SUSPENSION PYLON FOR AN AIRCRAFT ENGINE WITH A COUNTERFLOW COOLING EXCHANGER

Description

Technical field of the invention

[0001] The invention relates to a suspension pylon (or mast) for an aircraft engine equipped with a heat exchange device, such as a cooling exchanger, intended to equip an air system of an aircraft, such as an air conditioning system. A pylon as defined by the preamble of claim 1 is known from document US 5,729,969. Technological background

[0002] An aircraft air system such as an aircraft cabin environmental control system, better known by the acronym ECS for the English term " Environmental Control System » is intended to provide the aircraft cabin (which generally refers to any space inside the aircraft whose air pressure and / or temperature must be controlled, such as a passenger cabin, the pilot's cockpit, a cargo hold, etc.) with air at controlled pressure and / or temperature.

[0003] For this, it is known to take high pressure air from the aircraft's propulsion engines and to treat this air (also designated by the terminology of air bleed ) by a plurality of equipment to bring it to a temperature and pressure compatible with the needs of the cabin.

[0004] Among these devices, there is at least one pre-cooling air / air heat exchanger which aims to cool the air taken from the aircraft's propulsion engines with a flow of cold air. This exchanger is often referred to by its English terminology of precooler.

[0005] Such a heat exchanger generally comprises a transverse hot circuit and a cold circuit configured to be able to ensure heat exchanges between the air flow carried by the hot circuit (also referred to hereinafter as the hot pass) and the cold air flow carried by the cold circuit (also referred to hereinafter as the cold pass).

[0006] There are also exchangers whose hot and cold circuits are counter-current, that is to say that the hot and cold air flows follow parallel directions opposite each other.

[0007] Whatever the structure of the exchanger, the cold circuit can, for example, be supplied by a flow of air taken from the secondary flow of the engine, known as fan air, the temperature of which is close to the external environment of the aircraft, and which can therefore reach temperatures of around -50°C and a pressure of around 200 mbar in flight.

[0008] The cold circuit can also be supplied by a flow of air taken from a scoop of the aircraft which supplies an air channel, better known as RAM air.

[0009] The hot circuit can be supplied directly by air taken from the propulsion engines or by air from the engines and already partially treated by equipment upstream of the air conditioning system.

[0010] Most heat exchangers used on board aircraft today consist of a generally rectangular heat exchange chamber that houses a stack of plates or fins (also referred to as a "bundle" of plates or fins) that form stacked circulation channels, alternately for the hot pass and the cold pass. Thus, the hot pass that feeds one face of the exchanger circulates in the channels of the different layers and the cold pass that feeds one face of the exchanger (perpendicular for transverse exchangers and opposite for counter-current exchangers) circulates in the channels inserted between two channels of the hot pass. This architecture makes it possible to insert each hot channel between two cold channels over the entire length or height of the exchanger and therefore to ensure heat exchanges between the two fluids.

[0011] Applications EP3521589 and EP3521590 in the name of the applicant describe examples of precooler.

[0012] These heat exchangers cool the air taken from the engines or the ambient air compressed by dedicated compressors, before being processed by the other equipment in the air conditioning system to supply the aircraft cabin. The cooling capacity of an exchanger is directly proportional to its size.

[0013] The inventors therefore sought a new solution to increase the exchange surfaces within an exchanger while limiting the size of the exchanger as much as possible, with a view to optimizing the installation of the exchanger in an aircraft pylon.

[0014] The inventors have sought in particular to develop an aircraft pylon equipped with a heat exchanger which can be used, not only in the context of the air conditioning systems of a transport vehicle, such as an aircraft, but also in all types of cooling systems requiring the cooling of a hot fluid from a source of hot fluid by a cold fluid from a source of cold fluid. Objectives of the invention

[0015] The invention aims to provide an aircraft pylon equipped with a cooling exchanger (better known under the English name of precooler ) intended for use in an aircraft air system.

[0016] The invention aims more particularly to provide a pylon equipped with a cooling exchanger which makes it possible to increase the exchange surfaces while limiting the size of the exchanger.

[0017] The invention also aims to provide, in at least one embodiment, a pylon equipped with a cooling exchanger which makes it possible to optimize its integration volume in the pylon.

[0018] The invention also aims to provide, in at least one embodiment, a pylon equipped with a cooling exchanger which can be connected to various sources of hot and cold air according to the integration constraints. Statement of the invention

[0019] To this end, the invention relates to a suspension pylon for a propulsion engine of an aircraft under a wing of an aircraft having a main axis, characterized in that it comprises: a counter-current cooling exchanger of a hot primary air flow by a cold secondary air flow circulating in opposite directions to each other along a direction, called the longitudinal direction, coinciding with said main axis, said exchanger comprising two plate exchanger blocks, called bundles, juxtaposed next to each other on either side of a central juxtaposition axis extending along said longitudinal direction, and each comprising: ∘ a plurality of longitudinal parallel plates alternately forming circulation channels for the hot primary air flow which define a hot pass of the bundle, and circulation channels for the cold secondary air flow which define a cold pass of the bundle, ∘ a hot air inlet and a hot air outlet arranged respectively at each longitudinal end of said bundle,∘ a cold air inlet and a cold air outlet arranged respectively at each longitudinal end of said bundle, said hot passes of the two bundles being in fluid communication with a central inlet common to the two bundles forming said hot air inlets of the two bundles and with a central outlet common to the two bundles forming said hot air outlet of said bundles, and said cold passes of the two bundles being in fluid communication with separate lateral inlets and lateral outlets which deviate laterally from said central axis, these separate lateral inlets being supplied with fresh ambient air taken from the vicinity of said pylon, hot air distribution pipes adapted to fluidly connect an air sampling device on said aircraft engine and said central inlet common to the two bundles.

[0020] Thus, and unlike most cooling exchangers currently installed on aircraft, which generally comprise a simple heat exchange circuit (a hot pass and a cold pass which cross at 90° to each other), the pylon exchanger according to the invention comprises a complex heat exchange circuit (two hot passes and two cold passes arranged counter-current to each other).

[0021] The cooling exchanger of the pylon according to the invention has the particularity of comprising two adjacent bundles juxtaposed and supplied by a common inlet and opening into a common outlet.

[0022] The pylon cooling exchanger according to the invention therefore makes it possible to provide a large cold supply surface (the exchanger being supplied with cold air via the side inlets) and a central and common hot supply.

[0023] The pylon exchanger according to the invention optimizes its integration volume in the engine environment.

[0024] According to the invention, said hot passes of the two bundles are in fluid communication with said common inlet and said common outlet, and said cold passes of the two bundles are in fluid communication with the disjointed lateral inlets and the disjointed lateral outlets. In other words, said hot passes of the two bundles are fed by a common inlet and open into a common outlet, and said cold passes of the two bundles are fed by the disjointed lateral inlets and open into the disjointed lateral outlets.

[0025] Thus and according to the invention, the exchanger comprises a hot air supply common to the two bundles and two lateral cold air supplies each dedicated to one bundle. The hot pass is therefore split in two, in the two juxtaposed bundles, and each bundle ensures cooling by a dedicated cold pass. This allows significant cooling of the hot air flow supplying the exchanger.

[0026] According to the invention, the hot pass outlet is also common to both beams and the cold outlets are separate and each dedicated to one beam.

[0027] The invention optimizes the integration of the exchanger within the pylon of an aircraft by orienting the exchanger in such a way that the longitudinal direction of the exchanger (which coincides with the juxtaposition axis) coincides with the main direction of the pylon (which coincides with the main axis of the engine), the cold air inlets being arranged towards the front of the aircraft. In this way, the lateral cold air inlets can be supplied by the ambient air present on either side of the pylon and penetrating into the pylon through cold air intakes arranged on either side of the pylon opposite the lateral inlets of the exchanger. The movement of the aircraft in flight naturally and spontaneously leads to the intake of cold air on either side of the pylon to supply the cold passes of the exchanger.

[0028] Advantageously and according to the invention, the cold and / or hot passes of the two beams are separated by a central closing bar.

[0029] According to this variant, there is a separation of the hot and / or cold flows between the two beams in the counter-current circulation zone of the air flows by the presence of central closing bars.

[0030] Advantageously and according to the invention, each bundle of the exchanger is housed in a casing comprising at each longitudinal end an end wall formed of two openwork planes inclined relative to the longitudinal direction and connected by a junction edge which extends perpendicular to said longitudinal direction, each inclined openwork plane forming a lateral inlet or a lateral outlet of one of the passes of said bundle, and each pair of inclined openwork planes of the two bundles arranged opposite one another forming a common inlet and / or a common outlet for said bundles.

[0031] The exchanger according to this particular structure makes it possible in a simple and economical manner to form the common central inlet and the common central outlet for the two adjacent bundles by the combination of two openwork inclined planes facing each other. The inclination with respect to the longitudinal direction of the inclined planes forming the common inlet and / or the common outlet is preferably between 0 and 90°, preferably between 30 and 60°. A supply pipe for the common central inlet and a collection pipe for the common central outlet may be mounted respectively on the common central inlet and on the common central outlet to ensure the supply and collection of the corresponding air flows, for example by resting on the junction edges.

[0032] The invention also extends to a system for cooling a flow of hot air by a flow of cold air.

[0033] The cooling system according to the invention comprises: at least one hot air source and at least one cold air source, at least one hot air collector and at least one cold air collector, a cooling exchanger according to the invention, a network of air circulation pipes connecting at least said hot air source to said hot air inlets of said exchanger, at least said cold air source to said cold air inlets of said exchanger, at least said hot air outlets of said exchanger to said hot air collector, at least said cold air outlets of said exchanger to said cold air collector.

[0034] Advantageously and according to the invention, each circulation pipe is equipped with at least one valve for regulating the air flow circulating in the pipe. List of figures

[0035] Other aims, characteristics and advantages of the invention will appear on reading the following description given solely for non-limiting purposes and which refers to the appended figures in which: [ Fig. 1 ] is a schematic sectional view of a cooling exchanger of a pylon according to a first variant embodiment of the invention, [ Fig. 2 ] is a schematic perspective view of a cooling exchanger of a pylon according to an embodiment of the invention making it possible to understand the overall shape of the exchanger, [ Fig. 3 ] is a schematic view of a suspension pylon of an aircraft engine according to an embodiment of the invention equipped with the exchanger of the figure 1 . Detailed description of an embodiment of the invention

[0036] In the figures, scales and proportions are not strictly observed for the purposes of illustration and clarity. Throughout the detailed description which follows with reference to the figures, unless otherwise indicated, each element of the exchanger is described as it is arranged when the exchanger is arranged within a suspension pylon of an aircraft engine. This configuration is notably represented by the figure 3 .

[0037] Furthermore, identical, similar or analogous elements are designated by the same references in all figures.

[0038] There figure 1 illustrates in longitudinal section an exchanger 10 according to an embodiment of the invention which comprises two bundles 10a, 10b juxtaposed next to each other, on either side of a central juxtaposition axis 12 which extends along the longitudinal direction L.

[0039] In the embodiment of the figures, the two beams are separated by a closing bar.

[0040] Each beam 10a, 10b comprises a plurality of plates 15 which each extend along the longitudinal direction. These plates 15 are for example metal plates which are brazed onto an external frame to hold them in a parallelepiped arrangement.

[0041] These plates 15 delimit, two by two, channels for the circulation of air flows which themselves form the hot and cold passes counter-current to the beam.

[0042] The beam 10a is housed in a casing which comprises, at a first longitudinal end, an end wall formed of two inclined openwork planes 24a, 24b and, at a second opposite longitudinal end, an end wall formed of two inclined openwork planes 26a, 26b. The planes 24a and 24b are connected to each other by a connecting edge 24c which extends perpendicular to the longitudinal direction L. The planes 26a and 26b are connected to each other by a connecting edge 26c which extends perpendicular to the longitudinal direction L and parallel to the edge 24c.

[0043] The adjacent beam 10b is housed in a casing which comprises at a first longitudinal end an end wall formed of two inclined openwork planes 25a, 25b and at a second opposite longitudinal end an end wall formed of two inclined openwork planes 27a, 27b. The planes 25a and 25b are connected to each other by a joining edge 25c which extends perpendicular to the longitudinal direction L. The planes 27a and 27b are connected to each other by a joining edge 27c which extends perpendicular to the longitudinal direction L and parallel to the edge 25c.

[0044] The inclined openwork planes 24a, 25a, 26a and 27a each form a lateral entrance or a lateral exit of one of the passes (hot or cold) of the beam.

[0045] The inclined openwork planes 26b and 27b of the two beams arranged opposite each other form a common inlet or a common outlet of the beams and the inclined openwork planes 24b, 25b arranged at the other longitudinal end form a common inlet or a combined common outlet.

[0046] In all figures, the solid arrows represent the main direction of circulation of the cold air flow within (and in the vicinity of) the exchanger and the dotted arrows represent the main direction of circulation of the hot air flow within (and in the vicinity of) the exchanger.

[0047] On the figure 1 , the hot passes of the two bundles 10a, 10b are in fluid communication with the common inlet 30 formed by the walls 26b and 27b and the common outlet 32 ​​formed by the walls 24b and 25b.

[0048] The cold passes of the two bundles are in fluid communication with the separate lateral inlets formed by the openwork planes 24a and 25a and the separate lateral outlets formed by the openwork planes 26a and 27a.

[0049] In other words, the hot passes of the two bundles 10a, 10b are supplied by the common inlet 30 and open into the common outlet 32, and the cold passes of the two bundles 10a, 10b are supplied by the separate lateral inlets 24a, 25a and open into the separate lateral outlets 26a, 27a.

[0050] There figure 2 schematically illustrates in perspective a pylon exchanger according to an embodiment of the invention allowing the general shape of the exchanger to be understood. In this view, one can also observe some of the openwork walls forming the inlets and / or outlets.

[0051] There figure 3schematically illustrates a pylon 40 according to an embodiment of the invention comprising the exchanger of the figure 1 This exchanger can be fixed in the pylon by any means within the immediate reach of the person skilled in the art.

[0052] The pylon houses the exchanger 10 such that the longitudinal direction L of the exchanger coincides with the main direction of the pylon (which coincides with the main axis of the engine and the main direction of movement of the aircraft).

[0053] The cold air inlets formed by the walls 24a and 25a are arranged towards the front of the aircraft. In this way, the lateral cold air inlets can be supplied by the ambient air present on either side of the pylon 40, when the aircraft moves in the direction of the arrow referenced F on the figure 3 .

[0054] Air intakes arranged on either side of the pylon 40 make it possible to supply air from the cold passes of the exchanger 10 and thus to ensure the cooling of the hot air conducted to the exchanger 10 by appropriate pipes from a source of hot air, which is for example air taken from the propulsion engine (not shown in the figure 3 ) carried by pylon 40.

Claims

1. Suspension pylon (40) for a propulsion engine of an aircraft under a wing of an aircraft having a main axis, characterized in that it comprises: - a counterflow cooling exchanger (10) of a flow of hot primary air (22) by a flow of cold secondary air (24) flowing oppositely to each other in a direction, referred to as the longitudinal direction (L), coinciding with said main axis of said engine, said exchanger comprising two plate exchanger blocks, referred to as bundles (10a, 10b), juxtaposed one beside the other on both sides of a central juxtaposition axis (12) extending in said longitudinal direction (L), and each comprising: ∘ a plurality of parallel longitudinal plates (15) forming in alternation flow ducts for the flow of hot primary air, which define a hot pass of the bundle, and flow ducts for the flow of cold secondary air, which define a cold pass of the bundle, ∘ a hot air inlet and a hot air outlet arranged respectively at each longitudinal end of said bundle, ∘ a cold air inlet and a cold air outlet arranged respectively at each longitudinal end of said bundle, said hot passes of the two bundles being in fluid communication with a central inlet (30) common to the two bundles forming said hot air inlets of the two bundles and a central outlet (32) common to the two bundles (10a, 10b) forming said hot air outlets of said bundles, and said cold passes of the two bundles being in fluid communication with separate side inlets and side outlets which diverge laterally from said central axis (12), said separate side inlets being supplied by fresh ambient air drawn from the proximity of said pylon, - conduits for distribution of hot air suitable for fluidly connecting a device for drawing air from said aircraft engine and said central inlet common to the two bundles.

2. Pylon as claimed in claim 1, characterized in that said cold and / or hot passes of the two bundles of said exchanger are separated by a central closure bar (38).

3. Pylon as claimed in any one of claims 1 or 2, characterized in that each bundle (10a, 10b) of said exchanger is housed in a housing comprising, at each longitudinal end, an end wall formed from two openwork planes (24a, 24b; 25a, 25b; 26a, 26b; 27a, 27b) inclined with respect to the longitudinal direction (L) and connected by a joint edge (24c, 25c, 26c, 27c) which extends perpendicularly to said longitudinal direction (L), each inclined openwork plane (24a, 25a, 26a, 27a) forming a side inlet or a side outlet of one of the passes of said bundle, and each pair of inclined openwork planes (24b, 25b; 26b, 27b) of the two bundles arranged facing each other forming an inlet (30; 32) common to said bundles and / or an outlet (30; 32) common to said bundles.