System for cooling an internal partition of an air inlet for an aircraft nacelle and associated method

Abstract

The invention relates to an air inlet (1) for an aircraft nacelle comprising a radially inner wall (11) and a radially outer wall (12) extending around a longitudinal axis (X), together forming an outer casing (10), an inner partition (2) attached on the one hand to the radially inner wall (11) and on the other hand to the radially outer wall (12) and defining, together with the outer casing (10), an annular chamber (3), the inner partition (2) comprising an upstream face (21) oriented towards the annular chamber (19) and a downstream face (22) opposite the upstream face (21), a de-icing duct (4) for injecting a de-icing air flow (FD) into the annular chamber (3), a cooling system (5) of the inner partition (2) configured to perform forced circulation of a cooling air flow (FR) over the downstream face (22) of the inner partition (2).

Description

Cooling system for an internal partition of an air intake for an aircraft nacelle and associated method

[0001] The present invention relates to the field of de-icing of aircraft nacelle air intakes.

[0002] As is known, an aircraft propulsion system comprises a turbomachine and a nacelle extending around a longitudinal axis oriented from upstream to downstream. The nacelle surrounds the turbomachine and includes an upstream air intake to ensure the admission of an incoming airflow into the turbomachine.

[0003] As is known, the air inlet comprises a radially inner wall and a radially outer wall extending around the longitudinal axis and connected upstream by a leading edge, thus forming an outer casing. The air inlet also includes an internal bulkhead, also called the forward bulkhead, attached at one end to the radially inner wall and at the other to the radially outer wall. The internal bulkhead and the outer casing together define an annular chamber, known as a D-duct due to its roughly D-shaped profile in longitudinal section.

[0004] To prevent the formation and accumulation of frost on the air intake, a defrosting system is commonly used. This system circulates a defrosting fluid within the annular chamber to warm the outer casing by convection. The defrosting fluid is typically in the form of hot air drawn from the turbomachine, specifically from the primary airflow, for example, at the compressor.

[0005] A defrosting system is known to include an inlet duct mounted in the internal partition and equipped with an injection orifice, such as a nozzle, which injects the defrosting fluid into the annular chamber. To ensure the internal partition can withstand the high temperatures of the defrosting fluid, it is known to be made of titanium. Such an internal partition is complex to manufacture and mount with precise tolerances in an air inlet, thus increasing the cost of the air inlet.

[0006] CN116517696A1 teaches you to provide a cooling system in a chamber downstream of an air inlet to cool a connection area.

[0007] One of the objectives of the present invention is to provide an air inlet with a simple design and an internal partition at a reduced cost while allowing for effective defrosting. PRESENTATION OF THE INVENTION

[0008] The invention relates to an air inlet for an aircraft nacelle comprising: A radially inner wall and a radially outer wall extending around a longitudinal axis oriented upstream to downstream and connected upstream by a leading edge, together forming an outer envelope, An internal partition fixed on one side to the radially inner wall and on the other side to the radially outer wall and defining with the outer envelope an annular chamber, the internal partition comprising an upstream face oriented towards the annular chamber and a downstream face opposite to the upstream face, A de-icing duct for injecting a de-icing airflow into the annular chamber.

[0009] The invention is remarkable in that it includes an internal partition cooling system configured to achieve forced circulation of a cooling airflow over the downstream face of the internal partition.

[0010] Advantageously, the temperature of the internal partition is regulated. It can therefore be made of a material that expands thermally. Such a material, for example aluminum, can be machined to precise tolerances at a reduced cost. This makes such an internal partition simpler to manufacture and install, while also being less expensive.

[0011] In one design, the air inlet includes a cooling chamber through which the cooling airflow circulates. The cooling chamber is delimited upstream by the internal partition and radially by a downstream inner wall, extending downstream of the radially inner wall, and a downstream outer wall, extending downstream of the radially outer wall. Such a cooling chamber confines the cooling airflow, thereby improving the cooling of the downstream face of the internal partition.

[0012] In one aspect, the cooling system includes at least one closing partition, mounted downstream of the internal partition, fixed on one side to the downstream inner wall and on the other side to the downstream outer wall, the closing partition delimiting the cooling enclosure downstream. Such a cooling enclosure confines the circulation of the cooling airflow to the downstream face of the internal partition.

[0013] The nacelle extends along a longitudinal axis. Preferably, the cooling enclosure has a height, defined radially with respect to the longitudinal axis along which the nacelle extends, greater than the width, defined longitudinally with respect to the longitudinal axis along which the nacelle extends.

[0014] According to one aspect, the cooling system includes at least one initial opening formed in the downstream inner wall to allow the circulation of the cooling airflow. Such an initial opening allows, in particular, the injection of a cooling airflow into the cooling chamber.

[0015] In one aspect, the defrosting airflow is a pressurized airflow from the turbomachine, delivered to the cooling chamber via an auxiliary duct. Preferably, the cooling airflow is drawn downstream of a turbomachine blower.

[0016] In one aspect, the cooling system comprises a plurality of initial openings, designated injection openings, and a plurality of radial partitions configured to guide the cooling airflow radially after its injection through the injection openings. This ensures homogeneous cooling of the internal partition by constraining the circulation of the cooling airflow. Preferably, at least one injection opening is positioned between two radial partitions.

[0017] According to one aspect, the cooling system includes at least one second opening formed in the downstream outer wall to allow circulation of the cooling airflow, in particular, an injection or evacuation of the cooling airflow.

[0018] In one aspect, the cooling system includes a single second opening, preferably fitted with a valve to allow or prevent the flow of cooling air. This single second opening promotes circumferential circulation of cooling air.

[0019] In one respect, the valve is controlled by the defrosting system. Thus, the cooling system is controlled as a slave by the defrosting system, which is the master. Therefore, a separate control system for the cooling system is not required. Furthermore, the cooling can be adjusted to achieve a specific defrosting intensity, for example, by adapting the cooling based on the mass flow rate or the temperature of the defrosting airflow.

[0020] In one aspect, the cooling system includes at least one jet pump to supply the annular chamber with de-icing fluid. The jet pump is positioned within the cooling chamber and generates suction to draw in the cooling airflow during the circulation of the de-icing fluid. Using a jet pump reduces drag, simplifies the integration of the cooling system, and improves cooling when the aircraft is moving at low speeds or at zero ground speed.

[0021] The cooling system includes a control device configured to stop or limit the flow of cooling air. This control device is a diverter mounted removably on the jet pump. In one aspect, the cooling system includes at least one control device configured to stop or limit the flow of cooling air if the de-icing intensity is insufficient or excessive. This control device is a diverter mounted removably on the jet pump. This reduces the cooling output to maintain effective de-icing, depending on the turbomachine speed or the aircraft's flight phase.

[0022] In one aspect, the cooling system includes a blocking device configured to stop the flow of cooling air if the defrosting intensity falls below a predetermined level. This blocking device is a diverter mounted removablely on the jet pump. This advantageously allows operation in the event of a defrosting system control failure.

[0023] In one design, the diversion device includes a removable scoop configured to draw cooling air from the outside. This advantageously allows the direction of the cooling airflow to be reversed in the event of a defrost system control malfunction. In another design, the scoop is mounted in a removable manner.

[0024] In one aspect, the deflection device includes a shuttering wall configured to at least partially block the supply of cooling air to the jet pump. This reduces the amount of cooling airflow in the annular chamber, preventing excessive cooling of the defrosting airflow.

[0025] Depending on the design, the internal partition is made of a material such as aluminum, magnesium, or a composite material. Such an internal partition is lightweight and inexpensive. Alternatively, the internal partition is machined from a solid block. Such an internal partition is simpler to machine, produce, assemble, and manufacture compared to a conventional internal partition made of titanium.

[0026] According to one aspect, the cooling system is configured to inject a flow of cooling air into the cooling chamber and eject it outwards from the air inlet.

[0027] In one aspect, the cooling system is configured to inject a flow of cooling air into the cooling chamber and eject it into the annular chamber. This advantageously reduces the temperature of the defrosting airflow in the annular chamber.

[0028] Also shown is an aircraft nacelle including an air intake as previously shown.

[0029] Also presented is an aircraft including a nacelle as previously shown.

[0030] Also presented is a process comprising a step of achieving forced circulation of a cooling airflow on the downstream face of the internal partition.

[0031] According to one aspect, the process includes a step of adjusting or even stopping the forced circulation according to the intensity of defrosting and / or the circulation of the defrosting fluid in the annular chamber.

[0032] According to one aspect, the process includes a step of stopping the forced circulation of the cooling airflow if the defrosting intensity is less than a predetermined intensity, in particular, if the temperature of the defrosting airflow is below a temperature threshold or if the mass flow rate of the defrosting airflow is below a defrosting fluid flow rate threshold.

[0033] According to one aspect, the process includes a step of controlling the forced circulation of the cooling airflow as a function of the circulation of the defrosting fluid in the annular chamber. PRESENTATION OF THE FIGURES

[0034] The invention will be better understood upon reading the following description, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0035] This is a schematic representation in a longitudinal half-section of a turbomachine equipped with a nacelle.

[0036] This is a close schematic representation of an air inlet during the cooling of the internal partition.

[0037] This is a schematic representation of a first circulation of the cooling airflow.

[0038] This is a schematic representation of a second circulation of the cooling airflow.

[0039] This is a schematic representation of an initial form of implementation of the cooling system.

[0040] This is a schematic longitudinal cross-sectional representation of a variant of the cooling system with radial partitions.

[0041] This is a schematic cross-sectional representation of the cooling chamber of the variant of the.

[0042] This is a schematic representation of the variant of the.

[0043] This is a schematic representation of an example of cooling system control.

[0044] This is a schematic longitudinal cross-sectional representation of a drain valve in the closed position.

[0045] This is a schematic longitudinal cross-sectional representation of a drain valve in the open position.

[0046] This is a schematic representation of a cooling chamber being supplied by a pressurized airflow taken downstream of the blower.

[0047] This is a schematic representation of a cooling system according to a second embodiment comprising a jet pump in longitudinal section view and in cross-section view.

[0048] This is a schematic representation according to section CC of the.

[0049] This is a schematic representation of an injection opening according to the second embodiment.

[0050] This is a schematic representation of the jet pump according to the second embodiment.

[0051] This is a schematic representation of the operation of the jet pump mounted in the cooling chamber.

[0052] This is a schematic representation of an example of cooling system control according to the second embodiment with a cold air injection valve.

[0053] This is a schematic representation of the cold air injection valve in the open position.

[0054] This is a schematic representation of the cold air injection valve in the closed position.

[0055] This is a schematic representation of another example of cooling system control.

[0056] This is a schematic representation of another example of cooling system control.

[0057] This is a schematic representation of an example of cooling system control with a mechanical link connecting a defrost valve with the cold air injection valve.

[0058] This is a schematic representation of the mechanical linkage of the.

[0059] This is a schematic representation of a defrost valve closure position associated with a cold air injection valve closure position.

[0060] This is a schematic representation of an open position of the defrost valve associated with a closed position of the cold air injection valve.

[0061] This is a schematic representation of a partially open defrost valve position associated with a fully open cold air injection valve position.

[0062] This is a schematic representation of the cooling system when a removable deflection device is present.

[0063] This is a schematic representation of the assembly step of the removable deflection device.

[0064] This is a schematic representation of the removable deflection device in the mounted position.

[0065] It should be noted that the figures explain the invention in detail for implementing the invention, said figures being of course able to serve to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0066] With reference to the aforementioned, the invention relates to an aircraft propulsion system comprising a turbomachine 100 and a nacelle 101 extending along a longitudinal axis X oriented from upstream to downstream. The nacelle 101 surrounds the turbomachine 100 and includes at its upstream end an air inlet 1 which provides the admission of an airflow F entering the turbomachine 100.

[0067] With reference to the figure, the air inlet 1 comprises an outer casing 10 and an inner partition 2 which together define an annular chamber 3. As illustrated in the figure, the outer casing 10 comprises a radially inner wall 11 extending around the longitudinal axis X, a radially outer wall 12 extending around the radially inner wall 11 along the longitudinal axis X, and a leading edge 13 connecting upstream the radially inner wall 11 and the radially outer wall 12. The leading edge 13 is configured to separate the incoming airflow F into an inner airflow guided by the radially inner wall 11 into the turbomachine 100, in particular towards a blower 102, and an outer airflow guided by the radially outer wall 12 out of the turbomachine 100. The outer casing 10 is preferably made of aluminum.

[0068] As illustrated in the figure, the internal partition 2, known by the English term "forward bulkhead", extends between the radially inner wall 11 and the radially outer wall 12, downstream of the leading edge 13. The internal partition 2 is fixed on one side to the radially inner wall 11 and on the other side to the radially outer wall 12. The internal partition 2 comprises an upstream face 21 oriented towards the annular chamber 3 and a downstream face 22 opposite the upstream face 21.

[0069] With reference to the diagram, the air inlet 1 includes a radially external wall 12b, which extends downstream the radially external wall 12 of the annular chamber 3, which will hereafter be referred to as the "downstream external wall 12b". Similarly, with reference to the diagram, the air inlet 1 includes a radially internal wall 11b, which extends downstream the radially internal wall 11 of the annular chamber 3, which will hereafter be referred to as the "downstream internal wall 11b". In this example, the downstream internal wall 11b is in the form of an acoustic panel.

[0070] As illustrated in the figure, to prevent the formation and / or accumulation of frost on the outer casing 10, the air inlet 1 includes a defrosting system 400 configured to circulate a defrosting fluid FD through the annular chamber 3 to warm the outer casing 10 by convection. The defrosting fluid FD is usually in the form of hot air drawn from the turbomachine 100, particularly from the primary flow, for example, at the high-pressure compressor. The defrosting system 400 includes a defrosting duct 4 configured to inject the defrosting fluid FD into the annular chamber 3. Preferably, the defrosting duct 4 passes through the internal partition 2. In this example, the defrosting duct 4 is a circumferential pipe of the piccolo type, but other shapes are possible.

[0071] In this example, the internal partition 2 is made of an aluminum alloy, magnesium alloy, or composite material. Generally, it is possible to replace conventionally used materials, such as titanium, with a lighter, easier-to-work-with, and less expensive material.

[0072] The air inlet 1 is notable in that it includes a cooling system 5 for the internal partition 2, configured to achieve forced circulation of a cooling airflow FR over the downstream face 22 of the internal partition 2, as illustrated in the figure. Thus, the upstream face 21 of the internal partition 2, which is in contact with the defrosting fluid FD during defrosting, is effectively cooled by convention following the forced circulation of a cooling airflow FR over the downstream face 22 of the internal partition 2. The internal partition 2 can therefore be made of a material with lower mechanical properties at high temperature than titanium, such as aluminum, since its temperature can be lowered.

[0073] With reference to the, the air inlet 1 includes a cooling chamber 7 through which the cooling airflow FR circulates. The cooling chamber 7 is delimited upstream by the internal partition 2 and radially by the downstream inner wall 11b and the downstream outer wall 12b.

[0074] According to a first embodiment, with reference to Figures 3 and 4, the cooling system 5 is configured to inject a flow of cooling air FR into the cooling enclosure 7 and eject it outwards, or vice versa, the direction of circulation of the cooling air flow in the cooling enclosure depending on the pressure difference between the radially internal wall 11 and the radially external wall 12.

[0075] With reference to Figures 3 and 4, the cooling system 5 includes at least a first opening 51 formed in the downstream inner wall 11b downstream of the internal partition 2 and at least a second opening 52 formed in the downstream outer wall 12b downstream of the internal partition 2.

[0076] In this example, with reference to the diagram, the cooling system comprises a plurality of first openings 51, preferably distributed circumferentially. Similarly, with reference to the diagram, the cooling system comprises a plurality of second openings 52, preferably distributed circumferentially. Advantageously, depending on the pressure difference between the downstream inner wall 11b and the downstream outer wall 12b, a forced circulation of a cooling airflow FR occurs in the cooling chamber 7. With reference to the diagram, when the aircraft is moving at its rated speed, a cooling airflow FR flows radially outwards in the cooling chamber 7, the air pressure being higher in the air intake sleeve (side of the downstream inner wall 11b).With reference to the, when the aircraft is moving at a low speed, for example taxiing on the ground at low speed, or when stationary, a cooling airflow FR circulates radially inwards into the cooling enclosure 7, the air pressure being lower in the air intake sleeve.

[0077] In this example, with reference to the downstream inner wall 11b, the acoustic panel has acoustic attenuation cells. The first openings 51 are preferably formed directly in the acoustic panel or upstream of it.

[0078] With reference to Figures 3 to 5, the cooling system 5 includes at least one closing partition 53, mounted downstream of the internal partition 2, fixed on one side to the downstream inner wall 11b and on the other side to the downstream outer wall 12b. The cooling enclosure 7 is delimited downstream by the closing partition 53. This allows the cooling airflow FR to be concentrated in contact with the downstream face 22 of the internal partition 2 to improve its cooling.

[0079] According to a variant of the first embodiment, with reference to Figures 7 to 8, the cooling system 5 includes a single second opening 52, designated as the exhaust opening 52u. Thus, the cooling chamber 7 is supplied by one or more first openings 51 so that the cooling airflow FR circulates circumferentially within the cooling chamber 7 before reaching the exhaust opening 52u. This increases heat exchange and allows for optimal cooling. A single exhaust opening 52 also helps to limit drag.

[0080] According to one aspect, with reference to Figures 6 to 8, the cooling system 5 comprises a plurality of radial partitions 54 attached to the inner partition 2 and configured to guide the cooling airflow FR radially after its injection through the first openings 51. Such radial partitions 54 force radial circulation before allowing natural circumferential circulation towards the exhaust opening 52u. To this end, the radial partitions 54 have a radial length less than the radial distance between the downstream inner wall 11b and the downstream outer wall 12b, as illustrated in Figure 1. The radial partitions 54 are spaced angularly apart to allow homogeneous cooling, as illustrated in Figure 1. Alternatively, the radial partitions 54 can be distributed non-homogeneously, in particular, to adapt the cooling of the annular chamber 3.

[0081] According to one aspect, with reference to the, the cooling system 5 includes at least one drain valve 60 mounted in the drain opening 52u, in particular, a single drain valve 60. The use of a drain valve 60 advantageously allows the drain opening 52u to be closed when the cooling system 5 is not in use in order to reduce pressure losses and aircraft drag.

[0082] It is understood that the first opening(s) 51 and the second opening(s) 52 could also be fitted with one or more shutters to limit drag when the cooling system 5 is not in use. A shutter can take various forms, for example, a valve or a rotating ring comprising openings configured to be aligned with the openings 51, 52 when the cooling system 5 is in use.

[0083] The 60 discharge valve can come in various forms, a rotary flap, a movable partition and the like.

[0084] With reference to the above, the drain valve 60 comprises an elastic element 61 (spring, diaphragm, or other) mounted on a piston 62 configured to constrain the drain valve 60 to a closed position PF. It is understood that the drain valve 60 could, in particular, be in the form of a pivoting butterfly valve.

[0085] According to one aspect, and again referring to the above, the drain valve 60 is configured to be controlled by the defrosting system 400. In this example, the defrosting system 400 has a main branch 41 on which a defrost valve 40 is mounted. This valve is opened when defrosting is required. The defrosting system 400 also has a first branch 42 connecting the main branch 41 to the defrost line 4, and a second branch 43 connecting the main branch 41 to the drain valve 60 to open it (open position PO) when the defrost valve 40 is activated. In particular, the defrosting fluid FR applies pressure to the piston 62 to counteract the stress on the elastic element 61.Alternatively, in the case of an air-controlled valve, the so-called "muscle" pressure used to control the defrost valve 40, and delivered when a control solenoid actuates its opening, can be used to control the opening of the drain valve 60. In other words, part of the air pressure downstream of the defrost valve 40 is used to control the drain valve 60.

[0086] Thus, when no defrosting is required, the defrost valve 40 is closed and the drain valve 60 is in the closed position PF () under the action of the elastic element, which closes the drain opening 52u and limits drag. Therefore, there is no cooling in the absence of defrosting.

[0087] Conversely, when defrosting is desired, the defrost valve 40 is opened, which applies pressure to the piston 61 which moves to the open position PO (), which opens the evacuation opening 52u to allow the cooling airflow FR to circulate in the cooling chamber 7 to cool the internal partition 2.

[0088] It goes without saying that the drain valve 60 could be controlled differently so as to operate simultaneously with the defrosting process. For example, the drain valve 60 can be temperature-controlled via an actuator connected to a temperature sensor mounted in the annular chamber 3 in order to activate cooling upon detection of defrost activation (a temperature increase in the annular chamber 3). Other control methods are presented later, particularly with reference to Figures 21 to 23, and are perfectly applicable to a cooling system 5 according to the first embodiment.

[0089] A fault may occur in the control of the de-icing system 400. Therefore, during light maintenance, i.e., following a flight, an operator may need to block the de-icing valve 40 in a forced-open position. Advantageously, the operator can then block the drain valve 60 in a forced-open position to ensure continuous cooling.

[0090] According to one variant, with reference to the, the cooling enclosure 7 can also be supplied by a cooling airflow FR which has been accelerated by the turbomachine 100, in particular by the blower 102, and which is conveyed downstream via an auxiliary duct 51a. The cooling airflow FR is preferably taken downstream of the blower 102.

[0091] According to a second embodiment, with reference to Figures 13 to 18, the cooling system 5 is configured to inject a flow of cooling air FR into the cooling enclosure 7 and eject it into the annular chamber 3 with the defrosting fluid FD.

[0092] In this embodiment, the defrosting system 400 includes a jet pump 46 to supply the defrosting line 4 in the annular chamber 3. With reference to figures 16 and 17, the jet pump 46 is positioned in the cooling enclosure 7 and allows to generate a suction of the cooling airflow FR, during the circulation of defrosting fluid FD, which mixes with the defrosting fluid FD and is injected into the annular chamber 3.

[0093] With reference to the, the cooling system 5 includes for this purpose at least one injection opening 56 which can be a first opening 51 formed in the downstream inner wall 11b or a second opening 52 formed in the downstream outer wall 12b downstream of the inner partition 2. In this example, with reference to the, the injection opening 56 is formed in the downstream outer wall 12b.

[0094] Preferably, the injection opening 56 is angled away from the jet pump 46, preferably diametrically opposite, to allow for homogeneous lateral cooling between the injection opening 56 and the jet pump 46. In this example, the jet pump 46 is at 0° (corresponding to the top vertical point) and the injection opening is at 180° (corresponding to the bottom vertical point). As illustrated in Figure 1, the cooling airflow FR moves circumferentially within the cooling chamber 7 to cool the internal partition 2.

[0095] With reference to the figure in which the downstream outer wall 12b is not shown, the cooling chamber 7 is supplied by the injection opening 56 via an injection line 57. According to one aspect, the cooling system 5 includes at least one injection valve 65 mounted in the injection opening 56; in particular, a single injection valve 65. The use of an injection valve 65 advantageously allows the injection opening 56 to be closed when the cooling system 5 is not in use in order to reduce pressure losses and aircraft drag. In this example, the injection valve 65 is a butterfly valve, but it is understood that other technologies could be suitable. A butterfly valve is advantageous for drawing cooling air from the dynamic flow. The butterfly valve is preferably positioned as close as possible to the downstream outer wall 12b.

[0096] With reference to figures 16 and 17, the defrosting system 400 is shown, comprising a main branch 41 supplying, in the cooling enclosure 7, the jet pump 46 which opens into the defrosting line 4. When the jet pump 46 is supplied with the defrosting fluid FD, a flow of cooling air FR is also drawn into the defrosting line 4 as illustrated in the.

[0097] According to one aspect, with reference to the diagram, the injection valve 65 is configured to be controlled by the defrosting system 400. In this example, the defrosting system 400 has a main branch 41 on which the defrosting valve 40 is mounted. The defrosting valve is opened when defrosting is desired. The defrosting system 400 further has a first branch 42 connecting the main branch 41 to the jet pump 46 and a second branch 43 connecting the main branch 41 to the injection valve 65 to open it (open position PO) when the defrosting valve 40 is activated. In this example, the injection valve 65 has an elastic element (spring, diaphragm, or other) mounted on a piston configured to constrain the injection valve 65 to the closed position PF. The FR defrosting fluid allows pressure to be applied to the piston and opposes the stress on the elastic element.

[0098] Thus, when no defrosting is required, the defrost valve 40 is closed and the injection valve 65 is in the closed position PF () under the action of the elastic element, which closes the injection opening 56 and limits drag. Therefore, there is no cooling in the absence of defrosting, which is advantageous.

[0099] Conversely, when defrosting is desired, the defrost valve 40 is opened, which applies pressure to the piston which moves the injection valve 65 to the open position PO (), which opens the injection opening 56 to allow the cooling airflow FR to circulate in the cooling chamber 7 to cool the internal partition 2.

[0100] According to one aspect, the cooling system 5 may include a heat exchanger with the internal partition 2 to allow homogeneous and efficient cooling, for example the heat exchanger has the form of a set of fins.

[0101] Preferably, the injection valve 65 is configured to stop the cooling airflow FR if the supply pressure of the de-icing fluid FD is below a predetermined threshold (e.g. 1.5 bar (0.15 MPa) to 2 bar (0.2 MPa) relative to ambient pressure) in order to limit cooling for the coldest cases and thus maintain good de-icing performance for a low turbomachine 100 speed.

[0102] According to one aspect, the cooling system 5 includes a cooling inhibition device configured to stop the circulation of the cooling airflow FR when the defrosting intensity is less than a predetermined threshold intensity, for example, if the temperature of the defrosting airflow FD is less than a temperature threshold or if the mass flow rate of the defrosting airflow FD is less than a defrosting fluid flow rate threshold.

[0103] With reference to the [reference to the previous section], the injection valve 65 can be temperature-controlled via an actuator connected to a thermostatic valve 64 mounted in the annular chamber 3 or on the internal partition 2 in order to limit or even stop cooling if defrosting is insufficient, for example, if the temperature is below 150°C. If the temperature is too low, the pressure applied to the injection valve 65 by the second branch 43 is diverted to close the injection valve 65 to the PF position. The thermostatic valve 64 thus acts as a cooling inhibiting device if the defrosting temperature is insufficient.

[0104] It goes without saying that the injection valve 65 could be controlled differently. With reference to the defrosting system 400, a Venturi device 48 is configured to control the injection valve 65 based on the pressure difference between the inlet and outlet of the Venturi device 48, which is a function of the defrost airflow rate. In this example, the inlet and outlet of the Venturi device 48 are connected to the injection valve 65 by a second branch 43 and a third branch 44, respectively. This allows the cooling to be limited or even stopped when the flow rate is too low. The Venturi device 48 acts as a cooling inhibitor if the defrost fluid flow rate FD is insufficient. It goes without saying that the cooling inhibitor could take other forms.

[0105] With reference to the diagram, the defrost valve 40 and the injection valve 65 are connected by a mechanical linkage 69, for example, gears, connecting rods, or linkages. Thus, the control of the defrost valve 40 mechanically controls the injection valve 65. The injection valve 65 therefore acts as a slave to the defrost valve 40, which acts as the master. As will be shown later, the mechanical linkage 69 forms the cooling inhibition element.

[0106] For example, with reference to the mechanical linkage 69, the linkage device is a linkage device. In this example, the position of the defrost valve 40, in particular its angular position, modifies the position of the injection valve 65, in particular its angular position.

[0107] As an example, Figures 25 to 27 show several angular positions of the defrost valve 40 and the injection valve 65 to which it is connected. Figure 1 represents a closed position of the defrost valve 40 (without defrosting) which is associated with a first closed position PF of the injection valve 65. Thus, in the absence of defrosting, cooling is not activated, which limits drag.

[0108] This represents a configuration with a low defrosting fluid pressure FD. The defrosting valve 40 is in a fully open position and is associated with a second closed position PF of the injection valve 65. Thus, during defrosting with a low defrosting fluid pressure FD, cooling is not activated, in order to maintain efficient defrosting.

[0109] Lare represents a configuration with a high defrosting fluid pressure FD. The defrosting valve 40 is in a partially open position which is associated with an open position PO of the injection valve 65. Thus, during defrosting with a high defrosting fluid pressure FD, the defrosting valve 40 reduces the defrosting flow rate and the injection valve 65 allows a flow of cooling air FR to be injected to cool the internal partition 2.

[0110] Preferably, the cooling system 5 may include a fault detection device, for example, for detecting insufficient cooling. The fault detection device may be configured to measure the temperature of the internal partition 2 or the pressure in the cooling enclosure 7 and optionally generate an alarm if a fault is detected, for example, in the event of overheating.

[0111] A fault may occur in the control of the de-icing valve 40. Therefore, during light maintenance, i.e., following a flight, an operator may need to block the de-icing valve 40 in a forced open (POF) position as illustrated in the figure. To ensure optimal operation, the injection valve 65 is also blocked in a forced open (POF) position. In this example, the mechanical linkage 69 is disconnected between the de-icing valve 40 and the injection valve 65 to allow both valves 40 and 65 to be positioned in the forced open (POF) position.

[0112] As previously mentioned, excessive cooling must be avoided for certain operating configurations. To this end, the cooling system 5 includes a removable inhibiting element, designed for use only in case of a fault. In this example, the inhibiting element takes the form of a diverter device 9, which can be mounted in the cooling chamber 7 to cooperate with the jet pump 46, thereby allowing the injection of a cooling airflow FR into the cooling chamber 7 at the level of the jet pump 46. In this example, the diverter device 9 is mounted in the downstream outer wall 12b.

[0113] For this purpose, with reference to figures 28 to 30, the deflection device 9 includes a scoop 91 configured to draw a flow of cooling air FR from outside in order to supply the cooling enclosure 7. When using the deflection device 9, the flow of cooling air FR is discharged through the injection opening 56, i.e., in the opposite direction to the nominal operation.

[0114] The diverter device 9 includes a sealing wall 92 configured to at least partially block the supply of the jet pump 46 with the cooling airflow FR. Thus, the cooling airflow FR circulates mainly between the scoop 91 and the injection opening 56, which prevents or limits the supply of cold air into the annular chamber 3.

[0115] Thanks to the invention, the internal partition 2 can be efficiently cooled during de-icing, allowing this internal partition to be made of a material less sensitive to high temperatures. Furthermore, the cooling system 5 can adapt in case of a failure of the de-icing system 400 and prevent excessive cooling depending on the aircraft's flight conditions.

Claims

Air inlet (1) for an aircraft nacelle (101) comprising: A radially inner wall (11) and a radially outer wall (12) extending around a longitudinal axis (X) oriented from upstream to downstream and connected upstream by a leading edge (13), together forming an outer shell (10), An internal partition (2) fixed on one side to the radially inner wall (11) and on the other side to the radially outer wall (12) and defining with the outer shell (10) an annular chamber (3), the internal partition (2) comprising an upstream face (21) oriented towards the annular chamber (3) and a downstream face (22) opposite the upstream face (21), A de-icing duct (4) for injecting a de-icing airflow (DF) into the annular chamber (3),a cooling system (5) of the internal partition (2) configured to achieve forced circulation of a cooling airflow (FR) on the downstream face (22) of the internal partition (2). Air inlet characterized in that it comprises a cooling chamber (7) in which the cooling airflow (FR) circulates, the cooling chamber (7) being delimited upstream by the internal partition (2) and radially by a downstream inner wall (11b), extending downstream of the radially inner wall (11), and a downstream outer wall (12b), extending downstream of the radially outer wall (12), and at least one closing partition (53), mounted downstream of the internal partition (2), fixed on one side to the downstream inner wall (11b) and on the other side to the downstream outer wall (12b), the closing partition (53) delimiting the cooling chamber (7) downstream. Air inlet (1) according to claim 1, wherein the cooling system (5) includes at least a first opening (51) formed in the downstream inner wall (11b) to allow the circulation of the cooling airflow (FR). Air inlet (1) according to claim 2, wherein the cooling system (5) comprises a plurality of first openings (51), designated injection openings, the cooling system (5) comprising a plurality of radial partitions (54) configured to guide the flow of cooling air (FR) radially following its injection through the injection openings (51). Air inlet (1) according to any one of claims 1 to 3, wherein the cooling system (5) includes at least a second opening (52) formed in the downstream outer wall (12b) to permit the circulation of the cooling airflow (FR), in particular, an injection or evacuation of the cooling airflow (FR). Air inlet (1) according to claim 4, wherein the cooling system (5) includes a single second opening (52u, 56) in which a valve (60, 65) is mounted so as to permit or prohibit the circulation of the cooling airflow (FR). Air inlet (1) according to claim 5, wherein the valve (60, 65) is controlled by a defrosting system (400). Air inlet (1) according to any one of claims 1 to 6, wherein the cooling system (5) includes at least one jet pump (46) for supplying the annular chamber (3) with a defrosting fluid (FD), the jet pump (46) being positioned in the cooling enclosure (7) and enabling the generation of a suction of the cooling airflow (FR) during the circulation of the defrosting fluid (FD). Air inlet (1) according to claim 7, wherein the cooling system (5) includes an inhibition element configured to stop or limit the circulation of the cooling airflow (FR), the inhibition element being in the form of a deflection device (9) removably mounted on the jet pump (46). Air inlet (1) according to any one of claims 1 to 8, wherein the internal partition (2) is made of an aluminum alloy, magnesium or composite material. Air inlet (1) according to any one of claims 1 to 9 excluding claim 7, wherein the cooling system (5) is configured to inject a cooling airflow (FR) into the cooling enclosure (7) and eject it out of the air inlet (1). Air inlet (1) according to any one of claims 1 to 9 taken in combination with claim 7, wherein the cooling system (5) is configured to inject a cooling airflow (FR) into the cooling enclosure (7) and eject it into the annular chamber (3). Aircraft nacelle (101) comprising an air inlet (1) according to any one of claims 1 to 11. Method for defrosting an air inlet (1) according to any one of claims 1 to 11, the method comprising a step of carrying out a forced circulation of a cooling airflow (FR) on the downstream face (22) of the internal partition (2).

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