Combustion assembly

Abstract

The invention relates to a combustion assembly for a gas turbine, the fuel assembly comprising a flame tube (14) and a fuel supply member, the fuel supply member comprising a flow restrictor (18) supplying an injector (19), the flow restrictor (18) and the fuel injector (19) being formed integrally.

Description

Technical Field

[0001] The present disclosure relates to a combustion assembly for a turbomachine. Background Art

[0002] A turbomachine traditionally includes, from upstream to downstream in the direction of gas circulation within the turbomachine, a fan, one or more compressor stages (e.g., a low-pressure compressor and a high-pressure compressor), a combustion chamber, one or more turbine stages (e.g., a high-pressure turbine and a low-pressure turbine), and an exhaust nozzle.

[0003] The combustion chamber is defined by an inner and outer rotating shell, which are coaxial and connected upstream to the chamber bottom annular shell. The outer shell of the chamber is fastened to the outer shell of the turbine, and the inner shell of the chamber is fastened to the inner shell or connected to the outer shell.

[0004] Furthermore, the combustion chamber includes a flame tube or hearth, which is where the gases are burned.

[0005] The fuel supply of the flame tube is performed by a plurality of fuel injection devices which open into the flame tube. Each injection device comprises a fuel flow restrictor which, due to its shape, allows controlling the fuel flow supplied downstream of a fuel injector, one downstream end of which opens into the flame tube.

[0006] Traditionally, fuel flow injectors and fuel flow restrictors are manufactured independently due to their complex three-dimensional configuration. However, the manufacturing separation of the components that perform the injector supply, which in turn performs the mixing of fuel with air for spraying in the chamber, does not allow the restrictor to be optimally placed relative to the injector, so that knocks may result in fuel spraying into the flame tube. Summary of the invention

[0007] The present disclosure therefore relates to a combustion assembly for a gas turbine, comprising a flame tube and a fuel supply member comprising a flow restrictor supplying an injector, characterised in that the flow restrictor and the fuel injector are formed in one piece.

[0008] This embodiment allows to ensure an optimal placement of the fuel spray injector relative to the flow restrictor, thereby achieving an optimal combustion in the flame tube.The flow restrictor and the fuel injector are advantageously manufactured by additive manufacturing, which may be of the laser powder fusion type.

[0009] The flow restrictor may include a first fuel conduit and a second fuel conduit, each fuel conduit including a series of chambers interconnected by reduced segment sections, the first conduit and the second conduit being connected to the fuel inlet, the first conduit opening downstream to a first passage of the fuel injector and the second conduit opening downstream to a second passage of the injector.

[0010] The serial arrangement of chambers allows to obtain a better flow metering accuracy only if the individual holes are manufactured with the same production tool by statistical dispersion effects. This is especially true for injectors manufactured by additive manufacturing, whose manufacturing tolerances on the isolated throttle holes are not compatible with the manufacturing tolerances of the fuel metering. Therefore, by connecting the chambers and the reduced segment parts in series, the shape defects generated by additive manufacturing can be averaged, which allows to obtain the desired final accuracy, which is better the greater the number of chambers and reduced segment parts of the throttle holes in series.

[0011] The first duct and the second duct may extend in one plane, and more precisely in the same plane. This arrangement, called a "flat" arrangement, allows the first and second ducts to be integrated into an already existing flange for fastening the injector without increasing space requirements and weight.

[0012] The fuel injector may have a generally L-shape, a first branch of the fuel injector comprising a first passage including an upstream end connected to a first conduit of a flow restrictor and a downstream end leading to a first fuel outlet end part, and a second branch of the fuel injector comprising a second fuel outlet end part connected to a downstream end of a second passage extending in the first branch and the second branch. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Other features, details and advantages will become apparent upon reading the following detailed description and analyzing the accompanying drawings, in which:

[0014] [ Figure 1 ] is a schematic perspective view of a combustion assembly according to the present invention.

[0015] [ Figure 2 ] is a schematic perspective view of a fuel supply member according to the present invention;

[0016] [ Figure 3 ] is a Figure 2 a schematic perspective view of a cutaway portion of a

[0017] [ Figure 4 ] is a schematic cross-sectional view of a fuel injector. DETAILED DESCRIPTION

[0018] The drawings and descriptions hereinafter mainly contain elements of certain characteristics. Therefore, they can be used not only to better understand the present disclosure but also to contribute to its definition when appropriate.

[0019] Figure 1 1 shows a housing 10 and a combustion assembly 12 supported by the housing 10 according to the present disclosure. Figure 1As shown in , the combustion assembly 12 includes a flame tube 14, in which the fuel supply components open. The flame tube 14 includes an inner annular shroud (not visible) and an outer annular shroud 16. These fuel supply components include a flow restrictor 18 that supplies fuel to a fuel injector 19. More specifically, the flow restrictor 18 includes a base 20 or a radially outer plate that is fastened to the outer surface of a boss 22 of the housing 10 in order to ensure the positioning reference of the flow restrictor 18 on the housing 10. The fuel injector 19 has a generally L-shape formed by a first branch 19a and a second branch 19b connected to each other.

[0020] like Figures 2 to 4 As shown in , the injector 19, here a fuel pre-evaporation tube, thus comprises a first branch 19a, in which a first channel 24 for the flow of an air / fuel mixture is formed, which exits at the downstream end of the first channel 24 via a first end piece 26. A second channel 28 extends into the first branch 19a and into the second branch 19b and opens at its downstream end into a second end piece 30. The first channel 24 is supplied with fuel via a first channel 32 of the flow restrictor, and the second channel 28 is supplied with fuel via a second duct 34 of the flow restrictor 18.

[0021] Thus, the flow restrictor 18 comprises a first fuel conduit 32 and a second fuel conduit 34 separated from each other. The two fuel conduits 32, 34 are supplied by a common fuel source, but comprise different fuel outlets. The first conduit 32 opens at the outlet of the upstream end of the first passage 24 facing the injector 19. The second conduit 34 opens at the outlet of the upstream end of the second passage 28 facing the injector 19. The first conduit 32 and the second conduit 34 each comprise a series of chambers interconnected by reduced section portions.

[0022] like Figure 3 As shown in the example shown, the first duct 32 and the second duct 34 are in one plane and extend in the same plane in the example represented. This arrangement, called a "flat" arrangement, allows the first duct 32 and the second duct 34 to be integrated into an already existing flange for fastening the injector without increasing the space requirements and weight.

[0023] like Figure 1 and Figure 2 As shown in FIG. 1 , an air inlet 36 is provided at a junction of the fuel injector 19 and the fuel restrictor 18 . This air inlet 36 is arranged in an annular space formed between the housing 10 and the outer shroud 16 .

[0024] According to the present disclosure, the ejector 19 and the restrictor 18 are manufactured as one piece, for example, by additive manufacturing. Specifically, it is conceivable to manufacture this component by laser powder fusion.

Claims

1. A combustion assembly for a gas turbine, comprising a flame tube (14) and a fuel supply member, the fuel supply member comprising a flow restrictor (18) supplying a fuel injector (19), characterized in that The flow restrictor (18) and the fuel injector (19) are formed as one body, and wherein the flow restrictor (18) comprises a first fuel conduit (32) and a second fuel conduit (34), each fuel conduit comprising a series of chambers, each chamber having a section, the chambers being interconnected by a portion having a section that is reduced in size compared to the chamber section, the first fuel conduit (32) and the second fuel conduit (34) being connected to a fuel inlet, the first fuel conduit (32) leading downstream to a first channel (24) of the fuel injector (19) and the second fuel conduit (34) leading downstream to a second channel (28) of the fuel injector (19).

2. The assembly according to claim 1, characterized in that The fuel injector (19) has a substantially L-shape, a first branch (19a) of the fuel injector comprising the first passage (24), the first passage comprising an upstream end connected to a first fuel conduit (32) connected to the flow restrictor (18) and a downstream end leading to a first fuel outlet end part (26), and a second branch (19b) of the fuel injector comprising a second fuel outlet end part (30) connected to a downstream end of a second passage (28) extending in the first branch (19a) and the second branch (19b).

3. The assembly according to claim 1 or 2, characterized in that: At least one air inlet (36) can be formed at a junction of the fuel injector (19) and the flow restrictor (18).

4. A turbomachine comprising an assembly according to any one of claims 1 to 3.

5. Method for manufacturing an assembly according to any one of claims 1 to 3, wherein the flow restrictor (18) and the fuel injector (19) are manufactured by additive manufacturing.

6. The method according to claim 5, characterized in that Additive manufacturing is of the laser powder fusion type.

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