Patent Description:
Typically, fuel nozzles are connected to an external manifold on a gas turbine engine. These connections are often made using o-rings to seal the joints and threaded or flanged connections to make the mechanical connection. In the case of hot fuels, the temperatures may be too high for polymeric seal materials used in o-rings and would melt them.

The conventional techniques have been considered satisfactory for their intended purpose. However, there is an ever present need for improved systems and methods for joining injectors, nozzles, and the like to fuel manifolds. This disclosure provides a solution for this need.

<CIT> (basis for the preamble of claim <NUM>) relates to a joint for a fuel injector spoke. <CIT> relates to support structures of injectors and atomizers for gas turbine engines. <CIT> relates to a rotor for a turbine or a compressor, in particular for a supercharging device.

A method according to the present invention is defined in claim <NUM>.

Joining the plurality of injection components can be performed one injection component at a time. Joining the plurality of injection components can be performed using only local heating to join each of the injection components in the plurality of injection components to the manifold without heating an entire assembly of the manifold and fuel injection components in an oven.

According to the present invention, fuel injection components are fuel injectors, each including a feed arm and nozzle tip extending from the feed arm, wherein the feed arm is where the fuel injector is joined to the manifold. The fuel manifold is outside of a high pressure case of a gas turbine engine. The nozzle tips are inside the high pressure case. The nozzle tips are in fluid communication with a combustion space within a combustor that is inside the high pressure case.

According to the present invention, joining includes welding or brazing. Joining can include, for each fuel injection component in the plurality of fuel injection components, locally heating a joint portion of the fuel manifold, a joint portion of the fuel injection component, and braze for forming the metallic joint between the joint portion of the fuel manifold and the joint portion of the fuel injection component. Locally heating can include using an induction heater. Using an induction heater can include seating a circumferentially segmented induction coil about one of the joint locations of the manifold and a corresponding joint location of one of the fuel injection components to locally heat the j oint locations and form a respective braze joint.

According to the present invention, the manifold is mounted to a gas turbine engine, and joining the plurality of injection components to the manifold is performed in situ on the gas turbine engine. The method can include for at least one of the injection components, cutting the injection component free from the manifold, and dressing the manifold for repair and/or replacement of the at least one injection component.

These and other features of the method of the present invention 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.

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 is shown in <FIG> and is designated generally by reference character <NUM>. Other embodiments of systems, or aspects thereof, are provided in <FIG>, as will be described. The systems and methods described herein can be used to connect fuel nozzles and injectors to manifolds without the need for o-ring seals or the like, allowing for higher fuel temperatures than in more traditional systems.

The system <NUM> includes a high pressure engine case <NUM> of a gas turbine engine including a compressor section (not pictured in <FIG>, but indicated by the flow arrow for compressed air flowing in from the compressor section), a combustor <NUM> in fluid commination to receive the compressed air from the compressor section, and a turbine section (not pictured in <FIG>, but indicated by the flow arrow for combustion products flowing from the combustor <NUM> to the turbine section). A fuel manifold <NUM> is included for supplying fuel for combustion with the compressed air in the combustor <NUM>. A plurality of fuel injection components <NUM> are connected in fluid communication with the fuel manifold <NUM> with metallic joints <NUM> sealing between each of the plurality of fuel injection components <NUM> and the fuel manifold <NUM> to prevent leakage from between the manifold <NUM> and the plurality of fuel injection components <NUM>. Those skilled in the art will readily appreciate that while only one fuel injection component <NUM> is shown in the cross-section of <FIG>, the plurality of fuel injection components <NUM> are distributed circumferentially around the annular space defined by the cross-section in <FIG>, see, e.g. <FIG> below with their circumferential distribution of fuel injection components <NUM>.

With reference now to <FIG>, the fuel manifold <NUM> defines a main fuel plenum <NUM>. Each of the plurality of fuel injection components is connected in fluid communication with the main fuel plenum <NUM> along a respective fuel path that is devoid of o-ring seals or other polymeric seals, where the flow path passes from the plenum <NUM>, through a respective manifold tube <NUM>, and into the respective fuel injection component <NUM> as indicated in <FIG> by the flow arrows. The metallic joints <NUM> are braze joints and/or weld joints joining each manifold tube <NUM> to its respective fuel injection component <NUM>.

The fuel injection components <NUM> are fuel injectors, each including a feed arm <NUM> and nozzle tip <NUM> extending from the feed arm <NUM>. The feed arm <NUM> is where the fuel injector is joined to the manifold <NUM>, i.e. an inlet end of each feed arm <NUM> is joined at the metallic joint <NUM> to a respective one of the manifold tubes <NUM>. The fuel manifold <NUM> is outside of the high pressure case <NUM>, but the nozzle tips <NUM> are inside the high pressure case <NUM>. The nozzle tips <NUM> are in fluid communication with combustion space <NUM> within the combustor <NUM>, which is inside the high pressure case <NUM>. The nozzle tips <NUM> are configured to atomize fuel from the manifold <NUM> in a flow of compressor discharge air for combustion in the combustion space <NUM>. A mounting flange <NUM> extends from the feed arm <NUM> of each fuel injector, for mounting the feed arm <NUM> to the high pressure engine case <NUM>, and the feed arm <NUM> and its internal flow passage pass through the high pressure engine case <NUM> and through the mounting flange <NUM>.

With continued reference to <FIG>, a method includes joining a fuel plurality of injection components, e.g. fuel injection components <NUM>, to a fuel manifold, e.g. fuel manifold <NUM>, wherein for each fuel injection component in the plurality of fuel injection components, a metallic joint, e.g. metallic joint <NUM>, is formed joining and sealing the fuel injection component to the manifold.

Joining the plurality of injection components is performed one injection component at a time, e.g., each feed arm <NUM> is joined to its respective manifold tube <NUM> on an individual basis for each joint <NUM>, rather than heating the entire assembly of the manifold <NUM> and fuel injectors such as in a brazing oven. Joining the plurality of injection components is performed using only local heating to join each of the injection components to the manifold without having to heat the entire assembly of the manifold and fuel injection components, e.g. in an oven.

According to one configuration defined in claim <NUM>, joining is performed by welding, e.g. welding around the joint <NUM> to seal the feed arm <NUM> to the manifold tube <NUM>. According to another configuration defined in claim <NUM>, joining includes brazing. This can include, locally heating a joint portion of the fuel manifold, e.g. an end portion of the manifold tube <NUM>, and a joint portion of the fuel injection component, e.g. the end of the feed arm <NUM> that is outside the high pressure case <NUM>, and braze, e.g. the braze ring <NUM> shown in <FIG>, for forming the metallic joint <NUM> between the joint portion of the fuel manifold and the joint portion of the fuel injection component. The braze material of the braze ring <NUM> flows into the joint location of the metallic joint <NUM> during the brazing process, and when it later cools, the braze joins the manifold <NUM> to the fuel injection component <NUM>. The local heating can be provided, for example, by using an induction heater <NUM> to locally heat the joint portions of the manifold tube <NUM> and fuel injection component <NUM>, and/or the braze ring <NUM>. The induction heater <NUM> can be circumferentially segmented, e.g. having the c-shaped cross-section shown in <FIG> to allow it to be seated around the joint locations of the manifold tubes <NUM> and feed arms <NUM> (not visible in <FIG> but see <FIG>). Using the induction heater <NUM> can include includes seating a circumferentially segmented induction coil about one of the joint locations of the manifold and a corresponding joint location of one of the fuel injection components to locally heat the joint locations and form a respective braze joint. Both components being joined can be metallic, or one can be ceramic.

According to the present invention, the manifold is mounted to a gas turbine engine, joining the plurality of injection components to the manifold is performed in situ on the gas turbine engine, e.g. by moving the induction coil <NUM> from manifold tube <NUM> to manifold tube <NUM> joining a respective fuel injector to each. If it is ever needed to remove one of the fuel injectors, e.g. for repair or replacement, the injection component can be cut free from the manifold. The cut portion of the manifold can be dressed joining a repaired fuel injector or a replacement injector using techniques as disclosed herein.

With reference now to <FIG>, not covered by the present invention, a fuel manifold <NUM> is shown having a fuel plenum <NUM> similar to manifold <NUM> above. However, in the case of manifold <NUM>, the fuel injection components <NUM> are pressure atomizing nozzles, joined to the manifold <NUM> using techniques as described above. The respective manifold tubes <NUM> extend in an axial direction A from the fuel plenum <NUM> to each respective fuel injection component <NUM>. This manifold configuration can allow for the manifold <NUM> and pressure atomizing nozzles <NUM> to be positioned inside the high pressure case <NUM> shown in <FIG>, and in fluid communication with the combustion space <NUM>, shown in <FIG>, that is inside the high pressure case <NUM>. It is also contemplated that the pressure atomizing nozzles <NUM> could instead be nozzle tips, or that the nozzle tips <NUM> of <FIG> could be replaced with pressure atomizing nozzles where the manifold <NUM> itself is outside of the high pressure case <NUM>.

Claim 1:
A method comprising:
joining a plurality of fuel injection components (<NUM>) to a fuel manifold (<NUM>), wherein
for each fuel injection component in the plurality of fuel injection components, a metallic joint (<NUM>) is formed joining and sealing the fuel injection component to the manifold by welding or brazing,
the method being characterised in that:
the fuel injection components (<NUM>) are fuel injectors, each including a feed arm (<NUM>) and nozzle tip (<NUM>) extending from the feed arm, wherein the feed arm is where the fuel injector is joined to the manifold, wherein the fuel manifold (<NUM>) is outside of a high pressure case (<NUM>) of a gas turbine engine, and wherein the nozzle tips (<NUM>) are inside the high pressure case, and wherein the nozzle tips are in fluid communication with a combustion space (<NUM>) within a combustor that is inside the high pressure case, wherein the manifold (<NUM>) is mounted to the gas turbine engine, and wherein joining the plurality of injection components (<NUM>) to the manifold is performed in situ on the gas turbine engine.