Sub-compartment of an aircraft nacelle intended to accommodate electrical equipment

Abstract

The invention relates to a sub-compartment of an aircraft nacelle intended to accommodate a turboprop engine, the sub-compartment (1) comprising at least one fastening plate (2) and at least three lateral walls (3), the at least one fastening plate (2) comprising at least one electric circuit and at least one cooling circuit, and also at least one piece of electrical equipment mechanically fastened to the fastening plate (2) and connected to the electric circuit and to the cooling circuit of the fastening plate (2) to which it is fastened, the sub-compartment (1) furthermore comprising a ventilation system (5) comprising means (5a) for moving air connected at the inlet to a fresh-air suction mouth (5b), in order to admit fresh air into the sub-compartment (1) to cool the at least one piece of electrical equipment.

Description

[0001] DESCRIPTION

[0002] TITLE: Sub-compartment of an aircraft nacelle designed to house electrical equipment

[0003] technical field

[0004] The present invention relates to the technical field of mounting associated electrical equipment on an aeronautical turbomachine, in particular a turbojet engine. More specifically, it concerns an electrical equipment mounting plate fixed to the turbomachine casing.

[0005] Previous techniques

[0006] A turboprop engine, particularly a turbofan engine, comprises a high-pressure (HP) turbine and a low-pressure (LP) turbine driven by the gas flow from the combustion of an air-fuel mixture in a combustion chamber. The air admitted into the combustion chamber is compressed by compressors known as the high-pressure (HP) compressor and the low-pressure (LP) compressor, driven respectively by the high-pressure (HP) turbine and the low-pressure (LP) turbine.

[0007] Furthermore, depending on the specific configuration of the turbomachine, the HP turbine can drive the HP compressor and the LP turbine, the LP turbine which in turn drives the LP compressor and the blower.

[0008] Furthermore, they are called dual-flow due to the separation of air into primary and secondary flows at the turbojet inlet, with the primary flow being directed towards the combustion chamber.

[0009] A turbomachine also requires a set of auxiliary systems, for example pumps for the production of hydraulic energy, fuel supply and lubrication, and electric generators for the production of electrical power, as well as the electrical supply of the turboprop and the aircraft.

[0010] These pumps and generators are generally arranged in an accessory gearbox (AGB). This is surrounded by various equipment necessary for supplying and controlling the fuel or oil to the turbomachine, but without any mechanical connection to the AGB.

[0011] The AGB housing is generally mounted in the turbofan compartment area where they are suspended from flanges formed on the metal retaining housing of this fan compartment.

[0012] However, for example in a context of increasing the diameter of the fan, the optimization of the aerodynamic drag of the nacelle requires, in order to limit the frontal area of ​​the nacelle, to position equipment not in the fan compartment of the nacelle but in the core compartment of the turbojet (see for example French patent application FR2981986 in the name of the applicant), that is to say a compartment which separates the primary flow stream from the secondary flow stream of a turbofan engine.

[0013] Installing all the equipment in this core compartment poses a problem of space, layout and fixing.

[0014] This problem of bulk, layout and fixing is amplified when considering the electrical hybridization of turbojets, requiring high voltage power electronics (approximately 800V DC).

[0015] The hybrid turboprop includes, for example, an LPMG machine (English acronym for "Low Pressure (shaft) Motor Generator") and an HPMG machine (English acronym for "High Pressure (shaft) Motor Generator").

[0016] It should be noted that an LPMG machine is located in the rear cone of the turbomachine and connected to the low-pressure (LP) shaft of said turbomachine. An HPMG machine is generally located on the accessory gearbox (AGB) in the core compartment and connected to the high-pressure (HP) shaft of said turbomachine. LPMG and HPMG machines are designed to generate power from the rotation of the LP and HP shafts, respectively, or to drive these shafts during electric or hybrid operation of the turbomachine.

[0017] The LPMG machine is connected to an LPPE power converter (English acronym for "Low Pressure (shaft) Power Electronics") while the HPMG machine is connected to an HPPE power converter (English acronym for "High Pressure (shaft) Power Electronics").

[0018] A Power Distribution and Management Unit (PDMU) manages the transmission of power from each LPPE / HPPE power converter to which it is connected to the rest of the engine and aircraft, for powering their respective electrical loads or for connection to electrical sources in the aircraft, including batteries.

[0019] In the context of turbomachine hybridization, the power transfer between the PDMU power distribution and management units and the consumers, the connected systems on the one hand and the LPMG / HPMG machines on the other hand, via the LPPE / HPPE power converters, is bidirectional.

[0020] All of these LPMG / HPMG power converters and PDMU power distribution and management units are installed in the core compartment and are both temperature-sensitive and heat sources (due to electrical losses).

[0021] The new engine nacelles must therefore achieve greater compactness while protecting the most sensitive electrical equipment from the conditions prevailing near the turbomachine, both in terms of temperature and vibration, particularly when the electrical equipment is involved in the turbomachine's hybrid system. These new nacelles must also maintain at least the same ease of repair as existing ones, especially regarding components that can be replaced online. These new nacelles must also resolve the issues of component mounting within the nacelle.

[0022] From the prior art, we know of document EP4073368A1 disclosing a hydraulic equipment plate for an aeronautical turbomachine.

[0023] However, this document only deals with the connectivity of electrical and mechanical components.

[0024] The technical problem remains unchanged.

[0025] Description of the invention

[0026] The invention relates to a sub-compartment of an aircraft nacelle intended to house a turboprop engine, said sub-compartment comprising at least one mounting plate and at least three side walls, the at least one mounting plate comprising at least one electrical circuit and at least one cooling circuit as well as at least one electrical equipment mechanically fixed to the mounting plate and connected to the electrical circuit as well as to the cooling circuit of the mounting plate to which it is fixed, the sub-compartment further comprising a ventilation system comprising means for moving air connected at the inlet to a fresh air intake, in order to admit fresh air into the sub-compartment to cool the at least one electrical equipment.

[0027] Electrical equipment can be connected to the electrical circuit via an electrical contact connection system comprising a contact area attached to the mounting plate and a contact area attached to the electrical equipment, the contact areas being designed to cooperate to allow the passage of an electrical signal.

[0028] Electrical equipment may be connected to at least one electrical harness, the electrical harness entering the sub-compartment via a passage provided in one of the side walls, the passage taking the form of a notch so as to pinch the electrical harness in order to hold the electrical harness in place, or taking the form of a connection to a ventilated duct.

[0029] Electrical equipment can be connected to the cooling circuit via a cold plate in contact with the electrical equipment, or via fluidic connections.

[0030] At least one mounting plate may comprise two faces, one face on which at least one electrical equipment is fixed, and another face provided with a thermally reflective layer.

[0031] The means of moving the air can be a fan or a compressor, preferably electric.

[0032] At least one electrical component and / or at least one mounting plate can be replaced online.

[0033] The invention also relates to a nacelle comprising a turboprop and a sub-compartment as described above, wherein the turboprop is at least a turbo-spin turboprop and wherein the sub-compartment is disposed in a core compartment of the nacelle, located between a primary flow duct and a secondary flow duct of the turboprop, the volume delimited by the at least one mounting plate and the at least three side walls being closed by a hood or a wall of the nacelle in order to have direct access for maintenance, the sub-compartment being connected to at least one other compartment housing a second electrical equipment by a duct, so that the air admitted for the ventilation of the sub-compartment propagates to the compartment housing the second electrical equipment.

[0034] The electrical equipment attached to a mounting plate can be a power converter and / or a power distribution and management unit, the second electrical equipment being an electric machine connected to a turboprop shaft.

[0035] The side walls of the sub-compartment may be fitted with a seal on their distal edge relative to the mounting plate, said seal cooperating with the gondola to isolate the sub-compartment from the rest of the gondola and to contain the ventilation air. Brief description of the drawings

[0036] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0037] - Figure [Fig 1] illustrates the main elements of a sub-compartment and a mounting plate according to the invention

[0038] - Figure [Fig 2] schematically illustrates a redundant electrical circuit comprising the various power converters and machines involved in the hybridization of a turbomachine, distributed across two mounting plates.

[0039] - Figures [Fig 3] and [Fig 4] illustrate electrical contact areas of an electrical contact connection system,

[0040] - Figure [Fig 5] illustrates the integration of a cooling circuit and electrical circuits on a circuit board,

[0041] - Figure [Fig 6] illustrates the electrical connections on two separate circuit boards as well as inter-circuit board connections,

[0042] - Figures [Fig 7] and [Fig 8] illustrate the connection of a power cable to electrical equipment via male-female connectors, and

[0043] - Figure [Fig 9] illustrates the connection of a power cable to electrical equipment via a lug.

[0044] Detailed description

[0045] In order to solve the problems not solved by the prior art, a cooled sub-compartment 1 comprising a mounting plate 2 and connection of electronic and / or electrical equipment is proposed.

[0046] This sub-compartment 1 is located within the core compartment of a turbomachine. The core compartment refers to the areas of an engine nacelle between the primary and secondary flows of the turbomachine. This core compartment includes all or at least part of the engine's electrical and hydraulic power supply, as well as the sensors and actuators necessary for the engine's operation and control. The core compartment is generally ventilated to dissipate heat and prevent the accumulation of flammable gases.

[0047] The proposed sub-compartment 1 includes at least one mounting plate 2 on which electrical circuits, connectors, and electronic or electrical equipment, as well as cooling circuits, are integrated. The mounting is achieved by any means, including screws.

[0048] The electronic equipment is primarily of the line replaceable unit (LRU) type. Each mounting plate 2, along with all the electronic equipment, electrical circuits, and cooling components it contains, can also be of the LRU type.

[0049] Structure :

[0050] Subcompartment 1 is presented as a volume defined by a rear face in a proximal position relative to the turbomachine, a front face in a distal position relative to the turbomachine and at least three lateral faces each in contact with the front face and the rear face.

[0051] The rear face of sub-compartment 1 is defined by at least one fixing plate 2, while the front face is defined by the opposite gondola s.

[0052] Each of the lateral faces of the sub-compartment 1 corresponds to a wall 3 connected to at least one fixing plate 2 and to two adj walls 3.

[0053] In a preferred embodiment, the shape of sub-compartment 1 is an angular section of a cylinder or a cone, coaxial with the axis A of the turbomachine.

[0054] A mounting plate 2 integrates at least one electrical device 22, 23 as well as input and output connections. Each electrical device 22, 23 is generally housed in an enclosure, which is attached to the mounting plate 2. In the example shown in Figure [Fig 1], the mounting plate 2 integrates the LPPE power converter connected to the LPMG machine, the HPPE power converter connected to the HPMG machine, and the PDMU power distribution and management unit. Each plate then forms one of the channels of a redundant system for controlling and exchanging power between each LPMG and HPMG machine.

[0055] Sub-compartment 1 also aims to provide vibration protection for the electrical equipment. The use of flexible pads to isolate each piece of equipment mounted on a plate is not feasible here due to the need for contact between each electronic unit and the mounting plate 2 to ensure electrical and thermal transmission. Furthermore, such flexible pads are generally incompatible with the temperature in the reactor compartment. Therefore, the preferred solution is the use of dampers located at the mounting point of the mounting plate 2 within the reactor compartment. Connecting rods or rigid suspensions attached to the turbomachine housing, such as the AGB, can also be used.

[0056] In a particular embodiment, the mounting plate 2 and all equipment fixed and connected to it form an inline replaceable element of type LRU.

[0057] Electric:

[0058] Sub-compartment 1 is connected to at least one ventilated duct linking sub-compartment 1 to another compartment. This duct allows the passage of an electrical harness connected on one side to electrical equipment in sub-compartment 1.

[0059] (LPPE / HPPE / PDMU) and, on the other hand, to other electrical equipment located in the other compartment (LPMG / HPMG / Engine Equipment / Aircraft Network). A ventilated duct maintains an acceptable ambient temperature for the harness by removing heat absorbed outside the duct and heat emitted by the harness. It also ventilates the compartment of the other electrical equipment simultaneously with the ventilation of sub-compartment 1. Figure 6 illustrates the connection of power harnesses 8a, 8b, 9a, 9b to power converters 22, 23 mounted on the plate 2 and through the walls 3 of the sub-compartment. The power converters 22, 23 are connected to each other by connections 30. Each power harness 8a, 8b, 9a, 9b can be placed in a ventilated duct.

[0060] The electrical equipment housings 22, 23 are mechanically fixed to the mounting plate 2 in such a way that the electrical connectors on the surface of the plate correspond to electrical connectors arranged on one of their faces, which is intended to be fixed to the plate. These electrical connectors on the surface of the plate form pressure contact areas.

[0061] The mounting plate 2 includes electrical connections for linking each of the pressure contact areas located under each electrical equipment enclosure 22, 23 to ensure their interconnection. This is illustrated in particular in Figure 5, where the PDMU 24 is connected to the LPPE / HHPE power converters 22, 23 and to a fan 5a.

[0062] Such pressure contact is ensured, for example, by spring clips interposed between the two contact areas and captive within the contact area of ​​the mounting plate or equipment. Figure [Fig 3] illustrates a contact area 6a formed in the mounting plate 2 and protected by a cover 6b when not in use. In a particular embodiment, the contact area 6a is formed in the mounting plate 2 so that its surface corresponds with the surface of the plate.

[0063] Figure [Fig 4] illustrates a contact area 6c provided in at least one of the electrical equipment housings 22,23. A contact area 6a integral with the mounting plate 2 and a contact area 6c integral with at least one of the electrical equipment housings 22,23 form an electrical contact connection system referenced 6 in Figure [Fig 1].

[0064] It should be noted that the contact area 6a attached to the mounting plate 2 is a male part of the electrical contact connection system 6, while the contact area 6c attached to at least one of the electrical equipment boxes 22,23 is a female part.

[0065] We will not depart from the scope of the invention if the contact area 6a attached to the mounting plate 2 is a female part and the contact area 6c attached to at least one of the electrical equipment housings 22,23 is a male part.

[0066] In yet another embodiment, the contact area 6a attached to the mounting plate 2 and the contact area 6c attached to at least one of the electrical equipment housings 22,23 are neither male nor female type, and other means are used to ensure the centering of the contact areas, for example a centering stud cooperating with a centering hole or a screw fixing system.

[0067] Figure 7 illustrates a power cable 40 whose core 41 is connected to a first connector 42. A connection area 44 fixed on the plate includes a second connector 43. The connectors 42 and 43 are designed to cooperate to ensure electrical contact and secure the electrical connection thus established.

[0068] Figure 8 illustrates the same power cable with connectors 42,43 connected.

[0069] Connectors 42,43 can notably be male and female parts of a connection system.

[0070] Figure 9 illustrates a power cable 40 whose core 41 is connected to a lug 42b, in particular by crimping. The lug 42b is then connected flat to a contact surface 46 of the plate or of an electrical equipment by any means 47, in particular by screwing, welding or brazing.

[0071] Sub-compartment 1 has the advantage of ensuring segmentation of electrical equipment 22,23, such as LPPE / HPPE power converters, in order to protect them against propagation of possible faults (for example, protection against electric arcs) external to sub-compartment 1 or conversely, to protect the rest of the core compartment against the propagation of faults from the electrical equipment 22,23 of sub-compartment 1.

[0072] These advantages are amplified when the fixing plate 2 and the walls 3 of the sub-compartment 1 are made of an electrically insulating material.

[0073] In one particular embodiment, all or part of the mounting plate 2, the walls 3 of the sub-compartment 1, and the nacelle cover are made of an electrically conductive material and connected to the engine structure, so as to provide additional protection to the other engine parts against electromagnetic emissions radiated by electrical equipment, in particular LPPE / HPPE power converters. Alternatively, all or part of the mounting plate 2, the walls 3 of the sub-compartment 1, and the nacelle cover are made by a superposition of at least two types of stacked materials. The material superposition includes an insulating layer on the inner side of the sub-compartment 1. The material superposition also includes an electrically conductive layer on the outer side of the sub-compartment 1.

[0074] The fixing plate 2 and the walls 3 of the sub-compartment 1 then provide protection for the electrical equipment 22,23 of the sub-compartment 1 against external electromagnetic emissions.

[0075] Finally, the structure of sub-compartment 1, due to the absence of an external face, allows quick and direct visual access to the electrical equipment and the at least one mounting plate 2 it contains. This enables rapid and easy inspection and maintenance. It also allows for the quick and individual removal of each component installed in sub-compartment 1 for replacement or verification.

[0076] It also allows for the removal of each mounting plate 2 with the permanently installed equipment, and its replacement with an identical one further accelerates maintenance of the engine nacelle. In the case of particularly heavy equipment and / or mounting plates, interfaces compatible with ground support equipment will be provided on the mounting plate 2 to facilitate maintenance.

[0077] In certain embodiments, the electrical harnesses 8a, 8b, 9a, 9b are directly connected to the electrical equipment 22, 23 that they serve. The electrical harnesses 8a, 8b, 9a, 9b are either power harnesses, intended to carry the power generated by the LPMG / HPMG machines, or control harnesses, intended to carry control signals to said LPMG / HPMG machines or LPPE / HPPE power converters.

[0078] In one embodiment, the electrical harnesses 8a, 8b, 9a, and 9b are connected to the LPMG and HPMG machines via a passage in a side wall 3. The passage in the side wall 3 pinches the power harness without damaging it, ensuring the seal of the sub-compartment 1 due to the close contact between the passage and the harness, and holding the harness in place by pinching it. A notch may be provided in the wall to hold the harness in place when the platform is open. This embodiment has the advantage of not requiring an interruption of the power harness, which then directly connects the LPMG / HPMG machine to the corresponding LPPE / HPPE power converter.

[0079] In a preferred embodiment, the power electrical harnesses are routed through ventilated conduits due to the currents involved and the associated heat generation. The electrical signal and low-power harnesses are routed between the side walls and the nacelle cowling or via bulkhead connectors.

[0080] In another embodiment, each cable of the electrical harness can be fitted with press-fit lugs to facilitate connection to the mounting plate. Each harness connection point on the mounting plate is then connected to an electrical link integrated into the mounting plate and connected to at least one of the LPPE / HPPE power converters. Alternatively, cooled cable trays can be used to route the electrical harnesses 8a, 8b, 9a, and 9b while minimizing heat exchange with the core compartment.

[0081] In one embodiment, the control harnesses are connected to the LPMG and HPMG machines via a passage provided in a side wall 3 of the sub-compartment 1 in a manner similar to the connection of the power harnesses.

[0082] In an alternative embodiment, the side walls 3 are provided with bulkhead connectors to which the control harnesses are connected. Inside sub-compartment 1, each bulkhead connector is connected to the relevant LPPE / HPPE electrical equipment 22, 23 via the control harness connected to the bulkhead connector outside sub-compartment 1.

[0083] Figure [Fig 2] schematically illustrates a redundant electrical circuit comprising the various electrical equipment present in the hybrid turboprop and distributed on two mounting plates 2a, 2b.

[0084] The LPMG machine referenced 20 is generally arranged for example in the rear cone 30 of the turbomachine while the HPMG machine referenced 21 is arranged in the core compartment (“Core” in English) referenced 3 1 which also includes the sub-compartment 1.

[0085] Still on the figure [Fig 1], the LPMG 20 machine is connected to two LPPE power converters referenced 22a, 22b by power harnesses 8a, 8b while the HPMG machine is connected to two HPPE power converters referenced 23a, 23b by power harnesses 9a, 9b.

[0086] The electrical circuit illustrated in Figure [Fig 1] includes a PDMU 24a, 24b power distribution and management unit for each redundant power channel.

[0087] Each PDMU 24a, 24b power distribution and management unit manages the transmission of power from each LPPE 22a, 22b power converter and each HPPE 23a, 23b power converter to which it is connected to the rest of the aircraft.

[0088] In other words, a first power transmission path is formed by a first LPPE 22a power converter and a first HPPE 23a power converter, connected to a first PDMU 24a, all arranged on a first mounting plate 2a. A second power transmission path is formed by a second LPPE 22b power converter and a second HPPE 23b power converter, connected to a second PDMU 24b, all arranged on a second mounting plate 2b.

[0089] Alternatively, a connection between the first PDMU 24a and the second PDMU 24b allows for a transverse exchange of power.

[0090] It is also possible to merge the two PDMU power distribution and management units into a single 24-way multi-way PDMU power distribution and management unit.

[0091] Thermal protection:

[0092] To protect the equipment in sub-compartment 1 from the thermal radiation of the turbomachine, sub-compartment 1 is fitted with a thermally reflective layer 4 positioned in contact with the mounting plate 2, on the face opposite to the face on which the electrical equipment housings 22, 23 LPPE / HPPE are fixed. As an alternative to the thermally reflective layer 4, a ceramic heat shield may be used.

[0093] In one particular embodiment, the thermally reflective layer can be replaced by a heat protection layer, for example a layer of silica wool or a ceramic coating in order to limit the heat exchange between the core compartment and sub-compartment 1.

[0094] Ventilation:

[0095] To maintain an ambient temperature compatible with the operation of the electrical equipment, a ventilation system 5 is provided in sub-compartment 1 to remove the hot air contained within it. The ventilation system 5 includes at least one means for moving the air 5a, such as a fan or compressor, connected at its inlet to a fresh air intake 5b and at its outlet to a discharge outlet 5c in sub-compartment 1. The fresh air intake 5b may, in particular, be a scoop located in the secondary intake of the turbomachine. In some embodiments, the outside air intake 5b is positioned to correspond with an opening in the nacelle casing to allow access to outside air, for example, from the engine's secondary intake.The air movement means 5a and the outlets are optionally connected by ducts not shown in Figure 1. The air movement means 5a is preferably electrically powered, so as not to depend on the operation of the turbomachine. Such an air movement means 5a is particularly advantageous in that it helps to combat the heat release phenomenon ("soakback") that occurs when the turbomachine is stopped.

[0096] In an alternative embodiment, the outside air intake 5b is formed by a vented duct opening into an area of ​​the aircraft that is colder than the engine compartment, such as the vented duct housing the power harness connected to the aircraft network.

[0097] It is worth recalling that the "soakback" phenomenon occurs due to the absence of airflow in the turbomachine and the thermal inertia of its components (particularly the turbine disks) after the turbomachine has stopped. The residual heat flux is transmitted to the nacelle structure and the hydraulic circuits, propagating this heat flux far beyond the area immediately surrounding the turbine. Such a "soakback" heat flux can then reach and damage the electrical components within sub-compartment 1.

[0098] The use of an electrical air movement means 5a allows it to be kept in operation after the turbomachine has stopped, and to evacuate the heat flow from the "soakback" phenomenon before it can damage the electrical equipment of sub-compartment 1.

[0099] Fresh air admitted into sub-compartment 1 is also admitted into ducts of electrical harnesses 8a, 8b, 9a, 9b, both power and control, connecting sub-compartment 1 to the compartment housing each machine.

[0100] In one particular embodiment, the ventilation system 5 includes a control means for the air movement means 5a, which can be controlled based on a temperature measurement of the air in subcompartment 1 and / or based on a temperature measurement of the air outside the nacelle. It is thus possible to regulate the temperature of subcompartment 1 to a temperature suitable for the electrical equipment enclosures 22, 23 LPPE / HPPE and for the compartments housing the LPMG / HPMG machines.

[0101] Furthermore, as described above, sub-compartment 1 is partially closed at the top by the nacelle. Such a closure of the nacelle may not provide an ideal seal, particularly due to its deformation. Consequently, the ventilation and thermal protection of the nacelle are not optimized due to air leaks into the nacelle's core compartment and air intakes from said core compartment. To resolve this issue, a set of seals is provided on the edges of the lateral walls to compensate for the distance between the edges of the lateral walls and the nacelle.

[0102] The combination of thermal protection, ventilation circuit and cooling system makes it possible to create a compartment that is cooler than the rest of the gondola.

[0103] Cooling:

[0104] To cool each piece of equipment installed on the mounting plate, particularly the electrical equipment enclosures 22, 23 LPPE / HPPE, an integrated cooling circuit is provided. Figure 5 illustrates a mounting plate equipped with such a cooling circuit. This circuit includes a cold plate 11a, 11b located in the mounting plate 2, opposite each of the aforementioned pieces of equipment installed on the mounting plate, particularly the electrical equipment enclosures 22, 23 LPPE / HPPE. A similar cold plate 11c is located under the PDME 24. A cold plate 11a, 11b, 11e refers to a face of a heat exchanger connected to heat transfer fluid lines 12a, 12b, 12c of the cooling circuit. The cold plates 11a, 11b, 11c are connected in parallel or in series depending on the cooling strategy implemented.The cooling circuit is connected to a fluid inlet 10a and a fluid outlet 10b for interfacing with a pump and a heat transfer fluid reservoir. These are not shown in Figure 5. A cooling circuit can be purged for maintenance operations requiring removal of the mounting plate 2.

[0105] The use of a thermal gasket or thermal paste may be envisaged in order to improve the interface between the cold plate lia, 1 1 b and the electrical equipment 22,23.

[0106] In another embodiment, the cold plate 11b is replaced or supplemented by quick fluid connections allowing at least one electrical component 22, 23 to be fluidly connected or disconnected from the cooling circuit. Preferably, the heat transfer fluid of the cooling circuit is provided for first reaching the electrical components before supplying the other components. Indeed, the electrical components require a heat transfer fluid at a particularly low temperature compared to the other components of the turboprop engine, for example, between 70°C and 110°C.

[0107] The above description was primarily made in relation to the support and connection of electrical equipment. However, mounting plate 2 can accommodate other equipment, such as an electric pump, including the LPMG lube pump for the LPMG machine, the LPMG soakback fan for the LPMG machine, and / or other electrical / electronic units related to turbomachine functions that could benefit from this less thermally demanding environment (PS3 acquisition unit, ODMS processing unit, etc.).

[0108] Even though the LPMG lubricant pump is integrated on mounting plate 2, the LPMG oil reservoir is excluded because it can be a source of heat due to potential heat transfer between the lubricant and the LPMG machine located on the turboprop's low-pressure shaft. It should be noted that sub-compartment 1, described above, is an environment that requires cooling.

[0109] Sub-compartment 1 may have other features such as fire protection or protection against admissible liquids.

[0110] Fire protection can result from the construction of the plate and / or the walls 3 in a fire-resistant material, as well as by the integration of means for detecting the presence of a fire and less than the admission of a fire-extinguishing fluid specific to the sub-compartment 1.

[0111] Fluid drainage is ensured by a drain at the lowest point specific to sub-compartment 1.

Claims

DEMANDS 1. A sub-compartment of an aircraft nacelle intended to house a turboprop engine, characterized in that said sub-compartment (1) comprises at least one mounting plate (2) and at least three side walls (3), the at least one mounting plate (2) comprising at least one electrical circuit and at least one cooling circuit, as well as at least one electrical component mechanically fixed to the mounting plate (2) and connected to the electrical circuit and the cooling circuit of the mounting plate (2) to which it is fixed, the sub-compartment (1) further comprising a ventilation system (5) comprising means for moving air (5a) connected at the inlet to a fresh air intake (5b) in order to admit fresh air into the sub-compartment (1) to cool at least one electrical piece of equipment.

2. Subcompartment according to claim 1, in which electrical equipment is connected to the electrical circuit via a contact electrical connection system (6) comprising a contact area (6a) integral with the mounting plate (2) and a contact zone (6c) integral with the electrical equipment, the contact zones (6a, 6c) being designed to cooperate to allow the passage of an electrical signal.

3. Sub-compartment according to claim 1 or 2, in which electrical equipment is connected to at least one electrical harness, the electrical harness entering the sub-compartment (1) via a passage formed in one of the side walls (3), the passage taking the form of a notch so as to pinch the electrical harness in order to hold the electrical harness in place, or taking the form of a connection to a ventilated duct.

4. Sub-compartment according to any one of claims 1 to 3, in which electrical equipment is connected to the cooling circuit via a cold plate ( lia, 1 1b) in contact with the electrical equipment, or via fluidic connections.

5. Sub-compartment according to any one of claims 1 to 4, in which at least one fixing plate (2) comprises two faces, one face on which at least one electrical equipment is fixed, and another face provided with a thermally reflective layer (4).

6. Sub-compartment according to any one of claims 1 to 5, wherein the means for setting the air in motion (5a) are a fan or a compressor, preferably electric.

7. Nacelle comprising a turboprop and a sub-compartment 1 according to any one of claims 1 to 6, wherein the turboprop is at least a turbo-spin turboprop and wherein the sub-compartment (1) is disposed in a core compartment of the nacelle, located between a primary flow duct and a secondary flow duct of the turboprop, the volume delimited by the at least one mounting plate (2) and the at least three side walls (3) being closed by a hood or a wall of the nacelle in order to have direct access for maintenance, the sub-compartment (1) being connected to at least one other compartment housing a second electrical equipment by a duct, so that the air admitted for the ventilation of the sub-compartment (1) propagates to the compartment housing the second electrical equipment.

8. Nacelle according to claim 7, wherein the electrical equipment fixed to a mounting plate (2) is a power converter (22,23) and / or a power distribution and management unit (24), the second electrical equipment being an electric machine connected to a shaft of the turboprop.

9. Nacelle according to claim 7 or 8, wherein the lateral walls (3) of the sub-compartment (1) are provided with a joint on their distal edge relative to the fixing plate (2), said joint cooperating with the nacelle in order to isolate the sub-compartment (1) from the rest of the nacelle and to contain the ventilation air.

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