Systems and methods for providing an output product to a combustor of a gas turbine engine

Abstract

A system and method includes a reformer stack that extends around a combustion chamber. The reformer stack is configured to provide an output product to the combustion chamber.

Description

Technical Field

[0001] The present disclosure relates to systems and methods for providing output products to a combustor of a gas turbine engine, and a propulsion system includes a reformer. Background Art

[0002] A gas turbine engine generally includes a turbine and a rotor assembly. A gas turbine engine (such as a turbofan engine) can be used for aircraft propulsion. In the case of a turbofan engine, the turbine includes a compressor section, a combustion section, and a turbine section in a serial flow order, and the rotor assembly is configured as a fan assembly.

[0003] During operation, air is compressed in the compressor and mixed with fuel and ignited in the combustion section to generate combustion gases, which flow downward through the turbine section. The turbine section extracts energy from the combustion gases to rotate the compressor section and the fan assembly, thereby powering the gas turbine engine and propelling an aircraft incorporating such a gas turbine engine in flight.

[0004] The burner power is adjusted to meet the fan speed demand or thrust demand. The temperature of the burner in the combustion section can depend on the burner power and can be an operating limit of the gas turbine engine. Thus, achieving the burner power can cause the burner temperature to change in a manner that increases emissions. If the burner temperature is too low, carbon monoxide (CO) may increase. And if the burner temperature is too high, nitrogen oxides (NO x ) may increase. Accordingly, systems and methods that can achieve a desired burner power while reducing emissions would be welcome in the art. Brief Description of the Drawings

[0005] A complete and enabling disclosure of the present disclosure, including its best mode, for a person of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0006] Figure 1 is a cross-sectional view of a gas turbine engine in accordance with an exemplary aspect of the present disclosure.

[0007] Figure 2 is a perspective view of an integrated reformer and burner assembly in accordance with the present disclosure.

[0008] Figure 3 is Figure 2 a partially cut-away cross-sectional perspective view of a reformer stack of the integrated reformer and burner assembly of

[0009] Figure 4 is a schematic diagram of a gas turbine engine including an integrated reformer and burner assembly in accordance with an exemplary aspect of the present disclosure.

[0010] Figure 5 is a cross-sectional view of an integrated reformer and combustor assembly in accordance with an exemplary aspect of the present disclosure.

[0011] Figure 6 is a cross-sectional view of an integrated reformer and combustor assembly in accordance with an exemplary aspect of the present disclosure.

[0012] Figure 7 is a cross-sectional view of an integrated reformer and combustor assembly in accordance with an exemplary aspect of the present disclosure.

[0013] Figure 8 is a cross-sectional view of an integrated reformer and combustor assembly in accordance with an exemplary aspect of the present disclosure. DETAILED DESCRIPTION

[0014] Reference will now be made in detail to the present embodiments of the disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Similar or like designations in the drawings and description have been used to refer to similar or like parts of the disclosure.

[0015] As used herein, the term "exemplary" means "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior or better than other embodiments. Further, unless expressly stated otherwise, all embodiments described herein are to be considered exemplary.

[0016] For purposes of the description hereinafter, the terms "up," "down," "right," "left," "vertical," "horizontal," "top," "bottom," "lateral," "longitudinal," and derivatives thereof shall relate to the embodiment as oriented in the drawings. However, it is to be understood that the embodiments may assume various alternative variations, unless expressly specified to the contrary. It is also to be understood that the specific devices illustrated in the drawings and described in the following specification are merely exemplary embodiments of the disclosure. Accordingly, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered limiting.

[0017] As used herein, the terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and are not intended to denote the position or importance of individual components.

[0018] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle and refer to the normal operating attitude of the gas turbine engine or vehicle. For example, with respect to a gas turbine engine, front refers to a position closer to the engine inlet, and rear refers to a position closer to the engine nozzle or exhaust.

[0019] The terms "upstream" and "downstream" refer to the relative directions with respect to the flow of fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction towards which the fluid flows.

[0020] Unless otherwise specified herein, the terms "coupled", "fixed", "attached to", etc. refer to both direct coupling, fixing, or attachment and indirect coupling, fixing, or attachment through one or more intermediate components or features.

[0021] Unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" include plural references.

[0022] The term "at least one" in the context of, for example, "at least one of A, B, and C" or "at least one of A, B, or C" refers to only A, only B, only C, or any combination of A, B, and C.

[0023] As used throughout the specification and claims, approximate language is applied to modify any quantitative representation that can vary without resulting in a change in the basic function associated therewith. Thus, values modified by terms such as "about", "approximately", and "substantially" are not limited to the specified exact values. In at least some instances, the approximate language can correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or system. For example, the approximate language can refer to within a margin of 1%, 2%, 4%, 10%, 15%, or 20%. These approximate margins can be applied to a single value, either endpoint defining a numerical range, or both endpoints, and / or the margins of the range between the endpoints.

[0024] Herein and throughout the specification and claims, range limitations are combined and interchanged, and unless the context or language indicates otherwise, such ranges are recognized and include all subranges subsumed therein. For example, all ranges disclosed herein include the endpoints, and the endpoints can be combined independently of one another.

[0025] As used herein, "tertiary flow" refers to a non-primary air flow that is capable of increasing the fluid energy to produce a small amount of total propulsion system thrust. The pressure ratio of the tertiary flow can be higher than the pressure ratio of the primary propulsion flow (e.g., bypass or propeller-driven propulsion flow). The thrust can be generated through a dedicated nozzle or by mixing the air flow through the tertiary flow with the primary propulsion flow or core air flow (e.g., mixing into a common nozzle).

[0026] In some exemplary embodiments, the operating temperature of the airflow through the third stream can be lower than the maximum compressor discharge temperature of the engine, and more specifically, can be lower than 350 degrees Fahrenheit (such as lower than 300 degrees Fahrenheit, such as lower than 250 degrees Fahrenheit, such as lower than 200 degrees Fahrenheit, and at least as high as the ambient temperature). In some exemplary embodiments, these operating temperatures can facilitate heat transfer to or from the airflow through the third stream and a separate fluid stream. Additionally, in some exemplary embodiments, during takeoff conditions, or more specifically, when operating at sea level rated takeoff power, static flight speed, and an ambient temperature of 86 degrees Fahrenheit, the airflow through the third stream can contribute less than 50% of the total engine thrust (and at least, for example, 2% of the total engine thrust).

[0027] Furthermore, in some exemplary embodiments, aspects of the airflow through the third stream (such as airflow, mixing, or exhaust properties), and thus the above-exemplified percentage contribution to the total thrust, can be adjusted passively during engine operation or modified purposefully by using engine control features (such as fuel flow, motor power, variable stators, variable inlet guide vanes, valves, variable exhaust geometry, or fluid characteristics) to adjust or optimize the overall system performance under a wide range of potential operating conditions.

[0028] The term "turbine" or "turbomachinery" refers to a machine that includes one or more compressors, a heat-generating section (such as a combustion section), and one or more turbines that together generate a torque output.

[0029] The term "gas turbine engine" refers to an engine that has a turbine as all or part of its power source. Example gas turbine engines include turbofan engines, turboprop engines, turbojet engines, turboshaft engines, etc., as well as hybrid electric versions of one or more of these engines.

[0030] When used in conjunction with components such as compressors, turbines, shafts, or spools, unless otherwise specified, the terms "low" and "high", or their respective comparatives (such as more "low" and more "high", where applicable) refer to relative speeds within the engine. For example, a "low turbine" or "low-speed turbine" defines a component that is configured to operate at a rotational speed lower than that of a "high turbine" or "high-speed turbine" at the engine (such as the maximum allowable rotational speed).

[0031] The term "equivalence ratio" refers to the ratio of the actual fuel / air ratio to the stoichiometric fuel / air ratio. Stoichiometric combustion occurs when all of the oxygen is consumed in the reaction and there is no molecular oxygen (O 2 ) in the products.

[0032] If the equivalence ratio is equal to one, the combustion is stoichiometric. If it is < 1, the combustion is lean (lean fuel), with excess air, while if it is > 1, the combustion is rich (rich fuel), with incomplete combustion. The equivalence ratio is inverse to the air-fuel ratio.

[0033] The exhaust from an aircraft gas turbine engine consists of CO, carbon dioxide (CO 2 ), water vapor (H 2 O), unburned hydrocarbons (UHC), particulate matter (mainly carbon), NO x and excess atmospheric oxygen and nitrogen.

[0034] If the burner temperature is too low, carbon monoxide (CO) may increase. While if the burner temperature is too high, nitrogen oxides (NO x ) may increase.

[0035] The system and method provide the output product from the reformer to the combustion chamber of a gas turbine engine. In particular, the output product can be provided according to the desired distribution of the output product. For example, the output product can be provided at a downstream location of the combustion chamber to reduce the residence time of the output product in the combustion chamber, thereby reducing the emissions of the combustion chamber.

[0036] In addition, the systems and methods described herein can provide a desired temperature distribution and / or a distribution of the output product along the length of the combustion chamber. For example, the distribution of the output product can be determined such that the temperature along the length of the combustion chamber is within a low-emission temperature range. The output product can be provided at different locations along the length of the combustion chamber to shift the temperature into the low-emission temperature range by increasing or decreasing the temperature, thereby reducing emissions.

[0037] Now referring to the drawings, where like numerals indicate like elements throughout the drawings, Figure 1 there is provided a schematic cross-sectional view of an engine according to an exemplary embodiment of the present disclosure. The engine can be incorporated into a vehicle. For example, the engine can be an aeroengine incorporated into an aircraft. However, alternatively, the engine can be any other suitable type of engine for any other suitable vehicle.

[0038] For the depicted embodiment, the engine is configured as a high-bypass gas turbine engine 100. As Figure 1 shown, the gas turbine engine 100 defines an axial direction A (extending parallel to the reference centerline axis 101), a radial direction R, and a circumferential direction (extending around the axial direction A; not shown in Figure 1 ). Generally, the gas turbine engine 100 includes a fan section 102 and a turbine 104 disposed downstream of the fan section 102.

[0039] The exemplary turbine 104 depicted generally includes a substantially tubular housing 106 that defines an annular inlet 108. The housing 106 surrounds, in serial flow relationship: a compressor section that includes a booster or low pressure (LP) compressor 110 and a high pressure (HP) compressor 112; a combustion section 114; a turbine section that includes a high pressure (HP) turbine 116 and a low pressure (LP) turbine 118; and an exhaust nozzle section 120. The compressor section, combustion section 114, and turbine section together at least partially define a core air flow path 121 that extends from the annular inlet 108 to the exhaust nozzle section 120. The turbofan engine further includes one or more drive shafts. More specifically, the turbofan engine includes a high pressure (HP) shaft or spool 122 that drivingly connects the HP turbine 116 to the HP compressor 112, and a low pressure (LP) shaft or spool 124 that drivingly connects the LP turbine 118 to the LP compressor 110.

[0040] For the depicted embodiment, the fan section 102 includes a fan 126 having a plurality of fan blades 128 that are coupled to a disk 130 in a spaced-apart manner. The fan blades 128 and the disk 130 are capable of rotating together about the centerline axis 101 via the LP shaft 124. The disk 130 is covered by a rotatable front hub 132 that is aerodynamically shaped to facilitate air flow through the plurality of fan blades 128. Additionally, an annular fan case or nacelle 134 is provided to circumferentially surround the fan 126 and / or at least a portion of the turbine 104. The nacelle 134 is supported relative to the turbine 104 by a plurality of circumferentially spaced outlet guide vanes 136. A downstream section 138 of the nacelle 134 extends over an outer portion of the turbine 104 to define a bypass air flow passage 140 therebetween.

[0041] In this manner, it will be appreciated that the gas turbine engine 100 generally includes a first flow (e.g., the core air flow path 121) and a second flow (e.g., the bypass air flow passage 140) that extends parallel to the first flow. In certain exemplary embodiments, the gas turbine engine 100 may further define a third flow, e.g., that extends from the LP compressor 110 to the bypass air flow passage 140 or to the environment. With this configuration, the LP compressor 110 may generally include a first compressor stage and a downstream compressor stage that are configured as a ducted intermediate fan. The inlet of the third flow may be positioned between the first compressor stage and the downstream compressor stage.

[0042] Still referring to Figure 1 , the gas turbine engine 100 further includes an accessory gearbox 142 and a fuel delivery system 146. For the illustrated embodiment, the accessory gearbox 142 is located within the shroud / housing 106 of the turbine 104. Additionally, it will be understood that for Figure 1In the embodiment schematically depicted, the accessory gearbox 142 is mechanically coupled to one or more shafts or spools of the turbine 104 and is capable of rotating with one or more shafts or spools of the turbine 104. For example, in the depicted exemplary embodiment, the accessory gearbox 142 is mechanically coupled to the HP shaft 122 via a suitable gear train 144 and is capable of rotating with the HP shaft 122. The accessory gearbox 142 can power one or more suitable accessory systems of the gas turbine engine 100 during at least some operations and can further supply power back to the gas turbine engine 100 during other operations. For example, for the illustrated embodiment, the accessory gearbox 142 is coupled to the starter motor / generator 152. The starter motor / generator can be configured to extract power from the accessory gearbox 142 and the gas turbine engine 100 to generate electricity during certain operations and can supply power back to the accessory gearbox 142 and the gas turbine engine 100 (e.g., to the HP shaft 122) during other operations to add mechanical work back to the gas turbine engine 10 (e.g., for starting the gas turbine engine 100).

[0043] In addition, the fuel delivery system 146 generally includes a fuel source 148 (such as a fuel tank) and one or more fuel delivery lines 150. The one or more fuel delivery lines 150 supply a fuel flow to the combustion section 114 of the turbine 104 of the gas turbine engine 100 via the fuel delivery system 146. As will be discussed in more detail below, the combustion section 114 includes an integrated reformer and burner assembly 200. For the described embodiment, the one or more fuel delivery lines 150 supply a fuel flow to the integrated reformer and burner assembly 200.

[0044] However, it will be understood that Figure 1 the exemplary gas turbine engine 100 depicted is provided only as an example. In other exemplary embodiments, any other suitable gas turbine engine can be used with aspects of the present disclosure. For example, in other embodiments, the turbofan engine can be any other suitable gas turbine engine, such as a turboshaft engine, a turboprop engine, a turbojet engine, etc.

[0045] In this way, it will be further understood that in other embodiments, the gas turbine engine can have any other suitable configuration, such as any other suitable number or arrangement of shafts, compressors, turbines, fans, etc. In addition, although Figure 1The exemplary gas turbine engine depicted is schematically shown as a direct drive fixed pitch turbofan engine, but in other embodiments, the gas turbine engines of the present disclosure can be geared gas turbine engines (i.e., including a gearbox between the fan 126 and the shaft driving the fan (such as the LP shaft 124)), can be variable pitch gas turbine engines (i.e., including a fan 126 having a plurality of fan blades 128 that are capable of rotating about their respective pitch axes), etc.

[0046] In addition, although the exemplary gas turbine engine 100 includes a ducted fan 126, in other exemplary aspects, the gas turbine engine 100 can include a non-ducted fan 126 (or an open rotor fan) without a nacelle 134. Further, although not depicted herein, in other embodiments, the gas turbine engine can be any other suitable type of gas turbine engine, such as a marine gas turbine engine.

[0047] Now referring to Figure 2 , a portion of the combustion section 114 according to an embodiment of the present disclosure is schematically shown, which includes Figure 1 of the gas turbine engine 100 (described above with respect to Figure 1 as the gas turbine engine 100) and is a part of the integrated reformer and burner assembly 200 used therein.

[0048] It will be understood that the combustion section 114 includes a compressor diffuser nozzle 202 and generally extends between an upstream end and a downstream end in the axial direction A. The combustion section 114 is fluidly coupled to the compressor section at the upstream end via the compressor diffuser nozzle 202 and is fluidly coupled to the turbine section at the downstream end.

[0049] The integrated reformer and burner assembly 200 generally includes a reformer assembly 204 ( Figure 2 only partially depicted therein; also see Figures 3 to 4 ) and a burner 206. The burner 206 includes a liner 208, an outer liner 210, a dome assembly 212, a shroud assembly 214, a swirler assembly 216, and a fuel flow line 218. The combustion section 114 generally includes a housing 220 that surrounds the burner 206 radially outward of the burner 206 and an inner housing 222 radially inward of the burner 206.

[0050] The inner housing 222 and the liner 208 define an inner passage 224 therebetween, while the housing 220 and the outer liner 210 define an outer passage 226 therebetween. The inner housing 222, the housing 220, and the dome assembly 212 together at least partially define a combustion chamber 228 of the burner 206.

[0051] The dome assembly 212 is disposed proximate to the upstream end of the combustion section 114 (i.e., closer to the upstream end as compared to the downstream end) and includes an opening 229 for receiving and holding the swirler assembly 216. The swirler assembly 216 also includes an opening for receiving and holding the fuel flow line 218.

[0052] The fuel flow line 218 is further coupled to a fuel source 148 disposed radially outward of the outer shell 220 along the radial direction R (see Figure 1 ), and is configured to receive fuel from the fuel source 148. In this manner, the fuel flow line 218 can be fluidly coupled to one or more of the fuel delivery lines 150 described above with reference to Figure 1 .

[0053] The swirler assembly 216 may include a plurality of swirlers (not shown) configured to swirl the compressed fluid before injecting the compressed fluid into the combustion chamber 228 to generate combustion gases. In the illustrated embodiment, the shroud assembly 214 is configured to hold the liner 208, the outer liner 210, the swirler assembly 216, and the dome assembly 212 together.

[0054] During operation, the compressor diffuser nozzle 202 is configured to direct the compressed fluid 230 from the compressor section to the burner 206, where the compressed fluid 230 is configured to mix with fuel within the swirler assembly 216 and combust within the combustion chamber 228 to generate combustion gases. The combustion gases are provided to the turbine section to drive one or more turbines (e.g., the high-pressure turbine 116 and the low-pressure turbine 118) of the turbine section.

[0055] During operation of the gas turbine engine 100 including the integrated reformer and burner assembly 200, the flame within the combustion chamber 228 is maintained by a continuous flow of fuel and air. To provide ignition of the fuel and air, for example, during startup of the gas turbine engine 100, the integrated reformer and burner assembly 200 further includes an igniter 231.

[0056] The igniter 231 can provide a spark or an initial flame to ignite the fuel and air mixture within the combustion chamber 228. In certain exemplary embodiments, the integrated reformer and burner assembly 200 may additionally include a dedicated reformer igniter 233 (depicted in dashed lines). For Figure 2 embodiments, the dedicated reformer igniter 233 is positioned downstream of at least a portion of the reformer and downstream of at least a portion of the reformer stack (described below). In this manner, the dedicated reformer igniter 233 can more effectively combust the output of the reformer.

[0057] As described above and Figure 2Schematically depicted in, the integrated reformer and combustor assembly 200 further includes a reformer assembly 204. The reformer stacks 232, 234 of the reformer assembly 204 may extend around the perimeter of the combustor chamber 228.

[0058] For example, the combustor 206 is an annular combustor, and the reformer stack 232 of the reformer assembly 204 extends around (or is integrated with) the outer liner 210 of the combustor 206 that defines the combustor chamber 228. This configuration will be discussed further and shown in more detail with reference to Figure 3 Further discussion and more detailed display.

[0059] Additionally or alternatively, the reformer stack 234 of the reformer assembly 204 extends around (or is integrated with) the inner liner 208 of the combustor that defines the combustor chamber 228.

[0060] In Figure 2 the embodiment of, the reformer stacks 232, 234 may be part of the same reformer assembly 204 (e.g., sharing common structures and components that facilitate the operation of the reformer assembly 204).

[0061] However, alternatively, in other exemplary embodiments, the first reformer stack 232 may be part of a first reformer assembly, and the second reformer stack 234 may be part of a second reformer assembly (e.g., each having separate components that facilitate operation).

[0062] The operation of the reformer assembly 204 will be described in more detail below, and more specifically, the operation of the reformer stacks 232, 234 of the reformer assembly 204. In other exemplary embodiments, the reformer assembly 204 may include any other suitable number and arrangement of reformer stacks 232, 234 to distribute the output products at various locations along the axial and circumferential directions of the combustor chamber 228 with different parameters (e.g., temperature, pressure, composition, etc.).

[0063] The integrated reformer and combustor assembly 200 further includes a controller 240 that is operably communicable with the reformer assembly 204 to, for example, send and receive communications and signals therebetween. For example, the controller 240 may send a conversion rate setpoint signal to the reformer assembly 204 and may receive, for example, a voltage or current feedback signal from the reformer assembly 204. The controller 240 may be configured in the same manner as the controller 240 described below with reference to Figure 4 described.

[0064] In certain embodiments described in further detail below, a plurality of reformer assemblies 204 are distributed along the axial direction A of the combustor 206. The fuel to the plurality of reformer assemblies 204 (e.g., from fuel source 148 or through elements of the reformer and combustor assembly 200 described herein) can be varied to distribute the output product or fuel along the axial direction A of the combustor 206.

[0065] For example, a "late lean" method uses more fuel burned at the downstream end of the combustor 206. The "late lean" method can be implemented to reduce the residence time of the fuel in the combustor 206.

[0066] As will be discussed in further detail below, the reformer stack is a fuel processing unit and can be any suitable configuration for generating a hydrogen-rich fuel stream. For example, the reformer stack 232 can include a fuel reformer or a catalytic partial oxidation converter (CPO x ) for generating a hydrogen-rich fuel stream for the combustion chamber 228.

[0067] However, it should be understood that the reformer stack 232 can additionally or alternatively include any suitable type of fuel reformer, such as an autothermal reformer and a steam reformer, which may require an additional steam inlet stream having a higher hydrogen component at the reformer outlet stream.

[0068] In steam reforming, only hydrocarbon fuel (e.g., natural gas) and water (steam) are introduced into the reformer reactor. The reaction is endothermic, so heat is continuously added to the reactor. The heat is generated outside (i.e., ectopic) the tubes holding the fuel and steam mixture. The steam reforming reaction is assisted by using a catalyst contained within the tubes.

[0069] For autothermal reforming and partial oxidation, steam and / or air are introduced into the reactor along with the fuel. Unlike steam reforming, these reactions (in the correct proportions) will be exothermic. Most of the heat required to carry out the primary reforming reaction is generated in situ (i.e., within the reactor, as a result of the chemical reactions involving the fuel and air). The ability of autothermal and partial oxidation reformers to generate heat in situ gives them potential advantages in terms of dynamic response - namely, they have fewer heat transfer limitations. The requirement to rapidly change the hydrogen production rate of the reformer system can be important in transportation, portable, and load-tracking stationary applications.

[0070] It will be understood that in at least some exemplary embodiments, the reformer stacks 232, 234 can extend substantially 360 degrees in the circumferential direction C of the gas turbine engine (i.e., the direction extending around the centerline axis 101 of the gas turbine engine 100). For example, now referring to Figure 3, depicts a cross-sectional cutaway perspective view of a reformer stack 232 according to an exemplary embodiment of the present disclosure. Additional reformer stacks described in more detail below may be constructed in a similar manner.

[0071] As shown, the reformer stack 232 extends circumferentially around the outer liner 210 of the combustion chamber 228 in the circumferential direction C and, in the illustrated embodiment, completely surrounds the outer liner 210 of the combustion chamber 288 around the centerline axis 101. More specifically, the reformer stack 232 (multiple reformers are referred to herein as a reformer stack) is arranged in the circumferential direction C.

[0072] In Figure 3 the visible reformer stack 232 may be a single ring or cylinder. As described in further detail below, the reformer stack 232 may have a thickness relative to the axial direction A (see Figure 2 ). In another example, multiple additional rings of reformers may be placed on top of or outside of each other (e.g., radially stacked or concentrically arranged) to form a reformer stack 232 having an elongate length in the radial direction R.

[0073] As will be explained in more detail below, with reference to Figure 4 , the reformer stack 232 is positioned to receive an oxidant 244 (e.g., for a CPO x reformer, air from the compressor section) and fuel 246 from the fuel delivery system 146. The reformer stack 232 may use air and / or steam as the oxidant 244 for the reformer. For example, if the reformer stack 232 is a CPO x reformer, the oxidant 244 will be air, while if the reformer stack 232 is an autothermal reformer (ATR), the oxidant 244 will be steam.

[0074] The reformer stack 232 may include a trench 247 around the outer side of the reformer stack 232. The trench 247 receives the oxidant 244 and fuel 246 and guides and distributes the oxidant 244 and fuel 246 around the outer surface of the reformer stack 232 and into the reformer stack 232.

[0075] The reformer stack 232 uses a mixture of the oxidant 244 and fuel 246 to produce a reformate or output product 248. With the help of a catalyst in the reformer stack 232, the fuel 246 is partially oxidized by the oxidant 244 in the reformer stack 232 to produce a hydrogen-rich syngas (e.g., the output product 248). The reformer stack 232 radially guides the output product 248 into the combustion chamber 228. The burner 206 burns the output product 248 in the combustion chamber 228 into combustion gases, which are directed downstream into the turbine section to drive or assist in driving one or more turbines therein.

[0076] The aviation fuel can be a hydrocarbon (e.g., a composition of carbon and hydrogen atoms, called C x H y ). In the reformer stack 232 (e.g., a CPO x reformer), using air or oxygen in the air, the fuel is oxidized in a controlled manner (e.g., flameless) on the surface of the catalyst bed. With the help of the catalyst, the fuel (C x H y ) is catalytically oxidized by air, where the carbon (C) atoms in the fuel (C x H y ) are stripped and combined with the oxygen (O) atoms in the air, producing H 2 rich gas. The catalyst enables this reaction to occur at a much lower temperature than, for example, in a furnace / burner.

[0077] The depicted reformer stack 232 can include a housing 250 having a combustion outlet side 252 and a fuel and air inlet side 254 opposite the combustion outlet side 522, as well as sides 256, 258. Side 258 is not visible in the Figure 3 perspective view.

[0078] It will be understood that, alternatively, the reformer stack 232 can include, for example, a plurality of reformer stacks "stacked" side by side and / or concentrically.

[0079] The combustion outlet side 252 includes a plurality of combustion outlets 264, and the fuel and air inlet side 254 includes a plurality of inlets 266. In the case where the reformer stack 232 is integrated with the outer liner 210 of the combustion chamber 228, the combustion outlet side 252 can be the outer liner 210 of the combustion chamber 228. Alternatively, the outer liner 210 of the combustion chamber can have an opening 271, and the output product 248 led out of the combustion outlet 264 is guided to move through the opening 271 and into the combustion chamber 228.

[0080] The trench 247 includes one or more fuel inlets 268 and one or more oxidant inlets 270. Optionally, one or more of the inlets 268, 270 can be on the other side of the housing 250. Each fuel inlet among the one or more fuel inlets 268 is in fluid communication with a fuel source of the reformer stack 232 (such as one or more pressurized containers of hydrogen-containing gas further described below). Each oxidant inlet among the one or more oxidant inlets 270 is in fluid communication with an oxidant 244 source of the reformer (such as air discharged from a compressor section and / or an air treatment unit further described below). The inlets 268, 270 separately receive fuel and oxidant from external fuel and oxidant sources and separately guide the fuel and oxidant into the reformer stack 232.

[0081] For the steam reformer stack 232, inlets 268, 270 receive fuel and steam from external sources of fuel and steam, respectively, and direct the fuel and steam into the steam reformer stack 232. For the autothermal reformer stack 232, inlets 268, 270 (which may include another inlet, for example) receive fuel, air, and steam from external sources of fuel, air, and steam, respectively, and direct the fuel, air, and steam into the autothermal reformer stack 232.

[0082] During operation, the trench 247 receives the oxidizer 244 and the fuel 246, and directs and distributes the oxidizer 244 and the fuel 246 around the inlet side 254 of the reformer stack 232 and directs and distributes them into the reformer stack 232 through the inlet 266. The reformer stack 232 generates an output product 248 (also referred to herein as "combustion gas").

[0083] The reformer stack 232 facilitates the chemical reaction between the received fuel and the received air. As a result of the chemical reaction, the reformer stack 232 produces hydrogen and by-products, such as carbon dioxide and water. The hydrogen generated by the fuel reformer stack 232 is supplied to the combustion chamber 228.

[0084] The output product 248 is directed out of the combustion outlet side 252 of the housing 250 through the opening 271 in the outer liner 210 of the combustion chamber 228, for example, from the combustion outlet 264. The output product 248 is supplied to the combustion chamber 228 and combusts during operation to generate combustion gas, which is used to generate thrust for the gas turbine engine 100 (and the carrier / aircraft incorporating the gas turbine engine 100).

[0085] In some exemplary embodiments, the reformer stack 232 may be constructed in a manner similar to one or more of the exemplary reformer systems described in U.S. Patent Application Publication No. 2018 / 0145351A1, filed on October 26, 2017, the entire content of which is incorporated herein by reference.

[0086] Now referring Figure 4 , the operation of the integrated reformer and burner assembly 200 according to an exemplary embodiment of the present disclosure will be described. More specifically, Figure 4 A schematic diagram of a gas turbine engine 100 and an integrated reformer and burner assembly 200 according to an embodiment of the present disclosure is provided. In some exemplary embodiments, the gas turbine engine 100 and the integrated reformer and burner assembly 200 may be constructed in a manner similar to one or more of the Figures 1 to 4 exemplary embodiments.

[0087] Accordingly, it will be understood that the gas turbine engine 100 generally includes a fan section 102 having a fan 126, an LP compressor 110, an HP compressor 112, a combustion section 114, an HP turbine 116, and an LP turbine 118. The combustion section 114 generally includes an integrated reformer and burner assembly 200 having a burner 206 and a reformer assembly 204.

[0088] The propulsion system including the gas turbine engine 100 further includes a fuel delivery system 146. The fuel delivery system 146 generally includes a fuel source 148 and one or more fuel delivery lines 150. The fuel source 148 may include a supply of fuel for the gas turbine engine 100 (e.g., a hydrocarbon fuel, including, for example, a carbon-neutral fuel or a synthetic hydrocarbon). Additionally, it will be understood that the fuel delivery system 146 also includes a fuel pump 272 and a diverter 274, and the one or more fuel delivery lines 150 include a first fuel delivery line 150A and a second fuel delivery line 150B.

[0089] The diverter 274 divides the fuel flow from the fuel source 148 and the fuel pump 272 into a first fuel flow through the first fuel delivery line 150A to the reformer stack 232 and a second fuel flow through the second fuel delivery line 150B to the burner 206.

[0090] The diverter 274 may include a series of valves (not shown) to facilitate such diversion of the fuel flow from the fuel source 148, or alternatively, may have a fixed geometry. Additionally, for the illustrated embodiment, the fuel delivery system 146 includes a first fuel valve 151A associated with the first fuel delivery line 150A (e.g., for controlling the first fuel flow) and a second fuel valve 151B associated with the second fuel delivery line 150B (e.g., for controlling the second fuel flow).

[0091] The gas turbine engine 100 further includes an air flow delivery system 153 (e.g., a compressor discharge system and an air flow delivery system). More specifically, the compressor discharge system of the air flow delivery system 153 includes an LP bleed duct 276 and an associated LP bleed valve 278, an HP bleed duct 280 and an associated HP bleed valve 282, an HP outlet air duct 284 and an associated HP outlet air valve 286.

[0092] The air flow delivery system 153 of the gas turbine engine 100 further includes an air flow supply duct 288 (in air flow communication with an air flow supply 290) and an associated air valve 292 for providing a compressed air flow to the reformer assembly 204 of the integrated reformer and burner assembly 200.

[0093] The air flow supply unit can be, for example, a second gas turbine engine configured to provide cross bleed air, an auxiliary power unit (APU) configured to provide bleed air, a ram air turbine (RAT), etc. If the compressor air source is insufficient or unavailable, the air flow supply unit can be a supplement to the compressor discharge system.

[0094] The compressor discharge system (and the air flow supply duct 288) supplies a compressed air flow to the reformer assembly 204, as will be explained in more detail below.

[0095] The reformer stack 232 is disposed downstream of the LP compressor 110, the HP compressor 112, or both. Additionally, from the above description of Figure 2 it will be understood that the reformer stack 232 can be coupled to or otherwise integrated with the outer liner 210 of the burner 206. Similarly, the reformer stack 234 can be coupled to or otherwise integrated with the inner liner 208 of the burner 206. In this way, the reformer stack 232 can also be arranged upstream of the combustion chamber 228 of the integrated reformer and burner assembly 200, and further upstream of the HP turbine 116 and the LP turbine 118.

[0096] The reformer stack 232 is a fuel processing unit, which can be any suitable structure for generating a hydrogen-rich fuel stream. For example, the reformer stack 232 can include a fuel reformer or a catalytic partial oxidation converter (CPO x ) for generating a hydrogen-rich fuel stream for the combustion chamber 228.

[0097] However, it should be understood that the reformer stack 232 can additionally or alternatively include any suitable type of fuel reformer, such as an autothermal reformer and a steam reformer, which may require an additional steam inlet stream with a higher hydrogen content at the reformer outlet stream.

[0098] As described above, the air flow delivery system 153 (e.g., the compressor discharge system and the air flow supply duct 288) supplies a compressed air flow to the reformer stack 232. The air flow delivery system 153 includes an air flow duct 310 for supplying an air flow to the fuel reformer stack 232 and an associated air flow valve 312, and a bypass air duct 318 for directly supplying an air flow to the combustion chamber 228 and an associated bypass air valve 320.

[0099] The fuel delivery system 146 is configured to supply a first fuel stream to the reformer stack 232 through the first fuel delivery line 150A. As Figure 4 shown in the embodiment of, the first fuel stream through the first fuel delivery line 150A is directed to the reformer stack 232 for generating a hydrogen-rich fuel stream (e.g., optimizing the hydrogen content of the fuel stream). The reformer stack 232 outputs the output product 248 into the combustion chamber 228 of the burner 206.

[0100] In addition, as Figure 4 further schematically depicted in [[ID=]], the propulsion system, the aircraft including the propulsion system, or both include a controller 240. For example, the controller 240 can be a stand-alone controller, a gas turbine engine controller (e.g., a full-authority digital engine controller or a FADEC controller), an aircraft controller, a supervisory controller of the propulsion system, and combinations thereof, etc.

[0101] The controller 240 is operatively connected to various sensors, valves, etc. within at least one of the gas turbine engine 100, the fuel delivery system 146, and the reformer and combustor assembly 200. More specifically, for the depicted exemplary aspect, the controller 240 is operatively connected to the reformer stack 232, valves (e.g., the air and fuel valves to the fuel reformer stack 232 and the combustor 206 discussed above), valves of the axially distributed fuel reformer stack (discussed below), valves of the compressor discharge system (valves 278, 282, 286), valves of the air flow delivery system (valves 312, 320), and valves of the fuel delivery system 146 (the diverter 274, valves 151A, 151B).

[0102] It will be understood from the following description that the controller 240 can communicate with these components either wired or wirelessly. In this way, the controller 240 can receive data from various inputs (including the supervisory controller), can make control decisions, and can provide data (e.g., instructions) to various outputs (including valves of the compressor discharge system that control the air flow discharge from the compressor section, valves of the air flow delivery system that direct the air flow discharged from the compressor section, valves of the fuel delivery system 146 that direct the fuel flow within the gas turbine engine 100, and the reformer stack 232 that controls the conversion rate).

[0103] With particular reference to the operation of the controller 240, in at least some embodiments, the controller 240 can include one or more computing devices 332. The computing device 332 can include one or more processors 332A and one or more memory devices 332B. The one or more processors 332A can include any suitable processing device, such as a microprocessor, a microcontroller, an integrated circuit, a logic device, and / or other suitable processing devices. The one or more memory devices 332B can include one or more computer-readable media, including but not limited to non-transitory computer-readable media, RAM, ROM, hard disk drives, flash drives, and / or other memory devices.

[0104] One or more memory devices 332B may store information accessible by one or more processors 332A, including computer-readable instructions 332C executable by one or more processors 332A. The instructions 332C may be any set of instructions that, when executed by one or more processors 332A, cause the one or more processors 332A to perform operations. In some embodiments, the instructions 332C may be executed by one or more processors 332A to cause the one or more processors 332A to perform operations such as any operations and functions for which the controller 240 and / or the computing device 332 is configured, operations for operating a propulsion system as described herein, and / or any other operations or functions of one or more computing devices 332. The instructions 332C may be software written in any suitable programming language or may be implemented in hardware.

[0105] Additionally or alternatively, the instructions 332C may be executed in logically and / or virtually separated threads on the processor 332A. The memory device 332B may further store data 332D accessible by the processor 332A. For example, the data 332D may include data indicative of power flow, data indicative of gas turbine engine 100 / aircraft operating conditions, and / or any other data and / or information described herein.

[0106] The computing device 332 further includes a network interface 332E configured to communicate, for example, with other components of the gas turbine engine 100 such as valves of a compressor discharge system (valves 278, 282, 286), valves of an air flow delivery system (valves 312, 320), and valves of a fuel delivery system 146 (diverter 274, valves 151A, 151B), as well as the fuel reformer stack 232, and with the aircraft of the gas turbine engine 100.

[0107] The network interface 332E may include any suitable components for interfacing with one or more networks, including, for example, transmitters, receivers, ports, controllers, antennas, and / or other suitable components. In this manner, it will be appreciated that the network interface 332E may utilize any suitable combination of wired and wireless communication networks.

[0108] The techniques discussed herein refer to computer-based systems, actions taken by computer-based systems, and information sent to and from computer-based systems. It will be appreciated that the inherent flexibility of computer-based systems permits a wide variety of possible configurations, combinations, and divisions of tasks and functionality between and among components. For example, the processing discussed herein may be implemented using a single computing device or multiple computing devices working in combination. Databases, memories, instructions, and applications may be implemented on a single system or distributed across multiple systems. Distributed components may operate sequentially or in parallel.

[0109] Reference Figure 5 and 6 ,an integrated reformer and combustor assembly 200 in accordance with an exemplary embodiment of the present disclosure will be described.

[0110] Specifically referring first to Figure 5 ,a plurality of reformer stacks 232 extend around or are integrated into a liner 210 that defines a combustion chamber 228. The plurality of reformer stacks 232 are distributed along an axial direction A and independently receive an oxidant 244 (e.g., air from an air delivery system 153) and fuel 246 from a fuel delivery system 146.

[0111] In Figure 5 ,a first reformer stack 232A among the plurality of reformer stacks 232 is connected to the air delivery system 153 through a first air line including a valve and is connected to the fuel delivery system 146 through a first fuel line including a valve; a second reformer stack 232B among the plurality of reformer stacks 232 is connected to the air delivery system 153 through a second air line including a valve and is connected to the fuel delivery system 146 through a second fuel line including a valve; a third reformer stack 232C among the plurality of reformer stacks 232 is connected to the air delivery system 153 through a third air line including a valve and is connected to the fuel delivery system 146 through a third fuel line including a valve; a fourth reformer stack 232D among the plurality of reformer stacks 232 is connected to the air delivery system 153 through a fourth air line including a valve and is connected to the fuel delivery system 146 through a fourth fuel line including a valve; and a fifth reformer stack 232E among the plurality of reformer stacks 232 is connected to the air delivery system 153 through a fifth air line including a valve and is connected to the fuel delivery system 146 through a fifth fuel line including a valve. In this embodiment, for clarity, the respective air lines, fuel lines, and valves are not labeled.

[0112] Because the fuel and air flows (e.g., flow rates) to reformer stacks 232A, 232B, 232C, 232D, 232E are independently controllable (e.g., by a controller 240 not shown, which can be operably coupled to respective valves), and the conversion rates of reformer stacks 232A, 232B, 232C, 232D, 232E are independently controllable (e.g., by controller 240), the output products 248 from reformer stacks 232A, 232B, 232C, 232D, 232E along the axial length of burner 206 are configured to be controlled to achieve an axial temperature profile to reduce emissions by, for example, a "late lean" method or the like. For example, reformer stacks 232A, 232B, 232C, 232D, 232E can be independently controllable to control the volume and composition (e.g., %H 2 ) of output product 248 along the axial length of burner 206 within the combustion chamber to affect the axial temperature profile therein and thereby reduce emissions by a "late lean" combustion method.

[0113] It will be understood that in the depicted embodiment, each of reformer stacks 232A, 232B, 232C, 232D, 232E is configured to receive an air flow from the same air flow delivery system 153 and a fuel flow through the same fuel delivery system 146. However, in an alternative exemplary embodiment, the depicted reformer system can include more than one air flow delivery system 153, more than one fuel delivery system 146, or both. In such an exemplary embodiment, the reformer system can be configured to provide an air flow to one of reformer stacks 232A, 232B, 232C, 232D, 232E at a temperature, pressure, flow rate, or combination thereof that is higher or lower than that of the other reformer stacks 232A, 232B, 232C, 232D, 232E; and can be configured to provide a fuel flow to one of reformer stacks 232A, 232B, 232C, 232D, 232E at a temperature, pressure, flow rate, or combination thereof that is higher or lower than that of the other reformer stacks 232A, 232B, 232C, 232D, 232E. This can facilitate a greater degree of control over the axial temperature profile through combustion chamber 228.

[0114] Although gaps are provided between reformer stacks 232A, 232B, 232C, 232D, 232E for purposes of illustration, reformer stacks 232A, 232B, 232C, 232D, 232E can completely cover liners 208, 210 of combustion chamber 228 along the length of burner 206 in the axial direction A.

[0115] In alternative embodiments described in more detail below, different reformer stacks 232 may extend along different lengths in the axial direction A. In some embodiments, the reformer stacks 232 cover portions of the liners 208, 210 of the combustion chamber 228 along the length of the burner 206 in the axial direction A.

[0116] In alternative embodiments described in more detail below, different reformer stacks 232 may have different sizes (represented by the height in the radial direction R). Here, the size of the reformer stacks 232 generally corresponds to a greater conversion rate (e.g., producing more hydrogen-rich fuel moving through the reformer stacks 232).

[0117] Still referring to Figure 5 , the depicted exemplary reformer system further includes a plurality of reformer stacks 234A, 234B, 234C, 234D, 234E.

[0118] However, here, the plurality of reformer stacks 234A, 234B, 234C, 234D, 234E extend around or are integrated into the inner liner 208 of the burner 206. The plurality of reformer stacks 234A, 234B, 234C, 234D, 234E are distributed along the axial direction A and are connected one after another in a cascaded arrangement (e.g., a serial flow arrangement) by connectors 440, 442, 444, 446. Here, the fuel 246 (and / or air from an air flow delivery system 153 not shown) received from the fuel delivery system 146 at one of the reformer stacks ( Figure 5 the first reformer stack 234A in the embodiment of Figure 5 is configured to be provided via the connectors 440, 442, 444, 446 to another one of the plurality of reformer stacks (

[0119] the remaining reformer stacks of the plurality of reformer stacks 234B, 234C, 234D, 234E in the embodiment of

[0120] In Figure 5In [the figure], the first reformer stack 234A is connected to the fuel delivery system 146 via the first fuel flow line 448; the second reformer stack 234B is connected to the first reformer stack 234A via the first connector 440; the third reformer stack 234C is connected to the second reformer stack 234B via the second connector 442; the fourth reformer stack 234D is connected to the third reformer stack 234C via the third connector 444; and the fifth reformer stack 234E is connected to the fourth reformer stack 234D via the fourth connector 446.

[0121] For example, the grooves 247 (see Figure 3 ) of the reformer stack 234 (see also Figure 3 ) can be connected via the connectors 440, 442, 444, 446.

[0122] Although not depicted, it will be understood that in at least some exemplary embodiments, the reformer system can be similarly constructed to provide an air flow to the plurality of reformer stacks 234A, 234B, 234C, 234D, 234E in a similar cascading manner.

[0123] It will be understood that this configuration provides control and distribution of the output products 248 from the plurality of reformer stacks 234A, 234B, 234C, 234D, 234E along the length of the burner 206 in the axial direction A.

[0124] Now referring specifically to Figure 6 , a plurality of reformer stacks 232A, 232B extend around or are integrated into the outer liner 210 that defines the combustion chamber 228. The plurality of reformer stacks 232 are distributed in the axial direction A and independently receive an oxidizer 244 (see Figure 3 , e.g., air from the air flow delivery system 153) and fuel 246 from the fuel delivery system 146 (see Figure 3 ).

[0125] In Figure 6In [the figure], a first reformer stack 232A among a plurality of reformer stacks 232 is connected to an air flow delivery system 153 through a first air flow pipeline 500 including a valve 502, and is connected to a fuel delivery system 146 through a first fuel flow pipeline 504 including a valve 506; and a second reformer stack 232B among the plurality of reformer stacks 232 is connected to the air flow delivery system 153 through a second air flow pipeline 510 including a valve 512, and is connected to the fuel delivery system 146 through a second fuel flow pipeline 514 including a valve 516. Here, the first reformer stack 232A covers a greater length of the outer liner 210 of the combustion chamber 228 in the axial direction A than the second reformer stack 232B. More specifically, the first reformer stack 232A has a greater length in the axial direction than the second reformer stack 232B.

[0126] For example, the length of the first reformer stack 232A in the axial direction A may be at least about 5% greater than the length of the second reformer stack 232B in the axial direction A, such as at least about 10% greater, such as at least about 20% greater, such as at least about 25% greater, such as at least about 40% greater, such as at least about 60% greater, such as up to about 1,000% greater.

[0127] In addition, for the illustrated embodiment, the first reformer stack 232A is upstream of the second reformer stack 232B, and the second reformer stack 232B is positioned at, adjacent to, close to, near, etc. the downstream end 526 of the combustion chamber 228 in the axial direction A (e.g., the most downstream position of the combustion chamber 228 in the axial direction A). For example, the upstream end of the second reformer stack 232B is spaced apart from the upstream end 520 of the combustion chamber 228 (e.g., the most upstream position of the combustion chamber 228 in the axial direction A, e.g., at the dome 212 or the opening 229) by a distance 522. The second reformer stack 232B provides an output product 248B to the combustion chamber 228 downstream of the distance 522 (e.g., at the downstream section 524 of the combustion chamber 228 or adjacent to the downstream end 526). The length 528 of the combustion chamber 228 in the axial direction A can be measured between the upstream end 520 and the downstream end 526.

[0128] Since the fuel and air flows (e.g., flow rates) to the reformer stacks 232A, 232B are independently controlled by the controller 240, the output products 248A, 248B from the reformer stacks 232A, 232B along the axial length of the burner 206 can be controlled to achieve an axial temperature distribution to reduce emissions by methods such as the "late lean" method, etc.

[0129] For example, the controller 240 can increase the fuel flow rate to the second reformer stack 232B and / or the hydrogen conversion rate of the second reformer stack 232B (e.g., represented by the longer output "arrow") relative to the fuel flow rate and / or hydrogen conversion rate of the first reformer stack 232A to modify the composition of the output products 248A, 248B. For example, to increase the %H in the output product 248B 2 , resulting in an increase in downstream secondary combustion in the combustion chamber. Such a distribution or composition of the output products 248A, 248B can provide more complete combustion of the combustion gases generated within the combustion chamber 228 and a reduction in certain emissions such as NO x . In addition, it will be understood that although for the Figure 6 embodiment, the first reformer stack 232A (upstream reformer stack) has a longer axial dimension than the second reformer stack 232B (downstream reformer stack), in other exemplary embodiments, this configuration can be reversed such that the downstream reformer stack has a longer axial dimension than the upstream reformer stack.

[0130] The distance 522 to the downstream section 524 can be at least 30% of the length 528 of the combustion chamber 228. For example, in certain exemplary embodiments, the distance 522 can be greater than or equal to half of the length 528 of the combustion chamber 228 in the axial direction A. For example, the distance 522 to the downstream section 524 can be at least two-thirds, at least three-fifths, or at least four-sevenths of the length 528 of the combustion chamber 228 in the axial direction A. Such a configuration can ensure that the second reformer stack 232B is positioned to provide a desired amount of secondary downstream combustion / heat addition to the combustion gases within the combustion chamber 228 to affect the amount of undesired components (such as NO x ) in the combustion gases.

[0131] Now referring to Figure 7 , an integrated reformer and burner assembly 200 according to an exemplary embodiment of the present disclosure will be described.

[0132] Figure 7 The exemplary integrated reformer and burner assembly 200 of Figure 6 can be constructed in a manner similar to the exemplary integrated reformer and burner assembly 200 of Figure 7 . For example, the reformer stack 232 extends around or is integrated into the outer liner 210 that defines the combustion chamber 228. The reformer stack 232 can receive an oxidizer 244 (e.g., air from the gas flow delivery system 153) and fuel 246 from a fuel delivery system 146 ( Figure 7 not shown in

[0133] The reformer stack 232 is positioned axially in the direction A at, adjacent to, close to, near, etc. the downstream end 526 of the combustion chamber 228. The upstream end of the reformer stack 232 is spaced from the upstream end 520 of the combustion chamber 228 (e.g., the dome 212 or the opening 229) by a distance 522.

[0134] Here, the reformer stack 232 is the foremost reformer stack 232.

[0135] In this embodiment, the distance 522 represents the distance between the upstream location (e.g., the upstream end 520 in the depicted embodiment) where fuel is first provided to the combustion chamber 228 through the opening 229 and the downstream location where fuel or the output product 248 is next provided to the combustion chamber 228. The reformer stack 232 provides the output product 248 to the combustion chamber 228 downstream of the distance 522 (e.g., at or adjacent to the downstream section 524 of the combustion chamber 228 or the downstream end 526). The length 528 of the combustion chamber 228 can be measured in the axial direction A between the upstream end 520 and the downstream end 526.

[0136] The distance 522 can be similar to the distance 522 described above with respect to Figure 6 For example, the distance 522 to the downstream section 524 can be at least 30% of the length 528 of the combustion chamber 228. In certain exemplary embodiments, the distance 522 can be greater than or equal to half of the length 528 of the combustion chamber 228 in the axial direction A. For example, the distance 522 to the downstream section 524 can be at least two-thirds, at least three-fifths, or at least four-sevenths of the length 528 of the combustion chamber 228 in the axial direction A.

[0137] The distance 522 to the downstream section 524 can be greater than or equal to half of the length 528 of the combustion chamber 228 in the axial direction A. For example, the distance 522 to the downstream section 524 can be two-thirds, three-fifths, four-sevenths, etc. of the length 528 of the combustion chamber 228 in the axial direction A.

[0138] The output product 248 from the reformer stack 232 along a portion of the length of the burner 206 in the axial direction A can be used to achieve a desired axial temperature profile, particularly a desired axial temperature profile within the downstream section 524. Such an arrangement can reduce emissions through a "late lean" combustion method. For example, the output product 248 will include hydrogen (H 2 ) which can promote secondary downstream combustion within the combustion chamber 228, potentially providing more complete combustion of the combustion gases flowing therethrough.

[0139] In some exemplary embodiments, the controller 240 may modify the fuel flow rate to the reformer stack 232, the air flow rate to the reformer stack 232, the temperature of the air provided to the reformer stack 232, the conversion rate of the reformer stack 232, or a combination thereof, to modify the composition, temperature, flow rate, or a combination thereof of the output product 248 provided to the combustion chamber 228, thereby promoting, for example, more complete combustion of the combustion gases within the combustion chamber 228 near or within the downstream section 524 of the combustion chamber 228.

[0140] According to an exemplary method, an aviation fuel flow is provided to the combustion chamber 228 of the burner 206 through an opening 229 defined at the upstream end 520 of the combustion chamber 228 to initiate an initial combustion within the combustion chamber 228. Additionally, an output product flow 248 is provided from the reformer stack 232 to the combustion chamber 228 at the downstream section 524 of the combustion chamber 228 to initiate a secondary combustion within the combustion chamber at a downstream location of the initial combustion within the combustion chamber 228.

[0141] Reference Figure 8 to exemplary embodiments of Figure 8 will describe an integrated reformer and burner assembly 200 according to additional exemplary embodiments of the present disclosure. Figure 6 The exemplary integrated reformer and burner assembly 200 of Figure 8 may be constructed in a manner similar to that of Figure 8 the exemplary integrated reformer and burner assembly 200 of

[0142] Figure 8 The reformer stack 232 of

[0143] The first reformer stack 232A provides an output product 248A to the combustion chamber 228 upstream of the distance 522, and the second reformer stack 232B provides an output product 248B to the combustion chamber 228 downstream of the distance 522 (e.g., in the downstream section 524 of the combustion chamber 228 or adjacent to the downstream end 526). The axial length 528 of the combustion chamber 228 can be measured between the upstream end 520 and the downstream end 526.

[0144] In addition, the size of the second reformer stack 232B (e.g., the height 550 in the radial direction R) is greater than the size of the first reformer stack 232A (e.g., the height 552 in the radial direction R). In some embodiments, a greater height in the radial direction can be achieved by stacking reformers end-to-end in the radial direction R or simply using a longer reformer.

[0145] The greater height can allow the second reformer stack 232B to have a higher conversion rate. Additionally or alternatively, the greater height can allow the second reformer stack 232B to provide the output product 248B to the combustion chamber 228 near the downstream end 526 in a manner that better promotes more complete combustion and thus less emissions.

[0146] For example, the greater height can allow for more catalyst to be provided in the reformer. In some embodiments, the height can refer to the amount of catalyst in the reformer. For example, the reformers can have the same height, but different amounts of catalyst. More catalyst can be provided in the downstream reformer stack to achieve a higher conversion rate. Here, the flow can be controlled because more catalyst can create a greater pressure drop across the reformer.

[0147] For example, the controller 240 controls the conversion rate of the second reformer stack 232B and controls the valve corresponding to the fuel flow to the second reformer stack 232B to control the output product 248B provided at the downstream section 524 of the combustion chamber 228.

[0148] Due to the increased conversion rate, the output product 248B is hydrogen-rich.

[0149] In addition, the second reformer stack 232B provides an output product (late lean) at the downstream section 524, which reduces the residence time of the output product 248B and thus reduces NO x .

[0150] The written description uses examples to disclose the present disclosure, including the best mode, and enables any person skilled in the art to practice the present disclosure, including making and using any device or system and performing any method of combination. The patent scope of the present disclosure is defined by the claims and may include other examples that occur to those skilled in the art. If these other examples include structural elements that are identical to the literal language of the claims, or if they include equivalent structural elements that do not materially differ from the literal language of the claims, then these other examples are intended to fall within the scope of the claims.

[0151] Further aspects are provided by the subject matter of the following clauses:

[0152] A propulsion system for an aircraft, the aircraft including an aircraft fuel supply, the propulsion system including: a turbine including a compressor section, a combustor, and a turbine section arranged in a serial flow order, the combustor defining a combustion chamber and an opening at an upstream end of the combustion chamber, the turbine defining an axial direction and a radial direction, the combustor being configured to receive an aviation fuel flow from the aircraft fuel supply through the opening; and a reformer stack extending around the combustion chamber and configured to provide an output product to the combustion chamber, the reformer stack including a plurality of reformers aligned in the radial direction.

[0153] The propulsion system according to one or more of these clauses, wherein the reformer stack is positioned in a downstream section of the combustion chamber in the axial direction.

[0154] The propulsion system according to one or more of these clauses, wherein the propulsion system defines a downstream distance in the axial direction between the opening of the combustor and an upstream end of the reformer stack, and wherein the downstream distance is at least 30% of the length of the combustion chamber in the axial direction.

[0155] The propulsion system according to one or more of these clauses, wherein the downstream distance is at least half of the length of the combustion chamber in the axial direction.

[0156] The propulsion system according to one or more of these clauses, wherein the downstream distance is greater than two-thirds of the length of the combustion chamber in the axial direction.

[0157] The propulsion system according to one or more of these clauses, wherein the downstream distance in the axial direction is the distance between the opening and the next downstream flow of the output product entering the combustion chamber.

[0158] A propulsion system according to one or more of these clauses, wherein the reformer stack is the foremost reformer stack.

[0159] A propulsion system according to one or more of these clauses, wherein the burner includes an outer lining and an inner lining that at least partially define the combustion chamber, and wherein the reformer stack extends around at least one of the outer lining and the inner lining or is integrated into at least one of the outer lining and the inner lining.

[0160] A propulsion system according to one or more of these clauses, wherein the reformer stack includes a groove that extends around one of the outer and inner sides of the reformer stack in the radial direction.

[0161] A propulsion system according to one or more of these clauses, wherein the reformer stack is one of a CPOx reformer and an autothermal reformer, and wherein if the reformer stack is a CPOx reformer, the reformer stack is configured to receive air, and if the reformer stack is an autothermal reformer, the reformer stack is configured to receive steam.

[0162] An integrated reformer and burner assembly for a turbine, the turbine defining an axial direction and a radial direction, the integrated reformer and burner assembly including: a burner that defines a combustion chamber and an opening at an upstream end of the combustion chamber, the burner being configured to receive an aviation fuel flow through the opening when incorporated into the turbine; and a reformer stack that extends around the combustion chamber and is configured to provide an output product to the combustion chamber, the reformer stack including a plurality of reformers aligned in the radial direction.

[0163] An integrated reformer and burner assembly according to one or more of these clauses, wherein the reformer stack is positioned in a downstream section of the combustion chamber in the axial direction.

[0164] An integrated reformer and burner assembly according to one or more of these clauses, wherein the integrated reformer and burner assembly defines a downstream distance in the axial direction between the opening of the burner and an upstream end of the reformer stack, and wherein the downstream distance is at least 30% of the length of the combustion chamber in the axial direction.

[0165] An integrated reformer and burner assembly according to one or more of these clauses, wherein the downstream distance is at least half of the length of the combustion chamber in the axial direction.

[0166] An integrated reformer and burner assembly according to one or more of these clauses, wherein the downstream distance is greater than two-thirds of the length of the combustion chamber in the axial direction.

[0167] An integrated reformer and burner assembly according to one or more of these clauses, wherein the downstream distance in the axial direction is the distance between the opening and the next downstream flow of the output product entering the combustion chamber.

[0168] An integrated reformer and burner assembly according to one or more of these clauses, wherein the reformer stack is the foremost reformer stack.

[0169] An integrated reformer and burner assembly according to one or more of these clauses, wherein the burner includes an outer liner and an inner liner that at least partially define the combustion chamber, and wherein the reformer stack extends around or is integrated into at least one of the outer liner and the inner liner.

[0170] An integrated reformer and burner assembly according to one or more of these clauses, wherein the reformer stack includes a groove that extends around one of the outer and inner sides of the reformer stack in the radial direction.

[0171] A method of operating a propulsion system, the propulsion system including a turbine and a reformer stack, the turbine defining an axial direction, the method including: providing an aviation fuel flow to the combustion chamber of the burner of the turbine through an opening defined at an upstream end of the combustion chamber to initiate an initial combustion in the combustion chamber; and providing an output product flow from the reformer stack to the combustion chamber at a downstream section of the combustion chamber to initiate a secondary combustion in the combustion chamber at a downstream location of the initial combustion in the combustion chamber.

Claims

1. A propulsion system for an aircraft, the aircraft including an aircraft fuel supply. Characterized in that, The propulsion system includes: A turbine including a compressor section, a burner, and a turbine section arranged in a serial flow order, the burner defining a combustion chamber and an opening at an upstream end of the combustion chamber, the turbine defining an axial direction and a radial direction, the burner being configured to receive an aviation fuel flow from the aircraft fuel supply through the opening; and A reformer stack extending around the combustion chamber and configured to provide an output product to the combustion chamber, the reformer stack including a plurality of reformers aligned in the radial direction.

2. The propulsion system according to claim 1, Characterized in that, Wherein the reformer stack is axially positioned at a downstream section of the combustion chamber.

3. The propulsion system according to claim 2, Characterized in that, Wherein the propulsion system defines a downstream distance in the axial direction between the opening of the burner and an upstream end of the reformer stack, and wherein the downstream distance is at least 30% of the length of the combustion chamber in the axial direction.

4. The propulsion system according to claim 3, Characterized in that, Wherein the downstream distance is at least half of the length of the combustion chamber in the axial direction.

5. The propulsion system according to claim 3, Characterized in that, Wherein the downstream distance is greater than two-thirds of the length of the combustion chamber in the axial direction.

6. The propulsion system according to claim 3, Characterized in that, Wherein the downstream distance in the axial direction is the distance between the opening and the next downstream flow of the output product entering the combustion chamber.

7. The propulsion system according to claim 3, Characterized in that, Wherein the reformer stack is the foremost reformer stack.

8. The propulsion system according to claim 1, Characterized in that, Wherein the burner includes an outer liner and an inner liner at least partially defining the combustion chamber, and wherein the reformer stack extends around or is integrated into at least one of the outer liner and the inner liner.

9. The propulsion system according to claim 1, Characterized in that, The reformer stack includes grooves extending around one of an outer side and an inner side of the reformer stack in the radial direction.

10. The propulsion system according to claim 1, Characterized in that, wherein the reformer stack is a CPO x one of a reformer and an autothermal reformer, wherein if the reformer stack is a CPO x reformer, the reformer stack is configured to receive air, and if the reformer stack is an autothermal reformer, the reformer stack is configured to receive steam.

11. An integrated reformer and burner assembly for a turbine, the turbine defining an axial direction and a radial direction, Characterized in that, The integrated reformer and burner assembly includes: A burner defining a combustion chamber and an opening at an upstream end of the combustion chamber, the burner being configured to receive an aviation fuel flow through the opening when incorporated into the turbine; and A reformer stack extending around the combustion chamber and configured to provide an output product to the combustion chamber, the reformer stack including a plurality of reformers aligned in the radial direction.

12. The integrated reformer and burner assembly according to claim 11, wherein: the reformer stack is positioned at a downstream section of the combustion chamber along the axial direction.

13. The integrated reformer and burner assembly according to claim 12, wherein: the integrated reformer and burner assembly defines a downstream distance in the axial direction between the opening of the burner and the upstream end of the reformer stack, and wherein the downstream distance is at least 30% of the length of the combustion chamber in the axial direction.

14. The integrated reformer and burner assembly according to claim 13, wherein: the downstream distance is at least half of the length of the combustion chamber in the axial direction.

15. The integrated reformer and burner assembly according to claim 13, wherein: the downstream distance is greater than two-thirds of the length of the combustion chamber in the axial direction.

16. The integrated reformer and burner assembly according to claim 13, wherein: the downstream distance in the axial direction is the distance between the opening and the next downstream flow of the output product entering the combustion chamber.

17. The integrated reformer and burner assembly according to claim 13, wherein: the reformer stack is the foremost reformer stack.

18. The integrated reformer and burner assembly according to claim 11, wherein: the burner includes an outer liner and an inner liner that at least partially define the combustion chamber, and wherein the reformer stack extends around or is integrated into at least one of the outer liner and the inner liner.

19. The integrated reformer and burner assembly according to claim 11, wherein: the reformer stack includes grooves that extend around one of the outer and inner sides of the reformer stack in the radial direction.

20. A method of operating a propulsion system that includes a turbine and a reformer stack, the turbine defining an axial direction, wherein: the method includes: providing an aviation fuel flow to the combustion chamber of the burner of the turbine through an opening defined at the upstream end of the combustion chamber to initiate an initial combustion in the combustion chamber; and providing an output product flow from the reformer stack to the combustion chamber at a downstream section of the combustion chamber to initiate a secondary combustion in the combustion chamber at a downstream location of the initial combustion in the combustion chamber.

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