacent plate to create said plurality of seals; optionally, wherein each of said first annular projections comprises an inner radial profile and an outer radial profile, wherein the inner radial profile of said first annular projection conforms substantially to the shape of the outer radial profile of said first annular projection.

Having inner and outer radial profiles which conform to substantially the same shape allows plates with an identical pattern of projections to nest closely together for storage prior to assembly. In addition, such a configuration provides a simple way of forming said first and second projections (e.g. by pressing sheet metal).

In exemplary embodiments, the heat exchanger is configured so that a first seal surface of the plurality of seal surfaces forms a first seal with a superjacent plate radially outboard of a second aperture of said superjacent plate, and wherein a second seal surface of the plurality of seal surfaces forms a second seal with said superjacent plate at a radially inner surface of said second aperture or at a radially inner surface of a second annular projection which surrounds said second aperture and projects from the first face of said superjacent plate; optionally, wherein each of said second annular projections comprises an inner radial profile and an outer radial profile, wherein the inner radial profile of said second annular projection conforms substantially to the shape of the outer radial profile of said second annular projection.

Having a first seal surface which contacts an adjacent plate radially outboard of a second aperture provides an effective means for sealing around said second aperture. Having a second seal surface which contacts a radially inner surface of said second aperture or at a radially inner surface of a second annular projection which surrounds said second aperture also provides an effective means for sealing around said second aperture. Furthermore, such a combination of seals are separated (i.e. with the first seal surfaces radially outboard of the second seal surfaces) which increases the effectiveness of the redundant seals. For example, if damage or manufacturing errors at the second aperture lead to a compromised second seal, the first seal radially outboard of said second aperture is unlikely to also be compromised.

In exemplary embodiments, said first face and said second face each define a substantially planar surface, wherein said first seal surface comprises an annular shoulder; optionally, wherein said annular shoulder is parallel to said planar surfaces of said first and second faces.

Having such an annular shoulder which is parallel to said planar surfaces allows the first seal to be formed between the annular shoulder and said planar surfaces without having to provide a modified/specially adapted seal surface for engagement with the annular shoulder.

In exemplary embodiments, said stack of plates comprises a group of first plates having a first array of projections and a group of second plates having a second array of projections, wherein said first and second arrays of projections are different, such that said stack of plates are spaced apart by said projections when said first plates are interspersed between said second plates.

In exemplary embodiments, each plate comprises a peripheral rim which extends from said first or second face of said plate, and wherein the plates are configured such that each peripheral rim co-operates with a peripheral rim of a superjacent plate for creating a peripheral seal therebetween; optionally, wherein at least a portion of each peripheral rim is angled or curved such that said peripheral rims partially overlap each other for creating said peripheral seal.

Such an arrangement of peripheral rims has been found to be particularly effective for sealing a periphery of said hot and cold fluid paths.

Furthermore, having angled peripheral rims has been found to improve seal performance as the angled rims slide down each other when the plates are compressed together during assembly. Improved seal performance inhibits contamination between hot fluid and cold fluid in the respective flow paths.

In exemplary embodiments, the heat exchanger further comprises a plurality of turbulators, each turbulator being provided in a spacing between adjacent plates.

Having a turbulator (i.e. a formation configured to induce turbulent flow) results in a more turbulent flow condition, which increases heat transfer between the fluids compared with a more laminar flow.

In exemplary embodiments, each turbulator is in contact with said second face of a plate located on a first side of said turbulator and said first face of a plate located on a second side of said turbulator; optionally, wherein each turbulator is configured to provide a structural support to said plates located on said first and second sides of the turbulator.

Each turbulator being in contact with the plates on its first and second sides (e.g. plates above and below the turbulator) allows the turbulator to facilitate a correct spacing distance between adjacent plates. Such an arrangement is also capable of supporting the plates over a larger surface area than said projections surrounding the apertures in the plates, which inhibits bowing/deflection of the plates which could compromise the seals between adjacent hot and cold fluid paths and lead to contamination of the respective fluid flows.

In exemplary embodiments, each aperture of each plate is arranged coaxially with one of the cold fluid inlet, cold fluid outlet, hot fluid inlet and hot fluid outlet; optionally, wherein each plate comprises an aperture coaxial with the cold fluid inlet, an aperture coaxial with the cold fluid outlet, an aperture coaxial with the hot fluid inlet, and an aperture coaxial with the hot fluid outlet.

Having apertures coaxially aligned with an inlet/outlet of the heat exchanger provides an effective means of transferring hot and cold fluid from their respective inlets, through their respective plurality of flow paths and then through their respective outlets.

In exemplary embodiments, the heat exchanger further comprises a first cover (e.g. a top cover) arranged superjacent said stack of plates and a second cover (e.g. a bottom cover) arranged subjacent said stack of plates; optionally, wherein said first cover comprises said cool fluid inlet, cool fluid outlet, hot fluid inlet and hot fluid outlet; and/or optionally, further comprising a mounting plate coupled to said first or second cover wherein said mounting plate comprises one or more mounting formations for mounting the heat exchanger to a fitting surface.

Such first and second covers provide an effective means of sealing the stack of plates at either end (e.g. at the top and bottom).

In addition, such a mounting plate provides a simple means of attaching the heat exchanger to a fixing surface (e.g. a fixing surface under the bonnet of an automobile).

In exemplary embodiments, each plate has a width in the range of 50 to 300 mm and a length in the range of 100 to 500 mm; optionally, wherein each plate has a width in the range of 80 to 120 mm and a length in the range of 220 to 300 mm; optionally, wherein each plate has a width of 100mm and a length of 260 mm.

Such a range of dimensions have been found to be particularly suitable for automobile heat exchanger applications, since they provide a relatively small size/weight for fitting around other engine/vehicle components, whilst providing a good cooling capacity of the heat exchanger.

In exemplary embodiments, each aperture has a diameter in the range of 5 to 30mm; optionally, wherein each aperture has a diameter in the range of 15 to 23 mm; optionally, wherein each aperture has a diameter of 19 mm.

Such a range of aperture diameters has been found to provide a good flow rate of hot/cold fluid through the heat exchanger at typical system pressures.

In exemplary embodiments, each plate is of metal material; optionally, wherein each plate is of aluminium material; and/or optionally, wherein each plate is formed of sheet metal.

Metal material provides good structural integrity and heat transfer properties of the heat exchanger.

In addition, aluminium material is easy to form into suitable plates and to join together via brazed joints in order to seal the respective hot and cold fluid paths.

Forming the plates of sheet metal provides a simple method of manufacturing (e.g. via stamping/pressing to form said apertures, projections and peripheral rims.

In exemplary embodiments, the heat exchanger comprises a plurality of joints between adjacent plates, and wherein said joints are brazed joints.

Brazing said joints increases their sealing capabilities over arrangements which rely on clamping/bolting pressure to achieve seals between adjacent hot/cold fluid paths. This allows a higher pressure of fluid to be provided to said heat exchanger without leaking or contamination of fluids.

In exemplary embodiments, said cold fluid is water, a water/glycol mix, refrigerant, oil or diesel, and wherein said hot fluid is oil, diesel, refrigerant, water or a water/glycol mix; optionally, wherein said heat exchanger is a water or water/glycol mix cooled oil cooler.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is an isometric view of a heat exchanger according to an embodiment; Figure 2 is an exploded isometric view of the heat exchanger of Figure 1; Figure 3A is an isometric view of a plate of the heat exchanger of Figures 1 and 2 having a first pattern of projections; Figure 3B is an isometric view of a plate of the heat exchanger of Figures 1 and 2 having a second pattern of projections; Figure 4A is a cross-sectional isometric view through a first annular projection of the plate of Figure 3A; Figure 46 is a cross-sectional isometric view through a second annular projection of the plate of Figure 3A; Figure 5A and 5B are cross-sectional views of an engagement between first and second annular projections of adjacent plates of Figures 3A and 36; Figure 6 is a cross-sectional isometric view of an engagement between first and second annular projections of adjacent plates of Figures 3A and 36; and Figure 7 is a cross-sectional view of a stack of adjacent plates of Figures 3A and 36.

DETAILED DESCRIPTION

Referring to Figures 1 and 2, a heat exchanger is indicated generally at 10. The heat exchanger 10 includes a plurality of plates 12A, 126 arranged in a stack 14, one plate on top of another. As will be described in more detail below, the plurality of plates 12A, 126 are spaced apart from one another.

The heat exchanger 10 also includes a plurality of cold fluid flow paths 16 and a plurality of hot fluid flow paths 18 defined between the plurality of plates 12A, 126, in which said plurality of cold fluid flow paths 16 are interspersed between said plurality of hot fluid flow paths 18. In other words, the hot and cold fluid paths are provided in alternating spaces between plates 12A, 126 (e.g. cold fluid path 16 on top of hot fluid path 18 on top of cold fluid path 16 on top of hot fluid path 18 etc.).

The heat exchanger 10 also includes a cold fluid inlet 20 for input of cold fluid to said plurality of cold fluid flow paths 16, a cold fluid outlet 22 for expulsion of cold fluid from said plurality of cold fluid flow paths 16, a hot fluid inlet 24 for input of hot fluid to said plurality of hot fluid flow paths 18, and a hot fluid outlet 26 for expulsion of hot fluid from said plurality of hot fluid flow paths 18.

As will be described in more detail below, each of the cold fluid paths 16 are connected to each other via sealed passageways through the hot fluid paths 18, and each of the hot fluid paths 18 are connected to each other via sealed passageways through the cold fluid paths. In this way, a single cold fluid inlet/outlet pair 20, 22 can facilitate a flow of cold fluid through each of the plurality of cold fluid flow paths 16, and a single hot fluid inlet/outlet pair 24, 26 can facilitate a flow of hot fluid through each of the hot fluid flow paths 18.

Referring now to Figures 3A and 3B, each plate 12A, 12B has a first face 28, a second face 30, a group of first apertures 32 extending through the plate 12A, 12B from the first face 28 to the second face 30, and a group of second apertures 34 extending through the plate 12A, 12B from the first face 28 to the second face 30.

Each plate 12A, 12B includes a group of first annular projections 36, each surrounding a respective aperture of the group of first apertures 32. Each of the first annular projections 36 projects from said first face 28 by a first distance dl (as best illustrated in Figure 7).

It will be understood that each of the first annular projections 36 defines a passageway for connecting two cold fluid flow paths 16 together or for connecting two hot fluid flow paths 18 together via a respective first aperture 32 (e.g. as best illustrated in Figures 6 and 7).

Each plate 12A, 12B also includes a group of second annular projections 38, each surrounding a respective aperture of the group of second apertures 34. Each of the second annular projections 38 projects from said first face 28 by a second distance d2 (as best illustrated in Figure 7). The first distance dl is greater than the second distance d2.

As will be described in more detail below, the plates 12A, 12B are configured such that the group of first annular projections 36 on a first plate 12A, 12B co-operate with the group of second annular projections 38 of a superjacent plate 12A, 12B for creating a seal between each first annular projection 36 and a respective second annular projection 38.

Having first annular projections 36 which co-operate with second annular projections 38 of a superjacent plate 12A, 12B has been found to facilitate effective sealing therebetween, which inhibits contamination between hot fluid and cold fluid in the respective flow paths 16, 18.

Referring still to Figures 3A and 3B, the stack 14 of plates 12A, 12B includes a group of first plates 12A in which said first and second apertures 32, 34 (and respective first and second projections 36, 38) are arranged in a first array, and a group of second plates 12B in which said first and second apertures 32, 34 (and respective first and second projections 36, 38) are arranged in a second array different to the first array.

15 20 25 The first and second arrays are configured to facilitate sealing co-operation between the first and second annular projections 36, 38 surrounding the respective apertures 32, 34 when said first plates 12A are interspersed between said second plates 126 (e.g. first plate 12A on top of second plate 12B on top of first plate 12A on top of second plate 12B etc.).

Put another way, each first aperture 32 of the first array is aligned with a second aperture 34 of the second array and each second aperture 34 of the first array is aligned with a first aperture 32 of the second array, so that the respective first and second annular projections 36, 38 are arranged to facilitate sealing co-operation therebetween.

Such a configuration allows the plates 12A, 12B of the stack 14 to be spaced apart by the projections 36, 38 of the respective arrays when the first plates 12A are interspersed between the second plates 126, without a need for any intermediate components such as spacing bars.

Each first annular projection 36 on a first plate 12A, 126 is configured to extend into a second annular projection 38 of a superjacent plate 12A, 12B in the stack, such that the seal is at least partly located beyond the first face 28 of said superjacent plate 12A, 126 (as best illustrated in Figures 5A to 7).

Having a seal at least partly located beyond the first face 28 of a superjacent plate 12A, 12B offers an alternative or additional seal location to a typical arrangement in which an annular projection of a first plate forms a seal with the second face of a superjacent plate radially outboard of an aperture in said superjacent plate.

Referring now to Figures 4A to 5B, each of the first annular projections 36 has an outer radial surface 40 and each of the second annular projections 38 has an inner radial surface 42. A seal is created between the outer radial surface 40 of a first annular projection 36 of a first plate 12A, 12B and the inner radial surface 42 of a respective second annular projection 38 of a superjacent plate 12A, 126.

It will be understood that said outer radial surfaces 40 each define a seal surface of the first annular projections 36 and said inner radial surfaces 42 each define a seal surface of the second annular projections 38 of a superjacent plate 12A, 126.

It will also be understood that the seal surfaces 40, 42 project from their respective apertures 32, 34, so that at least part of the seal is formed outboard of the first faces 28 of the respective plates 12A, 126.

As will be described in more detail below, the outer radial surface 40 of each first annular projection 36 extends in the direction of (e.g. is angled or curved towards) a centre of a respective first aperture 32, and the inner radial surface 42 of each second annular projection 38 extends in the direction of (e.g. is angled or curved towards) a centre of a respective second aperture 34.

In the illustrated embodiment, the first face 28 defines a substantially planar surface, and the outer radial surface 40 of each first annular projection 36 is arranged at a first angle 01 with respect to said planar surface of the first face 28. Similarly, the inner radial surface 42 of each second annular projection 38 is arranged at a second angle 02 with respect to said planar surface of the first face 28. Such a configuration has been found to improve seal performance as the angled inner radial surfaces 42 of the second annular projections 38 slide down the angled outer radial surfaces 40 of the first annular projections 36 when the plates 12A, 125 are compressed together during assembly.

In alternative embodiments, the outer radial surfaces 40 and/or inner radial surfaces 42 may instead be curved towards a centre of a respective aperture 32, 34.

As best illustrated in Figure 5B, the first angle 81 is greater than the second angle 82. In the illustrated embodiment, the first angle 01 is 3 degrees greater than the second angle 02. Having such a first angle 01 greater than such a second angle 02 has been found to facilitate a sliding contact between said outer radial surface 40 and said inner radial surface 42 which improves seal performance and inhibits contamination between hot fluid and cold fluid in the respective flow paths 16, 18.

In alternative embodiments, the first angle 01 is in the range of 2 to 10 degrees greater than the second angle 02. A difference of 2 to 10 degrees between the first and second angles 01, 02 has been found to be optimal for creating a good seal between said first and second projections 36, 38.

In alternative embodiments, the first angle 01 and second angle 02 are approximately equal.

In the illustrated embodiment, the first angle 01 is approximately 30 degrees and the second angle 02 is approximately 27 degrees. In alternative embodiments, the first angle 01 is in the range of 5 to 85 degrees or 20 to 40 degrees, and the second angle 02 is in the range of 3 to 83 degrees or 18 to 38 degrees.

Referring still to Figures 4A to 56, the first face 28 and second face 30 of the plates 12A, 126 each define a substantially planar surface, and each of the first annular projections 36 has an annular shoulder 44. The plates 12A, 12B are configured such that the second face 30 of a first plate 12A, 126 is located on the annular shoulders 44 of a subjacent plate 12A, 126 in the stack. In the illustrated embodiment each annular shoulder 44 is parallel to said planar surfaces of said first and second faces 28, 30.

The plates 12A, 126 are configured such that the second face 30 of a first plate 12A, 126 co-operates with the annular shoulders 44 of a subjacent plate 12A, 12B for creating a second seal between each annular shoulder 44 and a portion of said second face 30 radially outboard of a respective second aperture 34 of said first plate 12A, 126.

In other words, the plates 12A, 126 are configured such that each plate 12A, 12B cooperates with a superjacent plate 12A, 126 for creating a plurality of seals around each aperture 32, 34 in the stack 14 (the plurality of seals including a first seal between respective first and second projections 36, 38 and a second seal between a respective annular shoulder 44 and portion of a respective second face 30).

Having second seals between the annular shoulders 44 and the second faces 30 of adjacent plates 12A, 126 provides a redundant seal (e.g. as a back-up seal in case said first seal is compromised). Such a redundant seal inhibits contamination between hot fluid and cold fluid in the respective flow paths 16, 18, even in the presence of manufacturing flaws Or damage which affects one of the first or second seals.

Furthermore, such a combination of seals are separated (i.e. with the annular shoulder seal surfaces 44 radially outboard of the projection seal surfaces 40, 42) which increases the effectiveness of the redundant seals. For example, if damage or manufacturing errors at the second aperture 34 lead to a compromised first seal, the second seal radially outboard of said second aperture 32 is unlikely to also be compromised.

In alternative embodiments, the second projections 38 are omitted. For example, the first seal may be formed instead between the outer radial surface 40 of a first projection 36 and a radially inner surface of a second aperture 34. In such embodiments, redundant second seals between annular shoulders 44 and second faces 30 would still be present.

Each annular shoulder 44 is spaced apart from the planar surface of said first face 28 by a third distance d3 (as best illustrated in Figure 7). Such a third distance d3 defines a spacing between adjacent plates 12A, 12B and thus a height of the respective cold or hot fluid flow paths 16, 18.

In exemplary embodiments, the third distance d3 is in the range of 1 to lOmm or 2 to 4mm. Such a range of third distances d3 have been found to be particularly suitable for heat exchangers suitable for use in automotive applications. In the illustrated embodiment, the third distance d3 is approximately 3mm.

It will be understood that since the annular shoulder 44 of each first projection 36 is provided part way along said first projection 36, the first distance dl (which defines the total height of the first projections 36) is greater than the third distance d3. In other words, the outer radial surface 40 of each first projection 36 extends from the annular shoulder 44 to a height of dl in relation to the respective first face 28.

In alternative embodiments, the annular shoulders 44 are omitted. It will be understood that in such embodiments, first seals would still be provided between respective first and second projections 36, 38. Furthermore, the plates 12A, 12B would still be spaced apart by virtue of the co-operating angled or curved first and second projections 36, 38, and/or one or more turbulators 48 provided in the spacing between plates 12A, 12B, and/or one or more spacer bars or other spacing elements.

In the illustrated embodiment, each of the first annular projections 36 has an inner radial profile 56 and an outer radial profile 58, and the inner radial profile 56 confirms substantially to the shape of the outer radial profile 58. Similarly, each of the second annular projections 38 has an inner radial profile 60 and an outer radial profile 62, and the inner radial profile 60 conforms substantially to the shape of the outer radial profile 62.

Having inner and outer radial profiles 56, 58, 60, 62 which conform to substantially the same shape allows plates 12A, 12B with an identical array of projections (i.e. first plates 12A or second plates 12B) to nest closely together for storage prior to assembly. In addition, such a configuration provides a simple way of forming said first and second projections 36, 38 (e.g. by pressing sheet metal).

Furthermore, when the inner and outer radial profiles 56, 58, 60, 62 extend in the direction of (e.g. are angled or curved towards) a centre of a respective aperture 32, 34, this shape has been found to effectively guide a portion of fluid away from the respective aperture and into an associated hot or cold fluid path (e.g. as shown by arrow A on Figure 7).

As best illustrated in Figures 3A and 35, each plate 12A, 125 has a peripheral rim 46 which extends from the first face 28. In alternative embodiments, the peripheral rim 46 extends from the second face 30.

The plates 12A, 125 are configured such that each peripheral rim 46 co-operates with a peripheral rim 46 of a superjacent plate 12A, 126 for creating a peripheral seal therebetween. Such an arrangement of peripheral rims 46 has been found to be particularly effective for sealing a periphery of said hot and cold fluid paths 16, 18.

In particular, at least a portion of each peripheral rim 46 is angled or curved such that the peripheral rims 46 partially overlap each other for creating the peripheral seals (as best illustrated in Figure 7). Having angled peripheral rims 46 has been found to improve seal performance as the angled rims 46 slide down each other when the plates 12A, 125 are compressed together during assembly.

In exemplary embodiments, an edge of each peripheral rim 46 distal the first face 28 is curved or angled outwards with respect to the rest of the peripheral rim 46 (e.g. as illustrated in Figure 7). This shape provides a groove between adjacent peripheral rims 46 for receiving braze material, which improves peripheral sealing performance.

In the illustrated embodiment, the heat exchanger 10 also includes a plurality of turbulators 48. Each turbulator 48 is provided in a spacing between adjacent plates 12A, 12B. Having a turbulator 48 (i.e. a formation configured to induce turbulent flow) results in a more turbulent flow condition, which increases heat transfer between the fluids compared with a more laminar flow.

Each turbulator 48 is in contact with the second face 30 of a plate 12A, 125 located on a first side of said turbulator 48 and a first face 28 of a plate 12A, 125 located on a second side of said turbulator 48. Each turbulator 48 being in contact with the plates 12A, 12B on its first and second sides (e.g. plates 12A, 12B above and below the turbulator 48) allows the turbulator 48 to contribute to facilitating a correct spacing distance between the plates 12A, 125.

In exemplary embodiments, each turbulator 48 is configured to provide a structural support to the plates 12A, 12B located on the first and second sides of the turbulator 48. This arrangement is capable of supporting the plates 12A, 12B over a larger surface area than the projections 36, 38 surrounding the apertures 32, 34 in the plates 12A, 126, which inhibits bowing/deflection of the plates 12A, 12B which could compromise the seals between adjacent hot and cold fluid paths 16, 18 and lead to contamination of the respective fluid flows.

Referring again to Figure 2, each aperture 32, 34 of each plate 12A, 126 is arranged coaxially with one of the cold fluid inlet 20, cold fluid outlet 22, hot fluid inlet 24 and hot fluid outlet 26. In particular, each plate 12A, 126 has: an aperture 32, 34 coaxial with the cold fluid outlet 22 (i.e. with common axis al), an aperture 32, 34 coaxial with the hot fluid inlet 24 (i.e. with common axis a2), an aperture 32, 34 coaxial with the hot fluid outlet 26 (i.e. with common axis a3), and an aperture 32, 34 coaxial with the cold fluid inlet 20 (i.e. with common axis a4, not shown). Having apertures 32, 34 coaxially aligned with an inlet/outlet 20, 22, 24, 26 of the heat exchanger 10 provides an effective means of transferring hot and cold fluid from their respective inlets 20, 22, through their respective plurality of flow paths 16, 18 and then through their respective outlets 24, 26.

The heat exchanger 10 also includes a first cover 50 (e.g. a top cover in the illustrated embodiment) arranged superjacent said stack 14 of plates 12A, 126 and a second cover 52 (e.g. a bottom cover in the illustrated embodiment) arranged subjacent said stack 14 of plates 12A, 126. Such first and second covers 50, 52 provide an effective means of sealing the stack 14 of plates 12A, 126 at either end (e.g. at the top and bottom).

In the illustrated embodiment, the cool fluid inlet 20, cool fluid outlet 22, hot fluid inlet 24 and hot fluid outlet 26 are part of the first cover 50. In alternative embodiments, the inlets/outlets 20, 22, 24, 26 are part of the second cover 52. In alternative embodiments, some of the inlets/outlets 20, 22, 24, 26 are part of the first cover 50 and the rest of the inlets/outlets 20, 22, 24, 26 are part of the second cover 52.

In the illustrated embodiment, the heat exchanger 10 also includes a mounting plate 54 coupled to the second cover 52. The mounting plate 54 has four mounting formations 55 for mounting the heat exchanger 10 to a fitting surface. Such a mounting plate 54 provides a simple means of attaching the heat exchanger 10 to a fixing surface (e.g. a fixing surface under the bonnet of an automobile).

In alternative embodiments, the mounting plate 54 is coupled to the first cover 50. In alternative embodiments, the mounting plate 54 includes greater or fewer mounting formations 55 (i.e. one to three mounting formations 55, or five or more mounting formations 55).

In alternative embodiments, the mounting plate 54 is omitted. In such embodiments, the first cover 50 and/or second cover 52 may include one or more mounting formations 55 instead.

In exemplary embodiments, each plate 12A, 12B has a width in the range of 50 to 300 mm and a length in the range of 100 to 500 mm, or a width in the range of 80 to 120 mm and a length in the range of 220 to 300 mm. For example, in the illustrated embodiment each plate 12A, 12B has a width of approximately 100 mm and a length of approximately 260 mm.

Such a range of dimensions have been found to be particularly suitable for automobile heat exchanger applications, since they provide a relatively small size/weight for fitting around other engine/vehicle components, whilst providing a good cooling capacity of the heat exchanger 10.

In exemplary embodiments, each aperture 32, 34 has a diameter in the range of 5 to 30mm, or 15 to 23 mm. For example, in the illustrated embodiment each aperture 32, 34 has a diameter of approximately 19 mm.

Such a range of aperture diameters has been found to provide a good flow rate of hot/cold fluid through the heat exchanger 10 at typical system pressures.

In exemplary embodiments, each plate 12A, 12B is of metal material. Metal material provides good structural integrity and heat transfer properties of the heat exchanger 10.

In exemplary embodiments, each plate is of aluminium material. Aluminium material is easy to form into suitable plates 12A, 12B and to join together via brazed joints in order to seal the respective hot and cold fluid paths 16, 18.

In exemplary embodiments, each plate 12A, 12B is formed of sheet metal. Forming the plates 12A, 12B of sheet metal provides a simple method of manufacturing (e.g. via stamping/pressing to form the apertures 32, 34, projections 36, 38 and peripheral rims 46).

In exemplary embodiments, the heat exchanger 10 includes a plurality of brazed joints between adjacent plates 12A, 12B (e.g. at the positions of the first, second and peripheral seals described above). Brazing such joints increases the sealing capabilities over arrangements which rely on clamping/bolting pressure to achieve seals between adjacent hot/cold fluid paths 16, 18. This allows a higher pressure of fluid to be provided to the heat exchanger 10 without leaking or contamination of fluids.

In exemplary embodiments, the cold fluid is water, a water/glycol mix, refrigerant, oil or diesel, and the hot fluid is oil, diesel, refrigerant, water or a water/glycol mix.

For example, the heat exchanger 10 of the illustrated embodiment is particularly suitable for use as a water (or water/glycol mix) cooled oil cooler.

Although the invention has been described in relation to one or more embodiments, it will be appreciated that various changes or modifications can be made without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS1. A heat exchanger comprising: a plurality of plates arranged in a stack, one plate on top of another, wherein the plurality of plates are spaced apart from one another; a plurality of cold fluid flow paths and a plurality of hot fluid flow paths defined between the plurality of plates, in which said plurality of cold fluid flow paths are interspersed between said plurality of hot fluid flow paths; a cold fluid inlet for input of cold fluid to said plurality of cold fluid flow paths and a cold fluid outlet for expulsion of cold fluid from said plurality of cold fluid flow paths; and a hot fluid inlet for input of hot fluid to said plurality of hot fluid flow paths and a hot fluid outlet for expulsion of hot fluid from said plurality of hot fluid flow paths; wherein each plate comprises a first face, a second face, a group of first apertures extending through the plate from the first face to the second face, and a group of second apertures extending through the plate from the first face to the second face; wherein each plate comprises a group of first annular projections, each surrounding a respective aperture of the group of first apertures, and wherein each of the first annular projections projects from said first face by a first distance; wherein each plate comprises a group of second annular projections, each surrounding a respective aperture of the group of second apertures, wherein each of the second annular projections projects from said first face by a second distance; wherein the first distance is greater than the second distance; and wherein the plates are configured such that the group of first annular projections on a first plate co-operate with the group of second annular projections of a superjacent plate for creating a seal between each first annular projection and a respective second annular projection.
2. A heat exchanger according to claim 1, wherein said stack of plates comprises: a group of first plates in which said first and second apertures are arranged in a first array; and a group of second plates in which said first and second apertures are arranged in a second array different to the first array; wherein the first and second arrays are configured to facilitate sealing co-operation between the first and second annular projections surrounding the respective apertures when said first plates are interspersed between said second plates.
3. A heat exchanger according to claim 1 or 2, wherein each first annular projection on a first plate is configured to extend into a second annular projection of a superjacent plate in the stack, such that the seal is at least partly located beyond the first face of said superjacent plate.
4. A heat exchanger according to claim 3, wherein each of the first annular projections comprises an outer radial surface and each of the second annular projections comprises an inner radial surface, and wherein a seal is created between the outer radial surface of a first annular projection of a first plate and the inner radial surface of a respective second annular projection of a superjacent plate.
5. A heat exchanger according to claim 4, wherein the outer radial surface of each first annular projection extends in the direction of (e.g. is angled or curved towards) a centre of a respective first aperture, and the inner radial surface of each second annular projection extends in the direction of (e.g. is angled or curved towards) a centre of a respective second aperture.
6. A heat exchanger according to claim 5, wherein said first face defines a substantially planar surface, wherein the outer radial surface of each first annular projection is arranged at a first angle with respect to said planar surface of the first face, and the inner radial surface of each second annular projection is arranged at a second angle with respect to said planar surface of the first face, wherein said first angle is greater than said second angle; optionally, wherein said first angle is in the range of 2 to 10 degrees greater than the second angle; optionally, wherein said first angle is in the range of 5 to 85 degrees; optionally, wherein said first angle is in the range of 20 to 40 degrees; optionally, wherein said first angle is approximately 30 degrees; optionally, wherein said second angle is in the range of 3 to 83 degrees; optionally, wherein said second angle is in the range of 18 to 38 degrees; optionally, wherein said second angle is approximately 27 degrees.
7. A heat exchanger according to any preceding claim, wherein said first face and said second face each define a substantially planar surface, wherein each of the first annular projections comprises an annular shoulder, and wherein the plates are configured such that the second face of a first plate is located on said annular shoulders of a subjacent plate in the stack; optionally, wherein each annular shoulder is parallel to said planar surfaces of said first and second faces.
8. A heat exchanger according to claim 7, wherein the plates are configured such that the second face of a first plate co-operates with the annular shoulders of a subjacent plate for creating a second seal between each annular shoulder and a portion of said second face radially outboard of a respective second aperture of said first plate.
9. A heat exchanger according to claim 7 or 8, wherein each annular shoulder is spaced apart from the planar surface of said first face by a third distance in the range of 1 to lOmm; optionally, wherein said annular shoulder is spaced apart from said planar surface of said first face by a third distance in the range of 2 to 4 mm; optionally, wherein said annular shoulder is spaced apart from said planar surface of said first face by a third distance of 3mm.
10.A heat exchanger according to any preceding claim, wherein each of said first annular projections comprises an inner radial profile and an outer radial profile, wherein said inner radial profile of each first annular projection conforms substantially to the shape of the outer radial profile of said first annular projection; and/or wherein each of said second annular projections comprises an inner radial profile and an outer radial profile, wherein the inner radial profile of each second annular projection conforms substantially to the shape of the outer radial profile of said second annular projection.
11.A heat exchanger comprising: a plurality of plates arranged in a stack, one plate on top of another, wherein the plurality of plates are spaced apart from one another; a plurality of cold fluid flow paths and a plurality of hot fluid flow paths defined between the plurality of plates, in which said plurality of cold fluid flow paths are interspersed between said plurality of hot fluid flow paths; a cold fluid inlet for input of cold fluid to said plurality of cold fluid flow paths and a cold fluid outlet for expulsion of cold fluid from said plurality of cold fluid flow paths; and a hot fluid inlet for input of hot fluid to said plurality of hot fluid flow paths and a hot fluid outlet for expulsion of hot fluid from said plurality of hot fluid flow paths; wherein each plate comprises a first face, a second face, and a plurality of apertures; and wherein the plates are configured such that each plate co-operates with a superjacent plate for creating a plurality of seals around each aperture in the stack.
12.A heat exchanger according to claim 11, wherein said plurality of apertures comprises a group of first apertures and a group of second apertures, wherein each plate further comprises a group of first annular projections each surrounding a respective first aperture, wherein each first annular projection projects from said first face and comprises a plurality of seal surfaces for co-operating with a superjacent plate to create said plurality of seals; optionally, wherein each of said first annular projections comprises an inner radial profile and an outer radial profile, wherein the inner radial profile of said first annular projection conforms substantially to the shape of the outer radial profile of said first annular projection.
13.A heat exchanger according to claim 11 or 12, wherein the heat exchanger is configured so that a first seal surface of the plurality of seal surfaces forms a first seal with a superjacent plate radially outboard of a second aperture of said superjacent plate, and wherein a second seal surface of the plurality of seal surfaces forms a second seal with said superjacent plate at a radially inner surface of said second aperture or at a radially inner surface of a second annular projection which surrounds said second aperture and projects from the first face of said superjacent plate; optionally, wherein each of said second annular projections comprises an inner radial profile and an outer radial profile, wherein the inner radial profile of said second annular projection conforms substantially to the shape of the outer radial profile of said second annular projection.
14.A heat exchanger according to claim 13, wherein said first face and said second face each define a substantially planar surface, wherein said first seal surface comprises an annular shoulder; optionally, wherein said annular shoulder is parallel to said planar surfaces of said first and second faces.
15.A heat exchanger according to any preceding claim wherein said stack of plates comprises a group of first plates having a first array of projections and a group of second plates having a second array of projections, wherein said first and second arrays of projections are different, such that said stack of plates are spaced apart by said projections when said first plates are interspersed between said second plates.
16.A heat exchanger according to any preceding claim, wherein each plate comprises a peripheral rim which extends from said first or second face of said plate, and wherein the plates are configured such that each peripheral rim co-operates with a peripheral rim of a superjacent plate for creating a peripheral seal therebetween; optionally, wherein at least a portion of each peripheral rim is angled or curved such that said peripheral rims partially overlap each other for creating said peripheral seal.
17.A heat exchanger according to any preceding claim, further comprising a plurality of turbulators, each turbulator being provided in a spacing between adjacent plates.
18.A heat exchanger according to claim 17, wherein each turbulator is in contact with said second face of a plate located on a first side of said turbulator and said first face of a plate located on a second side of said turbulator; optionally, wherein each turbulator is configured to provide a structural support to said plates located on said first and second sides of the turbulator.
19.A heat exchanger according to any preceding claim, wherein each aperture of each plate is arranged coaxially with one of the cold fluid inlet, cold fluid outlet, hot fluid inlet and hot fluid outlet; optionally, wherein each plate comprises an aperture coaxial with the cold fluid inlet, an aperture coaxial with the cold fluid outlet, an aperture coaxial with the hot fluid inlet, and an aperture coaxial with the hot fluid outlet.
20.A heat exchanger according to any preceding claim, further comprising a first cover (e.g. a top cover) arranged superjacent said stack of plates and a second cover (e.g. a bottom cover) arranged subjacent said stack of plates; optionally, wherein said first cover comprises said cool fluid inlet, cool fluid outlet, hot fluid inlet and hot fluid outlet; and/or optionally, further comprising a mounting plate coupled to said first or second cover wherein said mounting plate comprises one or more mounting formations for mounting the heat exchanger to a fitting surface.
21.A heat exchanger according to any preceding claim, wherein each plate has a width in the range of 50 to 300 mm and a length in the range of 100 to 500 mm; optionally, wherein each plate has a width in the range of 80 to 120 mm and a length in the range of 220 to 300 mm; optionally, wherein each plate has a width of 100mm and a length of 260 mm.
22.A heat exchanger according to any preceding claim, wherein each aperture has a diameter in the range of 5 to 30mm; optionally, wherein each aperture has a diameter in the range of 15 to 23 mm; optionally, wherein each aperture has a diameter of 19 MM.
23.A heat exchanger according to any preceding claim, wherein each plate is of metal material; optionally, wherein each plate is of aluminium material; and/or optionally, wherein each plate is formed of sheet metal.
24. A heat exchanger according to any preceding claim, wherein the heat exchanger comprises a plurality of joints between adjacent plates, and wherein said joints are brazed joints.
25.A heat exchanger according to any preceding claim, wherein said cold fluid is water, a water/glycol mix, refrigerant, oil or diesel, and wherein said hot fluid is oil, diesel, refrigerant, water or a water/glycol mix; optionally, wherein said heat exchanger is a water or water/glycol mix cooled oil cooler.