Arrangement of a power electronics component in an aircraft

Abstract

Aircraft (1) comprising at least the following components: - a vehicle skin (2); - a cooling plate (3); - a power electronics component (4), wherein the power electronics component (4) is arranged to transfer heat on a cooling surface (5) of the cooling plate (3), characterized in that the cooling plate (3) is in direct contact with an inner surface of the vehicle skin (2) by means of a return cooling surface (6).

Description

The invention relates to an aircraft with a cooling plate for a power electronics component. Modern aircraft contain a multitude of power electronic components. These power electronic components require cooling. Various cooling methods for these components are known from industrial practice. For example, the power electronic component is cooled directly by an ambient airflow, either by a stream of air or by a coolant or a cooling plate containing a coolant. All these cooling systems for power electronics components, known from industrial practice, are heavy due to the coolant and / or a high number of components, require a comparatively large installation space, and cause efficiency losses. Direct airflow onto the power electronics component increases the aircraft's drag, and coolant-based cooling systems increase weight and sometimes require active recooling. US 7,325,772 B1, for example, discloses an aircraft component comprising a first section that can be attached to an outer surface of an aircraft to close an access opening through the outer surface; and a second section that extends outward from the first section and forms heat transfer surfaces to transfer heat from the first section to air passing over the outer surface and the second section during the aircraft's flight. The first and second sections are integrally formed as a single element. The object of the present invention is to overcome the disadvantages arising from industrial practice and to provide an aircraft by means of which the power electronic components of the aircraft can be cooled with low weight, efficiently and in a space-saving manner. Based on this, the present invention aims to overcome, at least partially, the disadvantages known from the prior art. The features of the invention are defined in the independent claims, for which advantageous embodiments are shown in the dependent claims. The features of the claims can be combined in any technically meaningful way, whereby the explanations in the following description and features from the figures, which comprise supplementary embodiments of the invention, can also be used. The invention relates to an aircraft comprising at least the following components: - a vehicle skin; - a cooling plate; - a power electronics component, wherein the power electronics component is arranged to transfer heat on a cooling surface of the cooling plate. The aircraft is characterized primarily by the fact that the cooling plate is in direct contact with an inner surface of the vehicle skin by means of a cooling surface. Unless explicitly stated otherwise, ordinal numbers used in the preceding and following descriptions serve solely for unambiguous differentiation and do not indicate any order or ranking of the components referred to. An ordinal number greater than one does not necessarily imply the presence of another such component. Such an aircraft therefore has at least a skin, a cooling plate, and a power electronics component. The power electronics component is arranged on the cooling plate in a heat-transferring manner. It is now proposed that the cooling plate be in direct contact with the vehicle skin or integrated into the vehicle skin, so that the cooling plate can be cooled via the cooling surface. The cooling plate is therefore in direct contact with the outside air surrounding the aircraft via its cooling surface, or its cooling surface rests against the vehicle skin, which in turn is exposed to the outside air. Thus, the cooling plate can only be cooled directly via the vehicle skin using the outside air. Consequently, no additional components for heat transfer or active cooling components are required. Furthermore, the entire cooling unit, which includes at least the cooling plate and the power electronics component, is very compact and can be designed to be particularly flat. An aircraft, in this context, is a vehicle designed to fly without contact with the ground or water. For example, the aircraft has wings and / or rotor blades. Furthermore, the aircraft preferably includes a propulsion unit, such as a turbine, an internal combustion engine, an electric motor, and / or a fuel cell. A jet engine is particularly preferred as the propulsion unit. The vehicle skin envelops the aircraft and separates it from the outside air. Preferably, the vehicle skin consists of metal and / or fiber-reinforced composites. For the metal used in the vehicle skin, aluminum or aluminum alloys, for example AlCu4Mg1 [dural aluminum] or AlMg [aluminum-magnesium alloy], are preferred, with lithium-aluminum alloys being particularly preferred. Fiber-reinforced composites for the vehicle skin are, for example, glass fiber-reinforced and / or carbon fiber-reinforced, wherein the base material or matrix material preferably consists of aluminum, another metal, or plastic. The vehicle skin is, for example, constructed using shell construction and / or applied to a supporting structure. The power electronics component is, for example, a component from the following list: - a pulse inverter (PWR); - a printed circuit board (PCB); - power semiconductors; - semiconductor modules; - capacitors; and - busbars. For example, a power electronics unit, which includes one or more of the power electronics components, is used to control the aircraft and / or certain components of the aircraft. Preferably, the cooling plate is not completely covered by the power electronics unit or one or more power electronics components, so that the cooling surface of the cooling plate has areas uncovered by the power electronics components. For example, a thermal paste, which preferably also acts as an adhesive, is applied between the power electronics component and the cooling plate. Preferably, the cooling surface and the cooling back surface are on opposite sides of the cooling plate. The cooling of the power electronics component is preferably passively controlled. For example, the usually direct correlation between cooling power requirement and flight speed results in suitable, demand-based cooling, since higher flight speeds require increased cooling power due to the faster flow of outside air. Direct contact between the power electronics component and the cooling plate, and direct contact between the cooling plate and the vehicle skin or ambient air, enables efficient cooling of the power electronics component in a compact design. For example, no conveying systems or active recirculating cooling fluids are required, which would lead to energy losses, require more installation space, and increase weight. This allows for a reduction in the aircraft's overall weight. In an advantageous embodiment of the aircraft, it is further proposed that the power electronics component and the cooling plate are arranged in a fuselage and / or wing of the aircraft, preferably adjacent to an underside of the fuselage and / or wing. According to one embodiment proposed here, a cooling system consisting of a power electronics component and a cooling plate is arranged in a wing of the aircraft. For example, the power electronics component and the cooling plate are arranged on an inner surface of the aircraft skin, which forms the underside of the wing. According to one embodiment proposed here, a cooling system consisting of power electronics components and a cooling plate is arranged in the fuselage of the aircraft. For example, the power electronics components and the cooling plate are arranged on an inner surface of the aircraft skin, which forms the underside of the fuselage. According to these embodiments, the cooling system, i.e. the cooling plate and the power electronics component, is arranged in an area of ​​the aircraft which offers sufficient installation space and also enables good recooling of the cooling plate via passive cooling using outside air. In an advantageous embodiment of the aircraft, it is further proposed that the cooling plate be a planar plate; preferably, the length and / or width of the plate defining the cooling surface is at least 10 times the thickness of the plate. According to this embodiment, the cooling plate is a flat plate. Preferably, the cooling plate, i.e., the cooling surface and / or the cooling surface of the cooling plate, occupies an area larger than the area occupied by the power electronics component(s) mounted on it. This allows for a large cooling surface and thus high cooling capacity. The ratio of the thickness of the cooling plate, in which the cooling plate extends orthogonally to the cooling surface and the cooling surface, to the cooling surface or cooling surface (i.e., the length and width of the cooling plate), is preferably dimensioned such that the heat emitted by the power electronics component during operation causes a uniform temperature increase on the opposite cooling surface, while simultaneously providing the cooling capacity required to cool the power electronics component at the cooling surface.Preferably, the length and / or width of the cooling plate is at least 10 times its thickness. According to this embodiment, the cooling system consisting of a cooling plate and power electronics component is particularly space-saving and simultaneously enables high cooling performance. It is further proposed in an advantageous embodiment of the aircraft that a plurality of power electronic components are arranged on the cooling plate. According to this embodiment, several power electronics components are arranged on a cooling plate. Preferably, several cooling plates with one or more power electronics components are arranged in an aircraft and distributed, for example, in the fuselage or one or more wings. Preferably, the power electronics components are arranged next to each other, that is, distributed in a planar plane on the cooling plate. According to this embodiment, interconnected power electronics components that are located close to each other can also be cooled. In an advantageous embodiment of the aircraft, it is further proposed that the cooling surface of the cooling plate be larger than the power electronics component(s) arranged on it. According to this embodiment, not the entire cooling surface of the cooling plate is covered by power electronic components. The cooling surface is therefore larger than the area occupied by the power electronic components on the cooling surface. According to this embodiment, a particularly high cooling capacity for the power electronics components is achievable. In a further advantageous embodiment of the aircraft, it is proposed that the cooling surface be in direct contact with the outside air and / or the vehicle skin. The cooling plate is in contact with an inner surface of the vehicle skin via its cooling surface. For example, the cooling plate is bonded to the vehicle skin. A thermal paste, preferably also acting as an adhesive, is applied between the vehicle skin and the cooling plate. In one of the embodiments proposed here, the cooling plate is arranged to be in direct contact with the outside air. For example, the cooling plate is integrated into the vehicle skin. For example, the cooling plate is a section of the vehicle skin onto which the power electronics component is mounted. For example, the corresponding section of the vehicle skin is coated differently on the inside and / or outside than the rest of the vehicle skin, provided with a thermal paste, and / or has a different wall thickness. Alternatively or additionally, the cooling plate is a component separate from the vehicle skin (but preferably firmly connected to it), which is arranged in a designated recess in the vehicle skin. For example, the cooling plate is flush with the outer surface of the vehicle skin by means of the cooling surface. According to these embodiments, the cooling system is particularly space-saving and can be implemented with few components. In an advantageous embodiment of the aircraft, it is further proposed that the cooling plate has a high thermal conductivity, preferably of at least 15 W / (mK), particularly preferably of at least 20 W / (mK), preferably the cooling plate is made of a metal with high thermal conductivity, for example aluminum or steel. According to this embodiment, the cooling plate has high thermal conductivity. Preferably, the thermal conductivity is greater than 15 W / (mK) [fifteen watts per meter Kelvin], particularly preferably 20 W / (mK) [twenty watts per meter Kelvin]. For this purpose, the cooling plate is preferably made of a material with high thermal conductivity, preferably a metal, for example aluminum and / or steel. According to this embodiment, a high passive cooling capacity of the power electronics component is achievable. It is further proposed in an advantageous embodiment of the aircraft that the aircraft be an airplane or a helicopter. In an advantageous embodiment of the aircraft, it is further proposed that the power electronics component comprises a semiconductor product, preferably a printed circuit board (PCB), a capacitor and / or a busbar. According to this embodiment, it is now proposed that the power electronics component comprises a printed circuit board (PCB), a capacitor, and / or a power rail. For example, the power electronics component consists of these components. Preferably, the power electronics component is a semiconductor product. In a further advantageous embodiment of the aircraft, it is proposed that the cooling plate can be cooled passively using outside air during operation. According to this embodiment, the cooling plate can be cooled during operation exclusively via the vehicle skin or directly by means of ambient air. That is, in this embodiment, the cooling plate does not have active cooling by means of a coolant. Preferably, the power electronics component is cooled exclusively by means of the cooling plate. This means that the power electronics component is not intentionally exposed to a further cooling airflow or cooled by means of a coolant. This design enables particularly efficient cooling of the power electronics component. The invention described above is explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, it should be noted that the drawings are not dimensionally accurate and are not suitable for defining size relationships. Fig. 1 shows an aircraft with power electronics components in a perspective view; and Fig. 2 shows a wing of the aircraft according to Fig. 1 with power electronics components in a sectional view. Figure 1 shows a perspective view of an aircraft 1 with power electronics components 4. In this embodiment, the aircraft 1 is an airplane 11 and comprises a fuselage 7 and two wings 8, although only one wing 8 is shown here due to the perspective. The wings 8 are exposed to outside air 10 and, together with the fuselage 7, generate lift. To reduce drag, the wings 8 and the fuselage 7 comprise a (technically smooth) skin 2. The airplane 11 shown includes two or four turbines (not shown here) that generate thrust, which is partially converted into lift by means of the wing 8. As shown, a plurality of cooling plates 3 are integrated into the vehicle skin 2 and / or arranged on the inside of the vehicle skin 2. At least one, preferably several, power electronic components 4 are arranged on each of the cooling plates 3. The power electronic components 4 are in heat-transferring contact with a cooling surface 5 (not shown here, see Fig. 2) of the cooling plate 3. Forced convection occurs at the cooling plate 3 by means of a cooling surface 6 (not shown here, see Fig. 2) of the cooling plate 3 and the (cold) outside air 10 flowing over the cooling surface 6 during operation, so that it can be cooled and thus represents a heat sink relative to the power electronic components 4 (as a heat source). In this embodiment, cooling plates 3 are arranged on the underside 9 of the vehicle fuselage 7 and the wings 8, so that components of the aircraft 1 distributed throughout the aircraft 11 can be controlled by means of the power electronics components 4. This passive cooling system, which does not require an actively pumped cooling medium and does not cause long heat conduction paths, allows for a reduction in the number of components and thus a reduction in the weight of the aircraft 11. Furthermore, there are no flow losses due to the introduction of outside air 10 into the aircraft interior, and the cooling system can be implemented in a particularly space-saving manner. Figure 2 shows a sectional view of a wing 8 of the aircraft 1 according to Figure 1, including power electronics components 4. The wing 8 is enclosed by a vehicle skin 2, separating it from the outside air 10. To generate lift for the aircraft 1, the (cold) outside air 10 flows around the vehicle skin 2. As shown, a cooling plate 3 is in heat-transferring contact with the vehicle skin 2 on the underside 9 of the wing 8. Alternatively, the cooling plate 3 is integrated into the vehicle skin 2. The cooling plate 3 comprises a cooling surface 6, which faces the outside air 10, and an opposing cooling surface 5. A plurality of power electronics components 4 are arranged on the cooling surface 5.The power electronics components 4 are implemented, for example, as printed circuit boards 12, a capacitor 13, a power rail 14, and / or a semiconductor module 15, and are connected to the cooling plate 3 for heat transfer. It should be noted that the power electronics components 4 are shown significantly enlarged for clarity. The power electronics components 4 emit heat during operation and constitute a heat source. This heat must be dissipated. Due to the forced convection at the cooling surface 6 of the cooling plate 3, the power electronics components 4 are cooled so that they can operate at a predetermined (temperature) operating point. The power electronics components proposed here for use in an aircraft make it possible to reduce the weight of the aircraft. Reference symbol list 1 Aircraft 2 Vehicle skin 3 Cooling plate 4 Power electronics component 5 Cooling surface 6 Cooling surface 7 Vehicle fuselage 8 Wing 9 Underside 10 Outside air 11 Aircraft 12 Printed circuit board 13 Capacitor 14 Busbar 15 Semiconductor module

Claims

Aircraft (1) comprising at least the following components: - a vehicle skin (2); - a cooling plate (3); - a power electronics component (4), wherein the power electronics component (4) is arranged to transfer heat on a cooling surface (5) of the cooling plate (3), characterized in that the cooling plate (3) is in direct contact with an inner surface of the vehicle skin (2) by means of a return cooling surface (6). Aircraft (1) according to claim 1, wherein the power electronics component (4) and the cooling plate (3) are arranged in a vehicle fuselage (7) and / or a wing (8) of the aircraft (1). Aircraft (1) according to claim 1 or claim 2, wherein the cooling plate (3) is a planar plate. Aircraft (1) according to one of the preceding claims, wherein a plurality of power electronic components (4) are arranged on the cooling plate (3). Aircraft (1) according to one of the preceding claims, wherein the cooling surface (5) of the cooling plate (3) is larger than the power electronics component(s) (4) / -n arranged thereon. Aircraft (1) according to one of the preceding claims, wherein the cooling plate (3) has a thermal conductivity of at least 15 W / (mK). Aircraft (1) according to any of the preceding claims, wherein the aircraft (1) is an airplane (11) or a helicopter. Aircraft (1) according to one of the preceding claims, wherein the power electronics component (4) comprises a semiconductor product, a capacitor (13) and / or a busbar (14). Aircraft (1) according to one of the preceding claims, wherein the cooling plate (3) can be cooled exclusively passively by means of outside air (10) during operation.

Images