Patent ID: 12196135

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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 inFIG.1and is designated generally by reference character100. Other embodiments of systems in accordance with the disclosure, or aspects thereof, are provided inFIGS.2-7, as will be described. The systems and methods described herein can be used to facilitate manufacturing of internally manifolded multipoint fuel injection systems such as in gas turbine engines.

The multipoint fuel injection system100comprises a plurality of injection system segments102, one of which is shown inFIG.1. The injection system segment102includes a circumferentially extending outer support104defining a fuel manifold therein with a plurality of manifold passages106(labeled inFIG.4) extending circumferentially therethrough. A first connector108is included at a first circumferential end of the outer support104. A second connector110is included at a second circumferential end of the outer support104opposite the first circumferential end. The first and second connectors108,110are each configured to connect each manifold passage106(schematically shown inFIG.1, but seeFIG.4) with a manifold passages106of a respective outer support104of a circumferentially adjacent injection system segment102, as shown inFIGS.2-3.

With continued reference toFIG.1, the injection system segment102includes a circumferentially extending inner support112and a plurality of circumferentially spaced apart feed arms114extending radially between the inner support112and the outer support104. A plurality of outlet openings116extend in an axial direction A (labeled inFIG.4, but which is into and out of the view inFIG.1) from each feed arm114for feeding respective injection nozzles118(labeled inFIG.3). The feed arm114defines a plurality of fuel passages120therethrough in fluid communication with the fuel manifold passages106and outlet openings to supply fuel from the fuel manifold to the outlet openings. The flow paths through two of the manifold passages106and respective fuel passages120are schematically indicated by the flow arrows inFIG.1, but those skilled in the art will readily appreciate that there are a total of six such flow paths feeding the six respective outlets116of each feed arm114.

With reference now toFIG.2, the system100includes five injection system segments102, each as described above with reference toFIG.1. Those skilled in the art will readily appreciate that any suitable number of segments besides five can be used for a given application. The injection system segments102are connected circumferentially together with each respective first connector108connected to a respective second connector110of a circumferentially adjacent one of the injection system segments102by a respective segment connector122. One of the segment connectors124includes a system inlet126for supplying fuel to the manifolds of the injection system segments102.

With reference now toFIG.3, the system100includes a combustor dome128configured for defining a combustion space downstream thereof. The combustor dome128can separate between upstream compressor components and downstream combustor and turbine components, i.e. in a gas turbine engine. A plurality of injection nozzles118extend from the outlet openings116(labeled inFIG.1) of the feed arms114through the combustor dome128for injection of fuel from the feed arms114, and for the injection of compressed air for mixing with the fuel, into the combustor space for combustion.

With reference now toFIG.4, each segment connector122includes a plurality of connector tubes130connecting between circumferentially adjacent connectors108and110of two respective segments102. Each of the first and second connectors108and110includes a transition region134wherein each manifold passage106transitions from the vaulted cross-sectional flow area shown inFIG.5to a circular flow area140as shown inFIG.6for connection to the connector tubes130.

With reference now toFIG.7, each segment connector122includes a heat shield132shielding the connector tubes130. A single heat shield136extends from the outer support104to the inner support112and extending about the outer support104and the feed arms114to provide heat shielding to the fuel manifold passages106and the fuel passages120(labeled inFIG.1). As shown inFIG.4, the feed arms114and a portion of the heat shield136adjacent to the feed arms can follow a vaulted angle θ relative to the axial direction A, and define a vaulted peak138pointed in an axial direction A opposite that of the outlet openings116. The manifold passages106(labeled inFIG.5) have a vaulted cross-sectional flow area defined by chevron-shaped surfaces oriented to peak in the axial direction A. The fuel passages120(labeled inFIG.1) in the feed arms114can define a plurality of similarly axially vaulted chambers to those of the manifold passages106, peaking in the same direction. The vaulted angles on surfaces described here facilitate self-supporting of the heat shield136, feed arms114, fuel passages120, and manifold passages106during additive manufacture.

The injection system segments102can be additively manufactured individually in a single additive manufacturing system, or multiple additive manufacturing systems (e.g. simultaneously). The outer supports104can define an outer diameter OD (labeled inFIG.2) greater than 10 inches (25.4 cm), or even greater than 15 inches (38.1 cm), but the individual segments102are small in enough to be additively manufactured in a build area much smaller than the outer diameter OD. For example, in a typical gas turbine engine the outer diameter OD for the fuel manifold may be 20 inches (50.8 cm), or even greater than 40 inches (101.6 cm), but using systems and method as disclosed herein, the fuel injection system100can be produced on additive manufacturing platforms (e.g., powder bed fusion) with build areas of 10 by 10 inches (25.4 cm) or 15 by 15 inches (38.1 cm). Additively manufacturing in this method includes building in an axial build direction A (identified inFIG.4) beginning from downstream portions (e.g. the bottom as oriented inFIG.4) of the inner and outer supports104,112for each injection system segment102.

The method includes joining the injection system segments102together circumferentially end to end to form a complete multipoint fuel injection system100. Joining the injection system segments102together can include brazing the openings of the circular flow areas140(labeled inFIG.6) of the connectors108,110of the segments102to connector tubes130connecting circumferentially between circumferentially adjacent ones of the segments102. The method can include assembling a respective heat shield132(labeled inFIG.7) about the connector tubes130connecting between circumferentially adjacent pairs of the segments102. The inlet connector124can be brazed to the respective connectors108,110of one pair of adjacent injection system segments102, and can be shielded with a similar heat shield to that shown inFIG.7.

The methods and systems of the present disclosure, as described above and shown in the drawings, provide for multipoint fuel injection systems with superior properties including improved manufacturability. 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.