Fuel Oxygen Reduction Unit with Integrated Water Removal

Abstract

A fuel delivery system for a gas turbine engine includes: a fuel source; a suction pump downstream of the fuel source for generating a liquid fuel stream from the fuel source; a main fuel pump downstream of the suction pump; and a fuel oxygen reduction unit downstream of the suction pump and upstream of the main fuel pump. The fuel oxygen reduction unit includes: a stripping gas line; a contactor fluidly connected to the stripping gas line and the suction pump for forming a fuel / gas mixture, the contactor receiving an inlet fuel stream from the suction pump; a separator fluidly connected to the contactor, the separator receiving the fuel / gas mixture and separating the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream at a location upstream of the main fuel pump; a catalytic converter disposed downstream of the separator, the catalytic converter receiving and processing the outlet stripping gas stream, the stripping gas stream flowing out of the catalytic converter; and a water removal member disposed between the catalytic converter and the contactor, the water removal member removing water from the stripping gas stream.

Description

Technical Field

[0001] The present subject matter generally relates to a fuel oxygen reduction unit for an engine and a method of operating the same. Background Art

[0002] Typical aircraft propulsion systems include one or more gas turbine engines. A gas turbine engine generally includes a turbine which, in a serial flow order, includes a compressor section, a combustion section, a turbine section, and an exhaust section. In operation, air is provided to the inlet of the compressor section where one or more axial compressors progressively compress the air until it reaches the combustion section. Fuel is mixed with and burned in the combustion section with the compressed air to provide combustion gases. The combustion gases are directed from the combustion section to the turbine section. The flow of combustion gases through the turbine section drives the turbine section and is then directed through the exhaust section to, for example, the atmosphere.

[0003] Certain operations and systems of gas turbine engines and aircraft can generate relatively large amounts of heat. Fuel has been identified as an efficient heat sink for receiving at least some of such heat during operation, at least in part due to the heat capacity of the fuel and the increased combustion operation efficiency that can be caused by burning fuel at higher temperatures.

[0004] However, heating the fuel without properly regulating it can cause the fuel to "coke", or form solid particles that can block certain components of the fuel system, such as fuel nozzles. Reducing the amount of oxygen in the fuel can effectively reduce the likelihood that the fuel will coke beyond an unacceptable amount. Summary of the Invention

[0005] Aspects and advantages of the present invention will be set forth in part in the following description, or may be obvious from the description, or may be learned by practicing the present invention.

[0006] In an exemplary embodiment of the present disclosure, a fuel delivery system for a gas turbine engine is provided. The fuel delivery system includes: a fuel source; a suction pump downstream of the fuel source for generating a liquid fuel stream from the fuel source; a main fuel pump downstream of the suction pump; and a fuel oxygen reduction unit downstream of the suction pump and upstream of the main fuel pump. The fuel oxygen reduction unit includes: a stripping gas line; a contactor in fluid communication with the stripping gas line and the suction pump for forming a fuel / gas mixture, wherein the contactor receives an inlet fuel stream from the suction pump; a separator in fluid communication with the contactor, the separator receiving the fuel / gas mixture and separating the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream at a location upstream of the main fuel pump; a catalytic converter disposed downstream of the separator, the catalytic converter receiving and processing the outlet stripping gas stream, wherein the stripping gas stream exits the catalytic converter; and a water removal member disposed between the catalytic converter and the contactor, wherein the water removal member removes water from the stripping gas stream.

[0007] In certain exemplary embodiments, the inlet stripping gas stream exits the water removal member and flows via the stripping gas line to the contactor.

[0008] In certain exemplary embodiments, the outlet fuel stream has a lower oxygen content than the inlet fuel stream.

[0009] In certain exemplary embodiments, the outlet fuel stream has a higher pressure than the inlet fuel stream.

[0010] In certain exemplary embodiments, the outlet stripping gas stream has a higher oxygen content than the inlet stripping gas stream.

[0011] In certain exemplary embodiments, the catalytic converter removes oxygen from the outlet stripping gas stream by chemically converting oxygen in the outlet stripping gas stream into water vapor and carbon dioxide in the stripping gas stream.

[0012] In certain exemplary embodiments, the water removal member removes water vapor from the stripping gas stream.

[0013] In certain exemplary embodiments, the water removal member includes a selectively permeable membrane that removes only water from the stripping gas stream.

[0014] In certain exemplary embodiments, the water removal member includes a desiccant that absorbs water from the stripping gas stream.

[0015] In certain exemplary embodiments, the water removal member includes a condenser.

[0016] In certain exemplary embodiments, the fuel oxygen reduction unit recirculates the stripping gas.

[0017] In another exemplary embodiment of the present disclosure, a fuel delivery system for a gas turbine engine is provided. The fuel delivery system includes a fuel oxygen reduction unit that defines a stripping gas flow path and includes an inlet fuel line and an outlet fuel line. The fuel oxygen reduction unit includes: an oxygen transfer assembly configured to use a stripping gas stream passing through the stripping gas flow path to reduce the amount of oxygen in an inlet fuel stream passing through the inlet fuel line; a catalyst in air flow communication with the stripping gas flow path at a location downstream of the oxygen transfer assembly, the catalyst receiving and processing the stripping gas stream in the stripping gas flow path from the oxygen transfer assembly, wherein the stripping gas stream exits the catalyst; and a water removal member disposed downstream of the catalyst, wherein the water removal member removes water from the stripping gas stream.

[0018] In certain exemplary embodiments, the oxygen transfer assembly includes: a contactor including a fuel inlet that receives the inlet fuel stream from a liquid fuel flow path and a stripping gas inlet that receives an inlet stripping gas stream from the stripping gas flow path, the contactor configured to form a fuel / gas mixture; and a separator including an inlet in fluid communication with the contactor, a fuel outlet, and a stripping gas outlet, the inlet receiving the fuel / gas mixture, wherein the separator is configured to separate the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream, and provide the outlet stripping gas stream to the stripping gas flow path through the stripping gas outlet and provide the outlet fuel stream to the outlet fuel line through the fuel outlet.

[0019] In certain exemplary embodiments, the inlet stripping gas stream exits the water removal member and flows via a stripping gas line to the contactor.

[0020] In certain exemplary embodiments, the outlet fuel stream has a lower oxygen content than the inlet fuel stream, and wherein the outlet stripping gas stream has a higher oxygen content than the inlet stripping gas stream.

[0021] In certain exemplary embodiments, the catalyst removes oxygen from the stripping gas stream by chemically converting oxygen in the outlet stripping gas stream into water vapor and carbon dioxide in the stripping gas stream.

[0022] In certain exemplary embodiments, the water removal member removes water vapor from the stripping gas stream.

[0023] In certain exemplary embodiments, the water removal member includes a selectively permeable membrane that removes water from the stripping gas stream.

[0024] In certain exemplary embodiments, the water removal member includes a desiccant that absorbs water from the stripping gas stream.

[0025] In certain exemplary embodiments, the water removal member includes a condenser.

[0026] In an exemplary aspect of the present disclosure, a method for operating a fuel delivery system for a gas turbine engine is provided. The method includes: receiving an inlet fuel stream in an oxygen transfer assembly of a fuel oxygen reduction unit for reducing the amount of oxygen in the inlet fuel stream using a stripping gas stream through a stripping gas flow path; separating the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream; receiving the outlet stripping gas stream in a catalytic converter at a location downstream of the oxygen transfer assembly, the catalytic converter receiving and processing the outlet stripping gas stream from the oxygen transfer assembly, wherein the stripping gas stream flows out of the catalytic converter; and removing water from the stripping gas stream downstream of the catalytic converter.

[0027] Technical solution 1. A fuel delivery system for a gas turbine engine, comprising:

[0028] A fuel source;

[0029] A suction pump downstream of the fuel source for generating a liquid fuel stream from the fuel source;

[0030] A main fuel pump downstream of the suction pump; and

[0031] A fuel oxygen reduction unit downstream of the suction pump and upstream of the main fuel pump, the fuel oxygen reduction unit including:

[0032] A stripping gas line;

[0033] A contactor in fluid communication with the stripping gas line and the suction pump for forming a fuel / gas mixture, wherein the contactor receives the inlet fuel stream from the suction pump;

[0034] A separator in fluid communication with the contactor, the separator receiving the fuel / gas mixture and separating the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream at a location upstream of the main fuel pump;

[0035] A catalytic converter disposed downstream of the separator, the catalytic converter receiving and processing the outlet stripping gas stream, wherein the stripping gas stream flows out of the catalytic converter; and

[0036] A water removal member disposed between the catalytic converter and the contactor, wherein the water removal member removes water from the stripping gas stream.

[0037] Technical solution 2. The fuel delivery system according to any of the foregoing technical solutions, characterized in that the inlet stripping gas stream leaves the water removal member and flows to the contactor via the stripping gas pipeline.

[0038] Technical solution 3. The fuel delivery system according to any of the foregoing technical solutions, characterized in that the outlet fuel stream has a lower oxygen content than the inlet fuel stream.

[0039] Technical solution 4. The fuel delivery system according to any of the foregoing technical solutions, characterized in that the outlet fuel stream has a higher pressure than the inlet fuel stream.

[0040] Technical solution 5. The fuel delivery system according to any of the foregoing technical solutions, characterized in that the outlet stripping gas stream has a higher oxygen content than the inlet stripping gas stream.

[0041] Technical solution 6. The fuel delivery system according to any of the foregoing technical solutions, characterized in that the catalytic converter removes oxygen from the outlet stripping gas stream by chemically converting the oxygen in the outlet stripping gas stream into water vapor and carbon dioxide in the stripping gas stream.

[0042] Technical solution 7. The fuel delivery system according to any of the foregoing technical solutions, characterized in that the water removal member removes the water vapor from the stripping gas stream.

[0043] Technical solution 8. The fuel delivery system according to any of the foregoing technical solutions, characterized in that the water removal member includes a selectively permeable membrane that removes only the water from the stripping gas stream.

[0044] Technical solution 9. The fuel delivery system according to any of the foregoing technical solutions, characterized in that the water removal member includes a desiccant that absorbs the water from the stripping gas stream.

[0045] Technical solution 10. The fuel delivery system according to any of the foregoing technical solutions, characterized in that the water removal member includes a condenser.

[0046] Technical solution 11. The fuel delivery system according to any of the foregoing technical solutions, characterized in that the fuel oxygen reduction unit recycles the stripping gas.

[0047] Technical solution 12. A fuel delivery system for a gas turbine engine, comprising:

[0048] A fuel oxygen reduction unit that defines a stripping gas flow path and includes an inlet fuel line and an outlet fuel line, the fuel oxygen reduction unit comprising:

[0049] An oxygen transfer component configured to use a stripping gas stream flowing through the stripping gas flow path to reduce the amount of oxygen in an inlet fuel stream flowing through the inlet fuel line;

[0050] A catalytic converter in air flow communication with the stripping gas flow path at a location downstream of the oxygen transfer component, the catalytic converter receiving and processing the stripping gas stream in the stripping gas flow path from the oxygen transfer component, wherein a stripping gas air stream flows out of the catalytic converter; and

[0051] A water removal member disposed downstream of the catalytic converter, wherein the water removal member removes water from the stripping gas air stream.

[0052] Technical solution 13. The fuel delivery system according to any one of the preceding technical solutions, characterized in that the oxygen transfer component comprises:

[0053] A contactor comprising a fuel inlet for receiving the inlet fuel stream from a liquid fuel flow path and a stripping gas inlet for receiving an inlet stripping gas stream from the stripping gas flow path, the contactor configured to form a fuel / gas mixture;

[0054] A separator comprising an inlet, a fuel outlet, and a stripping gas outlet in fluid communication with the contactor, the inlet receiving the fuel / gas mixture, wherein the separator is configured to separate the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream, and provide the outlet stripping gas stream to the stripping gas flow path through the stripping gas outlet and provide the outlet fuel stream to the outlet fuel line through the fuel outlet.

[0055] Technical solution 14. The fuel delivery system according to any one of the preceding technical solutions, characterized in that the inlet stripping gas stream exits the water removal member and flows to the contactor via a stripping gas line.

[0056] Technical solution 15. The fuel delivery system according to any one of the preceding technical solutions, characterized in that the outlet fuel stream has a lower oxygen content than the inlet fuel stream, and wherein the outlet stripping gas stream has a higher oxygen content than the inlet stripping gas stream.

[0057] Technical solution 16. The fuel delivery system according to any of the foregoing technical solutions, wherein the catalytic converter removes oxygen from the stripping gas stream by chemically converting the oxygen in the outlet stripping gas stream into water vapor and carbon dioxide in the stripping gas stream.

[0058] Technical solution 17. The fuel delivery system according to any of the foregoing technical solutions, wherein the water removal member removes the water vapor from the stripping gas stream.

[0059] Technical solution 18. The fuel delivery system according to any of the foregoing technical solutions, wherein the water removal member includes a selectively permeable membrane that removes the water from the stripping gas stream.

[0060] Technical solution 19. The fuel delivery system according to any of the foregoing technical solutions, wherein the water removal member includes a desiccant that absorbs the water from the stripping gas stream.

[0061] Technical solution 20. The fuel delivery system according to any of the foregoing technical solutions, wherein the water removal member includes a condenser.

[0062] Technical solution 21. A method for operating a fuel delivery system for a gas turbine engine, comprising:

[0063] Receiving an inlet fuel stream in an oxygen transfer component of a fuel oxygen reduction unit for reducing the amount of oxygen in the inlet fuel stream using a stripping gas stream through a stripping gas flow path;

[0064] Separating the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream;

[0065] Receiving the outlet stripping gas stream in a catalytic converter at a location downstream of the oxygen transfer component, the catalytic converter receiving and processing the outlet stripping gas stream from the oxygen transfer component, wherein the stripping gas stream flows out of the catalytic converter; and

[0066] Removing water from the stripping gas stream downstream of the catalytic converter.

[0067] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. Description of the Drawings

[0068] A complete and enabling disclosure of the present invention, including its best mode, for one of ordinary skill in the art is set forth in the specification, with reference to the accompanying drawings, in which:

[0069] Figure 1 FIG. 1 is a schematic cross-sectional view of a gas turbine engine according to an exemplary embodiment of the present disclosure.

[0070] Figure 2 FIG. 2 is a schematic diagram of a fuel oxygen reduction unit according to an exemplary embodiment of the present disclosure.

[0071] Figure 3 FIG. 3 is a schematic diagram of a fuel oxygen reduction unit according to another exemplary embodiment of the present disclosure.

[0072] Figure 4 FIG. 4 is a schematic diagram of a fuel oxygen reduction unit according to another exemplary embodiment of the present disclosure.

[0073] Figure 5 FIG. 5 is a schematic diagram of a fuel oxygen reduction unit according to another exemplary embodiment of the present disclosure.

[0074] Figure 6 FIG. 6 is a schematic diagram of a fuel oxygen reduction unit according to an exemplary embodiment of the present disclosure.

[0075] Figure 7 FIG. 7 is a schematic diagram of a fuel delivery system incorporating a fuel oxygen reduction unit according to an exemplary embodiment of the present disclosure.

[0076] Corresponding reference characters indicate corresponding parts throughout the several views. The illustrative examples set forth herein illustrate exemplary embodiments of the present disclosure, and such examples are not to be construed in any way as limiting the scope of the present disclosure. DETAILED DESCRIPTION

[0077] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and alphabetical designations to refer to features in the drawings. Identical or similar designations in the drawings and description have been used to refer to the same or similar parts of the present invention.

[0078] The following description is provided to enable one of ordinary skill in the art to make and use embodiments contemplated for carrying out the present invention. However, various modifications, equivalents, variations, and alternatives will still be readily apparent to one of ordinary skill in the art. Any and all such modifications, variations, equivalents, and alternatives are intended to fall within the spirit and scope of the present invention.

[0079] For the purposes described hereinafter, the terms "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom", "lateral", "longitudinal" and derivatives thereof shall relate to the present invention as oriented in the drawings. However, it will be understood that the present invention may assume a variety of alternative variations, except where expressly specified to the contrary. It will also be understood that the specific devices illustrated in the drawings and described in the following specification are merely exemplary embodiments of the present invention. Accordingly, the specific dimensions and other physical characteristics related to the embodiments disclosed herein will not be considered limiting.

[0080] As used herein, the terms "first", "second" and "third" may be used interchangeably to distinguish one member from another and are not intended to denote the position or importance of the individual members.

[0081] The terms "upstream" and "downstream" refer to the relative directions with respect to the flow of fluid in a fluid passage. For example, "upstream" refers to the direction from which the fluid flows and "downstream" refers to the direction to which the fluid flows.

[0082] 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 members or features.

[0083] Unless the context clearly dictates otherwise, the singular forms "a", "an" and "the" include plural referents.

[0084] As used throughout the specification and claims herein, approximating language is applicable to modify any quantitative representation that admits of variation without resulting in a change in the basic function associated therewith. Accordingly, values modified by one or more terms such as "about", "approximately" and "substantially" will not be limited to the precise values specified. In at least some instances, the approximating language may 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 approximating language may refer to within a margin of 10 percent.

[0085] Herein and throughout the specification and claims, ranges are combined and interchangeable, and such ranges are identified and include all subranges subsumed therein unless the context or language indicates otherwise. For example, all ranges disclosed herein include the endpoints, and the endpoints can be combined independently of each other.

[0086] In a fuel oxygen reduction unit, a catalytic converter receives and processes an outlet stripping gas stream flowing from a separator to reduce the oxygen content of the stripping gas for reuse of the stripping gas. In such a configuration, by-products such as water can be produced. Advantageously, the present disclosure provides a system including components (such as a water removal component) that remove water from the stripping gas stream after the stripping gas stream has been processed by the catalytic converter and before the stripping gas is reintroduced together with the inlet fuel at the contactor to prevent an increase in the water concentration in the fuel used for the engine. The fuel system can be sensitive to the amount of water present in the fuel. Thus, the fuel oxygen reduction unit including the water removal component of the present disclosure beneficially avoids such water addition to the fuel.

[0087] Reference is now made to the accompanying drawings, in which 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. Alternatively, however, the engine can be any other suitable type of engine for any other suitable vehicle.

[0088] For the depicted embodiment, the engine is configured as a high bypass turbofan engine 100. As Figure 1 shown, the turbofan engine 100 defines an axial direction A (extending parallel to a longitudinal centerline or axis 101 provided for reference), a radial direction R, and a circumferential direction (extending around the axial direction A; not depicted Figure 1 in the figures). Generally, the turbofan engine 100 includes a fan section 102 and a turbine 104 disposed downstream of the fan section 102.

[0089] The depicted exemplary turbine 104 generally includes a substantially tubular outer casing 106 that defines an annular inlet 108. The outer casing 106 surrounds in a serial flow relationship: a compressor section including a booster or low pressure (LP) compressor 110 and a high pressure (HP) compressor 112; a combustion section 114; a turbine section including a high pressure (HP) turbine 116 and a low pressure (LP) turbine 118; and a jet exhaust nozzle section 120. The compressor section, the combustion section 114, and the turbine section together at least partially define a core air flow path 121 that extends from the annular inlet 108 to the jet nozzle exhaust section 120. The turbofan engine further includes one or more drive shafts. More specifically, the turbofan engine includes a high pressure (HP) shaft or rotor shaft 122 that drivingly connects the HP turbine 116 to the HP compressor 112, and a low pressure (LP) shaft or rotor shaft 124 that drivingly connects the LP turbine 118 to the LP compressor 110.

[0090] For the depicted embodiment, the fan section 102 includes a fan 126 having a plurality of fan blades 128 coupled to a disk 130 in a spaced-apart manner. The fan blades 128 and the disk 130 are rotatable together about a longitudinal axis 101 by an LP shaft 124. The disk 130 is covered by a rotatable front hub 132, the profile of which is aerodynamically configured to promote air flow through the plurality of fan blades 128. Additionally, an annular fan casing or nacelle 134 is provided that circumferentially encloses at least a portion of the fan 126 and / or 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 so as to define a bypass air flow path 140 therebetween.

[0091] Still referring to Figure 1 , the turbofan engine 100 further includes an accessory gearbox 142, a fuel oxygen reduction unit 144, and a fuel delivery system 146. For the illustrated embodiment, the accessory gearbox 142 is positioned within the cowling / enclosure 106 of the turbine 104. Additionally, it will be appreciated that although not schematically depicted in Figure 1 , the accessory gearbox 142 may be mechanically coupled to one or more shafts or rotors of the turbine 104 and be rotatable therewith. For example, in at least some exemplary embodiments, the accessory gearbox 142 may be mechanically coupled to the HP shaft 122 and be rotatable therewith. Further, for the illustrated embodiment, the fuel oxygen reduction unit 144 is coupled to the accessory gearbox 142 or is otherwise rotatable therewith, whereas in other embodiments, the fuel oxygen reduction unit 144 may utilize other or additional rotational power sources (such as an electric motor). In this manner, it will be appreciated that the exemplary fuel oxygen reduction unit 144 is driven by the accessory gearbox 142. Notably, as used herein, the term "fuel oxygen conversion or reduction" generally means a device capable of reducing the free oxygen content of fuel.

[0092] Additionally, the fuel delivery system 146 generally includes a fuel source 148 (such as a fuel tank) and one or more fuel lines 150. The one or more fuel lines 150 provide a fuel flow through the fuel delivery system 146 to a combustion section 114 of the turbine 104 of the turbofan engine 100. A more detailed schematic of a fuel delivery system in accordance with an exemplary embodiment of the present disclosure is provided below with reference to Figure 7 FIG.

[0093] However, it will be appreciated that Figure 1The exemplary turbofan engine 100 depicted is provided by way of example only. In other exemplary embodiments, any other suitable engine may be utilized in conjunction with aspects of the present disclosure. For example, in other embodiments, the engine may be any other suitable gas turbine engine, such as a turboprop engine, a turbofan engine, a turbojet engine, etc. In this way, it will be further appreciated that in other embodiments, the gas turbine engine may have any other suitable configuration, such as any other suitable number or arrangement of shafts, compressors, turbines, fans, etc. Additionally, although Figure 1 the exemplary gas turbine engine depicted is schematically shown as a fixed pitch direct drive turbofan engine 100, in other embodiments, the gas turbine engines of the present disclosure may 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), 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 variable pitch axes), etc. Additionally, although not depicted herein, in other embodiments, the gas turbine engine may be any other suitable type of gas turbine engine, such as an industrial gas turbine engine incorporated into a power generation system, a marine gas turbine engine, etc. Additionally, in alternative embodiments, aspects of the present disclosure may be incorporated into any other type of engine (such as a reciprocating engine) or otherwise utilized in conjunction with any other type of engine.

[0094] Furthermore, it will be appreciated that although for the depicted embodiment, the turbofan engine 100 includes a fuel oxygen reduction unit 144 positioned within the turbine 104 (i.e., within the casing 106 of the turbine 104), in other embodiments, the fuel oxygen reduction unit 144 may be positioned at any other suitable location. For example, in other embodiments, the fuel oxygen reduction unit 144 may instead be positioned remote from the turbofan engine 100. Additionally, in other embodiments, the fuel oxygen reduction unit 144 may be additionally or alternatively driven by any other suitable power source (such as an electric motor, a hydraulic motor, or an independent mechanical coupling coupled to the HP or LP shaft, etc.).

[0095] Now referring to Figure 2 and Figure 6 , there is provided a schematic illustration of a fuel oxygen reduction unit or oxygen delivery assembly 200 for a gas turbine engine in accordance with an exemplary aspect of the present disclosure. In at least some exemplary embodiments, the exemplary fuel oxygen reduction unit 200 depicted may be incorporated into, for example, the exemplary engine 100 described above with reference to Figure 1 (e.g., may be the Figure 1 fuel oxygen reduction unit 144 depicted and described above).

[0096] As will be appreciated from the discussion herein, in an exemplary embodiment, the fuel oxygen reduction unit 200 generally includes a contactor 202, a separator 204, a catalytic converter 210, and a water removal member 211. In one exemplary embodiment, the separator 204 may be a dual separator pump, as described in more detail below and as Figure 6 shown. In other exemplary embodiments, other separators may be utilized with the fuel oxygen reduction unit 200 of the present disclosure. In other exemplary embodiments, the oxygen transfer assembly 200 may include a membrane that is intended to filter or draw oxygen from the fuel into a stripping gas, or chemically react with the oxygen in the fuel to reduce the oxygen in the fuel. In such an embodiment, the oxygen transfer assembly 200 may not include a contactor and a separator.

[0097] In the fuel oxygen reduction unit 200, the catalytic converter 210 receives and processes the outlet stripping gas stream 220 flowing out of the separator 204 to reduce the oxygen content of the stripping gas 220 for reuse of the stripping gas 220. In such a configuration, by-products such as water may be produced. Advantageously, the present disclosure provides a system including a member (e.g., the water removal member 211) that removes water from the stripping gas stream 220 after the stripping gas stream 220 has been processed by the catalytic converter 210 before the stripping gas 220 is reintroduced together with the inlet fuel 226 at the contactor 202, so as to prevent an increase in the water concentration in the fuel for the engine. The fuel system may be sensitive to the amount of water present in the fuel. Thus, the fuel oxygen reduction unit 200 including the water removal member 211 of the present disclosure advantageously avoids such water addition to the fuel.

[0098] The depicted exemplary contactor 202 may be configured in any suitable manner to significantly mix the received gas and liquid streams, as will be described below. For example, in certain embodiments, the contactor 202 may be a mechanically driven contactor (e.g., having blades for mixing the received streams), or alternatively, a passive contactor that is used to mix the received streams at least in part using the pressure and / or flow rate of the received streams. For example, the passive contactor may include one or more turbulators, a Venturi mixer, etc.

[0099] In addition, the exemplary fuel oxygen reduction unit 200 includes a stripping gas line 205, and more particularly, a plurality of stripping gas lines 205, which together at least partially define a circulating gas flow path 206 extending from the separator 204 to the contactor 202. In certain exemplary embodiments, in addition to the plurality of stripping gas lines 205 and structures or members within the circulating gas flow path 206, the circulating gas flow path 206 may also be formed by any combination of one or more conduits, tubes, pipes, etc.

[0100] As will be explained in more detail below, the fuel oxygen reduction unit 200 generally provides a flow of stripping gas 220 through a plurality of stripping gas lines 205 and a stripping gas flow path 206 during operation. It will be appreciated that the term "stripping gas" is used herein as a convenient term to refer to a gas that is generally capable of performing the functions described herein. The stripping gas 220 flowing through the stripping gas flow path / circulation gas flow path 206 may be the actual stripping gas used to strip oxygen from the fuel within the contactor, or alternatively may be a sparging gas that foams the liquid fuel to reduce the oxygen content of such fuel. For example, as will be discussed in more detail below, the stripping gas 220 may be an inert gas (such as nitrogen or carbon dioxide (CO2)), a gas mixture consisting of at least 50% (by mass) inert gas, or some other gas or gas mixture having a relatively low oxygen content.

[0101] In addition, for the depicted exemplary oxygen reduction unit, the fuel oxygen reduction unit 200 further includes a gas booster pump 208, a catalytic converter 210, a water removal member 211, and a preheater 212. For the illustrated embodiment, the gas booster pump 208, the catalytic converter 210, the preheater 212, and the water removal member 211 are each arranged in series flow within the circulation gas flow path 206.

[0102] The gas booster pump 208, the catalytic converter 210, the preheater 212, and the water removal member 211 may be arranged within the circulation gas flow path 206 in different configurations.

[0103] For example, referring to Figure 2 , in a first exemplary embodiment, the arrangement includes the gas booster pump 208, the catalytic converter 210, and the preheater 212 and the water removal member 211 in series flow. Thus, the flow of stripping gas 220 exits the stripping gas outlet 214 of the separator 204 and then flows through the gas booster pump 208, the catalytic converter 210, and the preheater 212 and the water removal member 211 in series flow. Next, the resulting relatively low oxygen content stripping gas (where water is removed from the stripping gas stream 220) is then provided, which passes through the remainder of the circulation gas flow path 206 and returns to the contactor 202 such that the cycle can be repeated.

[0104] Referring to Figure 3 and Figure 6, in a second exemplary embodiment, the arrangement includes a preheater 212 and a catalytic converter 210, a water removal member 211, and a gas booster pump 208 in serial flow. Thus, the stream of stripping gas 220 exits the stripping gas outlet 214 of the separator 204 and then flows through the catalytic converter 210 and preheater 212, the water removal member 211, and the gas booster pump 208 in serial flow. Next, the resulting stripping gas with a relatively low oxygen content (where water is removed from the stripping gas stream 220) is provided, which passes through the remainder of the recycle gas flow path 206 and returns to the contactor 202 so that the cycle can be repeated.

[0105] Reference Figure 4 , in a third exemplary embodiment, the arrangement includes a catalytic converter 210 and a preheater 212, a gas booster pump 208, and a water removal member 211 in serial flow. Thus, the stream of stripping gas 220 exits the stripping gas outlet 214 of the separator 204 and then flows through the catalytic converter 210 and preheater 212, the gas booster pump 208, and the water removal member 211 in serial flow. Next, the resulting stripping gas with a relatively low oxygen content (where water is removed from the stripping gas stream 220) is provided, which passes through the remainder of the recycle gas flow path 206 and returns to the contactor 202 so that the cycle can be repeated.

[0106] Additionally, the gas booster pump 208 can be configured as a rotary gas pump that is coupled to and driven by a power source (such as Figures 2 - 4 shown). In certain embodiments, the power source for the gas booster pump 208 can be the same power source as for the separator 204 (discussed below), or alternatively, any other suitable power source. For example, in certain embodiments, the gas booster pump 208 and / or the separator 204 can be coupled to an accessory gearbox 142, other gearboxes, or a suitable electrical power source, such as a permanent magnet alternator (PMA), which can also be used to provide power to a full authority digital engine controller (FADEC).

[0107] In an exemplary embodiment using a permanent magnet alternator (PMA) as a power source for a gas boost pump 208 and / or a separator 204, a full authority digital engine controller (FADEC) is powered by a dedicated PMA, which in turn is rotated / driven by an accessory gearbox of a gas turbine engine. The PMA is thus sized to be able to provide a sufficient amount of electrical power to the FADEC during substantially all operating conditions, including relatively low speed operating conditions such as start-up and idle. However, when the engine reaches a certain speed, the PMA may generate an increasing amount of electrical power, while the amount of electrical power required to operate the FADEC may remain relatively constant. Thus, when the engine reaches a certain speed, the PMA may generate a certain amount of excess electrical power, which may need to be dissipated through an electrical radiator.

[0108] The inventors of the present disclosure have found that the power consumption requirements for a fuel oxygen reduction unit can supplement the power generation of the PMA. More specifically, the fuel oxygen reduction unit may require a relatively small amount of electrical power during low rotational speeds of the gas turbine engine (when the PMA does not generate much excess electrical power), and a relatively large amount of electrical power during high rotational speeds of the gas turbine engine (when the PMA generates excess electrical power). Thus, by using the PMA to power the fuel oxygen reduction unit, the electrical power generated by the PMA can be utilized more efficiently.

[0109] However, it will be recognized that such a configuration is by way of example only, and in other embodiments, the FADEC can be any other suitable engine controller, the PMA can be any other suitable electric machine, etc. Thus, in certain embodiments, there is provided an engine system for an aircraft, having an engine and an engine controller. The engine system includes: an electric machine configured to be in electrical communication with the engine controller for providing power to the engine controller; and a fuel oxygen reduction unit defining a liquid fuel flow path and a stripping gas flow path, and configured to transfer the oxygen content of a fuel stream passing through the liquid fuel flow path to a stripping gas stream passing through the stripping gas flow path, the fuel oxygen reduction unit also being in electrical communication with the electric machine such that the electric machine at least partially powers the fuel oxygen reduction unit.

[0110] Reference Figure 6 , in an exemplary embodiment, the separator 204 generally includes a stripping gas outlet 214, a fuel outlet 216, and an inlet 218. It will also be recognized that the depicted exemplary fuel oxygen reduction unit 200 can be associated with a fuel delivery system 146 (such as the fuel delivery system 146 of a gas turbine engine including the fuel oxygen reduction unit 200 (see, for example Figure 1)) Operate together. Exemplary fuel delivery system 146 generally includes multiple fuel pipelines, and more particularly, includes an inlet fuel pipeline 222 and an outlet fuel pipeline 224. The inlet fuel pipeline 222 is fluidly connected to the contactor 202 for providing a liquid fuel stream or an inlet fuel stream 226 (e.g., from a fuel source such as a fuel tank) to the contactor 202, and the outlet fuel pipeline 224 is fluidly connected to the fuel outlet 216 of the dual separator pump 204 for receiving a deoxygenated liquid fuel stream or an outlet fuel stream 227.

[0111] In addition, during typical operation, the stream of stripping gas 220 flows from the stripping gas outlet 214 of the separator 204 to the contactor 202 through the recycle gas flow path 206. More specifically, during typical operation, the stripping gas 220 flows from the stripping gas outlet 214 of the separator 204 through a preheater 212 (configured to add thermal energy to the gas flowing therethrough), through a catalytic converter 210, through a water removal member 211, and flows to / through a gas booster pump 208, where the pressure of the stripping gas 220 is increased to provide the flow of the stripping gas 220 through the recycle gas flow path 206. The relatively high-pressure stripping gas 220 from which water is removed by the water removal member 211 from the stripping gas stream 220 (i.e., relative to the pressure upstream of the booster pump 208 and the fuel entering the contactor 202) is then provided to the contactor 202, where the stripping gas 220 is mixed with the flow of inlet fuel 226 from the inlet fuel pipeline 222 to generate a fuel gas mixture 228. The fuel gas mixture 228 generated within the contactor 202 is provided to the inlet 218 of the separator 204.

[0112] Generally, it will be appreciated that during operation of the fuel oxygen reduction unit 200, the inlet fuel 226 provided to the contactor 202 through the inlet fuel pipeline 222 may have a relatively high oxygen content. The stripping gas 220 provided to the contactor 202 may have a relatively low oxygen content or other specific chemical structures. Within the contactor 202, the inlet fuel 226 is mixed with the stripping gas 220, thereby creating a fuel gas mixture 228. As a result of such mixing, physical exchange may occur, whereby at least a portion of the oxygen within the inlet fuel 226 is transferred to the stripping gas 220, such that the fuel component of the mixture 228 has a relatively low oxygen content (compared to the inlet fuel 226 provided through the inlet fuel pipeline 222), and the stripping gas component of the mixture 228 has a relatively high oxygen content (compared to the inlet stripping gas 220 provided to the contactor 202 through the recycle gas flow path 206).

[0113] Within the separator 204, the stripping gas 220 with a relatively high oxygen content is then separated from the fuel 226 with a relatively low oxygen content and returned to the respective streams of the outlet stripping gas 220 and the outlet fuel 227.

[0114] In one exemplary embodiment, the separator 204 can be a dual-separator pump, such as Figure 6 as shown. For example, the dual-separator pump 204 defines a central axis 230, a radial direction R, and a circumferential direction C extending around the central axis 230. Additionally, the dual-separator pump 204 is configured as a mechanically driven dual-separator pump, or more specifically, as a rotary / centrifugal dual-separator pump. Thus, the dual-separator pump 204 includes an input shaft 232 and a single-stage separator / pump assembly 234. The input shaft 232 is mechanically coupled to the single-stage separator / pump assembly 234, and the two components are capable of rotating together around the central axis 230. Further, the input shaft 232 can be mechanically coupled to, for example, an accessory gearbox (such as Figure 1 the exemplary accessory gearbox 142) and driven by the accessory gearbox. However, in other embodiments, the input shaft 232 can be mechanically coupled to any other suitable power source, such as an electric motor. As will be appreciated, the single-stage separator / pump assembly 234 can simultaneously separate the mixture 228 into the streams of the outlet stripping gas 220 and the outlet fuel 227 from the mixture 228, and increase the pressure of the separated outlet fuel 227 (as will be discussed in more detail below).

[0115] Additionally, the depicted exemplary single-stage separator / pump assembly 234 generally includes an internal gas filter 236 disposed along the central axis 230 and a plurality of vanes 238 positioned radially outside the internal gas filter 236 along the radial direction R. During operation, the rotation of the single-stage separator / pump assembly 234 around the central axis 230 and more specifically the rotation of the plurality of vanes 238 around the central axis 230 (i.e., in the circumferential direction C) can generally force the heavier liquid fuel 226 outward along the radial direction R and force the lighter stripping gas 220 inward along the radial direction R through the internal gas filter 236. In this way, the outlet fuel 227 can leave through the fuel outlet 216 of the dual-separator pump 204, and the outlet stripping gas 220 can leave through the gas outlet 214 of the dual-separator pump 204, as indicated.

[0116] In addition, it will be appreciated that with such a configuration, the outlet fuel 227 exiting the dual separator pump 204 through the fuel outlet 216 can be at a higher pressure than the inlet fuel 226 provided through the inlet fuel line 222 and further higher than the fuel / gas mixture 228 provided through the inlet 218. This can be at least in part due to the centrifugal force exerted on such liquid fuel 226 and the rotation of the plurality of vanes 238. Additionally, it will be appreciated that for the depicted embodiment, the liquid fuel outlet 216 is positioned radially outward of the inlet 218 (i.e., the fuel gas mixture inlet). This can also help increase the pressure of the outlet fuel 227 provided through the fuel outlet 216 of the separator 204.

[0117] For example, it will be appreciated that with respect to such an exemplary embodiment, the separator 204 of the fuel oxygen reduction unit 200 can generate a pressure increase in the fuel stream during operation. As used herein, the term "pressure increase" refers to the net pressure difference between the pressure of the stream of outlet fuel 227 provided to the fuel outlet 216 of the separator 204 (i.e., the "liquid fuel outlet pressure") and the pressure of the inlet fuel 226 provided to the contactor 202 through the inlet fuel line 222. In at least some exemplary embodiments, the pressure increase of the liquid fuel 226 can be at least about sixty (60) pounds per square inch ("psi"), such as at least about ninety (90) psi, such as at least about one hundred (100) psi, such as up to about seven hundred fifty (750) psi. With such a configuration, it will be appreciated that in at least some exemplary embodiments of the present disclosure, the liquid fuel outlet pressure can be at least about seventy (70) psi during operation. For example, in at least some exemplary embodiments, the liquid fuel outlet pressure can be at least about one hundred (100) psi during operation, such as at least about one hundred twenty-five (125) psi during operation, such as up to about eight hundred (800) psi during operation. Additional details regarding these dual functions of the separator 204 will be discussed below with reference to Figure 7 discussed.

[0118] In addition, it will be appreciated that the outlet fuel 227 that has interacted with the stripping gas 220 provided to the fuel outlet 216 can have a relatively low oxygen content, such that a relatively large amount of heat can be added to the outlet fuel 227 with a reduced risk of fuel coking (i.e., chemically reacting to form solid particles that can block or otherwise damage components within the fuel flow path). For example, in at least some exemplary aspects, the outlet fuel 227 provided to the fuel outlet 216 can have an oxygen content of less than about five (5) parts per million ("ppm"), such as less than about three (3) ppm, such as less than about two (2) ppm, such as less than about one (1) ppm, such as less than about 0.5 ppm.

[0119] Further, as will be appreciated, the depicted exemplary fuel oxygen reduction unit 200 recycles and re-uses the stripping gas 220 (i.e., the stripping gas 220 operates in a substantially closed loop). However, the stripping gas 220 that has interacted with the liquid fuel 226 exiting the separator 204 has a relatively high oxygen content. Thus, in order to re-use the stripping gas 220, it is necessary to reduce the oxygen content of the stripping gas 220 exiting the outlet 214 of the separator 204. For the depicted embodiment, and as noted above, the stripping gas 220 flows through the preheater 212, through the catalytic converter 210 (where the oxygen content of the stripping gas 220 is reduced), and through the water removal member 211 (where water is removed from the stripping gas stream 220). More specifically, within the catalytic converter 210, the relatively oxygen-rich stripping gas 220 reacts to reduce its oxygen content. It will be appreciated that the catalytic converter 210 can be configured in any suitable manner to perform such a function. For example, in some embodiments, the catalytic converter 210 can be configured to combust the relatively oxygen-rich stripping gas 220 to reduce its oxygen content. However, in other embodiments, the catalytic converter 210 can additionally or alternatively include a geometry of catalytic members through which the relatively oxygen-rich stripping gas 220 flows to reduce the oxygen content of the stripping gas 220. In one or more of these embodiments, the catalytic converter 210 can be configured to reduce the oxygen content of the stripping gas 220 to less than about five percent (5%) by mass of oxygen (O2), such as less than about two percent (2)(3%) by mass of oxygen (O2), such as less than about one percent (1%) by mass of oxygen (O2).

[0120] In one or more of these configurations, by-products (such as water) can be produced, which are removed using the water removal member 211. Advantageously, the present disclosure provides a system including a member that removes water from the stripping gas stream 220 after the stripping gas 220 has been processed by the catalytic converter 210 and before the stripping gas 220 is re-introduced with the inlet fuel 226 at the contactor 202, so as to prevent an increase in the water concentration in the fuel for the engine. The fuel system can be sensitive to the amount of water present in the fuel. Thus, the fuel oxygen reduction unit 200 including the water removal member 211 of the present disclosure beneficially avoids such water being added to the fuel.

[0121] As described herein, the catalytic converter 210 is disposed downstream of the separator 204, and the catalytic converter 210 receives and processes the outlet stripping gas stream 220 exiting the stripping gas outlet 214 of the separator 204. In an exemplary embodiment, the catalytic converter 210 removes oxygen from the outlet stripping gas stream 220 by chemically converting the oxygen in the outlet stripping gas stream 220 into water vapor and carbon dioxide in the stripping gas stream 220. Next, the stripping gas stream 220 exits the catalytic converter 210 and flows to the water removal member 211 of the present disclosure.

[0122] In an exemplary embodiment of the present disclosure, the water removal member 211 is disposed between the catalytic converter 210 and the contactor 202. Advantageously, the water removal member 211 removes water from the stripping gas stream 220 flowing from the catalytic converter 210. For example, the water removal member 211 removes water vapor from the stripping gas stream 220.

[0123] In a first exemplary embodiment, the water removal member 211 may include a selectively permeable membrane. In one embodiment, the selectively permeable membrane is configured to remove water molecules from the stripping gas stream 220 only after the stripping gas stream 220 has been processed by the catalytic converter 210.

[0124] In a second exemplary embodiment, the water removal member 211 may include a desiccant. In one embodiment, the desiccant absorbs water molecules from the stripping gas stream 220 after the stripping gas stream 220 has been processed by the catalytic converter 210. In such an embodiment, the desiccant may be updated or replaced as needed. In an exemplary embodiment, the desiccant may include a bead system that selectively extracts water molecules from the stripping gas stream 220 after the stripping gas stream 220 has been processed by the catalytic converter 210.

[0125] In a third exemplary embodiment, the water removal member 211 may include a condenser. In one embodiment, the condenser is configured to lower the temperature of the gas stream below the condensation point. In this way, water and other vapors can be removed from the stripping gas stream 220 after the stripping gas stream 220 has been processed by the catalytic converter 210 and used for other purposes or discarded.

[0126] In other exemplary embodiments, the water removal member 211 may include other devices, systems, or components that remove water from the stripping gas stream 220 after the stripping gas stream 220 has been processed by the catalytic converter 210.

[0127] The resulting gas with a relatively low oxygen content (from which water is removed from the stripping gas stream 220) then passes through the remainder of the recycle gas flow path 206 and returns to the contactor 202 to provide for a repeatable cycle. In this manner, it will be appreciated that the stripping gas 220 can be any suitable gas capable of undergoing the chemical transformations described above. For example, the stripping gas can be air from, for example, the core air flow path of a gas turbine engine including a fuel oxygen reduction unit 200 (e.g., compressed air discharged from the HP compressor 112; see Figure 1 ). However, in other embodiments, the stripping gas can instead be any other suitable gas, such as an inert gas (such as nitrogen or carbon dioxide (CO2)), a gas mixture composed of at least 50% (by mass) inert gas, or some other gas or gas mixture having a relatively low oxygen content.

[0128] However, it will be appreciated that the exemplary fuel oxygen reduction unit 200 described above is provided by way of example only. In other embodiments, the fuel oxygen reduction unit 200 can be configured in any other suitable manner.

[0129] In other embodiments, the stripping gas 220 may not flow through the recycle gas flow path 206. Instead, the fuel oxygen reduction unit 200 can include an open-loop stripping gas flow path that is in fluid communication with a suitable source of stripping gas, such as an exhaust air source, and is configured to dump such air to the atmosphere downstream of the fuel gas separator 204.

[0130] For example, referring to Figure 5 , in another exemplary embodiment of the present disclosure, the fuel oxygen reduction unit 200 having a water removal member 211 can be part of a single-pass stripping gas system. For example, a gas source or stripping gas source 250 can provide an inlet stripping gas stream 252 to the contactor 202. As described herein, the stripping gas stream 252 is first processed before it reaches the contactor 202. For example, the stripping gas stream 252 first flows through a catalytic converter 210 and a preheater 212, and then through the water removal member 211. In the single-pass stripping gas system shown in Figure 5 , the stripping gas stream 220 leaving the separator 204 does not recycle through the system.

[0131] Now referring to Figure 7 , a schematic diagram of a fuel delivery system 300 for a gas turbine engine according to an exemplary embodiment of the present disclosure is provided. In certain exemplary embodiments, Figure 7 The exemplary fuel delivery system 300 depicted in Figure 1The described exemplary gas turbine engine is utilized together (i.e., configured as an exemplary fuel delivery system 146, which is capable of operating with the exemplary turbofan engine 100), and / or may be configured as the exemplary fuel oxygen reduction unit 200 described above. However, in other embodiments, the fuel delivery system 300 may be utilized with any other suitable gas turbine engine, vehicle (including, for example, an aircraft), etc. Figure 2 and Figure 6 the described exemplary fuel oxygen reduction unit 200. However, in other embodiments, the fuel delivery system 300 may be utilized with any other suitable gas turbine engine, vehicle (including, for example, an aircraft), etc.

[0132] As depicted, the fuel delivery system 300 generally includes a fuel source 302, a suction pump 304, and a first fuel line 306 extending between the fuel source 302 and the suction pump 304. The suction pump 304 may refer to a first pump that is positioned downstream of the fuel source 302 for generating a fuel flow from the fuel source 302. Thus, the depicted suction pump 304 is positioned downstream of the fuel source 302 for generating a liquid fuel flow from the fuel source 302 through the first fuel line 306 (note that the direction of the fuel flow through Figure 7 the fuel delivery system is schematically indicated by arrows on the respective fuel lines). When the exemplary fuel delivery system 300 is utilized with a gas turbine engine of an aircraft, the fuel source 302 may be a fuel tank, such as a fuel tank positioned within one of the wings of the aircraft, within the fuselage of the aircraft, or any other suitable location.

[0133] The fuel delivery system 300 further includes a main fuel pump 308 positioned downstream of the suction pump 304, as will be discussed in more detail below. The main fuel pump 308 may refer to a fuel pump for providing a pressurized fuel flow to a component for combusting such fuel (i.e., providing the final pressure increase upstream of such a component for combusting fuel, as will be described in more detail below). For the depicted embodiment, the main fuel pump 308 is mechanically coupled to a first power source 310, and the suction pump 304 is mechanically coupled to the main fuel pump 308 and is capable of rotating with the main fuel pump 308. In this way, the main fuel pump 308 and the suction pump 304 may share the first power source 310. For example, in certain embodiments, the first power source 310 may be a first pad of an accessory gearbox of a gas turbine engine (e.g., see Figure 1 the accessory gearbox 142). However, in other embodiments, the suction pump 304 may be powered by an independent power source relative to the main fuel pump 308. Additionally, in other embodiments, one or both of the suction pump 304 and the main fuel pump 308 may be powered by any other suitable power source.

[0134] Figure 7The exemplary fuel system further includes a fuel oxygen reduction unit 312 and a second fuel line 314. The fuel oxygen reduction unit 312 generally includes a stripping gas line 316 and a contactor 318. More specifically, the fuel oxygen reduction unit 312 defines a recycle gas flow path 320, wherein the stripping gas line 316 at least partially defines the recycle gas flow path 320. The contactor 318 is in fluid communication with the stripping gas line 316 (and the recycle gas flow path 320) and the suction pump 304 (via the second fuel line 314 for the illustrated embodiment) for forming a fuel / gas mixture. Notably, for the depicted embodiment, the exemplary fuel oxygen reduction unit 312 further includes a gas booster pump 322, a preheater 324, a catalytic converter 326, and a water removal member 327, each arranged in series within the recycle gas flow path 320. These components can be configured to provide a stripping gas having desired properties through the recycle gas flow path 320 and the stripping gas line 316 to mix with the fuel within the contactor 318 to reduce the oxygen content of the fuel and remove water from the stripping gas stream.

[0135] In addition, the exemplary fuel oxygen reduction unit 312 further includes a separator 328, which is in fluid communication with the contactor 318 for receiving the fuel / gas mixture from the contactor 318 and separating the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream at a location upstream of the main fuel pump 308. Notably, Figure 7 the fuel oxygen reduction unit 312 and the exemplary separator 328 can be constructed in substantially the same manner as the exemplary fuel oxygen reduction unit 200 and separator 204 described above with reference to Figure 2 and Figure 6 Accordingly, it will be appreciated that the separator 328 can be a mechanically driven dual separator pump 328 that is coupled to a second power source 330. For Figure 7 the embodiment, the second power source 330 can be a second pad of an accessory gearbox. In this way, the separator 328 and the main fuel pump 308 (and the suction pump 304 for the illustrated embodiment) can each be driven by, for example, the accessory gearbox. However, it will be appreciated that for the depicted embodiment, the main fuel pump 308 and the separator 328 can be coupled to different pads of the accessory gearbox such that the main fuel pump 308 and the separator 328 can rotate at different rotational speeds.

[0136] However, it will be recognized that in other exemplary embodiments, the fuel oxygen reduction unit 312 may have any other suitable configuration. For example, in other embodiments, the fuel oxygen reduction unit 312 may have any other suitable separator 328, may have its components arranged in any other suitable flow order, may not include each of the depicted components, may include components configured in any other suitable manner, or may include other components not depicted or described herein.

[0137] Still referring to Figure 7 the embodiment of Figure 2 and Figure 6 described above with reference to Figure 7 the exemplary separator 204 as Figure 6 depicted in

[0138] the separator 328 depicted in Figure 7 is further configured to generate a pressure rise of at least about sixty (60) psi (such as at least ninety (90) psi and up to about seven hundred fifty (750) psi) in the fuel stream. In this way, the liquid fuel outlet pressure generated by the separator 328 can be at least about seventy (70) psi or greater. In certain exemplary embodiments, this can be achieved by a single-stage separator / pump assembly (see, for example,

[0139] the assembly 234 of Figure 7For the embodiments shown, substantially all of the fuel flow from the suction pump 304 to the main fuel pump 308 flows through the separator 328 of the fuel oxygen reduction unit 312. More specifically, for the depicted exemplary embodiment, substantially all of the fuel flow from the suction pump 304 to the main fuel pump 308 flows through the separator 328 of the fuel oxygen reduction unit 312, without an option for a bypass (i.e., no bypass line around the separator 328 for the shown embodiment). This can thus ensure that the separator 328 of the fuel oxygen reduction unit 312 can provide a desired amount of pressure rise in the fuel flow between the suction pump 304 and the main fuel pump 308. However, note that in other exemplary aspects of the present disclosure, the fuel delivery system 300 may include one or more bypass lines and / or fuel boost pumps. However, in cases where the separator 328 is included, the sizing of any such fuel boost pumps may not need to be as large.

[0140] The outlet fuel flow is provided from the fuel oxygen reduction unit 312 to the third fuel line 332 of the fuel delivery system 300. The third fuel line 332 of the fuel delivery system 300 is in fluid communication with one or more engine system heat exchangers, each of which thermally couples the third fuel line 332 (or rather, the fuel flow through the third fuel line 332) to a corresponding engine system. More specifically, for the shown embodiment, the third fuel line 332 is in thermal communication with the first engine system heat exchanger 334 and the second engine system heat exchanger 336. The first engine system heat exchanger 334 and the second engine system heat exchanger 336 may be thermally coupled to the corresponding first engine system 338 and second engine system 340. The first engine system 338 and the second engine system 340 may be any suitable engine systems, such as one or more of a main lubrication oil system, a variable frequency generator system, etc.

[0141] A third fuel line 332 further extends to a main fuel pump 308 such that one or more of the aforementioned heat exchangers 334, 336 are positioned upstream of the main fuel pump 308 and downstream of the fuel oxygen reduction unit 312. The main fuel pump 308 may further increase the pressure of the fuel flow from the third fuel line 332 and provide such a relatively high-pressure fuel flow through a fourth fuel line 342 of the fuel delivery system 300. Notably, the exemplary fuel delivery system 300 further includes a fuel metering unit 344 and a fifth fuel line 346. For the depicted embodiment, the fourth fuel line 342 extends to the fuel metering unit 344 of the fuel delivery system 300. The exemplary fuel metering unit 344 generally includes a fuel metering valve 348 and a bypass valve 350. For the illustrated embodiment, the fuel metering valve 348 is positioned downstream of the bypass valve 350, but these positions may be reversed. The fuel metering valve 348 may be configured to meter the fuel flow provided to the fifth fuel line 346 and through the fifth fuel line 346 to, for example, a combustion device. More specifically, for the depicted embodiment, the fifth fuel line 346 is configured to provide a fuel flow to one or more burner assemblies 352 (which may be, for example, within a combustion section of a gas turbine engine; see, for example Figure 1 ). In this manner, the fuel metering valve 348 may control the operation of a gas turbine engine including one or more combustion assemblies 352 by adjusting the fuel flow to such burner assemblies 352. Thus, it will be appreciated that when such fuel is not needed or desired by the combustion device (as indicated by the fuel metering valve 348), the bypass valve 350 of the fuel metering unit 344 may return the fuel flow to a location upstream of the fuel metering unit 344. Specifically, for the illustrated embodiment, the bypass valve 350 is configured to return such fuel through a sixth fuel line 354 of the fuel delivery system 300 to a junction 356 in the third fuel line 332 upstream of one or more heat exchangers (i.e., heat exchangers 334, 336 for the depicted embodiment).

[0142] Briefly, it will also be appreciated that for the illustrated embodiment, the fuel delivery system 300 includes a third heat exchanger 358, which is positioned downstream of the fuel metering unit 344 and upstream of the burner assemblies 352. The third heat exchanger 358 may also be an engine system heat exchanger configured to thermally connect the fuel flow through the fifth fuel line 346 to such an engine system (i.e., a third engine system 360). The third engine system 360 thermally coupled to the third heat exchanger 358 may be the same as one of the engine systems 338, 340 described above, or alternatively, may be any other suitable engine system.

[0143] In this manner, it will be appreciated that a fuel oxygen reduction unit 312 including a separator 328 as described herein and positioned in the manner described herein can permit a more efficient fuel delivery system 300. For example, with the fuel oxygen reduction unit 312 positioned downstream of the suction pump 304 and upstream of the main fuel pump 308, heat can be added to the deoxygenated fuel upstream (and downstream) of the main fuel pump 308. Additionally, including a separator 328 according to the embodiments described herein can permit reducing the size of a boost pump, or eliminating such a boost pump (such as in the depicted embodiment), potentially saving cost and weight of the fuel delivery system 300.

[0144] In an exemplary aspect of the present disclosure, a method for operating a fuel delivery system for a gas turbine engine is provided. The method includes: receiving an inlet fuel stream in an oxygen transfer assembly of a fuel oxygen reduction unit for reducing an amount of oxygen in the inlet fuel stream using a stripping gas stream through a stripping gas flow path; separating the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream; receiving the outlet stripping gas stream in a catalytic converter at a location downstream of the oxygen transfer assembly, the catalytic converter receiving and processing the outlet stripping gas stream from the oxygen transfer assembly, wherein the stripping gas stream exits the catalytic converter; and removing water from the stripping gas stream downstream of the catalytic converter.

[0145] Additional aspects of the invention are provided by the subject matter of the following clauses:

[0146] 1. A fuel delivery system for a gas turbine engine, comprising: a fuel source; a suction pump downstream of the fuel source for generating a liquid fuel stream from the fuel source; a main fuel pump downstream of the suction pump; and a fuel oxygen reduction unit downstream of the suction pump and upstream of the main fuel pump, the fuel oxygen reduction unit including: a stripping gas line; a contactor in fluid communication with the stripping gas line and the suction pump for forming a fuel / gas mixture, wherein the contactor receives an inlet fuel stream from the suction pump; a separator in fluid communication with the contactor, the separator receiving the fuel / gas mixture and separating the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream at a location upstream of the main fuel pump; a catalytic converter disposed downstream of the separator, the catalytic converter receiving and processing the outlet stripping gas stream, wherein the stripping gas stream exits the catalytic converter; and a water removal member disposed between the catalytic converter and the contactor, wherein the water removal member removes water from the stripping gas stream.

[0147] 2. The fuel delivery system according to any of the preceding clauses, wherein the inlet stripping gas stream exits the water removal member and flows via the stripping gas line to the contactor.

[0148] 3. The fuel delivery system according to any of the preceding clauses, wherein the outlet fuel stream has a lower oxygen content than the inlet fuel stream.

[0149] 4. A fuel delivery system according to any of the preceding clauses, wherein the outlet fuel stream has a higher pressure than the inlet fuel stream.

[0150] 5. A fuel delivery system according to any of the preceding clauses, wherein the outlet stripping gas stream has a higher oxygen content than the inlet stripping gas stream.

[0151] 6. A fuel delivery system according to any of the preceding clauses, wherein the catalytic converter removes oxygen from the outlet stripping gas stream by chemically converting the oxygen in the outlet stripping gas stream into water vapor and carbon dioxide in the stripping gas stream.

[0152] 7. A fuel delivery system according to any of the preceding clauses, wherein the water removal member removes water vapor from the stripping gas stream.

[0153] 8. A fuel delivery system according to any of the preceding clauses, wherein the water removal member includes a selectively permeable membrane that removes only water from the stripping gas stream.

[0154] 9. A fuel delivery system according to any of the preceding clauses, wherein the water removal member includes a desiccant that absorbs water from the stripping gas stream.

[0155] 10. A fuel delivery system according to any of the preceding clauses, wherein the water removal member includes a condenser.

[0156] 11. A fuel delivery system according to any of the preceding clauses, wherein the fuel oxygen reduction unit recirculates the stripping gas.

[0157] 12. A fuel delivery system for a gas turbine engine, comprising: a fuel oxygen reduction unit that defines a stripping gas flow path and includes an inlet fuel line and an outlet fuel line, the fuel oxygen reduction unit including: an oxygen transfer assembly for reducing the amount of oxygen in an inlet fuel stream passing through the inlet fuel line using a stripping gas stream passing through the stripping gas flow path; a catalytic converter in airflow communication with the stripping gas flow path at a location downstream of the oxygen transfer assembly, the catalytic converter receiving and processing the stripping gas stream in the stripping gas flow path from the oxygen transfer assembly, wherein the stripping gas stream exits the catalytic converter; and a water removal member disposed downstream of the catalytic converter, wherein the water removal member removes water from the stripping gas stream.

[0158] 13. A fuel delivery system according to any of the preceding clauses, wherein the oxygen transfer component comprises: a contactor including a fuel inlet receiving an inlet fuel stream from a liquid fuel flow path and a stripping gas inlet receiving an inlet stripping gas stream from a stripping gas flow path, the contactor being configured to form a fuel / gas mixture; and a separator including an inlet in fluid communication with the contactor, a fuel outlet, and a stripping gas outlet, the inlet receiving the fuel / gas mixture, wherein the separator is configured to separate the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream, and to provide the outlet stripping gas stream to the stripping gas flow path through the stripping gas outlet and to provide the outlet fuel stream to an outlet fuel line through the fuel outlet.

[0159] 14. A fuel delivery system according to any of the preceding clauses, wherein the inlet stripping gas stream exits the water removal member and flows to the contactor via a stripping gas line.

[0160] 15. A fuel delivery system according to any of the preceding clauses, wherein the outlet fuel stream has a lower oxygen content than the inlet fuel stream, and wherein the outlet stripping gas stream has a higher oxygen content than the inlet stripping gas stream.

[0161] 16. A fuel delivery system according to any of the preceding clauses, wherein the catalytic converter removes oxygen from the stripping gas stream by chemically converting oxygen in the outlet stripping gas stream into water vapor and carbon dioxide in the stripping gas airflow.

[0162] 17. A fuel delivery system according to any of the preceding clauses, wherein the water removal member removes water vapor from the stripping gas airflow.

[0163] 18. A fuel delivery system according to any of the preceding clauses, wherein the water removal member comprises a selectively permeable membrane that removes water from the stripping gas airflow.

[0164] 19. A fuel delivery system according to any of the preceding clauses, wherein the water removal member comprises a desiccant that absorbs water from the stripping gas airflow.

[0165] 20. A fuel delivery system according to any of the preceding clauses, wherein the water removal member comprises a condenser.

[0166] 21. A fuel oxygen reduction unit according to any of the preceding clauses, wherein the gas booster pump is electrically connected to a permanent magnet alternator (PMA).

[0167] 22. A fuel oxygen reduction unit according to any of the preceding clauses, wherein the separator is electrically connected to a permanent magnet alternator (PMA).

[0168] 23. A fuel oxygen reduction unit according to any of the preceding clauses, wherein the stripping gas stream leaving the separator does not recycle through the system.

[0169] 24. A fuel oxygen reduction unit according to any of the preceding clauses, wherein the gas booster pump, the catalytic converter, the preheater, and the water removal member are in serial flow.

[0170] 25. A fuel oxygen reduction unit according to any of the preceding clauses, wherein the preheater, the catalytic converter, the water removal member, and the gas booster pump are in serial flow.

[0171] 26. A fuel oxygen reduction unit according to any of the preceding clauses, wherein the catalytic converter, the preheater, the gas booster pump, and the water removal member are in serial flow.

[0172] 27. A method for operating a fuel delivery system for a gas turbine engine is provided. The method includes: receiving an inlet fuel stream in an oxygen transfer component of a fuel oxygen reduction unit for reducing the amount of oxygen in the inlet fuel stream using a stripping gas stream through a stripping gas flow path; separating the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream; receiving the outlet stripping gas stream in a catalytic converter at a location downstream of the oxygen transfer component, the catalytic converter receiving and processing the outlet stripping gas stream from the oxygen transfer component, wherein the stripping gas stream exits the catalytic converter; and removing water from the stripping gas stream downstream of the catalytic converter.

[0173] This written description uses examples to disclose the invention (including the best mode), and also enables any person skilled in the art to practice the invention (including making and using any device or system, and performing any incorporated method). The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. If such other examples include structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims, then such other examples are intended to be within the scope of the claims.

[0174] Although this disclosure has been described as having an exemplary design, the disclosure may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of this disclosure that use the general principles of this disclosure. In addition, this application is intended to cover such departures from this disclosure as come within known or customary practice in the art to which this disclosure pertains and fall within the limits of the appended claims.

Claims

1. A fuel delivery system for a gas turbine engine, comprising: Fuel source; A suction pump downstream of the fuel source for generating a liquid fuel stream from the fuel source; A main fuel pump downstream of the suction pump; And A fuel oxygen reduction unit downstream of the suction pump and upstream of the main fuel pump, the fuel oxygen reduction unit comprising: A stripping gas line; A contactor in fluid communication with the stripping gas line and the suction pump for forming a fuel / gas mixture, wherein the contactor receives an inlet fuel stream from the suction pump; A separator in fluid communication with the contactor, the separator receiving the fuel / gas mixture and separating the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream at a location upstream of the main fuel pump; A catalytic converter disposed downstream of the separator, the catalytic converter receiving and processing the outlet stripping gas stream, wherein a stripping gas air stream exits the catalytic converter; A water removal member disposed between the catalytic converter and the contactor, wherein the water removal member removes water from the stripping gas air stream; and A booster pump downstream of the separator and upstream of the contactor, wherein both the separator and the booster pump are coupled to and driven by an accessory gearbox of the gas turbine engine.

2. The fuel delivery system according to claim 1, wherein The inlet stripping gas stream exits the water removal member and flows via the stripping gas line to the contactor.

3. The fuel delivery system according to claim 2, wherein The outlet fuel stream has a lower oxygen content than the inlet fuel stream.

4. The fuel delivery system according to claim 2, wherein The outlet fuel stream has a higher pressure than the inlet fuel stream.

5. The fuel delivery system according to claim 2, wherein The outlet stripping gas stream has a higher oxygen content than the inlet stripping gas stream.

6. The fuel delivery system according to claim 1, wherein The catalytic converter removes oxygen from the outlet stripping gas stream by chemically converting the oxygen in the outlet stripping gas stream into water vapor and carbon dioxide in the stripping gas air stream.

7. The fuel delivery system according to claim 6, wherein The water removal member removes the water vapor from the stripping gas air stream.

8. The fuel delivery system according to claim 1, wherein The water removal member includes a selectively permeable membrane that removes only the water from the stripping gas air stream.

9. The fuel delivery system according to claim 1, wherein The water removal member includes a desiccant that absorbs the water from the stripping gas air stream.

10. The fuel delivery system according to claim 1, wherein The water removal member includes a condenser.

11. The fuel delivery system according to claim 1, wherein The fuel oxygen reduction unit recycles the stripping gas.

12. A fuel delivery system for a gas turbine engine, comprising: A fuel oxygen reduction unit that defines a stripping gas flow path and includes an inlet fuel line and an outlet fuel line, the fuel oxygen reduction unit comprising: An oxygen transfer assembly for reducing the amount of oxygen in an inlet fuel stream passing through the inlet fuel line using a stripping gas stream passing through the stripping gas flow path, the oxygen transfer assembly comprising: A contactor including a fuel inlet for receiving the inlet fuel stream from the liquid fuel flow path and a stripping gas inlet for receiving an inlet stripping gas stream from the stripping gas flow path, the contactor configured to form a fuel / gas mixture; A separator including an inlet, a fuel outlet, and a stripping gas outlet in fluid communication with the contactor, the inlet receiving the fuel / gas mixture, wherein the separator is configured to separate the fuel / gas mixture into an outlet stripping gas stream and an outlet fuel stream and to provide the outlet stripping gas stream to the stripping gas flow path through the stripping gas outlet and the outlet fuel stream to the outlet fuel line through the fuel outlet; A catalytic converter in air flow communication with the stripping gas flow path at a location downstream of the oxygen transfer component, the catalytic converter receiving and processing the stripping gas stream in the stripping gas flow path from the oxygen transfer component, wherein a stripping gas air stream exits the catalytic converter; A water removal member disposed downstream of the catalytic converter, wherein the water removal member removes water from the stripping gas air stream; and A booster pump downstream of the separator and upstream of the contactor, wherein both the separator and the booster pump are coupled to an accessory gearbox of the gas turbine engine and are driven by the accessory gearbox of the gas turbine engine.

13. The fuel delivery system according to claim 12, wherein The inlet stripping gas stream exits the water removal member and flows via a stripping gas line to the contactor.

14. The fuel delivery system according to claim 13, wherein The outlet fuel stream has a lower oxygen content than the inlet fuel stream, and wherein the outlet stripping gas stream has a higher oxygen content than the inlet stripping gas stream.

15. The fuel delivery system according to claim 12, wherein The catalytic converter removes oxygen from the stripping gas stream by chemically converting the oxygen in the outlet stripping gas stream to water vapor and carbon dioxide in the stripping gas air stream.

16. The fuel delivery system according to claim 15, wherein The water removal member removes the water vapor from the stripping gas air stream.

17. The fuel delivery system according to claim 12, wherein The water removal member includes a selectively permeable membrane that removes the water from the stripping gas air stream.

18. The fuel delivery system according to claim 12, wherein The water removal member includes a desiccant that absorbs the water from the stripping gas air stream.

19. The fuel delivery system according to claim 12, wherein The water removal member includes a condenser.

20. A method for operating a fuel delivery system for a gas turbine engine, comprising: An inlet fuel stream is received in an oxygen transfer component of a fuel oxygen reduction unit for reducing the amount of oxygen in the inlet fuel stream using a stripping gas stream through a stripping gas flow path; The fuel / gas mixture is separated into an outlet stripping gas stream and an outlet fuel stream by a separator; The outlet stripping gas stream is received in a catalytic converter at a location downstream of the oxygen transfer component and in a booster pump downstream of the oxygen transfer component, wherein both the separator and the booster pump are coupled to an accessory gearbox of the gas turbine engine and are driven by the accessory gearbox of the gas turbine engine, the catalytic converter receiving and processing the outlet stripping gas stream from the oxygen transfer component, wherein a stripping gas air stream exits the catalytic converter; and Water is removed from the stripping gas air stream downstream of the catalytic converter.

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