Electrical equipment cooled by immersion in a dielectric fluid

Abstract

The present invention relates to electrical equipment (2) comprising: - a casing defining a housing configured to receive a flow of dielectric fluid (3); - at least one electronic component (4) arranged in the housing, the component (4) being immersed directly in the dielectric fluid (3), the dielectric fluid (3) being configured to dissipate heat generated by the electronic component (4) via thermal convection between the dielectric fluid (3) and a conductive heat-exchange zone of each electronic component (4); the electrical equipment (2) being characterized in that the conductive heat-exchange zone of the electronic component (4) comprises a heatsink structure (8) that creates turbulence in the flow of dielectric fluid (3), and the heatsink structure (8) also increases a total surface area for the exchange of heat between the conductive heat-exchange zone and the dielectric fluid (3).

Description

DESCRIPTION Title of the invention: Electrical equipment cooled by immersion in a dielectric fluid TECHNICAL FIELD

[0001] The present invention relates to the technical field of electrical equipment, in particular configured to be installed on board a vehicle, for example a hybrid or electric vehicle.

[0002] More particularly, the invention relates to the cooling of such electrical equipment by immersion in a dielectric fluid. STATE OF THE ART

[0003] To cool electrical equipment such as a voltage converter, in particular of an electric or hybrid vehicle, it is known in the prior art to provide a conduit through a housing of the electrical equipment, the conduit being configured to circulate a fluid such as water, making it possible to dissipate by thermal conduction the heat generated inside the housing. However, certain electronic components such as electrical conductors, commonly referred to in English by the term "busbar", conduct very high intensity currents and generate a quantity of heat that cannot be dissipated satisfactorily in this way in such electrical equipment.

[0004] It is known in the technical field of computers, particularly supercomputers, to fully immerse supercomputer electronic components in a pool of phase-change dielectric fluid, allowing the heat generated by said components to be dissipated by thermal conduction, which results in the formation of bubbles within the phase-change fluid. This cooling method is commonly referred to in English as "immersive cooling". However, the electrical currents circulating in a supercomputer are much lower than those circulating in the components of electrical equipment in a motor vehicle, and in fact generate less heat than that generated by components of electrical equipment in a motor vehicle. Furthermore, the architecture of immersion in a pool of phase-change dielectric fluid is not transposable to cooling within a vehicle.The issues are therefore very different.

[0005] The invention aims to remedy all or part of the drawbacks of the state of the art by proposing electrical equipment cooled by immersion in a dielectric fluid whose cooling performance is significantly improved. PRESENTATION OF THE INVENTION

[0006] More specifically, the invention relates to electrical equipment, comprising: - a housing delimiting a housing configured to receive a flow of dielectric fluid in which a flow of dielectric fluid flows; - at least one electronic component arranged in the housing, the component being immersed directly in the dielectric fluid, the dielectric fluid being configured to dissipate heat generated by the electronic component via thermal convection between the dielectric fluid and a conductive exchange zone of each electronic component;

[0007] The electrical equipment is remarkable in that the conductive exchange zone of the electronic component comprises a dissipation structure creating turbulence in the flow of dielectric fluid, and said dissipation structure further increasing a total exchange surface of the conductive exchange zone with the dielectric fluid.

[0008] On the one hand, the disturbance of the dielectric fluid flow by the dissipation structure, i.e. the increase in the Reynolds number of the flow, also corresponds to an increase in the thermal convection coefficient of said flow, and therefore, to a decrease in the thermal convection resistance of the conductive exchange zone. On the other hand, the increase in the total exchange surface of the conductive exchange zone by the dissipation structure also results in a decrease in the thermal convection resistance of the conductive exchange zone. Thus, thanks to such a combination of characteristics, the thermal transfer of the heat generated by the electronic component by thermal convection to the dielectric fluid is significantly improved.

[0009] Advantageously, the dissipation structure has on at least a first portion a surface condition disturbing the flow of dielectric fluid. By increasing the roughness of the surface of the dissipation structure, the flow is further disturbed.

[0010] Advantageously, the surface condition of the dissipation structure is obtained by at least one treatment among the following treatments: welding of a honeycombed surface, drilling of orifices, extrusion, sandblasting, stamping. The surface condition of the dissipation structure can naturally be obtained by a combination of surface treatments among those cited, so as to further disrupt the flow of dielectric fluid. Alternatively, different surface treatments may be applied to distinct parts of the first portion of the dissipation structure, depending for example on the nature of the electronic component in question.

[0011] Advantageously, the dissipation structure has on at least a second portion a shape disturbing the flow of dielectric fluid and increasing a total exchange surface of the conductive exchange zone with the dielectric fluid. The shape of the second portion is advantageously three-dimensional.

[0012] Advantageously, the dissipation structure has on at least a first portion a surface state disturbing the flow of dielectric fluid, the first portion and the second portion being merged. In such a configuration, the same portion disturbs the flow of dielectric fluid and increases the total surface area of ​​the conductive exchange zone, making it possible to locate, for example, a privileged heat exchange point between the electronic component and the dielectric fluid.

[0013] Advantageously, the dissipation structure has on at least a first portion a surface state disturbing the flow of dielectric fluid, the first portion and the second portion being distinct. In such a configuration, the component making it possible to reduce the thermal convection resistance of the conductive exchange zone can be adapted to the environment close to the electronic component, for example adapted to a size around the electronic component.

[0014] Advantageously, the shape of the dissipation structure is included among the following shapes: a fin shape, a curved edge shape, a wave shape. Naturally, each electronic component can have a dissipation structure having a different shape, adapted to the nature of said electronic component in question.

[0015] Advantageously, the electronic component is an electrical connector.

[0016] Advantageously, the electronic component is a power electronic component, such as an inductor, a capacitive module, a power module, a sensor.

[0017] Advantageously, the dielectric fluid is a single-phase dielectric liquid. In such a configuration, the flow of the dielectric fluid before disturbance is substantially uniform in the housing.

[0018] According to another aspect of the invention, it relates to an electric or hybrid vehicle, comprising electrical equipment as described above. PRESENTATION OF THE FIGURES

[0019] The invention will be better understood on reading the description which follows, given solely by way of example, and referring to the appended drawings given by way of non-limiting examples, in which identical references are given to similar objects and in which:

[0020] Figure 1 is a schematic top view representation of electrical equipment, in a position removed from the housing;

[0021] Figure 2 is a schematic representation in isometric perspective of an electronic component of the electrical equipment of Figure 1, according to a first embodiment of the invention;

[0022] Figure 3 is a schematic cross-sectional representation of a portion of the electronic component of Figure 2, in three distinct variants;

[0023] Figure 4 is a schematic representation in isometric perspective of an electronic component of the electrical equipment of Figure 1, according to another embodiment of the invention;

[0024] Figure 5 is a schematic representation in isometric perspective of an electronic component of the electrical equipment of Figure 1, according to another embodiment of the invention;

[0025] Figure 6 is a schematic representation in isometric perspective of an electronic component of the electrical equipment of Figure 1, according to another embodiment of the invention;

[0026] Figure 7 is a schematic representation in isometric perspective of an electronic component of the electrical equipment of Figure 1, according to another embodiment of the invention;

[0027] It should be noted that the figures set out the invention in detail to enable the invention to be implemented; although not limiting, said figures serve in particular to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0028] The invention relates to an electrical equipment 2, in particular configured to be carried by an electric or hybrid vehicle. The electrical equipment 2 is for example a voltage converter such as an inverter, as illustrated in FIG. 1.

[0029] The electrical equipment 2 comprises a housing delimiting a housing configured to receive a flow of dielectric fluid 3 in which a flow of dielectric fluid 3 flows. For reasons of readability, the housing and the dielectric fluid 3 are not illustrated in FIG. 1. The dielectric fluid 3 is preferably a dielectric single-phase liquid. Thus, in the absence of a phase change, the flow of the liquid without disturbance is substantially uniform in the housing.

[0030] The electrical equipment 2 further comprises at least one electronic component 4 arranged in the housing, the component being immersed directly in the dielectric fluid 3, the dielectric fluid being configured to dissipate heat generated by the electronic component 4 by means of thermal convection between the dielectric fluid 3 and a conductive exchange zone of the electronic component 4. The heat generated by the electronic component 4 comes from the Joule effect generated by an electric current passing through the electronic component 4 during operation of the electrical equipment 2.

[0031] The conductive exchange zone comprises at least one dissipation structure 8, as illustrated in FIG. 2. The dissipation structure 8 creates on the one hand turbulence in the flow of dielectric fluid 3. The disturbance of the flow of dielectric fluid 3 by the dissipation structure 8, that is to say the increase in the Reynolds number of the flow, also corresponds to an increase in the thermal convection coefficient of said flow, and therefore, to a reduction in the thermal convection resistance of the conductive exchange zone.

[0032] On the other hand, the dissipation structure 8 increases a total exchange surface area of ​​the conductive exchange zone 8 with the dielectric fluid 3. The increase in the total exchange surface area of ​​the conductive exchange zone by the dissipation structure 8 also results in a reduction in the thermal convection resistance of the conductive exchange zone. Thus, thanks to such a combination of characteristics, the thermal transfer of the heat generated by the electronic component 4 by thermal convection to the dielectric fluid 3 is significantly improved.

[0033] In the embodiment depicted in Figure 2, the illustrated electronic component 4 is an electrical connector, commonly referred to as a “busbar.” Alternatively, the component electronic component 4 may be an inductor, a capacitive module, a power module, a sensor, or any other electronic component generating heat, usually present in electrical equipment such as a voltage converter. In the case of an electrical connector as illustrated, the conductive exchange zone covers the entire surface of the electronic component 4, so that the heat exchange by convection with the dielectric fluid 3 is maximized. For reasons of readability, in the remainder of the description, the flow of dielectric fluid 3 is represented by one or more current lines.

[0034] the dissipation structure 8 has on at least a first portion 10 a surface condition disturbing the flow of dielectric fluid 3. By increasing the roughness of the surface of the dissipation structure, the flow is further disturbed. The surface condition of the dissipation structure 8 is obtained by at least one surface treatment. Figure 3 illustrates three examples of surface treatments, from top to bottom: welding of a honeycombed surface, extrusion, drilling of orifices. Alternatively, the surface treatment can be carried out by sandblasting or stamping. The surface condition of the first portion 10 of the dissipation structure 8 can naturally be obtained by a combination of surface treatments among those mentioned, so as to further disturb the flow of dielectric fluid 3.The dissipation structure 8 may comprise a plurality of first portions 10, each first portion having a surface state obtained by a different surface treatment, depending for example on the nature of the electronic component 4.

[0035] The dissipation structure 8 also has, on at least one second portion 12, a shape that disrupts the flow of dielectric fluid 3 and increases the total exchange surface area of ​​the conductive exchange zone with the dielectric fluid 3. Figure 4, Figure 5 and Figure 6 illustrate possible shapes of second portions 12. Here, the shapes of the second portions 12 are three-dimensional and disrupt the flow, as illustrated by the directions taken by current lines of the dielectric fluid. Here, the electronic component 4 has a substantially symmetrical envelope, in the form of so-called "edges", straight in Figure 4, or curved for Figure 5 and Figure 6, so that the cooling is uniform over the entire electronic component 4. By curving the second portions 12, the size of the dissipation structure 8 can be adapted to the environment close to the electronic component 4.Other three-dimensional shapes, symmetrical or not, are conceivable, for example a fin shape or a wave shape. Furthermore, the dissipation structure 8 may comprise a plurality of second portions 12 each having a different shape.

[0036] Figure 7 illustrates an electronic component 4 according to another embodiment of the invention. Here, the first portion 10 of the dissipation structure 8 and the second portion of the dissipation structure 12 are merged, making it possible to maximize the heat exchange by convection with the electric fluid 3. Thus, a privileged heat exchange point between the electronic component 4 and the dielectric fluid 3 is located.

[0037] It will also be noted that the invention is not limited to the embodiments described above. It will indeed appear to those skilled in the art that various modifications can be made to the embodiment described above, in light of the teaching which has just been disclosed to them.

[0038] In the detailed presentation of the invention given above, the terms used should not be interpreted as limiting the invention to the embodiment set forth in the present description, but should be interpreted to include all equivalents whose prediction is within the reach of a person skilled in the art by applying his general knowledge to the implementation of the teaching just disclosed to him.

Claims

CLAIMS 1. Electrical equipment (2), comprising: - a housing delimiting a housing configured to receive a flow of dielectric fluid (3) in which a flow of dielectric fluid (3) flows; - at least one electronic component (4) arranged in the housing, the component (4) being immersed directly in the dielectric fluid (3), the dielectric fluid (3) being configured to dissipate heat generated by the electronic component (4) via thermal convection between the dielectric fluid (3) and a conductive exchange zone of each electronic component (4); the electrical equipment (2) being characterized in that the conductive exchange zone of the electronic component (4) comprises a dissipation structure (8) creating turbulence in the flow of dielectric fluid (3), and said dissipation structure (8) further increasing a total exchange surface of the conductive exchange zone with the dielectric fluid (3).

2. Electrical equipment (2) according to claim 1, in which the dissipation structure (8) has on at least a first portion (10) a surface state disturbing the flow of dielectric fluid (3).

3. Electrical equipment (2) according to claim 2, in which the surface condition of the dissipation structure (8) is obtained by at least one of the following treatments: welding of a honeycomb surface, drilling of orifices, extrusion, sandblasting, stamping.

4. Electrical equipment (2) according to any one of the preceding claims, in which the dissipation structure (8) has on at least a second portion (12) a shape disturbing the flow of dielectric fluid (3) and increasing a total exchange surface of the conductive exchange zone with the dielectric fluid (3).

5. Electrical equipment (2) according to claim 4, in which the dissipation structure (8) has on at least a first portion (10) a surface state disturbing the flow of dielectric fluid (3), the first portion (10) and the second portion (12) being merged.

6. Electrical equipment (2) according to claim 4, in which the dissipation structure (8) has on at least a first portion (10) a surface state disturbing the flow of dielectric fluid (3), the first portion (10) and the second portion (12) being distinct.

7. Electrical equipment (2) according to any one of claims 4 to 6, in which the shape of the dissipation structure (8) is included among the following shapes: a fin shape, a curved edge shape, a wave shape.

8. Electrical equipment (2) according to any one of the preceding claims, in which the electronic component (4) is an electrical connector.

9. Electrical equipment (2) according to any one of claims 1 to 7, in which the electronic component (4) is a power electronic component (4), such as an inductor, a capacitive module, a power module.

10. Electrical equipment (2) according to any one of the preceding claims, in which the dielectric fluid (3) is a single-phase dielectric liquid.

11. Electric or hybrid vehicle, comprising electrical equipment according to any one of claims 1 to 10.

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