AIRCRAFT PROPULSION ASSEMBLY

Abstract

AIRCRAFT PROPULSION ASSEMBLY The invention relates to an aircraft propulsion assembly (151) comprising a combustion chamber (168), a fairing (172), an ejection nozzle (174) disposed downstream of the combustion chamber (168) and delimited by a rear portion of the fairing (172), called nozzle wall (180), for ejecting the combustion gases and a supply line (176) supplying the combustion chamber (168) with fuel, wherein the supply line (176) comprises portions in the form of omega profiles wrapped around the nozzle wall (180), wherein free ends of the omega are fixed in a hermetic manner to the nozzle wall (180), an inlet manifold fluidly connected to an inlet end of each portion and an outlet manifold fluidly connected to an outlet end of each portion. With such an arrangement, the calories from the combustion gases are transferred to the fuel for more efficient combustion. Fig. 2

Description

Title of the invention: PROPULSION ASSEMBLY FOR AIRCRAFT Technical field

[0001] The present invention relates to a propulsion assembly for an aircraft, said propulsion assembly comprising a propulsion system comprising an ejection nozzle ensuring the ejection of combustion gases from the propulsion system and a heat exchange system arranged at the ejection nozzle to ensure a transfer of calories to the fuel of the propulsion system, as well as an aircraft comprising at least one such propulsion system. STATE OF THE PRIOR ART

[0002] In order to move, an aircraft conventionally comprises at least one propulsion unit comprising a propulsion system arranged in a nacelle and which may take the form of a turbojet or a turboprop. In each case, the propulsion system comprises a rotating assembly which drives a fan or a propeller. The rotating assembly constitutes a core of the propulsion system and comprises from front to rear an air inlet which allows the introduction of air into a vein of the core, a compressor which compresses the air thus introduced, a combustion chamber in which the air thus compressed and a fuel are mixed, and a turbine which allows the expansion of the combustion gases and which generates the rotation which is transmitted to the fan or to the propeller.

[0003] Downstream of the turbine, an ejection nozzle ensures the ejection of the combustion gases.

[0004] It is also known, particularly in the case of dihydrogen, that the yield of The combustion of a fuel is improved if the fuel is heated before combustion. It is also known to use part of the hot combustion gases discharged through the exhaust nozzle to heat the fuel. Statement of the invention

[0005] An object of the present invention is to propose another solution for heating the fuel before its combustion without taking the combustion gases.

[0006] For this purpose, a propulsion unit is proposed for an aircraft comprising:

[0007] - a nacelle,

[0008] - a propulsion system arranged inside the nacelle and comprising a fairing, a rotating assembly comprising a combustion chamber and housed in the fairing, an ejection nozzle arranged downstream of the combustion chamber and delimited by a rear portion of the fairing, called the nozzle wall, and ensuring the ejection of combustion gases resulting from the combustion of the fuel in the combustion chamber, and

[0009] - a supply pipe arranged to supply the combustion chamber with fuel, where the supply pipe comprises a plurality of portions, where each portion takes the form of a profile wrapped around the nozzle wall and having an omega section, where free ends of the omega are fixed in a sealed manner to the nozzle wall and on the outside thereof, an inlet manifold fluidly connected to an inlet end of each portion and an outlet manifold fluidly connected to an outlet end of each portion.

[0010] With such an arrangement, the calories from the combustion gases are transferred to the fuel for better combustion without taking any combustion gases.

[0011] Advantageously, the inlet manifold and the outlet manifold take the form of an omega profile, where free ends of the omega are fixed in a sealed manner to the nozzle wall and to the outside thereof.

[0012] According to a particular embodiment, each collector consists of a single element and each portion is fixed to one side of the collector.

[0013] According to another particular embodiment, each collector is made up of several elements, between two elements and a portion, an intermediate element is put in place, and the intermediate element comprises a first part and a second part, where the first part ensures the junction with the portion and where the second part ensures the junction with the two elements.

[0014] Advantageously, the first part takes the form of an omega profile, where the free ends of the omega are fixed in a sealed manner to the nozzle wall and on the outside thereof, the first part has a profile identical to that of the portion, one end of the first part is fixed edge to edge with the portion, and the second part is fixed edge to edge with each element.

[0015] According to another embodiment, each collector is made up of several elements, between two elements, a portion has an extension which is inserted between the two elements, and the extension is fixed edge to edge with each element.

[0016] Advantageously, each portion and each collector are made of a metal plate and the free ends are fixed to the nozzle wall by brazing.

[0017] Advantageously, the propulsion assembly comprises fins fixed to the nozzle wall and on the outside of the latter and inside each portion.

[0018] The invention also proposes an aircraft comprising at least one propulsion unit according to one of the preceding variants. Brief description of the drawings

[0019] The above-mentioned features of the invention, as well as others, will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the attached drawings, among which:

[0020] [Fig.l] is a side view of an aircraft comprising a propulsion unit according to the invention,

[0021] [Fig.2] is a schematic representation seen from the side and in section of a propulsion unit according to the invention,

[0022] [Fig.3] is a schematic perspective representation of a nozzle of the propulsion unit according to the invention,

[0023] [Fig.4] is a sectional view through a radial plane of a detail of the propulsion assembly according to the invention,

[0024] [Fig.5] is a perspective view of a junction between a manifold and a portion of a supply pipe of the propulsion unit according to the invention,

[0025] [Fig.6] is a perspective view of the junction of [Fig.5] from another angle of view,

[0026] [Fig.7] is an exploded perspective view of an example of a particular assembly between a manifold and a portion of a supply pipe of the propulsion assembly according to the invention, and

[0027] [Fig.8] is an exploded perspective view of another example of a particular assembly between a manifold and a portion of a supply pipe of the propulsion assembly according to the invention.

[0028] DETAILED DESCRIPTION OF EMBODIMENTS

[0029] In the following description, terms relating to a position are taken with reference to an aircraft in a forward position, that is to say as shown in [Fig.l], where the arrow F shows the direction of forward movement of the aircraft.

[0030] [Fig.l] shows an aircraft 100 which has a fuselage 102 on either side of which a wing 104 is fixed. Under each wing 104 is fixed at least one propulsion unit 151.

[0031] [Fig. 2] shows the propulsion assembly 151 which comprises a nacelle 149 and a propulsion system 150 surrounded by the nacelle 149. In the embodiment of the invention presented here, each propulsion system 150 takes the form of a turboprop with a propeller 152 driven in rotation by a rotating assembly mounted inside a fairing 172 of the propulsion system 150 housed inside the nacelle 149, but each propulsion system 150 can also take the form of a turbojet driving a fan. Thus, in general, the propulsion system 150 comprises a rotating assembly and a movable element 152 (propeller or fan).

[0032] In the following description, and by convention, X is the longitudinal axis which corresponds to the axis of rotation of the mobile element 152 oriented positively in the direction of advancement of the aircraft 100, Y is the transverse axis which is horizontal when the aircraft is on the ground, and Z is the vertical axis or vertical height when the aircraft is on the ground, these three axes X, Y and Z being orthogonal to each other.

[0033] [Fig. 2] shows the propulsion system 150 in the case of a turboprop. The rotating assembly 160 constitutes a core of the propulsion system 150 and it comprises from front to rear an air inlet 162 which allows the introduction of air into a vein 164 of the core, a compressor 166 which compresses the air thus introduced, a combustion chamber 168 in which the air thus compressed and a fuel mix and burn, and a turbine 170 which allows the expansion of the combustion gases and which generates the rotation which is transmitted to the mobile element here the propeller 152. The elements of the rotating assembly 160 are surrounded by the fairing 172 formed of structural casings mounted around the elements of the rotating assembly 160 and allow it to be stiffened in order in particular to limit its distortions in operation.

[0034] The fairing 172 is, on the one hand, open at the front at the air inlet 162 and delimits the vein 164 and is, on the other hand, open at the rear at the level of an ejection nozzle 174 which is downstream of the turbine 170 and therefore of the combustion chamber 168 and ensures the ejection of the combustion gases resulting from the combustion of the fuel and the air in the combustion chamber 168. The rear part of the fairing 172 which surrounds the ejection nozzle 174 forms the nozzle wall 180.

[0035] The space between the nacelle 149 and the fairing 172 is occupied by various systems for ensuring the operation of the propulsion system 150. In particular, in order to supply the combustion chamber 168 with fuel, the propulsion assembly 151 comprises a fuel tank 178 which is here housed in the wing 104, a supply pipe 176 arranged to supply the combustion chamber 168 with fuel and which therefore connects the tank 178 and the combustion chamber 168, and a pump 179 which sets the fuel in motion from the tank 178 to the combustion chamber 168 through the supply pipe 176. The fuel may be, for example, kerosene or dihydrogen (H2).

[0036] In order to heat the fuel before its injection into the combustion chamber 168, and to obtain better combustion, the propulsion assembly 151 also comprises a heat exchanger system 200, which is arranged in the space between the nacelle 149 and the fairing 172, and which is arranged, when the propulsion system 150 is in operation, to ensure an exchange of calories between the hot combustion gases circulating in the nozzle 174 and the cooler fuel circulating in the supply pipe 176. This transfer of calories is carried out by thermal radiation through the nozzle wall 180 which is brought to a high temperature during operation of the propulsion system 150.

[0037] In the embodiment of Figs. 1 and 2, the supply pipe 176 comprises a plurality of portions 176a which form the heat exchanger system 200.

[0038] Each portion 176a takes the form of a profile wrapped around the nozzle wall 180 around the axis of the nozzle 174 and each portion 176a thus generally takes the shape of a cylinder arc. In the embodiment of the invention presented here, the angular extent of each portion 176a is slightly less than 360°, but a smaller extent is also possible depending on the need to heat the fuel.

[0039] As shown in [Fig.4], the profile forming each portion 176a has an omega-shaped section with a central part 404a forming a U and on either side of the central part 404a, legs 404b constituting free ends of the omega.

[0040] Along the length of each portion 176a, these free ends are fixed in a sealed manner to the nozzle wall 180 and to the outside thereof in order to form a cowling inside which the fuel circulates between the nozzle wall 180 and the portion 176a in order to heat up in contact with the nozzle wall 180.

[0041] Each portion 176a has an inlet end 302a through which the fuel enters the portion 176a and an outlet end 302b through which the fuel leaves the portion 176a.

[0042] The portions 176a, which are three in number here, may be more numerous and generally speaking, there are at least two. The number of portions 176a depends on the volume of each portion 176a and the volume of fuel to be heated.

[0043] The portions 176a are mounted in parallel with each other, and the supply pipe 176 also comprises an inlet manifold 176b fluidly connected to the inlet end 302a of each portion 176a and an outlet manifold 176c fluidly connected to the outlet end 302b of each portion 176a.

[0044] The inlet manifold 176b is thus between the tank 178 and the portions 176a, and the outlet manifold 176c is thus between the portions 176a and the combustion chamber 168. The arrows 304a and 304b respectively show the fuel arriving from the tank 178 and the fuel going to the combustion chamber 168.

[0045] With such an arrangement, the fuel is heated as it passes through the portions 176a before arriving at the combustion chamber 168.

[0046] Preferably, the inlet manifold 176b and the outlet manifold 176c also take the form of an omega profile like that shown in [Fig.4], where the free ends 404b of the omega are fixed in a sealed manner to the nozzle wall 180 and on the outside thereof in continuity with the portions 176a.

[0047] In the embodiment of the invention shown in Figs. 2 and 3, the profiles forming the inlet manifold 176b and the outlet manifold 176c are parallel to the nozzle axis 174.

[0048] According to a preferred embodiment, each portion 176a and each collector 176b-c are made from a stamped / folded metal plate in the form of the omega profile and even more preferably in the same material as the wall. nozzle 180 to have identical behaviors with respect to temperature and thus avoid thermal constraints between them.

[0049] As shown in [Fig. 4], the propulsion assembly 151 comprises fins 402 which are made of thermally conductive material such as metal and which are fixed to the nozzle wall 180 and on the outside thereof and inside each portion 176a. The fins 402 are thus immersed in the fuel and ensure better heat transfer between the nozzle wall 180 and the fuel.

[0050] Figs. 5 and 6 show an example of fixing a portion 176a and the inlet manifold 176b to the nozzle wall 180. In the embodiment of the invention shown in [Fig.5] and 6, each portion 176a is fixed to one side of the manifold 176b-c at a window arranged on said side. In this embodiment, the nozzle wall 180 has a simple shape and the manifold 176b-c may be made of a single element that follows the shape of the nozzle wall 180.

[0051] Figs. 7 and 8 show two examples of fixing a portion 176a and the collector 176b on the nozzle wall 180. These embodiments are more particularly implemented when the nozzle wall 180 has a complex shape and a collector 176b-c consisting of a single element is not suitable. The collector 176b-c is then made up of several smaller elements 702, 802 which adapt more easily to the shape of the nozzle wall 180.

[0052] In each of the embodiments presented, and according to a particular embodiment, each portion 176a and each collector 176b-c are made up of a metal plate fixed to the nozzle wall 180 by brazing at the free ends 404b of the omega profile.

[0053] In the embodiment shown in Figs. 5 and 6, each collector 176b-c and the associated ends 302a-b of each portion 176a are fixed together by welding. Here, the portion 176a has tabs 502a-c which are fixed around the collector 176b to form an overlap, and the fixing is carried out for example by welding, for example by TIG welding.

[0054] [Fig.7] shows the inlet manifold 176b, but the configuration is identical for the outlet manifold 176c. Thus, in general, and as specified above, the manifold 176b-c is made up of several elements 702 arranged one after the other and a portion 176a is arranged at the junction between two successive elements 702.

[0055] To ensure the junction, an intermediate element 704 is placed between the two elements 702 and the portion 176a.

[0056] The intermediate element 704 comprises a first part 704a which ensures the junction of the intermediate element 704 with the portion 176a and a second part 704b which ensures the junction of the intermediate element 704 with the two elements 702.

[0057] The first part 704a also takes the form of an omega profile, where the free ends 404b of the omega are fixed in a sealed manner to the nozzle wall 180 and on the outside thereof by brazing. The first part 704a has a profile identical to that of the portion 176a and one end of the first part 704a is fixed, for example by welding, edge to edge with the portion 176a.

[0058] Opposite the end welded to the portion 176a, the second part 704b is inserted between the ends of two elements 702 arranged on either side of said intermediate element 704. The second part 704b is fixed edge to edge, for example by welding with each element 702.

[0059] In the embodiment of the invention shown in [Fig.7], in top view, the second part 704b is triangular in shape and the elements 702 are trapezoidal in shape.

[0060] In the embodiment of the invention presented in [Fig.8] and as specified above, the collector 176b-c is made up of several elements 802 arranged one after the other and a portion 176a is arranged at the junction between two successive elements 802.

[0061] To ensure the junction, the portion 176a has an extension 804 which is inserted between the ends of two elements 802 arranged on either side of the extension 804 and ensures the junction of the portion 176a with the two elements 802.

[0062] The extension 804 is fixed edge to edge, for example by welding with each element 802.

[0063] In the embodiment of the invention shown in [Fig.8], in top view, the extension 804 is triangular in shape and the elements 802 are trapezoidal in shape.

Claims

Claims

1. Propulsion assembly (151) for an aircraft (100) comprising: - a nacelle (149), - a propulsion system (150) arranged inside the nacelle (149) and comprising a fairing (172), a rotary assembly (160) comprising a combustion chamber (168) and housed in the fairing (172), an ejection nozzle (174) arranged downstream of the combustion chamber (168) and delimited by a rear portion of the fairing (172), called the nozzle wall (180), and ensuring the ejection of combustion gases resulting from the combustion of the fuel in the combustion chamber (168), and - a supply pipe (176) arranged to supply the combustion chamber (168) with fuel, where the supply pipe (176) comprises a plurality of portions (176a), where each portion (176a) takes the form of a profile wrapped around the nozzle wall (180) and having an omega section,wherein free ends (404b) of the omega are sealingly attached to the nozzle wall (180) and on the outside thereof, an inlet manifold (176b) fluidly connected to an inlet end (302a) of each portion (176a) and an outlet manifold (176c) fluidly connected to an outlet end (302b) of each portion (176a).,

2. Propulsion assembly (151) according to claim 1, characterized in that the inlet manifold (176b) and the outlet manifold (176c) take the form of an omega profile, where free ends (404b) of the omega are fixed in a sealed manner to the nozzle wall (180) and on the outside thereof.

3. Propulsion assembly (151) according to claim 2, characterized in that each collector (176b-c) consists of a single element and each portion (176a) is fixed to one side of the collector (176a-b).

4. Propulsion assembly (151) according to claim 2, characterized in that each collector (176b-c) is made up of several elements (702), in that between two elements (702) and a portion (176a), an intermediate element (704) is placed, and in that the intermediate element (704) comprises a first part (704a) and a second part (704b), where the first part (704a) ensures the junction with the portion (176a) and where the second part (704b) ensures the junction with the two elements (702).

5. Propulsion assembly (151) according to claim 4, characterized in that the first part (704a) takes the form of an omega profile, where the free ends (404b) of the omega are fixed in a sealed manner to the nozzle wall (180) and on the outside thereof, in that the first part (704a) has a profile identical to that of the portion (176a), in that one end of the first part (704a) is fixed edge to edge with the portion (176a), and in that the second part (704b) is fixed edge to edge with each element (702).

6. Propulsion assembly (151) according to claim 2, characterized in that each collector (176b-c) is made up of several elements (802), in that between two elements (802), a portion (176a) has an extension (804) which is inserted between the two elements (802), and in that the extension (804) is fixed edge to edge with each element (802).

7. Propulsion assembly (151) according to one of claims 1 to 6, characterized in that each portion (176a) and each collector (176b-c) consist of a metal plate and in that the free ends (404b) are fixed to the nozzle wall (180) by brazing.

8. Propulsion assembly (151) according to one of claims 1 to 3, characterized in that it comprises fins (402) fixed to the nozzle wall (180) and on the outside thereof and inside each portion (176a).

9. Aircraft (100) comprising at least one propulsion unit (151) according to one of the preceding claims.

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