Drainage system for an aircraft engine air supply system

Abstract

The present invention relates to a drainage system (50) for draining an internal volume (INT) of an air distributor (40) of an engine (10). The drainage system (50) comprises a drainage pipe (55) including an interface section (56) equipped with a fire screen (60) configured to interface with the internal volume (INT). The drainage system (50) has a check valve (70) attached to an outlet section (57) of the drainage pipe (55). The check valve (70) opens into an external environment (EXT). The check valve (70) closes automatically when a first pressure (P1) in the drainage pipe (55) between the fire screen (60) and the check valve (70) is less than a second pressure (P2) in the external environment (EXT). The check valve (70) opens automatically when the first pressure (P1) is greater than or equal to the second pressure (P2). (Shorthand figure: Figure 3)

Description

Title of the invention: Drainage system for an aircraft engine air supply system

[0001] The present invention relates to a drainage system for draining an air supply system of an aircraft engine, and to an aircraft having such a system. Such an aircraft may be a rotorcraft. The technical field of the invention therefore relates to the field of drainage systems for engine air supply systems.

[0002] To supply an engine with combustion air from the outside, the aircraft includes an air supply system. In particular, an engine may be a turboshaft engine comprising a gas generator and at least one turbine. The gas generator is equipped with a compressor assembly that supplies compressed air to a combustion chamber. Furthermore, the gas generator is equipped with an assembly comprising at least one turbine driven by the hot gases exiting the combustion chamber, and rotationally fixed to the compressor assembly. Therefore, the aircraft includes an air supply system to supply fresh air to the gas generator, and in particular to the compressor assembly.

[0003] Depending on the architecture of the engine and the aircraft, the air supply system may include at least one radial or axial air inlet section.

[0004] The air intake section(s) are connected to the engine by an air distributor.

[0005] For example, such an air distributor may include a component conventionally referred to by those skilled in the art as a "plenum." A plenum comprises a duct arranged around a central axis along which the engine extends. The duct and the engine then define an annular cavity in communication with one or more air inlet sections and the engine. Consequently, air outside the aircraft enters the air supply system through an air inlet section and is then directed radially through the plenum toward the engine. Such a plenum allows the air to be distributed around the engine.

[0006] Document FR 3007798 A thus describes a plenum.

[0007] When the aircraft is flying, particularly in icing conditions, water, snow, or ice may accumulate at the bottom of the plenum. The bottom of the plenum may be defined as the lowest point of the plenum for predetermined permissible aircraft pitch angles. The engine is designed to operate normally after ingesting a certain amount of water, snow, or ice. Therefore, the air supply system is designed to meet this requirement.

[0008] Thus, a plenum may include drains to evacuate the water contained in this plenum to an engine compartment. The aircraft's roll maneuvers may It can also allow water, snow, or ice to be removed from the plenum. A heating system can also be installed to melt ice located at the bottom of the plenum, for example.

[0009] However, due to engine suction, some of the water may not be drained. This is because the pressure in the engine compartment can be higher than the pressure in the plenum during certain phases of flight. Consequently, this pressure difference induces airflow from the engine compartment to the plenum through the drains. This airflow prevents the water from being drained and can lead to an accumulation of water, ice, or snow, which may exceed the maximum amount the engine can handle.

[0010] US2023340895 A1 describes a drainage system with a tube opening directly into an internal volume of a plenum. The tube comprises successively a vertical section attached to a drainage fitting integral with the plenum, a curved section, and a horizontal section opening onto a flapper valve to provide a fire-stopping function.

[0011] The present invention then aims to provide a drainage system designed to limit the amount of water trapped in a plenum in use.

[0012] The present invention relates to a drainage system for draining an internal volume of an air distributor of an engine, for example of a vehicle.

[0013] The drainage system comprises a drainage pipe including an interface section. The section may be equipped with a fitting configured to be attached to the air distributor. The interface section is equipped with a fire screen configured to interface with the internal volume. The drainage system has a non-return valve attached to an outlet section of the drainage pipe, the non-return valve opening into an external environment, namely an environment located outside the air distributor and the drainage pipe. The non-return valve closes automatically when a first pressure in the drainage pipe between the fire screen and the non-return valve is less than a second pressure in the external environment. The non-return valve opens automatically, possibly by elastic deformation, when the first pressure is greater than or equal to the second pressure.

[0014] Therefore, when the engine is stopped, the first pressure upstream of the non-return valve is equal to the second pressure downstream of the non-return valve, the terms "upstream" and "downstream" being understood in the direction from the fire screen towards the non-return valve. The non-return valve is thus open and allows water to flow, unlike a flap system which would remain closed.

[0015] When the engine is running, it can generate a vacuum in the air distributor. The first pressure can become lower than the second pressure, causing the non-return valve to close, for example, by deformation. With the check valve closed, water present in the air distributor can flow by gravity into the drain pipe. A column of water can then form in the drain pipe. As soon as the water column reaches a predetermined threshold height, its hydrostatic pressure exceeds the vacuum generated by the engine. At this point, the water column generates sufficient pressure to open the check valve. The water trapped in the drain pipe can then flow out through the check valve.

[0016] Furthermore, the fire-resistant grille contributes to the fire-resistant function. The perforations in the fire-resistant grille are designed to prevent the spread of flaming fluid. Consequently, the components downstream of the fire-resistant grille do not need to provide fire resistance. The fire-resistant grille also has a cross-section that does not compromise the concentration of extinguishing agent in the engine compartment in the event of a fire. The drain piping can then be made of a material from the plastics or metal group, for example, while the non-return valve can be made of elastomer.

[0017] Thus, the fire guard, the drainage pipe, and the non-return valve work together to not only contribute to the fire guard function by preventing the spread of flaming fluid through the guard, but also to limit the amount of water ingested into the engine. This drainage system can also limit the amount of water trapped in the air distributor, which could lead to ice formation.

[0018] Furthermore, the drainage piping and / or the non-return valve can be relatively simple, and / or made using lightweight and / or inexpensive materials. For example, the non-return valve can be in the form of an elastomer valve that closes by elastic deformation.

[0019] The drainage system may also include one or more of the following features, taken alone or in combination.

[0020] According to one possibility, the firewall grille can be made of titanium.

[0021] This material proves advantageous for contributing to the firewall function.

[0022] According to a possibility compatible with the preceding ones, the firewall grid may include perforations each having a diameter less than or equal to 2 millimeters.

[0023] Such dimensions allow the fireguard grid to perform its two functions described above, namely to prevent the spread of a flaming fluid while allowing water to flow from the air distributor to the drainage piping.

[0024] According to a possibility compatible with the preceding ones, the fire screen can be located in a high horizontal plane which overhangs the non-return valve when the drainage system is in a predetermined rest position to allow liquid to flow by gravity from the fire screen to the non-return valve.

[0025] For example, the resting position may correspond to the position reached when the drainage system is arranged on a device resting on a flat and horizontal ground.

[0026] For example, the upper horizontal plane may be tangent to the firewall while being between the firewall and the check valve. For example, the upper horizontal plane is above a lower horizontal plane that passes through the outlet section through which water exits the open check valve.

[0027] The height under gravity separating the fireguard grille from the outlet section then ensures that the drainage pipe can accommodate a column of water capable of generating a hydrostatic pressure greater than or equal to the vacuum that can be generated by the motor in question. For example, this height is greater than or equal to 9 centimeters.

[0028] According to a possibility compatible with the preceding ones, the non-return valve may have two lips movable relative to each other, the lips coming together when the first pressure is less than the second pressure, the lips moving away from each other to open the non-return valve when the first pressure is greater than or equal to the second pressure.

[0029] The lips can jointly form a spout which opens or closes depending on the pressure difference between the first pressure upstream of the non-return valve and the second pressure downstream of the non-return valve.

[0030] Such a non-return valve can, for example, be open at rest and close automatically by elastic deformation of at least one lip. Such a non-return valve proves to be simple and reliable, notably by not including a joint that could seize up.

[0031] According to a possibility compatible with the preceding ones, the drainage system may include a protective tube which surrounds the non-return valve.

[0032] Such a protective tube tends to limit the risks of damage to the non-return valve, for example during a maintenance operation.

[0033] The present invention also relates to a drive system comprising a motor supplied with air by an air supply system, the air supply system comprising an air distributor. This drive system then includes a drainage system as previously described.

[0034] The present invention also relates to a vehicle comprising such a powertrain. For example, the vehicle may be an aircraft, the air distributor being a plenum locally surrounding the engine. For example, the non-return valve opens into an engine compartment housing the engine.

[0035] The invention and its advantages will become apparent in more detail in the following description, with illustrative examples given by reference to the accompanying figures, which represent:

[0036] [Fig. 1], a diagram illustrating a drainage system according to the invention,

[0037] [Fig. 2], a three-dimensional view of a drainage system according to the invention, and

[0038] the [Fig.3], a cross-sectional view of the [Fig.2].

[0039] Elements present in several distinct figures are assigned a single and same reference.

[0040] Figure 1 shows a drainage system 50 according to the invention. This drainage system 50 has the function of draining an internal volume INT from an air distributor 40. The air distributor 40 supplies air to an engine 10 of a drive unit 5. The engine 10 is housed in an engine compartment 9, for example within a vehicle 1. Optionally, this vehicle 1 may be a rolling vehicle, a floating vehicle, or even an aircraft.

[0041] Regardless of the nature of the system equipped with the drive unit 5, this drive unit 5 therefore comprises a combustion engine 10 supplied with oxidizer by an air supply system 35. This air supply system 35 includes the air distributor 40. This air distributor 40 is in fluidic communication with, on the one hand, the engine 10 and, on the other hand, one or more air inlets capable of drawing in fresh air. For example, the air distributor 40 may take the form of a plenum that locally surrounds the engine 10 or simply the form of a duct that opens onto the engine. The air distributor 40 then includes a duct 46 supplied with fresh air by one or more air inlets. The duct 46 shown can be described as annular insofar as it delimits the annular internal volume INT surrounding the engine 10. To delimit the duct 46, the air distributor 40 can comprise two partitions 43, 44, connected by a section 45

[0042] According to the example shown and given by way of illustration, the engine 10 is a turboshaft engine. The turboshaft engine 10 is arranged at least partially within the engine compartment 9. This engine compartment 9 may open onto an outlet nozzle 90, the air present in the engine compartment 9 being drawn into the outlet nozzle 90 during operation. The turboshaft engine 10 includes a gas generator 15. The gas generator 15 is equipped with a compression assembly 20 supplied with fresh air by the air distributor 40. For example, the compression assembly 20 comprises one or more compression stages 21-23. Following the compression assembly 20 in the direction of gas flow within the turbomotor 10, the gas generator 15 comprises a combustion chamber 24, then a turbine assembly 25. The turbine assembly 25 is set in motion by the gases exiting the combustion chamber 24, and is fixed in rotation to the compression assembly 20.The turbine assembly 25 may include at least one turbine. Finally, the turboshaft engine 10 includes at least one working turbine 30, for example connected to a power transmission chain 7. For example, this power transmission chain 7 puts into operation... movement at least one rotor 6 participating in the propulsion and / or the lift and / or the control of the vehicle 1.

[0043] Regardless of the nature of the motor 10 and its arrangement, the invention therefore aims at a drainage system 50 for draining the air distributor 40.

[0044] This drainage system 50 includes a drainage pipe 55. The drainage pipe 55 extends from an interface section 56 to an outlet section 57.

[0045] The interface section 56 can be provided with a fastener 58 configured to be attached to the air distributor 40. For example, the interface section 56 has a funnel integral with a collar forming the fastener 58. The collar can thus be screwed, riveted, welded, and / or glued to the air distributor 40.

[0046] Furthermore, the interface section 56 is provided with a fire-resistant grille 60 configured to interface with the internal volume INT, namely to separate the internal volume INT from the other components of the drainage system and / or from the volume delimited by the drainage pipe 55. The fire-resistant grille 60 may be part of the drainage pipe 55 or may be conventionally attached to it. Moreover, the fire-resistant grille 60 and the drainage pipe 55 may be a single unit, for example, made of titanium.

[0047] The fire-resistant grille 60 is also opposite the internal volume INT to be drained. For example, the fire-resistant grille 60 is substantially flush with the flange and / or a wall of the air distributor 40. Thus, a liquid or gas passes from the internal volume INT into the drain pipe 55 by passing through the fire-resistant grille 60 and the interface section 56.

[0048] Optionally, the firewall grille 60 is made of titanium.

[0049] Optionally, the fireguard grid 60 has perforations 61 each having a diameter less than or equal to 2 millimeters.

[0050] Furthermore, the drainage system 50 includes a non-return valve 70 fixed to the outlet section 57 of the drainage pipe 55. This non-return valve 70 opens into a medium referred to as the "external medium EXT" for convenience, this external medium EXT being located, for example, in the engine compartment 9.

[0051] The non-return valve 70 is designed to close automatically, for example by elastic deformation, when a first pressure PI in the drainage pipe 55 between the fire screen 60 and the non-return valve 70 is lower than a second pressure P2 prevailing in the external environment EXT. Conversely, the non-return valve 70 opens automatically, for example by elastic deformation, when the first pressure PI is greater than or equal to the second pressure P2.

[0052] The check valve 70 can extend the outlet section 57. For example, the check valve 70 has a base 71 fixed to the outlet section 57 by means common methods include gluing, riveting, screwing, or possibly welding. Base 71 can take the form of a hollow cylinder.

[0053] The base 71 can carry two lips 72, 73 movable relative to each other to form a spout that opens or closes depending on a pressure difference on either side of the non-return valve 70. Thus, the lips 72, 73 come together when the first pressure PI is less than the second pressure P2 so as to be watertight. Conversely, the lips 72, 73 move apart to open the non-return valve 70 when the first pressure PI is greater than or equal to the second pressure P2.

[0054] According to another aspect, the fire screen 60 can be located in a horizontal high plane 96 which overhangs the non-return valve 70 to allow liquid to flow by gravity from the fire screen 60 to the non-return valve 70. For example, the fire screen 60 is located in a horizontal high plane 96 which overhangs a horizontal low plane 97 passing through the non-return valve 70 when the drainage system 50 is in a predetermined rest position.

[0055] The difference in height between the fire screen 60 and the non-return valve 70 makes it possible to obtain a water column in the drainage pipe 55 sufficient to compensate for any depression caused by the operation of the motor 10.

[0056] According to another aspect, the drainage system 50 can be provided with a protective tube 80 which surrounds the non-return valve 70. This protective tube 80 can be fixed to the outlet section 57, for example by a ring according to the illustrated example.

[0057] Figure 2 shows a drainage system 50 according to the invention in three dimensions.

[0058] Figure 3 shows a cross-sectional view of this drainage system to illustrate its functioning.

[0059] When the engine 10 is switched off, the first pressure PI is equal to the second pressure P2. The non-return valve 70 is open. The lips 72, 73 are in their rest positions, shown with dashed lines, being separated from each other. Water present in the internal volume INT of the air distributor 40 then flows into the drainage system 50 to reach the external environment EXT. If necessary, this water falls into the engine compartment 9, which can be drained, in the usual way, to the outside of the vehicle 1.

[0060] During operation, the motor 10 can generate a vacuum in the internal volume INT and consequently in the drainage system 50. The first pressure PI becomes lower than the second pressure P2. The lips 72, 73 deform elastically and come together as shown in solid lines. The non-return valve 70 is then closed. As a result, water can pass through the fire screen 60 in the direction of arrow F and accumulate in the drainage pipe 55, between the fire screen 60 and the non-return valve 70. When the water reaches a threshold level 99, the water column is then sufficient to cause the non-return valve 70 to open again. The lips 72, 73 deform as they open according to the arrows Fl, F2, and the water is evacuated as long as the lips 72, 73 are not pressed together again.

[0061] Naturally, the present invention is subject to numerous variations in its implementation. Although several embodiments have been described, it is understood that it is not conceivable to exhaustively identify all possible embodiments. It is, of course, conceivable to replace a described means with an equivalent means without departing from the scope of the present invention as defined by the claims.

Claims

Demands

1. A drainage system (50) for draining an internal volume (INT) of an air distributor (40) of an engine (10), characterized in that the drainage system (50) comprises a drainage pipe (55) including an interface section (56), the interface section (56) being equipped with a fire screen (60) configured to interface with the internal volume (INT), the drainage system (50) having a check valve (70) attached to an outlet section (57) of the drainage pipe (55), the check valve (70) opening into an external medium (EXT), the check valve (70) being automatically closed in the presence of a first pressure (PI) in the drainage pipe (55) between the fire screen (60) and the check valve (70) lower than a second pressure (P2) in the external medium (EXT), the check valve (70) being automatically opened when the first pressure (PI) is greater than or equal to the second pressure (P2).

2. Drainage system according to claim 1, characterized in that the firebreak grid (60) is made of titanium.

3. Drainage system according to any one of claims 1 to 2, characterized in that the firebreak grid (60) has perforations (61) each having a diameter less than or equal to 2 millimeters.

4. Drainage system according to any one of claims 1 to 3, characterized in that the fire screen (60) is located in a high horizontal plane (96) which overhangs the non-return valve (70) when the drainage system (50) is in a predetermined rest position to permit gravity flow of liquid from the fire screen (60) to the non-return valve (70).

5. A drainage system according to any one of claims 1 to 4, characterized in that the non-return valve (70) has two lips (72, 73) movable relative to each other, the lips (72, 73) coming together when the first pressure (P1) is less than the second pressure (P2), the lips (72, 73) moving apart to open the non-return valve (70) when the first pressure (PI) is greater than or equal to the second pressure (P2).

6. Drainage system according to any one of claims 1 to 5, characterized in that the drainage system (50) comprises a protective tube (80) which surrounds the non-return valve (70).

7. Power plant (5) comprising a motor (10) supplied with air by an air supply system (35), the air supply system (35) comprising an air distributor (40), characterized in that the power plant (5) includes a drainage system (50) according to any one of claims 1 to 6 connected to the air distributor (40).

8. Vehicle (1) comprising a drive unit (5) according to claim 7.

9. Vehicle according to claim 8, characterized in that the vehicle (1) is an aircraft, the air distributor (40) being a plenum locally surrounding the engine (10).

10. Vehicle according to any one of claims 8 to 9, characterized in that the non-return valve (70) opens into an engine compartment (9) housing the engine (10).

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