HEAT EXCHANGER

Abstract

A heat exchanger module including: a hollow chamber having an inner volume configured through which flows a first fluid in fluidic communication with a source of the first fluid, and a fluid outlet; a hollow enclosure extending outwardly from a surface of the hollow chamber wherein the hollow enclosure includes an inner volume through which flows a second fluid that undergoes a phase change in an operative mode of the heat exchanger module, wherein the hollow enclosure is in fluidic communication with a source of the second fluid, and an enclosure root of the hollow enclosure is inserted in the hollow chamber extending into the inner volume such that in an operative mode a second fluid flowing through the hollow chamber from the inlet to the outlet bathes the outer surface of said enclosure root.

Claims

1. A heat exchanger module comprising: at least one hollow chamber comprising an inner volume configured to contain a first fluid, said hollow chamber further comprising a first fluid inlet and a first fluid outlet, wherein the first fluid inlet is configured to be in fluidic communication with a source of a first fluid, and at least one hollow enclosure extending outwardly from a surface of the hollow chamber, said at least one hollow enclosure comprising an inner volume containing a working fluid, wherein said working fluid is configured to undergo a phase change during an operative mode of the heat exchanger module, wherein the at least one hollow enclosure is configured to be in fluidic communication with a source of a second fluid, wherein at least one enclosure root of the at least one hollow enclosure is interested into the inner volume of the at least one hollow chamber, and wherein, during the operative mode, the first fluid flowing through the hollow chamber from the first fluid inlet to the first fluid outlet bathes an outer surface of said at least on enclosure root.

2. The heat exchanger module according to claim 1, wherein the at least one hollow enclosure comprises a wick structure provided on at least a portion of an inner surface of the hollow enclosure.

3. The heat exchanger module according to claim 1, wherein the at least one hollow enclosure is a plurality of hollow enclosures, and each of the hollow enclosures are spaced apart from each other and arranged substantially parallel to each other, and the heat exchanger module further comprises at least one channel defined between consecutive ones of the hollow enclosures.

4. The heat exchanger module according to claim 3, further comprising fins in the at least one channel and the fins extend between the consecutive hollow enclosures.

5. The heat exchanger module according to claim 4, wherein the fins have an undulating profile shape.

6. The heat exchanger module according to claim 1, wherein the enclosure root has an aerodynamic profile including a leading edge oriented towards the first fluid inlet of the hollow chamber, and the enclosure root is configured to divert an incident flow through the at least one hollow chamber of the first fluid during the operative mode of the heat exchanger module.

7. The heat exchanger module according to claim 3, further comprising a working fluid distribution circuit comprising: a fluid distribution circuit inlet configured to be in fluidic communication with a source of the working fluid, branches, and a conduit connected to the fluid distribution circuit inlet, wherein the conduit includes branches each connected an inlet to of a respective one or more of the hollow enclosures.

8. The heat exchanger module according to claim 1, wherein the inner volume of the at least one hollow enclosure includes compartments each configured to form a flow passage for the second fluid to flow through the at least one hollow enclosure, wherein the compartments are in fluid communication with at least one of the enclosure roots.

9. The heat exchanger module according to claim 1, wherein the inner volume within at least one hollow enclosure includes ducts separated from each other, and the ducts branch from at least one of the enclosure roots.

10. A method for manufacturing a heat exchanger module of claim 1, using an additive manufacturing technique, the method comprising: providing a bed of powdered material; forming a plurality of layers by fusing together at least a portion of the powdered material to form the at least one hollow enclosure comprising the inner volume and a hollow chamber; and confining the working fluid within the inner volume of the hollow enclosure during the manufacturing process, layer by layer, of said hollow enclosure, such that the working fluid is contained within the inner volume after the hollow enclosure is formed by the forming of the plurality of layers.

11. The method for manufacturing a heat exchanger according to claim 10, wherein: the forming a plurality of layers includes forming a working fluid distribution circuit in the hollow chamber, wherein the working fluid distribution circuit includes a plurality of branches each configured to be connected to a pipe; and/or the hollow enclosure made integrally with a plurality of ducts each formed with a wick structure on at least a portion of a surface of the ducts.

12. A heat exchanger according comprising: the heat exchanger module of claim 1, which is a first heat exchanger module and the root is a first root, and, a second heat exchanger module including a second root the first heat exchanger module is coupled to the second heat exchanger module at distal ends of the first root and the second root.

13. An aircraft comprising at least the heat exchanger module of claim 1, wherein at least a distal end of the at least one hollow enclosure is in an outer skin of the aircraft.

14. The aircraft according to claim 13, wherein the outer skin where the distal end of at least one hollow enclosure is inserted is part of one of: a wing; an empennage; and a nacelle.

15. The aircraft according to claim 13, wherein the heat exchanger module is configured to be in fluidic communication with a source of air bled from a bypass stream flowing through from an engine fan duct of the aircraft.

16. A heat exchanger module comprising: a hollow chamber including an inner volume forming a flow passage for a first fluid and having a first surface; hollow enclosures each extending outwardly from the first surface and having a root extending through the first surface into the inner volume, wherein each of the hollow enclosures contains a working fluid which undergoes a phase change during an operative mode of the heat exchanger module, and the working fluid is in thermal communication with the first fluid through the root of each of the hollow enclosures, and channels defined by gaps between the hollow enclosures, wherein the channels form flow passages for a second fluid in thermal communication with the working fluid.

17. The heat exchanger module of claim 16, wherein the hollow enclosures have a hollow airfoil shape in cross section, and a leading edge of the airfoil shape faces a flow of the first fluid passing through the follow passage in the hollow chamber, and the hollow air foil shape includes an inner duct receiving the working fluid.

18. The heat exchanger module of claim 16, further comprising fins extending between adjacent ones of the hollow enclosures.

19. The heat exchanger module of claim 16, wherein heat exchanger module is a first heat exchanger module and the hollow enclosures of the first heat exchanger module each include a first distal edge opposite the root of the hollow enclosure, wherein the first distal edge of each of the hollow enclosures is configured to connect to a second distal edge of hollow enclosures of a second heat exchanger module.

20. The heat exchanger module of claim 19, wherein the connection between the first distal edges and the second distal edges forms a passage for working fluid to flow between the hollow enclosures of the first heat exchanger module and the hollow enclosures of the second heat exchanger module.

Description

DESCRIPTION OF THE DRAWINGS

[0069] These and other characteristics and advantages of the invention will become clearly understood in view of the detailed description of the invention which becomes apparent from preferred embodiments of the invention, given just as examples and not being limited thereto, with reference to the drawings.

[0070] FIG. 1 shows a schematic representation of a heat exchanger module according to an embodiment of the present invention.

[0071] FIG. 2 shows a schematic representation of a heat exchanger comprising two heat exchangers modules coupled to each other according to an embodiment of the present invention.

[0072] FIG. 3 shows a schematic representation of a heat exchanger comprising two heat exchanger modules coupled to each other, with a plurality of fins provided between consecutive hollow enclosures, according to an embodiment of the present invention.

[0073] FIG. 4 shows a schematic representation of a heat exchanger comprising two heat exchanger modules coupled to each other according to an embodiment of the present invention, with a working fluid distribution circuit connected to the hollow enclosures of a heat exchanger module, according to an embodiment of the present invention.

[0074] FIG. 5 shows a schematic representation of a front view of a heat exchanger according to an embodiment of the present invention.

[0075] FIGS. 6a to 6c show schematic views of the embodiment shown in FIG. 5 intersected by different planes.

[0076] FIG. 7 shows a schematic representation of an enlarged view of a compartment of a hollow enclosure according to an embodiment of the invention.

[0077] FIG. 8 shows a schematic representation of a plurality of enclosure roots provided with an aerodynamic profile geometry.

[0078] FIG. 9 shows a schematic representation of a heat exchanger module wherein the distal ends of two hollow enclosures are coupled to the outer fuselage skin of an aircraft according to an embodiment of the invention.

[0079] FIG. 10 shows an embodiment of an aircraft comprising a heat exchanger module according to the invention.

DETAILED DESCRIPTION

[0080] FIG. 1 shows a schematic representation of a heat exchanger module according to an embodiment of the present invention.

[0081] The first heat exchanger module (10) comprises a hollow chamber (11) comprising an inner volume defined within and configured to contain a first fluid, so that in an operative mode of the first heat exchanger module (10), a flow of hot/cold first fluid flows through the hollow chamber (11) for being cooled/evacuating heat, respectively by the heat-exchanging operation carried out by the first heat exchanger module (10). In this embodiment, the hollow chamber (11) is shaped as a rectangular prism, but other shapes are possible for the hollow chamber (11).

[0082] As will be described, the choice between hot or cold fluids will depend on the heat-exchanging operation to be carried out. In the context of the present invention, a hot fluid should be regarded as a fluid intended to be cooled by extracting heat from the hot fluid in the heat-exchanging operation from another fluid is the cold fluid. The cold fluid will evacuate heat energy from the hot fluid.

[0083] In one mode of operation, the first fluid flowing through a hollow chamber (11) may be a hot fluid intended to be cooled, or it may be a cold fluid intended to be used as a coolant for a second fluid.

[0084] For the provision of the flow the first fluid, the hollow chamber (11) comprises a fluid inlet (11.1) configured to be in fluidic communication with a source of the first fluid. The hollow chamber (11) has a fluid outlet (11.2) configured to extract the first fluid from the first heat exchanger module (10). The direction of advance (flow) of the flow of first fluid is schematically depicted in FIG. 1 with white unfilled arrows (horizontal). These arrows also schematically depict the first fluid.

[0085] In this embodiment, the first heat exchanger module (10) also includes three hollow enclosures (12) extending perpendicularly from a surface of the hollow chamber (11). The hollow enclosures are spaced from each other and are substantially parallel to each other, e.g., within 5 degrees of parallel. Channels are defined between consecutive ones of the hollow enclosures (12) of the first heat exchanger module (10). In other embodiments, the number of hollow enclosures may be less or more than the three shown in FIG. 1.

[0086] Each hollow enclosure (12) comprises an inner volume housing a working fluid, wherein said working fluid is configured to undergo a phase change in an operative mode of the first heat exchanger module (10).

[0087] A portion (12.1) of the hollow enclosures (12) is inserted in the hollow chamber (11), extending into the inner volume of said hollow chamber (11), such that in an operative mode a first fluid flowing through the hollow chamber (11) from the inlet (11.1) to the outlet (11.2) bathes the outer surface of said portion (12.1) of the hollow enclosures (12). Said portion (12.1) of the hollow enclosures (12) is referred to herein as enclosure root (12.1).

[0088] As can be seen, each hollow enclosure (12) of the heat exchanger module (10) is provided with a distal end (12.7) opposite the enclosure root (12.1).

[0089] In in an operative mode, in order to carry out the heat-exchanging operation, a source provides a second fluid.

[0090] In the particular embodiment shown, this second fluid is provided as a flow of gas passing through the channels defined between consecutive hollow enclosures (12), forcing convection with the lateral surfaces of said hollow enclosures (12). As can be seen in FIG. 1, the direction of advance of the flow of gas (second fluid) is represented with grey colored arrows (pointed into the figure). These arrows also depict the gas (second fluid).

[0091] In the particular embodiment of FIG. 1, the hollow enclosures (12) are arranged parallel to each other, forming conduits for the flow of gas.

[0092] The hollow enclosures (12) function, during operation, according to the principles of a heat pipe. In particular, each hollow enclosure (12) comprises an inner volume housing a working fluid which undergoes two phase changes during operation of the heat exchanger module (10). In particular, the fluid undergoes a phase change cycle in which part of the fluid in the liquid state is vaporized while with part of the fluid in the gaseous state is condensed.

[0093] With respect to the working fluid used in an embodiment such as the one depicted in FIG. 1, may be one of the following: ammonia, alcohol, ethanol or water.

[0094] In one example of operation of the embodiment shown in FIG. 1, a hot first fluid intended to be cooled circulates through the hollow chamber (11) of the heat exchanger module (10). Said first fluid transmits part of the stored energy in the form of heat to the working fluid contained within the hollow enclosures (12) through the outer surface of the enclosure root (12.1). As a result, the working fluid evaporates and expands through the inner volume of the hollow enclosures (12)

[0095] A second fluid, which in the embodiment considered is a flow of cold gas, and whose direction of advance is represented with grey colored arrows, passes through the channels defined between consecutive hollow enclosures (12), bathing the lateral surfaces of said hollow enclosures (12).

[0096] Convection forced by the flow of cold gas evacuates part of the thermal energy. Therefore, the working fluid within the hollow enclosures (12) condenses back into a liquid phase, releasing the latent heat, and returns to the enclosure roots (12.1), where the liquid working fluid is exposed again to the heat of the first fluid flowing through the hollow chamber (11), the heat evacuating cycle being maintained thereby.

[0097] In the embodiment of FIG. 1, the liquid phase of the working fluid returns to the enclosure roots (12.1) by the action of capillary forces. More in particular, in order to generate the capillary forces, the hollow enclosures (12) of the embodiment shown in FIG. 1 comprise a wick structure provided on at least a portion of the surface of the inner volume defined within said hollow enclosures (12).

[0098] Examples of wick structures which can be used within the scope of the present invention comprise at least one of the following structural elements: sintered metal powder, screen mesh, and/or grooves. Additionally wick structures can be generated by increasing the roughness or relief of the surface.

[0099] In other embodiments, the liquid phase of the working fluid returns to the hot interface of the hollow enclosures (12) for subsequent evaporation by other means, such as, for example, by the action of gravity and/or a centrifugal force.

[0100] FIG. 2 shows a schematic representation of an embodiment of a heat exchanger comprising two heat exchanger modules (10, 20) coupled to each other. In this embodiment, each heat exchanger module (10, 20) is according to the embodiment described in connection with FIG. 1.

[0101] As can be seen, each hollow enclosure (12) of the first heat exchanger module (10) is arranged with a distal end (12.7) mechanically coupled to a respective distal end (22.7) of an opposite hollow enclosure (22) extending outwardly from the hollow chamber (12) of the second heat exchanger module (20).

[0102] Structural continuity between the first (10) and second (20) heat exchanger modules is thus provided through the interface between the connected hollow enclosures (12, 22). Accordingly, channels are defined between consecutive pairs of coupled hollow enclosures (12.7, 22.7) and the opposite hollow chambers (11, 21).

[0103] In other embodiments, a plurality of the hollow enclosures (12) can be staggered with respect to each other, so that the distal ends (12.7) of the first (10) and second (20) heat exchanger modules are not coincident so that they cannot be mechanically coupled. In this case, additional structural elements between the first and second heat exchanger modules (10, 20) are required. The staggered position of the hollow enclosures (12) from the two modules (10, 20) can allow a higher lateral surface of the hollow enclosures (12, 22) in contact with the second fluid and higher heat transfer.

[0104] As described in connection with FIG. 1, in an operative mode of the heat exchanger (11) a second fluid is necessary to provide/evacuate thermal energy in each of the first heat exchanger module (10) and second heat exchanger module (10).

[0105] In particular, this second fluid is provided as a flow of gas passing through the channels defined between consecutive hollow enclosures (12, 22), forcing convection with the lateral surfaces of said hollow enclosures (12, 22). As can be seen in FIG. 2, the direction of advance of the flow of gas is represented with grey coloured arrows.

[0106] In the particular embodiment of FIG. 2, the hollow enclosures (12, 22) are arranged parallel to each other.

[0107] As mentioned, the hollow enclosures (12, 22) function, during operation, according to the principles of a heat pipe. In particular, each hollow enclosure (12, 22) comprises an inner volume housing a working fluid which undergoes a phase change during operation of the heat exchanger (100), that is, during operation of each of the first (10) and second (20) heat exchanger modules.

[0108] In one example of operation of the embodiment of the heat exchanger (100) shown in FIG. 2, a hot first fluid intended to be cooled circulates through the hollow chambers (11, 21) of each heat exchanger module (10, 20). Said first fluid transmits part of its thermal energy to the working fluid contained within the hollow enclosures (12, 22) through the outer surface of the enclosure roots (12.1, 22.1). As a result, the working fluid evaporates and expands through the inner volume of the hollow enclosures (12, 22).

[0109] A second fluid, which in the embodiment considered is a flow of cold gas, and whose direction of advance is represented with grey colored arrows, passes through the channels defined between consecutive hollow enclosures (12, 22), bathing the lateral surfaces of said hollow enclosures (12, 22). The cold gas is heated by radiation and convection along the hollow enclosures (12, 22), thereby cooling down the working fluid in the hollow enclosures.

[0110] In the particular embodiment shown in FIG. 2, the first and second fluids, that is, the cold fluid and the hot fluid, are flowing in perpendicular directions as showed by the grey and white arrows, respectively. This configuration with perpendicular flows is called cross flow. On additional embodiments these flows can be parallel, flowing in the same direction or in opposite direction. The latest configuration is called counter flow. Normally, the efficiency is increased with counter flow configurations.

[0111] The hollow enclosures (12, 22) can be provided with a combination of shapes adapted to reduce the pressure drop and increase the heat transmission in relation to the first or second fluid with which they are in contact in an operative mode. That is, the enclosure root (12.1) can have a shape adapted to reduce the pressure drop of the first fluid flowing in the hollow chambers (11, 21). In turn, the outer surface of the hollow enclosure (12) can have a shape adapted to reduce the pressure drop of the second fluid.

[0112] In one embodiment where the direction of the flow of the first fluid along the hollow chamber (11, 21) and the direction of the flow of the second fluid are crossed, the geometry of the enclosure root (12.1) is profiled towards the incident stream flowing through the hollow chamber (11, 21), while the geometry of the hollow enclosure body exposed to the incident flow of the second fluid tends to be profiled towards such incident flow, everything while maintaining tightness to avoid any leakage of the first fluid out of the hollow chamber (11, 21) or of the second fluid into the hollow chamber (11, 21).

[0113] Convection forced by the flow of cold gas evacuates part of the thermal energy. Therefore, the working fluid within the first and second hollow enclosures (12, 22) condenses back into a liquid phase, releasing its latent heat, and returns to the enclosure roots (12.1, 21.1), where the liquid working fluid is exposed again to the heat of the fluid flowing in the hollow chambers (11, 21), the heat evacuating cycle being maintained thereby.

[0114] As mentioned in connection with FIG. 1, in this embodiment the liquid phase of the working fluid returns to the enclosure roots (12.1, 21.1) by the action of capillary forces generated by the wick structure provided on at least a portion of the surface of the inner volume defined within said hollow enclosures (12, 22).

[0115] FIG. 3 shows a schematic representation of the very same heat exchanger (100) shown in FIG. 2, but further comprising a plurality of fins (13) provided in the channels defined between consecutive pairs of coupled hollow enclosures (12.7, 22.7) and the opposite hollow chambers (11, 21).

[0116] In particular, as can be seen, the plurality of fins (13) are attached by their respective side edges to two consecutive hollow enclosures (12, 22), and are spaced from and arranged substantially parallel to each other.

[0117] The fins (13) define a plurality of sub-channels along each channel. In an embodiment, said fins (13) are shaped with an undulating geometry. Advantageously, said undulating geometry allows to regard said sub-channels as corrugated tubes which contribute to improving the heat-exchanging operation.

[0118] Regarding said undulating geometry of the fins (13), smaller wavelengths promote local turbulent flow on the boundary layer, in turn promoting the boundary layer mixing and increase of heat transfer.

[0119] FIG. 4 shows a schematic representation of the very same heat exchanger (100) shown in FIG. 2, but further comprising a working fluid distribution circuit connected to the hollow enclosures (12) of the first (10) and second heat exchanger modules. More in particular, for illustrative purposes, reference numbers are provided only in relation to the working fluid distribution circuit connected to the first (10) heat exchanger module of the heat exchanger shown in FIG. 4. That is, the heat exchanger module (10) provided at the lowermost part.

[0120] As can be seen, each of the three hollow enclosures (12) shown in FIG. 4 comprises an inlet (12.2) connected to the working fluid distribution circuit. In particular, said fluid distribution circuit establishes a fluidic communication between a source of working fluid and the inner volume of the hollow enclosures (12), thus performing the function of recharging or extracting the working fluid from inside the hollow enclosures (12).

[0121] The working fluid distribution circuit shown comprises a main pipe (12.3) that includes flow regulator (12.4), such as an air nipple valve, downstream of which the pipe (12.3) branches into a plurality of branches (12.5) in fluidic communication with the hollow enclosures (12). The working fluid is housed in the working fluid distribution circuit and may flow continuously through the circuit or may remain in the branches (12.5) of the circuit until refilled from a source of the working fluid and/or vented from the circuit.

[0122] For illustrative purposes, only an inlet (12.2) connection for each hollow enclosure (12), and only a single valve (12.4) in the working fluid distribution circuit are represented, but it shall be understood that in further embodiments of the invention, additional connections (12.2) functioning as an additional inlet or outlet and valves (12.4) for each connection could be added to ease the recharging and extracting of the working fluid into and from the hollow enclosures (12).

[0123] In the case of additive manufacturing of the heat exchanger modules through powder bed fusion, this working distribution circuit can be also used to remove the powder that is captured into the hollow enclosures during the manufacturing process.

[0124] FIG. 5 shows a schematic representation of a cross-section of a heat exchanger (100) comprising a first (10) and a second (20) heat exchanger modules (10, 20) coupled to each other in the very same manner of the embodiments shown in FIGS. 2-4.

[0125] More in particular, FIG. 5 provides a view of a heat exchanger (100) showing three dashed straight lines which represent three intersecting planes AA, BB, CC, which are described in greater detail in relation to the following FIGS. 6a-6c.

[0126] Planes, AA, BB and CC, correspond respectively to:

[0127] a horizontal plane intersecting the hollow chamber of the first (10) heat exchanger module;

[0128] a horizontal plane intersecting the three hollow enclosures of the first (10) heat exchanger module; and

[0129] a vertical plane intersecting two connected hollow enclosures (12, 22) along their entire length, from end to end, that is, from the enclosure root of a hollow enclosure (12) to the respective enclosure root (12.1) of the opposite hollow enclosure (12).

[0130] FIGS. 6a shows the view resulting from intersecting the embodiment shown in FIG. 5 with the plane AA. In particular, it provides a plan view that allows to appreciate details of the interior of a hollow chamber (11) according to the embodiment of FIG. 5. This hollow chamber (11) is configured for the flow of a first fluid. For the provision of said flow of first fluid, the hollow chamber (11) comprises a fluid inlet (11.1) configured to be in fluidic communication with a source of fluid, and a fluid outlet (11.2). Said flow of first fluid is schematically depicted with white unfilled arrows.

[0131] The first fluid can be cold or hot depending on the heat exchange mode of operation that is intended to be performed. In any case, as can be seen, the cross section of the enclosure roots (12.1) are provided with an aerodynamic profile geometry, more specifically a NACA profile with the leading edge oriented towards the inlet (11.1) of the hollow chamber (11) for diverting an incident flow of first fluid during an operative mode of the heat exchanger module (10).

[0132] According to this particular shape of the enclosure roots (12.1), pressure drop of the first fluid flowing through the hollow chamber (11) is reduced.

[0133] In addition, in the embodiment of FIG. 6a, details of the working fluid distribution circuit are shown, which is responsible for recharging or extracting the working fluid from inside the hollow enclosures, by means of a main pipe (12.3) that includes flow regulating means (12.4), which in the particular case shown is an air nipple valve, downstream of which the pipe (12.3) branches into a plurality of branches (12.5) in fluidic communication the hollow enclosures.

[0134] FIGS. 6b shows the view resulting from intersecting the embodiment shown in FIG. 5 with plane BB. In particular, it provides a plan view that allows to appreciate details of the relative disposition of the hollow enclosures (12) between them and in relation to the hollow chamber (11), as well as the direction of the second fluid provided to carry out the heat-exchanging operation.

[0135] In particular, said hollow enclosures (12) are arranged parallel to each other. With respect to the hollow chamber (11), as in the previous embodiments shown, the hollow enclosures (12) project perpendicularly from the uppermost surface of the hollow chamber (11).

[0136] Regarding the second fluid, the direction of advance is represented with grey arrows. As can be seen, said second fluid travels essentially parallel to the very own hollow enclosures (12) passing through the channels defined between consecutive hollow enclosures (12), bathing the lateral surfaces thereof, thus carrying out the heat-exchanging operation.

[0137] FIGS. 6c shows the view resulting from intersecting the embodiment shown in FIG. 5 with plane CC.

[0138] FIG. 6c allows to see details of how the second fluid travels parallel to the hollow enclosures through the channels defined between them, bathing their lateral surfaces. Likewise, FIG. 6c allows to see a plurality of compartments (12.8) into which the hollow enclosure (12) is divided, each of said compartments (12.8) comprising an enclosure root (12.1) inserted within the chamber (11), that is, extending into the inner volume of the hollow chamber (11) in order to establish contact with a first fluid flowing through the hollow chamber (11) during operation of the heat exchanger module.

[0139] FIG. 7 shows a schematic representation of an enlarged view of the area of FIG. 6c delimited with a square drawn with a dashed line, that is, of one of the compartments (12.8) into which the hollow enclosure is divided. In particular, FIG. 7 represents an embodiment of the geometry of the portion of the inner volume provided within a single compartment (12.8) of a hollow enclosure (12), and where the working fluid is contained.

[0140] As can be seen, said inner volume is shaped as a plurality of ducts (12.6) separated from each other, said ducts (12.6) branching from the enclosure root (12.1).

[0141] In one example of an operative mode of the embodiment shown in FIG. 7, the plurality of ducts (12.6) are filled with working fluid in vapor phase, because a hot fluid flowing through the hollow chamber heats a liquid phase of the working fluid contained in the enclosure root (12.1). A flow of cold gas, whose direction of advance is represented with white unfilled arrows, passes through the channels defined between consecutive hollow enclosures, bathing the lateral surfaces thereof.

[0142] Convection forced by the flow of cold gas evacuates part of the thermal energy. Therefore, the working fluid condenses back into a liquid phase and returns, by the action of the capillary forces caused by wick structures provided on the internal surfaces of the ducts (12.6), to the enclosure root (12.1), where the liquid working fluid is exposed again to the heat of the fluid flowing therethrough, the heat evacuating cycle being maintained thereby.

[0143] FIG. 8 shows a schematic representation of a plurality of enclosure roots (12.1), that is, the portion of the hollow enclosures inserted into a hollow chamber, provided with an aerodynamic profile geometry. Preferably, said enclosure roots (12.1) have a NACA airfoil geometry, arranged with the leading edge oriented towards the inlet of the hollow chamber for diverting an incident flow of fluid during an operative mode of the heat exchanger module.

[0144] FIG. 9 shows a schematic representation of a heat exchange module wherein the distal ends (12.7), and a portion of the lateral surface of two hollow enclosures (12) are coupled to the outer fuselage skin (201) of an aircraft. As can be seen, the hollow enclosure (12) has an L shape and, part of the portion inserted into the outer fuselage skin (201) of the fuselage is flush with the external limit of the outer fuselage skin (201) exposed to the outside airflow. Thus, said portion of the hollow enclosures (12) is likewise directly in contact with the outer airflow of the aircraft (200). In another embodiment, a portion of the hollow enclosures (12) inserted in the skin (201) of the aircraft (200) may protrude outwardly from the external skin (201), entering the outer airflow.

[0145] According to this embodiment, it is possible to transfer heat directly to the exterior of the aircraft through the connection between the hollow enclosures (12) and the skin (201) of the aircraft as well as directly by the part of the hollow enclosures (12) in contact with the external airflow.

[0146] More specifically, in the example shown, a hot fluid intended to be cooled circulates through the hollow chamber (11) of the heat exchanger module. Said fluid transmits part of its thermal energy to the working fluid contained within the hollow enclosures (12) through the outer surface of the portion of the hollow enclosures (12) inserted in the hollow chamber (11).

[0147] Accordingly, said portion of the hollow enclosures (12) bathed by the hot fluid flowing through the hollow chamber (11) represents the hot interface at which the working fluid contained within the hollow enclosures (12) absorbs energy enough to turn into the vapor phase.

[0148] This vapor phase of the working fluid expands inside the internal volume of the hollow enclosure (12), thus travelling to the cold interface of the heat exchanger module, that is, to the area near the distal end (12.7) coupled to the outer fuselage skin (201) of the aircraft.

[0149] Convection forced by the surrounding airflow evacuates part of the thermal energy. Therefore, the working fluid condenses back into a liquid phase and returns, by the action of the capillary forces caused by wick structures provided on the internal surfaces of the hollow enclosures (12), to the portion of the hollow enclosure (12) inserted in the hollow chamber (11), where the liquid working fluid is exposed again to the heat of the fluid flowing therethrough, the heat evacuating cycle being maintained thereby.

[0150] In an operative mode of the embodiment shown in FIG. 9, the surrounding air can be at 50 C. (degrees Celsius) at cruise conditions thus being an optimal heat sink for evacuating heat.

[0151] Alternative examples of different aircraft structures which could benefit from the configuration shown in the embodiment of FIG. 9, wherein an outer fuselage skin (201) is used as a heat transfer surface are the wing or empennages, with their different elements such as the leading edge, trailing edge, torsion box or movable surfaces.

[0152] Additionally, the engine and nacelle surfaces can be used as heat transfer surface or even the flow in contact with the nacelle can be used as second fluid, providing the hollow enclosures with the advantage that the free stream of air flowing, for example, outside of the fan cowl, has higher relative velocity than the one on the rest of the aircraft, thus providing additional capability to remove heat.

[0153] FIG. 10 shows an embodiment of an aircraft (200) comprising a heat exchanger module according to the invention.

[0154] While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms comprise or comprising do not exclude other elements or steps, the terms a or one do not exclude a plural number, and the term or means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.