EP3614091B1

EP3614091B1 - Hybrid pin-fin-plate heat exchanger

Info

Publication number: EP3614091B1
Application number: EP18275131.3A
Authority: EP
Inventors: Aditya Deshpande; Stuart Astley; Philip SEWARD
Original assignee: HS Marston Aerospace Ltd
Current assignee: HS Marston Aerospace Ltd
Priority date: 2018-08-24
Filing date: 2018-08-24
Publication date: 2024-04-10
Anticipated expiration: 2038-08-24
Also published as: US20200064076A1; EP3614091A1

Description

The present disclosure relates to a hybrid heat exchanger including a pin geometry and a method of manufacturing such a hybrid heat exchanger, particularly for use in aerospace applications.
It is known to provide heat exchangers with a pin geometry in relation to flow of fluid through flow paths within the heat exchanger. It is also known to provide plate-fin heat exchangers using corrugated fin-stock in relation to flow of fluid through the heat exchanger. A typical heat exhanger comprises a core that has a plurality of first flow paths and a plurality of second flow paths. The first flow paths are in communication with a manifold that communicates a first fluid (such as oil or another liquid) through the first flow paths. The second flow paths are arranged to allow a second fluid (such as air or another gas) to pass. The first and second flow paths are generally planar and are arranged in a stacked arrangement, where second flow paths are located above and below a given first flow path, and first flow paths are located above and below a given second flow path, with an alternating sequence up until the ends of the stack, which may be a top and bottom of the stack when the heat exchanger is oriented with the flow paths generally horizontal.
The flow paths are kept separate via separating plates that allow heat to transfer between the first and second flow paths, but prevent mixing of fluid. To assist the transfer of heat in a fin-plate heat exchanger then fins are provided in the first and second flow paths, typically via fin-stock held between the separating plates. For example, US2018045469 discloses a heat exchanger arrangement formed of laminate layers with integrated pins, manifolds and enclosure bars. The fins extend between adjacent separating plates and may consist of corrugated layers or similar geometries promoting a required flow pattern. The fins are orientated in a direction to assist or guide fluid flow. In an alternative known arrangement, a pin geometry is used in place of the fins. For example, EP 2474803 discloses the use of pins within a layered laminate heat exchanger. GB2524059 A discloses a laminated plate heat exchanger with pins and fins.
The known heat exchangers also comprise a manifold that is in fluid communication with the first flow paths and not in fluid communication with the second flow paths. The manifold can supply and/or receive the first fluid to and/or from the core. The second fluid may flow across the width of the heat exchanger entering via a manifold or tank at one side and exiting via a manifold or tank at the other side.
The core typically is made by forming a stack of components. This is achieved by first providing a base plate. On top of the base plate, enclosure bars for the first fluid path are placed, and for a fin-plate heat exchanger then a fin component (such as a corrugated sheet) is placed. On top of these, a separating plate is placed. On top of this, enclosure bars for the second fluid path are placed, and a fin component (such as a corrugated sheet) is placed. On top of this, a separating plate is placed. This is repeated until the stack of a desired size is formed. To finish the stack, on top of the upper-most enclosure bars and the upper-most fin component, a top plate is placed. The stack is then brazed together to form the core.
The manifold is generally made by a separate process, such as by casting, machining or fabrication, and then welded to the core. However, the manifold may be integrated with enclosure bars in a laminate arrangement as in US2018045469 or EP 2474803 .
Viewed from a first aspect, the invention provides a heat exchanger for allowing heat to be exchanged between a first fluid and a second fluid, wherein the first fluid is a liquid, the heat exchanger comprising:
a core comprising:

a plurality of first flow paths for the first fluid and a plurality of second flow paths for the second fluid;
a plurality of pin components extending into the first flow paths;
a plurality of fin components extending through the second flow paths;
a plurality of first enclosure bars extending between adjacent separating plates that are either side of the first flow paths, the first enclosure bars being arranged to at least partially define the first flow path; and
a plurality of second enclosure bars extending between adjacent separating plates that are either side of the second flow paths, the second enclosure bars being arranged to at least partially define the second flow path, and

a manifold arranged in fluid communication with each of the first flow paths of the core, wherein:
the manifold and the core are formed as one integral piece, said integral piece comprising a stack of laminate members with said pin components for the first flow paths and said fin components for the second flow paths, wherein the plurality of laminate members comprise:
- a plurality of first fluid enclosure structures for enclosing the first flow path, each first fluid enclosure structure comprising a first manifold section, the first enclosure bars, a separating plate for separating the first flow path from the second flow path, and the pin components, wherein the pin components are formed integrally with the separating plate and extend from the separating plate into the first flow path;
- a plurality of second fluid enclosure structures for enclosing the second flow path, each second fluid enclosure structure comprising at least one second enclosure bar, and at least some of the of the second fluid enclosure structures comprising a second manifold section;
- a plurality of further separating plates for placement at the opposite side of the first flow paths to the separating plates that are integrated with the first fluid enclosure structures, each further separating plate comprising a third manifold section, and each separating plate separating each first enclosure structure from adjacent second enclosure structures such that adjacent first and second flow paths are separated by respective separating plates with each flow path being bounded by two separating plates,
wherein the first, second and third manifold sections are included in the laminate members (101, 201, 301) and are shaped to form the manifold when the plurality of laminate members are stacked.

It will be appreciated that through the use of one fin arrangement and one pin arrangement then this heat exchanger provides a hybrid arrangement. The pins are used for the first fluid which is a liquid. It has been found that advantages arise from this combination of features. The second fluid, on the fin side, may be a gas. The inventors have discovered that this provides improvements in the operation of the heat transfer within gas to liquid heat exchanger.
The first fluid enclosure structures including the first manifold section and the pins with integral separating plate may be on a plurality of first laminate members, the second fluid enclosure structures including the second manifold section may be on a plurality of second laminate members, and the further separating plates including the third manifold section may be on a plurality of third laminate members, with the first, second and third laminate members being stacked in sequence. This sequence may be repeated to build up a heat exchanger with multiple parallel flow paths formed via multiple sets of first, second and third laminate members.
The heat exchanger may comprise at least one flange for mounting the heat exchanger to other components, wherein the manifold, the core and the at least one flange are formed as one integral piece, such as via the stack of laminate members, wherein each of the first enclosure structures, each of the separating plates and at least some of the second enclosure structures comprise respective flange portions, wherein the flange portions are shaped to form the at least one flange when the plurality of laminate members are stacked.
The integral piece comprises the laminate members and the fin components brazed together where manifold is integral to the core.
The manifold may comprise manifold features for allowing the first fluid to be supplied to and/or received from the first flow paths, wherein the first, second and third manifold sections each comprise respective features that form the manifold features when the plurality of laminate members are stacked.
The heat exchanger may comprise a base plate and a top plate, wherein the laminate members comprise the base plate and the top plate, wherein the base plate forms the lower-most layer of the stack and the top plate forms the upper-most layer of the stack, wherein the base plate and the top plate each comprise a fourth manifold portion and a core portion, wherein the base plate and the top plate are each shaped such that the core portion encloses the core and the fourth manifold portion encloses the manifold.
The laminate members may be produced by additive manufacturing and/or subtractive manufacturing.
The pin components may be manufactured via any suitable technique that allows for their integration with the separating plate and preferably also with the first manifold section, and the first enclosure bars. For example, subtractive manufacturing or additive manufacturing may be used. One possibility is to form the pin members by machining or etching after the main shape for the separating plate, first manifold section, and first enclosure bars has been formed (e.g. via machining, stamping, or additive manufacturing). Another possibility is to form the entirety of a first laminate member via additive manufacturing including building up the pins via additive manufacturing.
The fin components are optionally not made by either additive manufacturing or subtractive manufacturing. Instead they may be made by any suitable technique as separate finstock, which can then be layered between the laminate members.
The invention further extends to a method of manufacturing a heat exchanger, wherein the heat exchanger is as discussed above including first, second and third laminate members, and the method comprises: stacking the laminate members and the fin components; and joining the laminate members and the fin components together to form the integral piece.
Optionally the method does not include joining the manifold and the core together. Instead the manifold and the core may be formed in one piece by the action of stacking the laminate members.
The method may comprise removing excess material from the integral piece after the joining process.
Certain embodiments of the disclosure will now be described by way of example only and with reference to the accompanying drawings in which:

Figure 1 shows an exemplary embodiment of the heat exchanger;
Figure 2 shows the core and manifolds of the heat exchanger with the outer coverings omitted highlighting second fluid fin stock;
Figure 3 shows more detail of the components of the heat exchanger of Figure 1 including the geometry of an exemplary first flow path using pins on a first laminate member;
Figure 4 illustrates an exemplary first laminate member including the first fluid enclosure structures, pin geometry and integral separating plate;
Figures 5a and 5b show examples of second fluid enclosure structures for enclosing the second fluid flow path;
Figure 6 shows another view of the of the heat exchanger of Figure 1 with laminate layers omitted to show an exemplary braze film and the form of a separating plate; and
Figure 7 shows an exemplary embodiment of a method of manufacturing a hybrid pin-fin-plate heat exchanger.

As mentioned above, in a first aspect, disclosed is a heat exchanger for allowing heat to be exchanged between a first fluid and a second fluid, wherein the first fluid is a liquid. The heat exchanger comprises a core comprising: a plurality of first flow paths for the first fluid and a plurality of second flow paths for the second fluid; a plurality of pin components extending into the first flow paths; a plurality of fin components extending through the second flow paths; a plurality of first enclosure bars extending between adjacent separating plates that are either side of the first flow paths, the first enclosure bars being arranged to at least partially define the first flow path; and a plurality of second enclosure bars extending between adjacent separating plates that are either side of the second flow paths, the second enclosure bars being arranged to at least partially define the second flow path. The heat exchanger also comprises a manifold arranged in fluid communication with each of the first flow paths of the core. The manifold and the core are formed as one integral piece, said integral piece comprising a stack of laminate members with said pin components for the first flow paths and said fin components for the second flow paths. The plurality of laminate members comprise: a plurality of first fluid enclosure structures for enclosing the first flow path, each first fluid enclosure structure comprising a first manifold section, the first enclosure bars, a separating plate for separating the first flow path from the second flow path, and the pin components, wherein the pin components are formed integrally with the separating plate and extend from the separating plate into the first flow path; a plurality of second fluid enclosure structures for enclosing the second flow path, each second fluid enclosure structure comprising a second enclosure bar, and at least some of the of the second fluid enclosure structures comprising a second manifold section; a plurality of further separating plates for placement at the opposite side of the first flow paths to the separating plates that are integrated with the first fluid enclosure structures, each further separating plate comprising a third manifold section, and each separating plate separating each first enclosure structure from adjacent second enclosure structures such that adjacent first and second flow paths are separated by respective separating plates with each flow path being bounded by two separation plates. The first, second and third manifold sections are shaped to form the manifold when the plurality of laminate members are stacked.
The first fluid enclosure structures including the first manifold section and the pins with integral separating plate may be on a plurality of first laminate members, the second fluid enclosure structures including the second manifold section may be on a plurality of second laminate members, and the further separating plates including the third manifold section may be on a plurality of third laminate members, with the first second and third laminate members being stacked in sequence. This sequence may be repeated to build up a heat exchanger with multiple parallel flow paths formed via multiple sets of first, second and third laminate members.
This heat exchanger should be more reliable than conventional heat exchangers due to the elimination of welding process. In conventional heat exchangers, the manifold and core are formed separately, and are then joined together, for example by a welding process. However, the inventors have identified that such welding joints are susceptible to thermomechanical fatigue cracking. The present heat exchanger does require any such weld, and therefore does suffer such reliability issues.
Further, the present heat exchanger may be lighter in weight than conventional heat exchangers, which is of particular relevance in industries such as aerospace. Due to the presence of the weld (which is a potential weakness, as mentioned above) conventional heat exchangers may be built heavier than the present heat exchanger.
Further still, the present heat exchanger may be built more rapidly and cheaply than conventional heat exchangers. Since both the manifold and the core are made as one integral piece from the laminate members, there is no need to manufacture the manifold and the core separately and then join them together, which reduces construction time. Further, the laminate members can be manufactured very quickly (for example from additive or subtractive manufacturing processes). The fin components can be provided as standard components and the pin components are formed integrally with the associated separating plate, which may be done in a single manufacturing process. Thus, all of the components that make up the heat exchanger can be made or provided very quickly. In addition, the form of the laminate members can be varied quickly, which allows great flexibility and quick changing of the overall heat exchanger design, especially in comparison to when a conventional manifold is made from a cast in a mould or machined from solid or fabricated joining individual components.
The present heat exchanger is hybrid arrangement including features similar to conventional fin-plate heat exchanger as well as features similar to conventional pin-plate heat exchangers. The pin components are used for the first fluid, which is a liquid. The fin components are used for the second fluid, which may be a gas. Advantages have been found from this combination of pins with liquid and fins with gas.
The heat exchanger may be arranged to exchange heat only between the first and second fluids, i.e. there may be no additional fluids present.
As can be understood from the description of the core above, the core of the present heat exchanger may be similar to or identical to the cores of conventional heat exchangers, aside from that it uses a hybrid arrangement comprising both pins and fins. Indeed, one of the purposes of the present invention is to produce a heat exchanger that has the same (or a similar) form to conventional heat exchangers, but also has the advantages listed above. The inventors have achieved this by the innovative design of the laminate members discussed herein, where the manifold sections are include in the laminate member along with other features as set out above.
Thus, the core may comprise a plurality of first flow paths arranged in a layered fashion. Between said first flow paths may be second flow paths. The first and second flow paths are separated by the separating plates. The first and second flow paths may be generally planar and the first and second fluids may move in parallel to said planes.
The core may comprise a first end and a second end, the first end being the end to which the manifold is attached and the second end being opposite said first end. The core may comprise a bottom and a top. The top and the bottom being the extremes of the core in the direction generally normal to the direction of the stack (i.e. generally parallel to the normal of the plane defined by the separating plates, see below). The core may comprise a first side and a second side, the first and second sides extending between the top and bottom and the first and second ends, and being opposite each other. The core may be shaped in a general cuboid-shape.
Adjacent first and second flow paths may be in thermal communication with each other (e.g. via the pins or fins and the separating plates). For example, one first flow path may be in communication with two second flow paths (the second flow paths above and below the first flow path); and one second flow path may be in communication with two first flow paths (the first flow paths above and below the first flow path).
The separating plates may be generally planar (herein "planar" may mean totally flat, or may be a curved plane). The first and second flow paths may be correspondingly planar. The separating plates (and hence the flow paths) may be stacked in a way such that they are separated from each other in a direction generally normal to said plane. The separating plates may have a rectangular area.
Each fin component may be an integral piece comprising multiple fins (such as a corrugated sheet). There may be only one integral piece per flow path. However, there may be more than one. Alternatively, each fin component can comprise only one fin, and a plurality of such components are provided separately within each flow path.
The fin components may be placed between adjacent separating plates and hence in said flow paths. The fins may guide the fluid in said flow paths.
As is known, fins are generally planar heat transfer elements that extend between adjacent separating plates and extend generally in the direction of fluid flow. They are different from pins and other heat transfer elements.
The pin components are integral with the associated separating plate and the first laminate member may be formed in a single piece that also comprises the first manifold section and first enclosure bars. The pin components may be manufactured via any suitable technique that allows for their integration with the separating plate and preferably also with the first manifold section, and the first enclosure bars. For example, subtractive manufacturing or additive manufacturing may be used. One possibility is to form the pin members by machining or etching after the main shape for the separating plate, first manifold section, and first enclosure bars has been formed (e.g. via machining, stamping, or additive manufacturing). Another possibility is to form the entirety of a first laminate member via additive manufacturing including building up the pins via additive manufacturing. The pin components may be arranged for a double pass, i.e. with the first fluid entering from an inlet manifold at a first end of the core, passing along the length of the first laminate member to the second end of the core, reversing in direction and passing back along the length of the first laminate member to the first end of the core to an outlet manifold.
The first enclosure bars may be located at the first and second sides of the core. The first enclosure bars may be located between separating plates at the periphery of the separating plates, whilst being integrated with one of those separating plates. There may be one first enclosure bar between two adjacent separating plates at the first side and another first enclosure between the same two adjacent separating plates at the second side. There may be second enclosure bars present on the other side of both said separating plates. The first enclosure bars and the separating plates define a first flow path where at least one end of the core is open.
The second enclosure bars may be located at the first and second ends of the core. The second enclosure bars may be located between separating plates at the periphery of the separating plates. There may be one second enclosure bar between two adjacent separating plates at the first end and another second enclosure between the same two adjacent separating plates at the second end. There may be first enclosure bars present on the other side of both said separating plates. The second enclosure bars and the separating plates define a second flow path where at least one side of the core is open.
Stated differently, a given separating plate will be separated from an adjacent separating plate above/below by first enclosure bars and by an adjacent separating plate below/above by second enclosure bars. One of those two separating plates will be integrated with the pins and optionally also with the first manifold section and the first enclosure bars.
The manifold is for supplying the first fluid to and/or receiving the first (liquid) fluid from the first fluid paths. It is not in communication with the second fluid paths.
The manifold may be located at the first end of core.
There may be only one manifold. In this case, the second end of the core of the first flow paths may be enclosed by another first enclosure bar. The manifold may comprise a supply and a return path for the first fluid and thus it may be split into an inlet (supply) manifold and an outlet (return) manifold. There may be a guiding structure present in the core to guide the fluid through the first flow paths from the supply to the return path.
There may be two manifolds. In this case, the inlet (supply) manifold and outlet (return) manifold may be present at either end of the core.
As mentioned above, in the present heat exchanger, the manifold and the core are formed as one integral piece since the laminate members include the manifold sections as well as the enclosure structures and so on. This means that they are not two separate pieces that have been joined together, for example by welding. Rather, they are formed in the same formation process (such as the brazing process mentioned below).
There may also be flanges formed in the same integral piece, with the flanges acting as interface flanges. These interface flanges may be formed by interface flange sections provided on some or all of the laminate members.
The stack of laminate members are laminated together. Lamination is known term in the art and is not discussed herein. The stack may be referred to as a laminated stack.
Each laminate member may be an integral piece, i.e. they are formed in one process and do not comprise any joints, such as welds.
The stack may be arranged by having repeated first, second and third laminate members as discussed above.
The first manifold sections of respective first enclosure structures may be the same as or different to each other. The second manifold sections of respective second enclosure structures may be the same as or different to each other (and the same as or different to the first manifold sections). The third manifold sections of respective separating plates may be the same as or different to each other (and the same as or different to the first and second manifold sections). The form of the respective first, second and third manifold sections can be such that, when the laminate members are stacked appropriately, a manifold with the correct form/features results. The first, second and third manifold sections are effectively cross-section slices of the overall manifold, such that when they are placed together the manifold is formed. Thus, first manifold section may be on a first laminate member, the second manifold section may be on a second laminate member, and third manifold section may be on a third laminate member, with the first ,second and third laminate member being stacked in sequence. This sequence may be repeated to build up a heat exchanger with multiple parallel flow paths formed via multiple sets of first, second and third laminate members.
Having the laminate members comprise such manifold sections is advantageous, not only because the manifold and the core can be formed as an integral piece, but also because it means the features of the manifold (e.g. the pipes/openings/etc.) do not need to be machined into the manifold after the stack is laminated. Further it allows the form of the manifold to be varied easily from one heat exchanger to the next.
The heat exchanger may comprise at least one flange for mounting the heat exchanger to other components. Such other components may be nearby supporting structures, such as an airframe, or other components such as ducts and pipes.
The manifold, the core and the at least one flange may be formed as one integral piece such that the flange(s) are formed by flange portion(s) of the laminate members. This may be achieved by having each of the first enclosure structures, each of the separating plates and at least some of the second enclosure structures (and preferably each of the second enclosure structures) comprise respective flange portions, wherein the flange portions are shaped to form the at least one flange when the plurality of laminate members are stacked.
Conventionally, such flanges are welded onto the core/manifold after the core is formed. However, by providing flange portions in the laminated members, the flanges can be formed at the same time as the core and can be integral with the core. This can improve reliability, reduce construction time and reduce weight. Thus, the flange may not be joined (e.g. welded) to the remainder of the heat exchanger.
There may be a plurality of flanges each formed by a respective plurality of flange portions in the laminate members. There may be (exactly) four flanges, one located proximate each corner of the core.
The integral piece may comprise (or consist of) the laminate members and the fin components adhered (e.g. brazed) together. There may of course be some adhering (e.g. brazing or bonding) material present too. The heat exchanger may be formed by using braze films placed between certain layers in order to allow for those layers to be attached together. Advantageously the shape of the braze films may mirror the outline of the adjacent laminate members, with appropriate cut-outs in the braze films at the locations of the manifold sections.
As mentioned above, the manifold may not be joined (e.g. welded) to the core. Said flange(s) may not be joined (e.g. welded) to the remainder of the heat exchanger. There may be no flange or manifold joined (e.g. welded) to the remainder of the heat exchanger. There may be no weld present in the heat exchanger.
The fins may only be provided in the fin components, which may not be laminate members and may hence be separate finstock to be layered with the laminate members. The fins may be provided in a conventional way, such as by a corrugated sheet. The fins may be placed in the stack (between separating plates) and adhered (e.g. brazed) together with the laminated members.
As mentioned above, the manifold may comprise manifold features for allowing the first fluid to be supplied to and/or received from the first flow paths. The first, second and third manifold sections may each comprise respective features that form the manifold features when the plurality of laminate members are stacked.
The manifold features may comprise fluid paths, pipes, openings, etc. for the first fluid.
If only one manifold is present in the heat exchanger, the manifold features may comprise a supply fluid path and a return fluid path, each being open to the first fluid paths.
If two manifolds are present (e.g. one at each end of the core), then a first manifold may comprise a supply fluid path and a second manifold may comprise a return fluid path, the supply and the return paths being open to the first fluid paths.
The heat exchanger may comprise a base plate and a top plate. These may also be referred to as "side plates" in the art. The base plate may be located at the bottom of the stack and the top plate may be located at the top of stack.
The laminate members may comprise the base plate and the top plate. The base plate and the top plate may each comprise a fourth manifold portion and a core portion. The base plate and the top plate may be each shaped such that the core portion encloses the core and the manifold portion encloses the manifold.
The top and the base plates may effectively provide some external structure to the heat exchanger and may seal the manifold and/or the core.
The integral member may be formed solely of the the repeated first, second and third laminate members, the base plate, the top plate and the fin components (and some adhering material, such as brazing material).
The laminate members may be produced by additive manufacturing (such as laser powder bed fusion or energy metal deposition) and/or subtractive manufacturing (such as etching, laser cutting, water jet cutting, wire eroding or high-speed machining). Different laminated members can be made by the same or different methods. The top plate, the base plate, the first enclosure structures or the second enclosure structures may be made by either additive manufacturing or subtractive manufacturing. However, the further separating plates are preferably made by subtractive manufacturing.
The present heat exchanger allows a large proportion of its constituent components to be made by these methods. Conventional methods do not allow this. This is advantageous since it allows a great deal of flexibility in design of heat exchanger, and the heat exchanger's form can be varied very quickly. Further, it can increase the speed of the manufacture.
The fin components may be manufactured by a different technique to the laminate members. Thus, they may be made during a separate process. In some examples fin components are not made by additive manufacturing or by subtractive manufacturing. Rather, the fins may be made (or supplied) in a conventional way for heat exchanger finstock (for example by pressing/bending a sheet to form a corrugated and/or perforated sheet).
The present heat exchanger allows the use of conventional fin components as one of its constituent components. This is advantageous since it allows the structure of the heat exchanger to be made quickly and strongly (as mentioned above), but can still use the conventional fin components, which are cheap and easy to make/supply.
As can be appreciated, the inventors have devised a sort of "hybrid" technology, that is somewhere between producing a pin-plate heat exchanger purely from a rapid manufacture process (such as additive manufacturing), producing a fin-plate heat exchanger by a pure laminated process (such as in EP 2474803 , discussed below) and by producing a fin-plate heat exchanger by conventional means (as discussed in the background section).
The present method is advantageous over these alternatives since it is quicker and more reliable than conventional means, but is more straightforward than using pure rapid manufacture (which may struggle to produce such a complex fin-plate heat exchanger) or by using a pure laminated process (where the fins would be required to be part of each laminate member making up a given layer). Thus, the inventors have found an improved way of manufacturing a fin-plate heat exchanger.
The heat exchanger may be for use in an aircraft. For instance, it may be for use in an aircraft engine, or possibly in an air management system in an aircraft.
The heat exchanger may be for use with a first fluid that can vary between -40°C to 210°C. The fin-plate heat exchanger may be for use with a second fluid that can very between -50°C to 100°C. The heat exchanger may be for use with a first fluid that can vary between 3 kPa to 150 kPa. The heat exchanger may be able to function over both of these ranges, and possibly beyond. The heat exchanger may comprise the first and second fluids.
The first fluid is a liquid, such as oil and the second fluid may be a gas, such as air or any combinations thereof.
In a second aspect, provided is a method of manufacturing a heat exchanger. The heat exchanger may be the heat exchanger of the first aspect. The method may comprise stacking the laminate members and the fin components; and adhering (e.g. brazing) the laminate members and the fin components together to form the integral piece.
The stacking may be as set out above, i.e. a first enclosure structure with the associated integrated separating plate, then a second enclosure structure, then an additional separating plate, then a first enclosure structure, etc.
In addition to these components, adhering (e.g. brazing) material may also be added during the stacking. For instance, adhering material may be added between the base plate and the lower most enclosure structure. Adhering material may be added between the top plate and the upper most enclosure structure.
Adhering material may be added between each layer of the stack. However, preferably it is only added in the positions mentioned in the paragraph above.
To bond the remainder of the structure, adhering material may be provided on both sides of the separating plates (i.e. the separating plates may be formed from a sheet of material that already has adhering material cladded onto both of its upper and lower surfaces), or separate braze films may be layered between the laminate members as the stack is formed.
The method may not include joining (e.g. welding) the manifold and the core together. As mentioned above, conventionally the manifold and the core of a fin-plate heat exchanger are manufactured separately, and then welded together. The inventors have devised a method where this step may not be necessary.
The method may comprise producing at least some of the laminate members by additive manufacturing. The first enclosure structures with integrated separating plates may be produced by additive manufacturing. The second enclosure structures may be produced by additive manufacturing. The top and base plates may be produced by additive manufacturing.
Additionally/alternatively, the method may comprise producing at least some of the laminate members by subtractive manufacturing. The first enclosure structures with integrated separating plates may be produced by subtractive manufacturing. The second enclosure structures may be produced by subtractive manufacturing. The top and base plates may be produced by subtractive manufacturing.
The method may use combinations of parts produced by additive and subtractive manufacturing.
The method may comprise producing the further separating plates by subtractive manufacturing. This may be preferable (instead of additive manufacturing), since the separating plates may be made from sheets where adhering material is already present. Such a material would be difficult to produce by additive manufacture.
The method may comprise removing excess material from the integral piece after the adhering process. There may be excess material present near the manifold and in other places, so as to provide enough structural integrity in the stack during adhering (where the stack may be held under pressure). Further, there may be excess material in the flange(s), which may be too big for their intended purpose. Further, holes can be drilled into the flange(s) so that they can be attached (e.g. bolted) to other components.
The method may not comprise machining the manifold or the core after the integral piece is formed as there may be no need to do so.
The method may comprise producing a first laminated heat exchanger using any of the methods above, and then producing a second laminated heat exchanger using any of the methods above. The first and the second laminated heat exchanger may differ in form, e.g. they be of different sizes, have different dimensions, have different manifold features, have different areas and thicknesses of flow paths, etc.
Due to the flexibility of the present method, the time taken to produce two such different heat exchangers may be dramatically reduced in comparison to conventional methods.
Turning now to Figure 1, shown is a heat exchanger 1 in accordance with an embodiment of the present heat exchanger.
The heat exchanger 1 comprises a core 100 in between a top plate 502 and a bottom plate 501. The core 100 comprises a plurality of first flow paths 200 for a first (liquid) fluid and a plurality of second flow paths 300 for the second fluid. The first 200 and second 300 flow paths are arranged in an alternating stack and are separated by a plurality of separating plates 101. A plurality of fin components 103 extend through respective first 200 and second 300 flow paths and extend between adjacent separating plates 101. In Figure 1, the fin components 103 in only one of the second flow paths 300 are shown as an example, but it will be appreciated that there would be fin components in each of the second flow paths.
First enclosure structures 201 act in cooperation with the separating plates 101 to define the first flow paths 200.
Second enclosure structures 301 act in cooperation with the separating plates 101 to define the second flow paths 300.
The core 100 comprises a first end 151 and a second end 152; a bottom 153 and a top 154; and a first side 155 and a second side 156.
The fin-plate heat exchanger 1 also comprises a manifold 400 arranged in fluid communication with each of the first flow paths 200 of the core 100.
The manifold 400 comprises manifold features, such as supply line 401 and a return line 402 for supplying the first fluid to the first fluid paths 200 and receiving fluid from the first fluid paths 200 respectively.
The fin-plate heat exchanger 1 comprises flanges 600. The flanges 600 are for attaching the heat exchanger 1 to other adjacent components.
The manifold 400, the flanges 600 and the core 100 are formed as one integral piece.
The integral piece comprises a stack of laminate members 101, 501, 502, 201, 301 and said fin components 103.
The plurality of laminate members 101, 501, 502, 201, 301 comprise: the first fluid enclosure structures 201; the second fluid enclosure structures 301; the plurality of separating plates 101; a base plate 501 and a top plate 502 (not shown in Figure 1).
The stack is formed by placing a first enclosure structure 201 with integral separating sheet and pin components on top of the base plate 501The first enclosure 201 hence provides a first separating plate 101. On top of the separating plate 101, a second enclosure structure 301 and a fin component 103 is placed. On top of these, another separating plate 101 is placed. This pattern is then repeated until the top 154 of the heat exchanger is reached, when a top plate 502 is placed on top of the uppermost enclosure structure(s) and fin component(s)..
As mentioned above, the stack may be brazed together to form the integral piece. An example form for a braze film is shown in Figure 6.
Figure 2 shows the stack of laminate members 101, 501, 502, 201, 301 without the top plate 502 and prior to a machining step. It will be seen that there is a honey-comb section in each layer. This is used to provide extra strength and/or stiffness for the outer walls of the manifold sections in order that the individual pieces for the laminate members are not too delicate to be handled. After forming the stack as in Figure 2, and once the integral piece is formed, then this excess material is removed, to form the end profile as in Figure 1. Also, holes are drilled in the flange as seen in Figure 1.
Regarding Figures 3 and 4, an exemplary first enclosure structure 201 is shown in more detail. The first enclosure structure 201 comprises a manifold section 202. The manifold section comprises manifold feature cut outs 208, 209. The manifold section 202 is shaped such that, when the first enclosure structure 201 is placed in the stack, the manifold 400 with the correct features 401, 402 is formed.
The first enclosure structure 201 also comprises a first enclosure bar 203 arranged to close off the first side 155 of the first fluid path 200 when placed between two separating plates 101.
The first enclosure structure 201 also comprises a second enclosure bar 204 arranged to close off the second side 156 of the first fluid path 200 when placed between two separating plates 101.
The first enclosure structure 201 may also comprise a third enclosure bar 206 arranged to close off the second end 152 of the first fluid path 200 when placed between two separating plates 101.
The first enclosure structure 201 may also comprise a guiding structure 207 arranged to guide the flow of the first fluid through the first flow path 200 from the supply 401 to the return 402 of the manifold.
The first enclosure structures 201 leave the first end 151 of the first flow path 200 open.
Other guides may be present, or no guides may be present. For instance, it may be that there are two manifolds present, one at either end 151, 153.
The first enclosure structure 201 also comprises a plurality of flange portions 210 arranged such that, when the first enclosure structure 201 is placed in the stack, the flanges 600 are formed.
Each first enclosure structure 201 may be the same as one another, or may be different. The precise form of each first enclosure structure will depend on the desired shape and features of the heat exchanger 1.
The first enclosure structure is a part of a first laminate member where it is integrally formed with a separating plate 101 and pin components 211 that are formed on a surface of the separating plate for example via machining, etching or an additive manufacturing process. This can be seen in further detail in Figure 4, which shows a first laminate member from a mid-height of the core of Figures 1 and 2. This first laminate member is the same as that of Figure 3 except that it includes an end tank feature 212 linked with the manifold sections.
Regarding Figures 5a and 5b, shown are exemplary second enclosure structures 301. The enclosure structures of Figures 5a and 5b work in combination with each other to close respective ends 151, 152 of the core 100 between two separating plates 101 so as to define a given second flow path. Fin components 103 are placed between the two enclosure structures in order to complete the second flow path. In the example shown here, the second enclosure structure 301 shown in Figure 3a closes the second end 152 and the second enclosure structure 301 shown in Figure 3b closes the first end 151 of the same second flow path 300.
Regarding Figure 5a, the first enclosure structure 301 comprises a second enclosure bar 306 arranged to close off the second end 152 of the second fluid path 300 when placed between two separating plates 101.
Regarding Figure 5b, the second enclosure structure 301 comprises a manifold section 302. The manifold section comprises manifold feature cut outs 308, 309. The manifold section 302 is shaped such that, when the first enclosure structure 301 is placed in the stack, the manifold 400 with the correct features 401, 402 is formed. In this example one manifold cut out 308 also includes an end tank feature 312, which would combine together with other end tank features (e.g. the end tank feature 212 in the second enclose structure 202) to form an end tank as shown in Figure 1.
The second enclosure structure 301 also comprises a first enclosure bar 305 arranged to close off the first end 151 of the second fluid path 300 when placed between two separating plates 101.
The second enclosure structures 301 leave the first and second sides 155, 156 of the second flow path 300 open.
The second enclosure structures 301 also comprise a plurality of flange portions 310 arranged such that, when the second enclosure structures 301 are placed in the stack, the flanges 600 are formed.
Each second enclosure structure 301 of Figure 5a may be the same as one another, or may be different to each other. Each first enclosure structure 301 of Figure 5b may be the same as one another, or may be different. The precise form of each first enclosure structure will depend on the desired shape and features of the heat exchanger 1.
Regarding Figure 6, an exemplary braze film and a separating plate 101 is shown in more detail. The braze film mirrors the shape of the separating plate 101 and can be supplied as a coating on the separating plate or as a separate film.
The separating plate 101 comprises a manifold section 102. The manifold section comprises manifold feature cut outs 108, 109. The manifold section 102 is shaped such that, when the separating plate 101 is placed in the stack, the manifold 400 with the correct features 401, 402 is formed.
The separating plate 101 has a core portion 104 that is solid (unbroken) and extends from the first end 151 of the core to the second end 152 and from the first side 155 of the core to the second side 156.
The separating plate 101 also comprises a plurality of flange portions 110 arranged such that, when the separating plate 101 is placed in the stack, the flanges 600 are formed.
Each separating plate 101 may be the same as one another, or may be different. The precise form of each separating plate 101 will depend on the desired shape and features of the heat exchanger 1.
The top and base plates 501, 502 are not shown in detail, but may be similar to the separating plate 101, but without the manifold features 108, 109 (i.e. the top and base plates 501, 502 may be solid (unbroken) so as to close the manifold 400 and the core 100).
The heat exchanger 1 of the above embodiment comprises only one manifold 400. However, it may be possible for two manifolds 400 to be present, one at each end 151, 152 of the core. In this case, one manifold may be for supply and one may be for return of the first fluid. To achieve this, additional manifold sections will be needed in the laminated members, and the manifold features of each will differ from what is shown in the Figures. For instance, third enclosure bar 206 may need to be replaced with a manifold section; a manifold section may be needed to be added to the enclosure bar 306; and a manifold section may need to be added at the second end 152 of the separating plate 101. In this case, there may be no need for guide 207.
Regarding Figure 7, a method of manufacturing the fin-plate heat exchanger is shown schematically.
In a first step 901, the laminate members 101, 201, 301, 501, 502 are produced. This may occur by additive or subtractive manufacturing and includes forming the pin components 211 integrated with the separating plate 101 of the first laminate member 201.
In a second step 902, the fin components 103 are formed. This may be achieved by cutting a corrugated sheet to size, and/or by punching a flat sheet such that corrugated fins are produced.
In a third step 903, the laminate members 101, 201, 301, 501, 502 and the fin components 103 are stacked. Possibly some brazing material is also placed in appropriate places in the stack.
In a fourth step 904, the stack is brazed to from the integral piece.
In a fifth step 905, excess material is cut off the integral piece, such as the sacrificial honey-comb sections.
In a sixth step 906, ancillary components such as relief valves are fitted.
This process can be repeated for a similarly-shaped or a differently-shaped heat exchanger.

Claims

A heat exchanger for allowing heat to be exchanged between a first fluid and a second fluid, wherein the first fluid is a liquid, the heat exchanger comprising:
a core (100) comprising:
a plurality of first flow paths (200) for the first fluid and a plurality of second flow paths (300) for the second fluid;

a plurality of pin components (211) extending into the first flow paths;

a plurality of fin components (103) extending through the second flow paths;

a plurality of first enclosure bars (203, 204, 206) extending between adjacent separating plates (101) that are either side of the first flow paths (200), the first enclosure bars (203, 204, 206) being arranged to at least partially define the first flow paths (200); and

a plurality of second enclosure bars (305, 306) extending between adjacent separating plates (101) that are either side of the second flow paths (300), the second enclosure bars (305, 306) being

arranged to at least partially define the second flow paths (300), and
a manifold (400) arranged in fluid communication with each of the first flow paths (200) of the core (100), wherein:
the manifold (400) and the core (100) are formed as one integral piece, said integral piece comprising a stack of laminate members (101, 201, 301, 501, 502)with said pin components (211) for the first flow paths (200) and said fin components (103) for the second flow paths (300), wherein the plurality of laminate members (101, 201, 301, 501, 502) comprise:
a plurality of first fluid enclosure structures (201) for enclosing the first flow path, each first fluid enclosure structure comprising a first manifold section (202), the first enclosure bars (203, 204, 206), a separating plate (101) for separating the first flow path (200) from the second flow path (300), and the pin components (211), wherein the pin components (211) are formed integrally with the separating plate (101) and extend from the separating plate (101) into the first flow path;

a plurality of second fluid enclosure structures (301) for enclosing the second flow path (300), each second fluid enclosure structure (301) comprising at least one second enclosure bar (305, 306), and at least some of the of the second fluid enclosure structures comprising a second manifold section (302);

a plurality of further separating plates (101) for placement at the opposite side of the first flow paths (200) to the separating plates (101) that are integrated with the first fluid enclosure structures (201), each further separating plate comprising a third manifold section (102), and each separating plate (101) separating each first enclosure structure (201) from adjacent second enclosure structures (301) such that adjacent first and second flow paths (200, 300) are separated by respective separating plates (101) with each flow path being bounded by two separating plates (101),

wherein the first, second and third manifold sections (202, 302, 102) are included in the laminate members (101, 201, 301) and are shaped to form the manifold (400) when the plurality of laminate members (101, 201, 301, 501, 502) are stacked.
A heat exchanger as claimed in claim 1 when in use and comprising the first fluid and the second fluid, wherein the second fluid is a gas.
A heat exchanger as claimed in claim 1 or 2, wherein the first laminate member 201 comprises a single integrally formed piece including the first enclosure bars (203, 204, 206), the first manifold section (202) the separating plate (101) and the pin components (211), which are formed on a surface of the separating plate (101).
A heat exchanger as claimed in claim 1, 2 or 3, comprising at least one flange (600) for mounting the heat exchanger (1) to other components, wherein the manifold (400), the core (100) and the at least one flange (600) are formed as one integral piece, wherein each of the first enclosure structures (201), the separating plates (101) and at least some of the second enclosure structures (301) comprise respective flange portions (210, 310, 110), wherein the flange portions (210, 310, 110) are shaped to form the at least one flange (600) when the plurality of laminate members (101, 201, 301, 501, 502) are stacked.
A heat exchanger as claimed in any preceding claim, wherein the first fluid enclosure structures (201) including the first manifold section (202) and the pins (211) with integral separating plate (101) are provided by a plurality of first laminate members (201), the second fluid enclosure structures (302) including the second manifold section (302) are provided by a plurality of second laminate members, and the further separating plates including the third manifold section may be on a plurality of third laminate members, with the first, second and third laminate members being stacked in sequence. This sequence may be repeated to build up a heat exchanger with multiple parallel flow paths formed via multiple sets of first, second and third laminate members.
A heat exchanger as claimed in any preceding claim, wherein the manifold (400) is not welded to the core (100).
A heat exchanger as claimed in any preceding claim, wherein the manifold (400) comprises manifold features (401, 402) for allowing the first fluid to be supplied to and/or received from the first flow paths (200), and wherein the first, second and third manifold sections (202, 302, 102) each comprise respective features (208, 209, 308, 309, 108, 109) that form the manifold features (401, 402) when the plurality of laminate members (101, 201, 301, 501, 502) are stacked.
A heat exchanger as claimed in any preceding claim, wherein the laminate members (101, 201, 301, 501, 502) are produced by additive manufacturing and/or subtractive manufacturing.
A heat exchanger as claimed in any preceding claim, wherein the fin components (103) are not made by additive manufacturing or subtractive manufacturing.
A method of manufacturing a heat exchanger, wherein the heat exchanger is the heat exchanger of any of the preceding claims, the method comprising:
stacking the laminate members (101, 201, 301, 501, 502) and the fin components (103); and

joining the laminate members (101, 201, 301, 501, 502) and the fin components (103) together to form the integral piece.
A method as claimed in claim 10, wherein the method does not include joining the manifold (400) and the core (100) together.
A method as claimed in claim 10 or 11, comprising producing at least some of the laminate members (101, 201, 301, 501, 502) by additive manufacturing.
A method as claimed in claim 10, 11 or 12, comprising producing at least some of the laminate members (101, 201, 301, 501, 502) by subtractive manufacturing.
A method as claimed in claim 13, comprising producing the further separating plates (101) by subtractive manufacturing.
A method as claimed in any of claims 10 to 14, comprising removing excess material from the integral piece after the joining process.