Patent Application
20240271787
The present disclosure relates to fuel injection and combustion systems, and more particularly to fuel injection and combustion systems for gas turbine engines.
Fuel injectors can be line replaceable. However, the typical line replaceable fuel injector requires the mechanical load to be carried by the engine case. This results in a large cantilevered mass, and therefore requires substantial strength in the flange and feedarm to be strong enough to prevent fatigue.
In addition, the fuel injector requires burner seals to allow for axial and radial movement caused by a mismatch due to differential thermal expansion between the combustor and the engine case. This can allow air to leak between injector and dome, can reduce the amount of thermal cooling on the dome, and can be a fretting point between the injector and burner seals.
The conventional techniques have been considered satisfactory for their intended purpose. However, there is an ever present need for improved systems and methods for line replaceable fuel injectors. This disclosure provides a solution for this need.
A system includes an engine case for a gas turbine engine defined around a longitudinal axis, wherein a plurality of access openings are defined through the engine case for access from outside the engine case to a space inside the engine case. A combustor is housed in the space inside the engine case. The combustor includes an inner annular wall and an outer annular wall radially outboard from the inner annular wall. The inner annular wall includes a first rail on an upstream end thereof with a radially outward opening slot. The outer annular wall includes a second rail on an upstream end thereof. The combustor includes a plurality of circumferentially spaced apart dome liners extending from the first rail to the second rail.
A plurality of fuel injector components can be assembled across the first and second rails to form a combustor dome together with the dome liners at an upstream end of a combustion space defined between the inner and outer annular walls of the combustor. Each access opening of the engine case and the fuel injector components can be configured so that the access opening is wide enough in a circumferential direction relative to the longitudinal axis to admit only one of the fuel injector components therethrough. Each access opening of the engine case can be covered by a radially outward flange of a respective one of the fuel injector components. Each of the fuel injector components can include an inner edge configured to seat in the radially outward opening slot. Each of the fuel injector components can include an outer edge configured to seat against the second rail. The radially outer edge of the combustor dome plate of each of the fuel injector components in the plurality of fuel injector components can be captured axially between the second rail on an axially downstream side and two of the dome liners on an axially upstream side.
Each fuel injector component in the plurality of fuel injector components can include a combustor dome plate extending from a radially inner edge to a radially outer edge and extending circumferentially from a first side edge to a second side edge. A fuel injector can be defined through the combustor dome plate. The fuel injector can include passages for air and fuel injection into the combustion space.
Each fuel injector component in the plurality of fuel injector components can include a fuel tube extending radially outward from the fuel injector for fluid communication of fuel from an external source into the injector. The fuel tube can pass through a radially outward flange of the fuel injector component configured to mount the fuel injector component to the engine case. The fuel tube can include a coiled section and a fuel inlet fitting for connection of the final fuel injector component to an external fuel manifold. The external fuel manifold can include a respective connection branch configured to connect to the fuel tube of each of the fuel injector components. Each fuel injector component in the plurality of fuel injector components can include a heat shield extending around the fuel tube from a radially outward flange to the fuel injector.
Each fuel injector component in the plurality of fuel injector components can further include a plurality of additional fuel injectors defined through the combustor dome plate and including passages for air and fuel injection in to the combustion space. A fuel tube can extend radially outward from the first fuel injector for fluid communication of fuel from an external source into the first injector. There can be a plurality of fuel tube branches, each of the plurality of fuel tube branches connecting from the first fuel injector to a respective one of the plurality of additional fuel injectors for fluid communication from the first fuel injector to each of the additional fuel injectors.
These and other features of the systems and methods of the subject disclosure will become more readily apparent to those skilled in the art from the following detailed description of the preferred embodiments taken in conjunction with the drawings.
So that those skilled in the art to which the subject disclosure appertains will readily understand how to make and use the devices and methods of the subject disclosure without undue experimentation, preferred embodiments thereof will be described in detail herein below with reference to certain figures, wherein:
Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, a partial view of an embodiment of a system in accordance with the disclosure is shown in
The system 100 includes an engine case 102 for a gas turbine engine defined around a longitudinal axis A, wherein a plurality of access openings 104 are defined through the engine case 102 for access from outside the engine case 102 to a space 106 inside the engine case 102. A combustor 108 is housed in the space 106 inside the engine case 102. The combustor 108 includes an inner annular wall 110 and an outer annular wall 112 radially outboard from the inner annular wall 110. The inner annular wall 110 includes a first rail 114 on an upstream end thereof with a radially outward opening slot 116. The outer annular wall 112 includes a second rail 118 on an upstream end thereof. The combustor 108 includes a plurality of circumferentially spaced apart dome liners 120 extending from the first rail 114 to the second rail 118.
A plurality of fuel injector components 122 are assembled across the first and second rails 114, 118 to form a combustor dome together with the dome liners 120 at an upstream end of a combustion space 124 defined between the inner and outer annular walls 110, 112 of the combustor 108. Each access opening 104 of the engine case 102 and the fuel injector components 122 are configured so that the access opening 104 is wide enough in a circumferential direction C relative to the longitudinal axis A to admit only one of the fuel injector components 122 therethrough. Each access opening 104 of the engine case 102 is covered by a radially outward flange 126 of a respective one of the fuel injector components 122, e.g. with flange bolts indicated by the arrows in
With reference now to
Each fuel injector component 122 includes at least one fuel tube 144 extending radially outward from the fuel injector 138 for fluid communication of fuel from an external source into the injector 138. In applications that involve staging different fuel circuits more than one fuel tube 144 can be included in parallel with each other. The fuel tube 144 passes through the radially outward flange 126 of the fuel injector component 122. The radially outward flange 126 is configured to mount the fuel injector component 122 to the engine case 102 as shown in
The configuration of
Systems and methods as disclosed herein provide potential benefits including the following. Systems and methods as disclosed herein can provide a way of supporting the fuel injector in which the injector is integrated into a dome panel, and the dome panels sit within and are supported by a combustor frame. This can distribute the stress load between the case and the combustor and can remove the need for burner seals.
The methods and systems of the present disclosure, as described above and shown in the drawings, provide for line replaceable fuel injector components for single-point or multi-point injection configurations. While the apparatus and methods of the subject disclosure have been shown and described with reference to preferred embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the scope of the subject disclosure.
