AIRCRAFT PROPULSION ASSEMBLY
The propulsion system heats fuel using combustion gas heat through a heat exchanger system with omega-shaped supply pipes, enhancing fuel combustion efficiency and propulsion performance.
Patent Information
- Application Number
- FR2023011781
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-10-30
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2043-10-30
AI Technical Summary
Existing aircraft propulsion systems inefficiently heat fuel before combustion, limiting the yield of fuel combustion, particularly with fuels like dihydrogen.
A propulsion system with a heat exchanger system using combustion gas heat to preheat fuel through a supply pipe with omega-shaped portions wrapped around the ejection nozzle, transferring heat via thermal radiation without diverting combustion gases.
Enhances fuel combustion efficiency by preheating fuel effectively, improving propulsion performance without diverting combustion gases.
Smart Images
Figure 00000010_0000 
Figure 00000010_0001 
Figure 00000011_0000
Abstract
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 having an ejection nozzle ensuring the ejection of combustion gases from the propulsion system and a heat exchange system arranged at the level of 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. PREVIOUS STATE OF THE ART
[0002] In order to move, an aircraft conventionally comprises at least one propulsion unit including a propulsion system arranged in a nacelle, which may take the form of a turbojet or a turboprop engine. In each case, the propulsion system includes a rotating assembly that drives a fan or a propeller. The rotating assembly constitutes the core of the propulsion system and comprises, from front to rear, an air intake that allows air to be introduced into a duct of the core, a compressor that compresses the air thus introduced, a combustion chamber in which the compressed air and a fuel are mixed, and a turbine that expands the combustion gases and generates the rotation that is transmitted to the fan or 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 some of the hot combustion gases expelled through the exhaust nozzle to preheat the fuel. Description of the invention
[0005] An object of the present invention is to propose another solution for heating the fuel before its combustion without collecting the combustion gases.
[0006] To this end, a propulsion system 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 within the fairing, an ejection nozzle located 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 line comprises a plurality of portions, where each portion takes the form of a profile wrapped around the nozzle wall and having an omega cross-section, where free ends of the omega are fixed hermetically 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 away any combustion gases.
[0011] Advantageously, the inlet manifold and outlet manifold take the form of an omega profile, where free ends of the omega are fixed in a hermetic 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 consists 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 consists 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 consists 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 thereof and inside each portion.
[0018] The invention also proposes an aircraft comprising at least one propulsion assembly according to one of the preceding variants. Brief description of the drawings
[0019] The features of the invention mentioned above, as well as others, will become clearer upon reading the following description of an exemplary embodiment, said description being made in relation to the accompanying drawings, among which:
[0020] [Fig. 1] is a side view of an aircraft comprising a propulsion assembly according to the invention,
[0021] [Fig.2] is a schematic side and cross-sectional representation of a propulsion assembly according to the invention,
[0022] [Fig.3] is a schematic perspective representation of a nozzle of the propulsion assembly according to the invention,
[0023] [Fig.4] is a radial plane cross-sectional view 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 assembly according to the invention,
[0025] [Fig.6] is a perspective view of the junction of [Fig.5] from another viewpoint,
[0026] [Fig.7] is an exploded perspective view of a particular assembly example 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 particular assembly example between a manifold and a portion of a supply pipe of the propulsion assembly according to the invention.
[0028] DETAILED STATEMENT OF IMPROVEMENTS
[0029] In the following description, terms relating to a position are taken with reference to an aircraft in a forward position, that is, as shown in [Fig.1], where arrow F shows the direction of forward movement of the aircraft.
[0030] Fig. 1 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 assembly 151.
[0031] Figure 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 engine 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 engine driving a fan. Thus, generally speaking, the propulsion system 150 comprises a rotating assembly and a moving element 152 (propeller or fan).
[0032] In the following description, and by convention, X is called the longitudinal axis which corresponds to the axis of rotation of the moving element 152 oriented positively in the direction of travel of the aircraft 100, Y is called the transverse axis which is horizontal when the aircraft is on the ground, and Z is called the vertical axis or vertical height when the aircraft is on the ground, these three axes X, Y and Z are orthogonal to each other.
[0033] Figure 2 shows the propulsion system 150 in the case of a turboprop engine. The rotating assembly 160 forms the core of the propulsion system 150 and comprises, from front to rear, an air inlet 162 which allows air to be introduced into a channel 164 of the core, a compressor 166 which compresses the air thus introduced, a combustion chamber 168 in which the compressed air and a fuel mix and burn, and a turbine 170 which allows the expansion of the combustion gases and generates the rotation which is transmitted to the moving element, here the propeller 152. The elements of the rotating assembly 160 are surrounded by the fairing 172 formed of structural housings mounted around the elements of the rotating assembly 160 and which make it rigid in order in particular to limit its distortions during operation.
[0034] The fairing 172 is, on the one hand, open at the front at the level of the air inlet 162 and delimits the duct 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 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 enabling the operation of the propulsion system 150. In particular, in order to supply the combustion chamber 168 with fuel, the propulsion assembly 151 includes a fuel tank 178 which is housed here in the wing 104, a supply line 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 moves the fuel from the tank 178 to the combustion chamber 168 through the supply line 176. The fuel can be, for example, kerosene or dihydrogen (H2).
[0036] In order to heat the fuel before its injection into the combustion chamber 168, and thus obtain better combustion, the propulsion assembly 151 also includes 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 heat between the hot combustion gases circulating in the nozzle 174 and the cooler fuel circulating in the supply pipe 176. This heat transfer takes place by thermal radiation through the nozzle wall 180 which is brought to a high temperature during the 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 takes on the overall shape of a cylindrical arc. In the embodiment of the invention presented here, the angular range of each portion 176a is slightly less than 360°, but a smaller range is also possible depending on the fuel heating requirements.
[0039] As shown in [Fig.4], the profile forming each portion 176a has an omega cross-section with a central part 404a forming a U and on either side of the central part 404a, tabs 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 fuel enters portion 176a and an outlet end 302b through which fuel exits portion 176a.
[0042] The three portions 176a, as shown here, may be more numerous, and generally 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 includes 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. Arrows 304a and 304b show respectively 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 by passing through 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 / bent metal plate in the form of the omega profile and, even more preferably, from the same material as the wall of 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 includes fins 402 made of a thermally conductive material such as metal, which are fixed to the nozzle wall 180 and to its exterior and to the interior of 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 attaching a portion 176a and the inlet manifold 176b to the nozzle wall 180. In the embodiment of the invention shown in [Figs. 5] and 6, each portion 176a is attached 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 can 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 manifold 176b to the nozzle wall 180. These embodiments are particularly useful when the nozzle wall 180 has a complex shape and a manifold 176b-c consisting of a single element is not suitable. The manifold 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 manifold 176b-c and the associated ends 302a-b of each portion 176a are joined together by welding. Here, the portion 176a has tabs 502a-c which are fixed around the manifold 176b to form an overlap, and the fastening is achieved, for example, by welding, for example by TIG welding.
[0054] Figure 7 shows the inlet collector 176b, but the configuration is identical for the outlet collector 176c. Thus, in general, and as specified above, the collector 176b-c consists 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 connection, 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 portion 704a also takes the form of an omega profile, where the free ends 404b of the omega are fixed tightly to the nozzle wall 180 and to its exterior by brazing. The first portion 704a has a profile identical to that of the portion 176a, and one end of the first portion 704a is fixed, for example by welding, edge to edge with the portion 176a.
[0058] Opposite the end welded to 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 consists 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 connection, 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 connection 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], top view, the extension 804 is triangular in shape and the elements 802 are trapezoidal in shape.
Claims
Demands
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 rotating assembly (160) comprising a combustion chamber (168) and housed within the fairing (172), an ejection nozzle (174) disposed downstream of the combustion chamber (168) and delimited by a rear portion of the fairing (172), referred to as the nozzle wall (180), and ensuring the ejection of combustion gases from the combustion of fuel in the combustion chamber (168), and - a supply line (176) arranged to supply the combustion chamber (168) with fuel, wherein the supply line (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 cross-section,where free ends (404b) of the omega are fixed in a hermetic fashion 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. Propulsive 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 hermetic manner to the nozzle wall (180) and on the outside thereof.
3. Propulsive assembly (151) according to claim 2, characterized in that each manifold (176b-c) is made up of a single element and each portion (176a) is fixed to one side of the manifold (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 put in place, 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. Propulsive 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. Propulsive assembly (151) according to any one of claims 1 to 6, characterized in that each portion (176a) and each collector (176b-c) are made of a metal plate and in that the free ends (404b) are fixed to the nozzle wall (180) by brazing.
8. Propulsive assembly (151) according to any 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 any one of the preceding claims.