Patent ID: 12207442

DETAILED DESCRIPTION

It should be noted that the structural and/or functional elements common to the different embodiments have the same references. Thus, unless otherwise stated, such elements have identical structural, dimensional and material properties.

FIG.1shows a housing10comprising a structure11having a base composite wall12and side composite walls13extending from the wall12. A composite wall12,13comprises woven or braided carbon fibers15covered with a thermoplastic or thermosetting resin16, as shown inFIG.3.

An electronic card18visible inFIGS.1and3and carrying electronic components19is mounted on a support20mechanically linked to the wall12(seeFIG.2). For this purpose, the electronic card18can be fixed on the support20by means of fixing members22, such as fixing screws, or a locking slide, or any other fixing means suitable for the application.

The electronic card18is thus raised relative to the composite wall12. An electronic component19to be cooled is carried by one face of the electronic card18located on the composite wall12side. The base composite wall12, the side walls13, as well as the electronic card18thus form an housing. The housing is closed by a lid (not shown).

A heat transfer device24comprises at least one cooling conduit25containing a cooling fluid. The cooling conduit25is inserted inside the composite wall12. At least a portion of the cooling conduit25is facing the electronic component19to be cooled.

Advantageously, several cooling conduits25are arranged inside the composite wall12. The number of cooling conduits25is however reduced, in particular less than or equal to 5, in order to limit the mass of the assembly.

The carbon fibers15with a high thermal conductivity arranged around the cooling conduits25ensure the homogeneity of the temperature of the housing10towards the lowest possible temperature. The carbon fibers15advantageously have a thermal conductivity comprised between 300 W/m/K and 800 W/m/K. Such a level of thermal conductivity makes it possible to have fibers that can be handled, without being too brittle. This type of fiber thus makes it possible to produce any curved shapes having radii of curvature that can match the rounded shapes of the cooling conduits25.

Preferably, the cooling conduits25are flush with an outer surface of the composite wall12while being protected by resin16. This makes it possible to avoid any risk of galvanic corrosion between the material of a conduit25and the carbon fibers15.

As can be seen inFIG.3, a compressible thermal interface28is arranged between the electronic component19to be cooled and the composite wall12in which the cooling conduit25is inserted. The compressible thermal interface28fills the gap and surface roughness while decreasing an induced thermal contact resistance. The thermal interface28has a greater thermal conductivity than air, for example between 2 W/m/K and 10 W/m/K. The thermal interface28may take the form of a thermal gel or a thermal cushion or a thermal sheet or a phase-change material.

Advantageously, the heat transfer device24takes the form of a diphasic loop. As can be seen inFIG.2, a cooling conduit25can then form a heat pipe having a hot end30close to the electronic component19to be cooled and a cold end31close to an edge of the housing10outside the composite wall12. The hot end30thus corresponds to an evaporation zone of the cooling fluid which can extract calories from the electronic component19to be cooled while the cold end31corresponds to a condensation zone of the cooling fluid which can transfer the stored calories to the external environment. The liquid phase and vapor phase of the fluid of a heat pipe are located in the same conduit. The heat pipe may take the form of a micro-heat pipe or a pulsed heat pipe.

Other types of diphasic loops can be envisaged, such as for example a diphasic capillary-pumping loop of the CPL (Capillary pump Loop) type, or LHP (Loop Heat Pipe) type. In this case, the liquid conduit and vapor conduit are separated from each other. A passive pumping system enables the system to be activated.

The cooling conduits25are advantageously made of copper or any other material suitable for the application. Due to the integration of the conduits inside the composite wall12, it is possible to use fluids other than water, in particular alcohol-based fluids, insofar as a diphasic loop does not run the risk, in the event of breakage, of releasing prohibited flammable products in the electronic components located in sensitive areas of an airplane engine.

In the embodiment ofFIG.4, the heat transfer device24inserted inside the composite wall12comprises a plate32, so-called “cold plate”, made of a heat-conducting material, in which is formed at least one circulation conduit25for a cooling fluid in the liquid phase.

The conduit25defines an open circuit having an inlet34and an outlet35for the cooling liquid. The cooling liquid will thus be able to evacuate calories from electronic components19during its circulation between the inlet34and outlet35. The temperature of the liquid at the outlet of the cold plate32depends on the flow rate thereof inside the plate32. In order to optimize the cooling process, the conduit25may have a serpentine shape.

Advantageously, the cooling liquid comes from a fluid circuit available on an aircraft engine, such as a fuel circuit. For this purpose, the conduit25in the cold plate32is intended to be connected to the fluid circuit. Once the fluid leaves the cold plate32, it continues to play its role in the engine.

As a variant, water or oil or any other cooling liquid suitable for the application having a high thermal conductivity may be used.

Alternatively, it is possible to create a closed cooling circuit by using a pumping system (not shown) ensuring the circulation of the liquid between the inlet34and outlet35for the cooling liquid.

The cooling conduits25inFIGS.2and3are added profile-shaped conduits. The cooling conduits25may have a cylindrical shape. A section of the cooling conduits25may be round, square, rectangular, or rectangular with rounded edges, or any shape suitable for the application.

In the embodiment ofFIGS.5a,5b, and5c, the heat transfer device24comprises at least one insert38made of a metallic material comprising a plurality of holes40forming the cooling conduits25. The dimensioning of the holes40depends on the desired thermal efficiency and the pressure drop not to be exceeded. The insert38can be made by a metal additive manufacturing process.

As can be seen inFIGS.6aand6b, the insert38may comprise a plurality of cooling fins41extending outwards said housing10.

As illustrated inFIGS.5cand6a, the support20may include holes43forming conduits for the passage of a cooling fluid. These conduits may form a diphasic loop or a cooling circuit in which a cooling liquid circulates. In other words, in addition to its function of holding the electronic card18, the support20made of a metallic material may be actively involved in cooling the components19. The support20may comprise several elongated portions so as to extend at least partly along a perimeter of the electronic card18(seeFIG.2). The support20can be inserted at least partly inside the composite wall12.

It is given below, with reference toFIGS.7aand7b, a description of a method for producing a thermal cooling housing10.

This method comprises a step of producing a dry fiber preform44as well as a step of inserting one or more cooling conduits25inside the fiber preform44, as shown inFIG.7a. The conduit25may be an added conduit as shown inFIG.7aor a conduit formed inside an insert38placed inside the fiber preform44.

The method also includes a step of injecting resin16into a mold in which the fiber preform44and the cooling conduit25are placed, as shown inFIG.7b.

As the fiber preform44is obtained by stacking a succession of sheets45of carbon fibers15, a cooling conduit25is arranged between two sheets45of the fiber preform44, in particular between a penultimate sheet in the stack and a last sheet in the stack.

The housing10can be obtained by a method of the RTM (Resin Transfer Molding) type or by infusion and autoclave.

Of course, the different characteristics, variants and/or embodiments of the present disclosure can be associated with each other in various combinations insofar as they are not incompatible or mutually exclusive.

Furthermore, the disclosure is not limited to the above-described embodiments, provided only as an example. It encompasses various modifications, alternative forms and other variants that can be considered by the skilled person within the framework of the present disclosure, including any combination of the various above-described modes of operation, which may be taken separately or in combination.

The subject matter of certain embodiments of this disclosure is described with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described.

It should be understood that different arrangements of the components depicted in the drawings or described above, as well as components and steps not shown or described are possible. Similarly, some features and sub-combinations are useful and may be employed without reference to other features and sub-combinations. Embodiments of the invention have been described for illustrative and not restrictive purposes, and alternative embodiments will become apparent to readers of this patent. Accordingly, the present invention is not limited to the embodiments described above or depicted in the drawings, and various embodiments and modifications may be made without departing from the scope of the claims below.