Fuel delivery system with fuel oxygen reduction unit

Abstract

A fuel oxygen reduction unit assembly for a fuel system is provided. The fuel oxygen reduction unit assembly includes: a fuel oxygen reduction unit located downstream of a fuel source and defining a stripping gas flow path and a liquid fuel flow path, the fuel oxygen reduction unit including a device for transferring a certain amount of oxygen from a liquid fuel flow passing through the liquid fuel flow path to a gas flow passing through the stripping gas flow path; and an oxygen conversion unit, the oxygen conversion unit being in flow communication with the stripping gas flow path, the oxygen conversion unit being configured to extract an oxygen flow from the gas flow passing through the stripping gas flow path, the oxygen conversion unit defining an oxygen outlet, the oxygen outlet being configured to provide the extracted oxygen flow to an external system.

Description

Technical Field

[0001] The present subject matter generally relates to a fuel oxygen reduction unit for a fuel delivery system of a vehicle. Background Art

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

[0003] Certain operations and systems of gas turbine engines and aircraft may generate relatively large amounts of heat. Fuel has been identified as an effective heat sink for receiving at least a portion of such heat during operation, at least in part due to its heat capacity and the increased efficiency of combustion operations that may result from burning high temperature fuel. However, heating the fuel without properly conditioning the fuel may cause the fuel to "coke," or form solid particles that may clog certain components of the fuel system, such as fuel nozzles. Reducing the amount of oxygen in the fuel may effectively reduce the likelihood of fuel coking beyond an unacceptable amount. Fuel oxygen reduction systems have been proposed for this purpose.

[0004] The inventors of the present disclosure have discovered that further efficiencies can be achieved based on the types of components used within a fuel oxygen reduction unit. Therefore, a fuel oxygen reduction unit that exploits these efficiencies would be useful. Summary of the invention

[0005] Aspects and advantages of the invention will be set forth in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0006] In an exemplary embodiment of the present disclosure, a fuel oxygen reduction unit assembly for a fuel system is provided. The fuel oxygen reduction unit assembly includes: a fuel oxygen reduction unit, the fuel oxygen reduction unit is located downstream of a fuel source and defines a stripping gas flow path and a liquid fuel flow path, the fuel oxygen reduction unit includes a device for transferring a certain amount of oxygen from a liquid fuel flow passing through the liquid fuel flow path to a gas flow passing through the stripping gas flow path; and an oxygen conversion unit, the oxygen conversion unit is in flow communication with the stripping gas flow path, the oxygen conversion unit is configured to extract an oxygen flow from the gas flow passing through the stripping gas flow path, the oxygen conversion unit defines an oxygen outlet, and the oxygen outlet is configured to provide the extracted oxygen flow to an external system.

[0007] Technical Solution 1. A fuel oxygen reduction unit assembly for a fuel system, the fuel oxygen reduction unit comprising:

[0008] a fuel oxygen reduction unit located downstream of a fuel source and defining a stripping gas flow path and a liquid fuel flow path, the fuel oxygen reduction unit comprising

[0009] means for transferring an amount of oxygen from a flow of liquid fuel through said liquid fuel flow path to a flow of gas through said stripping gas flow path; and

[0010] An oxygen conversion unit is in flow communication with the stripping gas flow path, the oxygen conversion unit being configured to extract an oxygen stream from the gas stream passing through the stripping gas flow path, the oxygen conversion unit defining an oxygen outlet configured to provide the extracted oxygen stream to an external system.

[0011] Technical Solution 2. The fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the fuel system is a fuel system for an aircraft, and wherein the external system is an accessory system of the aircraft.

[0012] Technical Solution 3. The fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the device for transferring the amount of oxygen from the liquid fuel flow to the gas flow comprises:

[0013] a contactor defining a liquid fuel inlet, a stripping gas inlet, and a fuel / gas mixture outlet; and

[0014] A fuel / gas separator defines a fuel / gas mixture inlet in flow communication with the fuel / gas mixture outlet of the contactor, a liquid fuel outlet, and a stripping gas outlet.

[0015] Technical Solution 4. The fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the means for transferring the amount of oxygen from the liquid fuel stream to the gas stream comprises a membrane fuel oxygen reduction unit.

[0016] Technical Solution 5. The fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the oxygen conversion unit is a static component.

[0017] Technical Solution 6. A fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the oxygen conversion unit comprises a membrane defining a porous structure configured to filter oxygen from the gas flow passing through the stripping gas flow path.

[0018] Technical Solution 7. The fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the oxygen conversion unit comprises a catalyst, wherein the catalyst is configured to produce water from the gas flow passing through the stripping gas flow path.

[0019] Technical Solution 8. The fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the oxygen conversion unit further comprises a water hydrolysis device for generating an oxygen flow from the water generated by the catalyst.

[0020] Technical Solution 9. The fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the water hydrolysis device is a water electrolysis device.

[0021] Technical Solution 10. A fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the oxygen conversion unit is connected to the stripping gas flow path flow at a position downstream of the device for transferring the amount of oxygen from the liquid fuel flow passing through the liquid fuel flow path to the gas flow passing through the stripping gas flow path.

[0022] Technical Solution 11. A fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the oxygen conversion unit is connected to the stripping gas flow path flow at a position upstream of the device for transferring the amount of oxygen from the liquid fuel flow passing through the liquid fuel flow path to the gas flow passing through the stripping gas flow path.

[0023] Technical Solution 12. The fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the fuel oxygen reduction unit assembly further comprises:

[0024] A sensor is operable with the fuel oxygen reduction unit for sensing data indicative of gas flow through the oxygen outlet of the oxygen conversion unit.

[0025] Technical Solution 13. The fuel oxygen reduction unit assembly according to any of the preceding technical solutions, wherein the sensor is configured to sense data indicating an oxygen content of the gas flow through the oxygen outlet, a fuel content of the gas flow through the oxygen outlet, or both.

[0026] Technical Solution 14. An aircraft, comprising:

[0027] Attachment systems; and

[0028] A fuel delivery system comprising a fuel source and a fuel oxygen reduction unit, wherein the fuel oxygen reduction unit is located downstream of the fuel source and defines a stripping gas flow path and a liquid fuel flow path, wherein the fuel oxygen reduction unit comprises

[0029] means for transferring an amount of oxygen from a flow of liquid fuel through said liquid fuel flow path to a flow of gas through said stripping gas flow path; and

[0030] An oxygen conversion unit is in flow communication with the stripping gas flow path, the oxygen conversion unit being configured to extract oxygen from a gas flow therethrough, the oxygen conversion unit defining an oxygen outlet in flow communication with an accessory system of the aircraft.

[0031] Technical solution 15. An aircraft according to any of the preceding technical solutions, wherein the device for transferring the amount of oxygen from the liquid fuel flow to the air flow comprises:

[0032] a contactor defining a liquid fuel inlet, a stripping gas inlet, and a fuel / gas mixture outlet; and

[0033] A fuel / gas separator defines a fuel / gas mixture inlet in flow communication with the fuel / gas mixture outlet of the contactor, a liquid fuel outlet, and a stripping gas outlet.

[0034] Technical Solution 16. An aircraft according to any preceding technical solution, wherein the means for transferring the amount of oxygen from the liquid fuel flow to the air flow comprises a membrane fuel oxygen reduction unit.

[0035] Technical Solution 17. An aircraft according to any of the preceding technical solutions, wherein the oxygen conversion unit is a static component.

[0036] Technical Solution 18. A method comprising:

[0037] Using a fuel oxygen reduction unit, wherein using the fuel oxygen reduction unit comprises

[0038] extracting oxygen from liquid fuel, and

[0039] The extracted oxygen is provided to an external system.

[0040] Technical Solution 19. The method according to any of the above technical solutions, wherein the external system includes any one or more of the following:

[0041] a system external to said fuel oxygen reduction unit;

[0042] Environmental control systems;

[0043] Cabin air maintenance system;

[0044] cabin oxygen delivery system, crew oxygen delivery system, or both; and

[0045] An oxygen consumption or storage system located external to the engine core cowl or nacelle of an engine incorporating or utilizing the fuel oxygen reduction unit.

[0046] Technical Solution 20. The method according to any of the above technical solutions, wherein the using step further comprises:

[0047] receiving a liquid fuel stream with the fuel oxygen reduction unit;

[0048] Extracting oxygen from liquid fuel includes

[0049] transferring an amount of oxygen from the liquid fuel stream to the stripping gas stream, and

[0050] An oxygen stream is extracted from the stripping gas stream using an oxygen conversion unit.

[0051] These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] A complete and open disclosure of the present invention including its best mode for those skilled in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0053] Figure 1 is a top view of an aircraft according to various exemplary embodiments of the present disclosure.

[0054] Figure 2 is a schematic diagram of a fuel delivery system according to an exemplary embodiment of the present disclosure.

[0055] Figure 3 is a partially enlarged schematic diagram of a portion of a fuel delivery system according to an exemplary embodiment of the present disclosure.

[0056] Figure 4 According to an exemplary embodiment of the present disclosure Figure 3 Schematic enlarged partial cross-sectional view of a fuel gas separator of an exemplary fuel oxygen reduction unit of a fuel delivery system.

[0057] Figure 5 is a partially enlarged schematic diagram of an oxygen conversion unit according to an exemplary embodiment of the present disclosure.

[0058] Figure 6 is a partially enlarged schematic diagram of a portion of a fuel delivery system according to another exemplary embodiment of the present disclosure.

[0059] Figure 7is a partially enlarged schematic diagram of a portion of a fuel delivery system according to yet another exemplary embodiment of the present disclosure.

[0060] Figure 8 is a partially enlarged schematic diagram of a portion of a fuel delivery system according to yet another exemplary embodiment of the present disclosure.

[0061] Fig. 9 is a flow chart of a method of operating a fuel oxygen reduction unit. DETAILED DESCRIPTION

[0062] 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 letter references to refer to features in the drawings. Similar or similar references in the drawings and the specification are used to refer to similar or similar parts of the present invention.

[0063] As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of the individual components.

[0064] The terms "upstream" and "downstream" refer to relative directions with respect to fluid flow in a fluid pathway. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction to which the fluid is flowing.

[0065] The terms “coupled,” “fixed,” “attached to,” and the like refer to both direct coupling, fixing, or attachment as well as indirect coupling, fixing, or attachment through one or more intermediate members or features, unless otherwise specified herein.

[0066] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0067] Approximate language, as used throughout the specification and claims herein, is used to modify any quantitative expression that is permissibly variable without causing a change in the basic function to which it relates. Thus, values ​​modified by one or more terms such as "about," "approximately," and "roughly" are not limited to the exact values ​​specified. In at least some cases, approximate language may correspond to the precision of an instrument for measuring a value, or the precision of a method or machine for constructing or manufacturing a component and / or system. For example, approximate language may refer to within a 10 percent margin.

[0068] Here and throughout the specification and claims, range limitations combine and interchange, such ranges are identified and include all sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.

[0069] As noted above, the inventors of the present disclosure have discovered that further efficiencies can be achieved within a fuel oxygen reduction unit based on the types of components used within the fuel oxygen reduction unit. Therefore, a fuel oxygen reduction unit that exploits these efficiencies would be useful.

[0070] The present disclosure provides for such benefits. More particularly, the present disclosure generally relates to a fuel oxygen reduction unit for a fuel system that can provide multiple benefits simultaneously. More particularly, the present disclosure generally provides for a fuel system having a fuel oxygen reduction unit located downstream of a fuel source and defining a stripping gas flow path and a liquid fuel flow path. The fuel oxygen reduction unit includes a device for transferring a certain amount of oxygen from a liquid fuel flow through the liquid fuel flow path to a gas flow through the stripping gas flow path. The device can be a combination of a contactor and a separator, a membrane-based system, a chemical injection-based system, or some other mechanical or chemical device for transferring a certain amount of oxygen from a liquid fuel flow through the liquid fuel flow path to a gas flow through the stripping gas flow path.

[0071] The fuel oxygen reduction unit also includes an oxygen conversion unit in flow communication with the stripping gas flow path, the oxygen conversion unit configured to extract an oxygen flow from the gas flow through the stripping gas flow path, the oxygen conversion unit defining an oxygen outlet, the oxygen outlet configured to provide the extracted oxygen flow to an external system. In certain embodiments, the fuel system is a fuel system for an aircraft, and the external system is an accessory system of the aircraft. Alternatively, however, when the fuel system is used for a different vehicle or non-vehicle system, the external system may be any other suitable system.

[0072] With the above configuration, the fuel oxygen reduction unit can provide further efficiencies by simultaneously reducing the oxygen content of the liquid fuel stream (allowing such fuel to be brought to higher temperatures where the risk of coking is reduced) while also extracting a usable oxygen stream. In the context of an aircraft, this can allow the aircraft to forgo the inclusion of potentially heavy and space-consuming oxygen tanks on board.

[0073] Referring now to the drawings, wherein like numerals refer to like elements throughout the drawings, Figure 1A top view of an exemplary aircraft 10 as may be incorporated with various embodiments of the present invention is provided. The aircraft 10 defines a longitudinal centerline 14 extending therethrough, a vertical direction (not shown), a lateral direction L, a front end 16, and a rear end 18. In addition, the aircraft 10 includes a fuselage 12 extending longitudinally from the front end 16 of the aircraft 10 toward the rear end 18 of the aircraft 10, and a pair of wings 20. A first wing 20A of such wings 20 extends laterally outward from a port side 22 of the fuselage 12 about the longitudinal centerline 14, and a second wing 20B of such wings 20 extends laterally outward from a right chord 24 of the fuselage 12 about the longitudinal centerline 14. For the depicted exemplary embodiment, each wing 20 includes one or more leading edge flaps 26 and one or more trailing edge flaps 28. The aircraft 10 also includes a vertical stabilizer 30 having a rudder flap 32 for yaw control, and a pair of horizontal stabilizers 34 each having an elevator flap 36 for pitch control. The fuselage 12 additionally includes an outer surface or skin 38. However, it should be appreciated that in other exemplary embodiments of the present disclosure, the aircraft 10 may additionally or alternatively include any other suitable configuration of stabilizing wings that may or may not extend directly in the vertical direction or the horizontal / lateral direction L. Furthermore, the aircraft 10 may include any other suitable configuration of wings 20, fuselage 12, etc. (e.g., canard configuration, blended wing configuration, etc.).

[0074] Figure 1 The exemplary aircraft 10 includes a propulsion system 50, referred to herein as "system 50." The exemplary system 50 includes one or more aircraft engines 52. For example, the depicted embodiment includes a plurality of aircraft engines 52, each of which is configured to be mounted to the aircraft 10, such as to one of a pair of wings 20. More particularly, for the depicted embodiment, the aircraft engines 52 are configured as gas turbine engines, such as turbofan jet engines, attached to and suspended below the wing 20 in an underwing configuration (it should be recognized that in other embodiments, the aircraft engines 52 may be any other suitable, at least partially combustion engine engines). For example, the aircraft engines 52 include a first aircraft engine 52A and a second aircraft engine 52B. The first aircraft engine 52A is configured to be mounted to a first wing 20A of the aircraft 10, while the second aircraft engine 52 is configured to be mounted to a second wing 20B of the aircraft 10 (i.e., on the opposite side of the aircraft 10). It will be recognized that although Figure 1 Only two aircraft engines 52 are depicted in the figure, and in other embodiments, the propulsion system 50 of the aircraft 10 may have any other suitable number and type of aircraft engines 52 installed in any other suitable location (e.g., installed on a wing, installed on the fuselage at the tail end of the aircraft 10, installed on one or more stabilizing wings, etc.).

[0075] As in Figure 1As further depicted in FIG. 1 , the aircraft 10 includes a fuel delivery system 100. More particularly, the fuel delivery system 100 is generally configured to deliver fuel to the aircraft engines 52 (i.e., Figure 1 , a first aircraft engine 52A and a second aircraft engine 52B) of the embodiment are supplied with a certain amount of fuel. More particularly, for the illustrated embodiment, the fuel delivery system 100 is configured to provide a relatively low oxygen content fuel to the aircraft engine 52 during operation, as will be explained in more detail below. In this manner, it will be appreciated that the fuel delivery system 100 generally includes a fuel source 102 (e.g., a fuel tank) and a fuel oxygen reduction unit 104. The fuel oxygen reduction unit 104 is configured to receive fuel from the fuel source 102, reduce the oxygen content of such fuel, and provide such fuel to the aircraft engine 52. In addition, as will be described below with reference to Figure 2 and 3 Explained in more detail, the fuel oxygen reduction system 104 is further configured to reduce the oxygen content of air within the ullage of the fuel source 102. Notably, as used herein, the term "fuel oxygen reduction unit" generally means a device capable of reducing the free oxygen content of a fuel, such as a fuel oxygen conversion unit, a fuel oxygen extraction unit, and the like.

[0076] However, it will be appreciated that in other exemplary embodiments, the aircraft 10 and / or the engine 52 may have any other suitable configuration. For example, in other embodiments, the aircraft 10 may have other wing and / or fuselage designs, engine numbers and / or configurations or locations, etc. Furthermore, in other embodiments, the aircraft 10 may be, for example, a vertical take-off and landing aircraft, such as a helicopter. Other embodiments are also contemplated.

[0077] It will also be appreciated that, although not depicted, the aircraft 10 may include one or more accessory systems. For example, the aircraft 10 may include one or more oxygen-consuming accessory systems, such as a cabin air maintenance system, a cabin and / or crew oxygen delivery system, etc. As will be appreciated from the discussion below, the fuel oxygen reduction unit may include an oxygen conversion unit defining an oxygen outlet in airflow communication with the aircraft 10 for providing an oxygen flow to the aircraft 10, such as providing an oxygen flow to one or more of these oxygen-consuming accessory systems of the aircraft 10.

[0078] More specifically, reference will now be made briefly to Figure 2 , providing that it can be combined with Figure 1Schematic diagram of a fuel delivery system 100 in an aircraft 10 of FIG. As depicted, the fuel delivery system 100 generally includes a fuel source 102 and a fuel oxygen reduction unit 104, and defines a plurality of flow paths. In particular, for the illustrated embodiment, the fuel delivery system 100 and the fuel oxygen reduction unit 104 generally define a liquid fuel supply path 106, a stripping gas supply path 108, a liquid fuel outlet path 110, and a stripping gas return path 112. The stripping gas supply path 108 and the stripping gas return path 112 are both in gas flow communication with the fuel source 102 to receive a gas flow 114 (which is a stripping gas, as will be explained below) from the fuel source 102, and to provide the gas flow 114 back to the fuel source 102. Similarly, for the illustrated embodiment, the liquid fuel supply path 106 is in fluid communication with the fuel source 102 to receive a liquid fuel flow 116 therefrom. Notably, for the illustrated embodiment, the fuel source 102 is configured as a fuel tank. Within the fuel tank, the fuel source 102 includes a certain amount of liquid fuel and a certain amount of vapor / air / gas. The space within the tank containing the vapor / air / gas (e.g., within the tank and above the fuel) may generally be referred to as an idle space 118. During operation, it will be appreciated that the fuel oxygen reduction unit 104 is generally configured to receive an air / gas flow 114 from the idle space 118 of the fuel source 102 and a liquid fuel flow 116 from the fuel source 102 to reduce the oxygen content of each, to provide a relatively low oxygen content gas 114 flow back to the idle space 118, and to provide a relatively low oxygen content flow of liquid fuel 116 to the aircraft engine 52. By reducing the oxygen content of the vapor / air / gas in the idle space 118, the risk of ignition or fire occurring within the tank in the event of a spark may be reduced. In addition, by reducing the oxygen content of the liquid fuel 116 provided to the engine 52, more heat may be added thereto, with a reduced risk of coking (allowing for increased efficiency of the combustion process and providing an effective heat sink).

[0079] In particular, for the illustrated embodiment, the fuel delivery system 100 is configured to provide fuel 116 having a relatively low oxygen content from the fuel oxygen reduction unit 104 to each of the plurality of aircraft engines 52, which for the illustrated embodiment includes a first aircraft engine 52A, a second aircraft engine 52B, through an “Nth” aircraft engine 52N (e.g., a third, fourth, fifth, sixth, etc. aircraft engine 52). In such a manner, it will be appreciated that the fuel deoxygenation unit 104 is fluidly coupled to each of the plurality of aircraft engines 52 via the liquid fuel outlet path 110, and is therefore configured to provide the relatively low oxygen content liquid fuel 116 to each such engine 52.

[0080] Notably, for the illustrated embodiment, the fuel delivery system 100 also includes a return valve 120 and a return line 122 for returning a quantity of relatively low oxygen content liquid fuel to the fuel source 102 in the event that such fuel is not required by the aircraft engine 52. However, in other embodiments, the system 100 may be configured without the return valve 120 and the return line 122, and instead regulate the liquid fuel flow 116 in other suitable manners.

[0081] In addition to the above, as will be explained in greater detail below, it will be appreciated that the fuel oxygen reduction unit 104 generally may include a means for transferring an amount of oxygen from a liquid fuel flow 116 passing through a liquid fuel flow path of the fuel oxygen reduction unit 104 to a gas flow 114 passing through a stripping gas flow path of the fuel oxygen reduction unit 104. The fuel oxygen reduction unit 104 generally may also include an oxygen conversion unit in flow communication with the stripping gas flow path, the oxygen conversion unit configured to extract oxygen from the gas flow 114 passing therethrough. The oxygen conversion unit defines an oxygen outlet that is in flow communication with the aircraft gas flow through an oxygen delivery conduit 121. For the depicted embodiment, the oxygen delivery conduit 121 is in flow communication with an accessory system 123 of the aircraft 100.

[0082] As will be discussed in greater detail below, a fuel delivery system 100 according to such exemplary embodiments is capable of maintaining lower oxygen content air within the neutral position 118 while also providing lower oxygen content fuel to a plurality of aircraft engines 52 while also producing a pure oxygen flow that may be utilized by accessory systems of the aircraft or other aspects of the aircraft.

[0083] Now refer to Figure 3 , provides a more detailed schematic diagram of a fuel delivery system 100 for an aircraft 10 according to an exemplary embodiment of the present disclosure. In at least some exemplary embodiments, Figure 3 The exemplary fuel delivery system 100 depicted in FIG. 1 may be incorporated into, for example, the fuel delivery system 100 described above with reference to FIG. Figure 1 The exemplary aircraft 10 described herein may be used in conjunction with Figure 2 1. Thus, it will be appreciated that the fuel delivery system 100 generally includes a fuel source 102 and a fuel oxygen reduction unit 104, and that the fuel delivery system 100 and the fuel oxygen reduction unit 104 generally define a liquid fuel supply path 106, a stripping gas supply path 108, a liquid fuel outlet path 110, and a stripping gas return path 112. For the depicted embodiment, the stripping gas return path 112 and the stripping gas supply path 108 are both in gas flow communication with the fuel source 102.

[0084] Furthermore, for the depicted embodiment, the liquid fuel supply path 106 of the fuel oxygen reduction unit 104 is in fluid communication with the fuel source 102. In this manner, it will be appreciated that the fuel oxygen reduction unit 104 is generally configured to receive a liquid fuel flow 116 from the fuel source 102, and is also configured to receive a gas flow 114 (referred to herein as "stripping gas") also from the fuel source 102. Furthermore, as will be described in detail below, the fuel oxygen reduction unit 104 is configured to return the stripping gas 114 to the fuel source 102. As noted with reference to the above embodiments, for Figure 3 In the embodiment of the present invention, the fuel source 102 generally includes a certain amount of liquid fuel 116 and defines a void 118 above the liquid fuel 116. The gas received by the stripping gas supply path 108 is received from the void 118, and the gas provided to the fuel source 102 by the stripping gas return path 112 is provided to the void 118.

[0085] To assist in the flow of the stripping gas 114 from the fuel source 102 or rather from the idle space 118 of the fuel source 102, the fuel delivery system 100 includes an idle space pump 124 in gas flow communication with the idle space 118 of the fuel source 102 and the stripping gas supply path 108 of the fuel oxygen reduction unit 104. Similarly, to assist in the flow of the liquid fuel 116 from the fuel source 102, the fuel delivery system 100 includes a fuel pump 126 in fluid communication with the fuel source 102 and the liquid fuel supply path 106.

[0086] In addition, for the depicted embodiment, the fuel oxygen reduction unit 104 defines a stripping gas flow path 132 and generally includes a device for transferring a certain amount of oxygen from the liquid fuel flow 116 through the liquid fuel flow path to the gas flow 114 through the stripping gas flow path 132. In particular, for the illustrated embodiment, the device includes the contactor 128 and the fuel gas separator 130. For the illustrated embodiment, the stripping gas flow path 132 includes the stripping gas supply path 108 and the stripping gas return path 112. Thus, the stripping gas flow path 132 generally extends from a location upstream of the contactor 128 through the contactor 128 and the separator 130 to a location downstream of the separator 130. In certain exemplary embodiments, the stripping gas flow path 132 may be formed by any combination of one or more conduits, tubes, pipes, etc. and the configuration of the components within the stripping gas flow path 132.

[0087] 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. In particular, for the depicted embodiment, the stripping gas 114 consists essentially of gas from the vacancy 118 of the fuel source 102. Thus, the stripping gas 114 may consist primarily of atmospheric air. Additionally or alternatively, the stripping gas 114 may be any other suitable gas, such as an inert gas or a substantially inert gas.

[0088] Still referring to the depicted embodiment, the fuel gas separator 130 is a mechanically driven fuel gas separator 130 that is mechanically coupled to and driven by a power source 134. Figure 3 In the embodiment of the present invention, the power source 134 driving the fuel gas separator 130 may be any suitable power source, such as an electric motor, a hydraulic motor, a pneumatic motor, a combustion engine, a power source shared with other components, etc. However, in other embodiments, the fuel gas separator 130 and the power source 134 driving the fuel gas separator 130 may be constructed in any other suitable manner.

[0089] As will be explained in more detail below, for Figure 3 In the embodiment of the present invention, the contactor 128 generally defines a gas inlet 136, a liquid fuel inlet 138, and a fuel / gas mixture outlet 140. In addition, the fuel gas separator 130 generally defines a gas outlet 142, a liquid fuel outlet 144, and a fuel / gas mixture inlet 146. The gas inlet 136 of the contactor 128 is in gas flow communication with the stripping gas supply path 108, the liquid fuel inlet 138 of the contactor 128 is fluidly connected to the liquid fuel supply path 106, and the fuel / gas mixture outlet 140 of the contactor 128 is fluidly connected to the inlet 146 of the fuel gas separator 130. In addition, the gas outlet 142 of the separator 130 is in gas flow communication with the stripping gas return path 112 of the stripping gas flow path 132, and the liquid fuel outlet 144 of the separator 130 is fluidly connected to the liquid fuel outlet path 110.

[0090] In addition, for Figure 3 , the exemplary fuel oxygen reduction unit 104 further includes an oxygen conversion unit in flow communication with the stripping gas flow path 132 and configured to extract oxygen from the gas flow 114 therethrough. The oxygen conversion unit defines an oxygen outlet 200 configured to communicate with the aircraft gas flow.

[0091] More particularly, for the illustrated embodiment, the oxygen conversion unit is a first oxygen conversion unit 202, and the fuel oxygen reduction unit 104 further includes a second oxygen conversion unit 204 in flow communication with the stripping gas flow path 132, the second oxygen conversion unit also configured to extract oxygen from the gas flow 114 passing therethrough. The second oxygen conversion unit 204 similarly defines an oxygen outlet configured to be in gas flow communication with the aircraft.

[0092] For the illustrated embodiment, the first oxygen conversion unit 202 includes a first catalyst 148, and the second oxygen conversion unit 204 includes a second catalyst 150. For the illustrated embodiment, the first catalyst 148 and the second catalyst 150 are each arranged in series along the stripping gas flow path 132. More particularly, for the illustrated embodiment, the first catalyst 148 is positioned at a position upstream of the contactor 128 (and downstream of the neutral 118) within the stripping gas flow path 132, and the second catalyst 150 is positioned at a position downstream of the separator 130 (and upstream of the neutral 118) within the stripping gas flow path 132. However, it will be appreciated that in other embodiments, the listed components may be provided in any suitable flow order, may not include all of the listed components, or may include additional components that are not listed. The operation of the first oxygen conversion unit 202 and the second oxygen conversion unit 204 will be explained in more detail below.

[0093] also, Figure 3 The exemplary fuel oxygen reduction unit 104 depicted in FIG. 1 further includes a heat exchanger 152 for reducing the temperature of the gas flowing into the idle 118 of the fuel source 102 .

[0094] During typical operation, the stripping gas 114 is pushed by the idler pump 124 through the stripping gas supply flow path 108 and through the upstream flame arrester 154. In short, the upstream flame arrester 154 can be configured to prevent flames from entering the fuel source 102 from the stripping gas supply path 108 and vice versa. For the illustrated embodiment, the stripping gas 114 passes from the idler pump 124 through the preheater 125 and flows into the first catalyst 148 of the first oxygen conversion unit 202. The preheater 125 can be configured to increase the temperature of the stripping gas 114 to or above the activation temperature of the first catalyst 148 (e.g., the minimum light-off temperature of the first catalyst 148, which allows the first catalyst 148 to operate properly). Although the exemplary preheater 125 is depicted as a separate component from the first catalyst 148, in other embodiments, the preheater 125 can be integrated into the first catalyst 148, or included as part of the first oxygen conversion unit 202.

[0095] Still refer to Figure 3As will be appreciated from the first catalyst 148, the stripping gas 114 is provided to the gas inlet 136 of the contactor 128. At the same time, the liquid fuel 116 is pushed from the fuel source 102 to and through the liquid fuel supply path 106 by the fuel pump 126. The liquid fuel 116 flows from the fuel pump 126 through the heat exchanger 152, wherein the liquid fuel 116 can receive heat from the stripping gas stream 114 through the stripping gas return path 112. From the heat exchanger 152, the liquid fuel 116 still flows through the liquid fuel supply path 106 to the liquid fuel inlet 138 of the contactor 128. Within the contactor 128, the stripping gas 114 received through the stripping gas inlet 136 is mixed with the liquid fuel stream 116 received through the liquid fuel inlet 138 to produce a fuel / gas mixture 156. The fuel gas mixture 156 produced within the contactor 128 is provided to the inlet 146 of the fuel gas separator 130.

[0096] In general, it will be appreciated that during operation of the fuel oxygen reduction unit 104, the liquid fuel 116 provided to the contactor 128 via the liquid fuel supply path 106 may have a relatively high oxygen content. In contrast, the stripping gas 114 provided to the contactor 128 may have a relatively low oxygen content or other specific chemical structure. Within the contactor 128, the liquid fuel 116 mixes with the stripping gas 114 to produce a fuel / gas mixture 156. As a result of such mixing, physical exchange may occur whereby at least a portion of the oxygen within the fuel 116 is transferred to the stripping gas 114, such that the fuel component of the mixture 156 has a relatively low oxygen content (compared to the fuel 116 provided via the liquid fuel supply path 106) and the stripping gas 114 component of the mixture 146 has a relatively high oxygen content (compared to the stripping gas 114 provided to the contactor 128 via the stripping gas supply path 108).

[0097] Now also briefly refer to Figure 4 , which provides Figure 3 15. Referring to the partially enlarged schematic cross-sectional view of an exemplary fuel gas separator 130, it will be appreciated that in the fuel gas separator 130, the stripping gas 114 having a relatively low oxygen content is generally separated from the fuel 116 having a relatively high oxygen content. In particular, for the illustrated embodiment, the fuel gas separator 130 defines a central axis 158 and a circumferential direction C extending about the central axis 158. In addition, the fuel gas separator 130 is configured as a mechanically driven fuel gas separator 130, or more particularly, as a rotating / centrifugal fuel gas separator 130. Thus, the fuel gas separator 130 includes an input shaft 160 and a separation assembly 162, the input shaft 160 being mechanically coupled to the separation assembly 162, the two components together being rotatable about the central axis 158. In addition, the input shaft 160 may be mechanically coupled to and driven by, for example, a suitable power source 134.

[0098] Additionally, the depicted exemplary separation assembly 162 generally includes an inner filter 164 disposed along the central axis 158, and a plurality of paddles 166 positioned radially outward of the inner filter 164. During operation, rotation of the separation assembly 162 about the central axis 158, and more particularly, rotation of the plurality of paddles 166 about the central axis 158 (i.e., in the circumferential direction C), generally can force the heavier liquid fuel 116 outward through the inner filter 164, and the lighter stripping gas 114 inward through the inner filter 240. In such a manner, as indicated, the liquid fuel 116 can exit through the liquid fuel outlet 144 of the fuel gas separator 130, and the stripping gas 114 can exit through the stripping gas outlet 142 of the fuel gas separator 130.

[0099] Thus, it will be appreciated that the liquid fuel 116 provided to the liquid fuel outlet 142 that has interacted with the stripping gas 114 can have a relatively low oxygen content, allowing a relatively large amount of heat to be added thereto, reducing the risk of the fuel coking (i.e., chemically reacting to form solid particles that may clog or damage components within the fuel flow path). For example, in at least certain exemplary aspects, the fuel 116 provided to the liquid fuel outlet 144 can have an oxygen content of less than 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.

[0100] Furthermore, it will be appreciated that the Figure 4 . In other embodiments, the separator 130 may have any other suitable configuration for separating the liquid fuel 116 from the stripping gas 114. For example, in other embodiments, the separator 130 is instead configured as a centrifugal separator, a gravity-assisted separator, or any other passive separator or another form of power separator or combination thereof.

[0101] Now refer back to Figure 3 Schematic diagram of the fuel delivery system 100 in FIG. 1 , liquid fuel 116 from the liquid fuel outlet 144 of the separator 130 is provided through the liquid fuel outlet path 110. The liquid fuel outlet path 110 is fluidly coupled to a liquid fuel source line 168, which can provide a relatively low oxygen content fuel to one or more engines 56 (e.g., see Figure 2 ).as Figure 2 In the embodiment of the present invention, the fuel delivery system 100 further includes a return valve 120 and a return line 122. Depending on the one or more engines 56 (see Figure 2), at least a portion of the fuel 116 passing through the liquid fuel outlet path 110 may be returned to the fuel source 102.

[0102] like Figure 3 As also depicted in FIG. 1 , it will be appreciated that the exemplary fuel oxygen reduction unit 104 returns the utilized stripping gas 114 to the idle 118 of the fuel source 102. As noted, the stripping gas 114 to be returned to the idle 118 (i.e., downstream of the separator 130 and through the stripping gas return path 112) may have a relatively high oxygen content. Therefore, as also noted above, the fuel oxygen reduction unit 104 also includes a second oxygen conversion unit 204 having a second catalyst 150. The stripping gas 114 from the gas outlet 142 of the separator 130 is provided to the second catalyst 150, wherein the oxygen content of the gas 114 is reduced. The second catalyst 150 is positioned in gas flow communication with the stripping gas return path 112 to reduce the oxygen content of the stripping gas 114 flowing through the stripping gas return path 112 before returning this stripping gas 114 to the idle 118 of the fuel source 102. It will be appreciated that in certain exemplary embodiments, the second catalyst 150 may operate in a manner similar to the operation described above with reference to the first catalyst 148 .

[0103] Still refer to Figure 3 In the embodiment of the present invention, the stripping gas 114 passing through the stripping gas return path 112 is further cooled by the heat exchanger 152 downstream of the second catalyst 150. Then, the resulting cooled stripping gas 114 with a relatively low oxygen content is provided back to the idle space 118 of the fuel source 102 through the remaining portion of the stripping gas flow path 132 or the stripping gas return path 112.

[0104] Still refer to Figure 3 , the operation of the first oxygen conversion unit 202 and the second oxygen conversion unit 204 will now be described in more detail.

[0105] Referring first to the first oxygen conversion unit 202, the oxygen content of the stripping gas 114 is reduced within the first catalyst 148. For example, the first catalyst 148 (or other gas oxygen reduction units discussed below) may be configured to reduce the oxygen content of the stripping gas 114 to less than about three percent (3%) oxygen (O2) by mass, such as less than one percent (1%) oxygen (O2) by mass.

[0106] More specifically, within the first catalyst 148, the stripping gas 114, which may be relatively oxygen-rich, may react to reduce its oxygen content. However, it will be appreciated that the first catalyst 148 may be configured in any suitable manner to reduce the oxygen content of the stripping gas 114. For example, in certain embodiments, the first catalyst 148 may be configured to react the stripping gas 114, which is rich in fuel vapor, with elements within the first catalyst 148 to provide a relatively oxygen-free stripping gas 114 upon exiting. For example, the first catalyst 148 may include a geometry of a catalytic component through which the relatively oxygen-rich stripping gas 114 flows to reduce its oxygen content. Such reactions may at least partially utilize the fuel content of the stripping gas 114 due to the stripping gas 114 originating from the fuel source 102 (i.e., in contact with the fuel therein).

[0107] Now briefly refer to Figure 5 , providing a partial enlarged view of an exemplary first oxygen conversion unit 202 including a first catalyst 148, it will be appreciated that the first catalyst 148 can be configured to produce a water stream 206 from the gas stream 114 passing through the stripping gas flow path 132. In addition, the first oxygen conversion unit 202 also includes a water hydrolysis device for producing an oxygen stream 208 from the water 206 produced by the first catalyst 148. More particularly, for the illustrated embodiment, the water hydrolysis device is a water electrolysis device 210. The water electrolysis device 210 is in fluid communication with the first catalyst 148 to receive the water stream 206 from the first catalyst 148, and is configured to decompose water into hydrogen and oxygen. The water electrolysis device 210 is in electrical communication with a power source 212 (e.g., a DC power source) and includes two electrodes, a cathode 214 and an anode 216, which are electrically coupled to the power source 212 and positioned in the water 206. During typical operation, hydrogen will appear at cathode 214 (where the electrons enter water 206), and oxygen will appear at anode 216. The amount of oxygen and hydrogen produced is proportional to the total charge conducted by the water.

[0108] like Figure 5 As schematically depicted in FIG, pure oxygen may be captured and provided to oxygen outlet 200 and conduit 121 of first oxygen conversion unit 202. Similarly, hydrogen may also be captured, delivered via hydrogen outlet 218 and utilized by the aircraft and / or one of the aircraft's engines or accessory systems.

[0109] Thus, such a configuration may produce flow-usable oxygen 208 to assist in various aircraft operations while also reducing the water content of the fuel flow 116 by reducing the water content of the stripping gas flow 114 .

[0110] Now refer back to Figure 3It will be further appreciated that the fuel delivery system 100 also includes a sensor 220 operable with the fuel oxygen reduction unit for sensing data indicative of gas flow through the oxygen outlet 200 of the first oxygen conversion unit 202 and a controller 222. More specifically, the sensor 220 is configured to sense data indicative of the oxygen content of the gas flow through the oxygen outlet 200, the fuel content of the gas flow through the oxygen outlet 200, or both. In this manner, the sensor 220 may be configured to sense data indicative of the purity of the oxygen flow through the oxygen outlet 200, the amount of oxygen flow, etc.

[0111] Controller 208 is configured to receive such data from sensor 220 and may make control decisions based on such data. In one or more exemplary embodiments, Figure 3 Controller 208 depicted in may be a stand-alone controller 208 for fuel delivery system 100, or alternatively, may be integrated into one or more of a controller for an aircraft into which fuel delivery system 100 is integrated, a controller for a gas turbine engine that receives fuel from fuel delivery system 100, or the like.

[0112] As used herein, the term "controller" broadly refers to one or more processing devices, including one or more of a microcontroller, a microcomputer, a programmable logic controller (PLC), an application-specific integrated circuit, and other programmable circuits, and these terms are used interchangeably herein. In the embodiments described herein, the controller 222 may additionally include a memory. The memory may include, but is not limited to, a computer-readable medium, such as a random access memory (RAM), a computer-readable non-volatile medium, such as a flash memory. Alternatively, a floppy disk, a compact disk-read only memory (CD-ROM), a magneto-optical disk (MOD), and / or a digital versatile disk (DVD) may also be used. In addition, in the embodiments described herein, the controller 222 may include one or more input channels and / or one or more output channels. The input channel may be, but is not limited to, a sensor, such as sensor 220. In addition, in an exemplary embodiment, the output channel may include, but is not limited to, an operator interface monitor, or the output channel may be linked to various components to control these components, for example, based on data reviewed from the input channel and / or data or instructions stored in the memory. For example, the memory may store software or other instructions that, when executed by a controller or processor, allow the controller to perform certain operations or functions.

[0113] In such a manner, it will be appreciated that the fuel oxygen reduction unit 104 can be configured to simultaneously reduce the oxygen content of the liquid fuel 116 provided to one or more aircraft engines 52 of an aircraft 10 including the fuel delivery system 100, while producing a usable oxygen flow that can be provided to the aircraft, such as to one or more components of the aircraft (e.g., one or more engines), one or more accessory systems of the aircraft (such as a cabin and / or crew), etc.

[0114] However, it will be appreciated that in other exemplary embodiments, the fuel delivery system 100 may be configured in any other suitable manner. For example, the fuel delivery system 100 may not provide low oxygen content fuel to each or even multiple aircraft engines. In addition, it will be appreciated that for the illustrated embodiment, the idle 118 whose oxygen content in the air is reduced is the idle 118 of the fuel source 102, which provides liquid fuel 116 through the liquid fuel supply path 106 of the fuel oxygen reduction unit 104. However, in other embodiments, the idle 118 may be any other suitable fuel source, so that the fuel oxygen reduction unit 104 can operate with more than one fuel source. For example, in certain embodiments, the fuel oxygen reduction unit 104 may be operable with a primary fuel tank and a separate secondary fuel tank.

[0115] Furthermore, in other exemplary embodiments, the fuel oxygen reduction unit 104 may not receive airflow from the idler 118, and instead, the airflow 114 to the fuel oxygen reduction unit 104 may be provided entirely or primarily from some other gas source (e.g., bleed air from an aircraft engine, an ambient air source, a stripping gas tank, etc.).

[0116] Furthermore, it should be appreciated that in other exemplary embodiments, the fuel delivery system 100 may be configured in any other suitable manner instead. Figure 6 , a fuel delivery system 100 according to another exemplary embodiment of the present disclosure is provided. Figure 6 The exemplary fuel delivery system 100 may be configured with Figure 3 The exemplary fuel delivery system 100 is configured in substantially the same manner.

[0117] However, with Figure 3 Compared with the embodiment of Figure 6In the exemplary fuel delivery system 100 of FIG. 1 , the first oxygen conversion unit 202 and the second oxygen conversion unit 204 do not include catalysts (i.e., the first catalyst 148 and the second catalyst 150), and instead include static components for extracting oxygen from the gas stream 114 passing through the stripping gas flow path 132. More specifically, the first oxygen conversion unit 202 includes a first membrane gas oxygen reduction unit 176, and the second oxygen conversion unit 204 includes a second membrane gas oxygen reduction unit 178. The first membrane gas oxygen reduction unit 176 is positioned in the stripping gas supply path 108 / stripping gas flow path 132, downstream of the booster pump 124 (for the illustrated embodiment), and upstream of the device for transferring a certain amount of oxygen from the liquid fuel stream to the gas stream, or, for the illustrated embodiment, upstream of the contactor 128 and the separator 130. The second membrane gas oxygen reduction unit 178 is positioned in the stripping gas return path 112 / stripping gas flow path 132 downstream of the fuel oxygen reduction components, ie, the contactor 128 and separator 130 for the illustrated embodiment, and upstream of the idle 118 of the fuel source 102 .

[0118] Each of the first membrane gas oxygen reduction unit 176 and the second membrane gas oxygen reduction unit 178 may be configured in any suitable manner to reduce the oxygen content of the stripping gas 114 flowing through the respective portion of the stripping gas flow path 132. For the illustrated embodiment, the first membrane gas oxygen reduction unit 176 and the second membrane gas oxygen reduction unit 178 each generally define a gas flow chamber 180 and an oxygen reduction chamber 182 through which the stripping gas 114 flows, and include a membrane 184. The oxygen reduction chamber 182 and the membrane 184 may have any suitable configuration for extracting oxygen from the stripping gas 114 flowing through the gas flow chamber 180. For example, the oxygen reduction chamber 182 may be a relatively low pressure chamber (e.g., a vacuum), and the membrane 184 may be an oxygen permeable membrane that allows oxygen within the stripping gas 114 within the gas flow chamber 180 to migrate therethrough and into the oxygen reduction chamber 182. More specifically, the membrane 184 may define a porous structure configured to filter oxygen from the gas flow passing through the gas flow chamber 180 / stripping gas flow path 132 .

[0119] However, other configurations are also contemplated, including various other chamber and membrane geometries.

[0120] It will be appreciated that with such a configuration, a preheater (e.g., Figure 3 preheater 125), so that a heat exchanger (e.g., heat exchanger 152) may not be required.

[0121] In such a manner, oxygen flow 208 may be extracted from air flow 114 within oxygen reduction chamber 182 and may be provided to the aircraft through outlet 200 and via conduit 121 so that the aircraft may utilize the oxygen flow, for example, within oxygen-consuming accessory systems.

[0122] It will be further appreciated that while the exemplary fuel oxygen reduction unit 104 includes a first membrane gas oxygen reduction unit 176 and a second membrane gas oxygen reduction unit 178 having a first oxygen reduction unit 202 and a second oxygen reduction unit 204, in other embodiments, Figure 6 The features of the fuel delivery system 100 may be related to Figures 3 to 5 For example, in other embodiments, one of the first membrane gas oxygen reduction unit 176 or the second membrane gas oxygen reduction unit 178 is instead configured as a catalyst. Alternatively, in other embodiments, the fuel delivery system 100 may include only one of the first oxygen reduction unit 202 or the second oxygen reduction unit 204 (particularly in embodiments with a closed-loop stripping gas flow path - see Figure 8 ).

[0123] Furthermore, it will be appreciated that in other exemplary embodiments, other configurations are also contemplated. Figure 7 , a fuel delivery system 100 according to yet another exemplary embodiment of the present disclosure is provided. Figure 7 The exemplary fuel delivery system 100 may be configured with Figure 3 The exemplary fuel delivery system 100 is configured in substantially the same manner.

[0124] However, for the depicted embodiment, the means for transferring an amount of oxygen from the liquid fuel flow through the liquid fuel flow path to the gas flow through the stripping gas flow path is not configured as a contactor and a separator, and is instead configured as a membrane fuel oxygen reduction unit 190. The membrane fuel oxygen reduction unit 190 defines a stripping gas chamber 192 and a fuel chamber 198, the stripping gas chamber defining a gas inlet 194 and a gas outlet 196, and the fuel chamber defining a fuel inlet 200 and a fuel outlet 202. The membrane fuel oxygen reduction unit 190 also includes a membrane 204 positioned between the stripping gas chamber 192 and the fuel chamber 198. The membrane 204 can be any suitable membrane for allowing oxygen-containing gas in the liquid fuel 116 flowing through the fuel chamber 198 to migrate to the stripping gas 114 flowing through the stripping gas chamber 192. For example, the membrane 204 can be any suitable oxygen-permeable membrane.

[0125] Such a configuration may allow for a reduction in oxygen in the liquid fuel flow 116 provided to the engine 50 while utilizing less mechanical work.

[0126] It will be further appreciated that in other exemplary embodiments, other configurations are also contemplated. Figure 8 , a fuel delivery system 100 according to yet another exemplary embodiment of the present disclosure is provided. Figure 8 The exemplary fuel delivery system 100 may be configured with Figure 3The exemplary fuel delivery system 100 is configured in substantially the same manner.

[0127] For example, Figure 8 The exemplary fuel delivery system 100 generally includes a fuel oxygen reduction unit 104 having a contactor 128 and a fuel gas separator 130. However, for the depicted embodiment, the fuel oxygen reduction unit 104 is not in gas flow communication with a fuel source 127 (e.g., an empty portion of a fuel storage tank). Instead, the depicted exemplary fuel oxygen reduction unit 104 is configured to receive a gas flow from an air source 126 that is separate from the fuel source 127. More specifically, the exemplary fuel oxygen reduction unit 104 is generally configured to recirculate the stripping gas flow 114 and is in gas flow communication with the air source 126 to replenish the volume of the stripping gas 114 (e.g., to accommodate some leakage, to integrate the stripping gas with the fuel flow, etc.), to provide an initial flow of the stripping gas 114 to the fuel oxygen reduction unit 104, etc. In such a manner, it will be appreciated that the stripping gas 114 flowing through the stripping gas flow path 132 / cycle gas flow path may be an inert gas such as nitrogen or carbon dioxide (CO2), an inert gas mixture, or some other gas or gas mixture having a relatively low oxygen content.

[0128] However, it will be appreciated that in other exemplary embodiments, any other suitable fuel oxygen reduction unit 104 may be provided. For example, in other exemplary embodiments, fuel oxygen reduction unit 104 may not include all of the structures depicted in one or more of these embodiments, may include any combination of the structures depicted in these embodiments, and / or may include any other suitable structure or component that facilitates reducing the oxygen content in a fuel flow while generating a separate oxygen flow for, for example, an aircraft.

[0129] Now refer to Fig. 9 , a flow chart of a method 300 of operating a fuel oxygen reduction unit for a fuel system is provided. The method 300 may be used with one or more of the exemplary fuel oxygen reduction units described above, or alternatively, may be used with any other suitable fuel oxygen reduction unit.

[0130] The method 300 includes using a fuel oxygen reduction unit at (301). For the exemplary aspect depicted, using a fuel oxygen reduction unit at (301) generally includes extracting oxygen from a liquid fuel and providing the extracted oxygen to an external system.

[0131] More particularly, for the exemplary aspect depicted, using a fuel oxygen reduction unit at (301) includes (302) providing a liquid fuel stream to a fuel oxygen reduction unit located downstream of a fuel source, the fuel oxygen reduction unit defining a stripping gas flow path and a liquid fuel flow path. The method also includes transferring an amount of oxygen from the liquid fuel stream passing through the liquid fuel flow path to the stripping gas stream passing through the stripping gas flow path at (304). This can be accomplished using a contactor and separator, a membrane transfer system, a chemical transfer arrangement, or any other suitable configuration or combination of configurations.

[0132] Still refer to Fig. 9 For the exemplary aspect of the method 300 shown, using the fuel oxygen reduction unit at (301) includes extracting an oxygen stream from the stripping gas stream passing through the stripping gas flow path with an oxygen conversion unit at (306). Extracting an oxygen stream from the stripping gas stream passing through the stripping gas flow path with an oxygen conversion unit at (306) may include extracting oxygen using a catalyst and water hydrolysis system, a membrane-based conversion system, a chemical conversion system, or any other suitable arrangement or configuration.

[0133] Furthermore, for the exemplary aspect of the method 300 shown, the extracted oxygen flow from the oxygen conversion unit is provided at (308) using a fuel oxygen reduction unit from the oxygen conversion unit to a system external to the fuel oxygen reduction unit. The system external to the fuel oxygen reduction unit may be an accessory system of the aircraft.

[0134] Alternatively, for example, if incorporated into a different vehicle or platform, the system external to the fuel oxygen reduction unit may be any other suitable system. Furthermore, regardless of the vehicle or platform, the external system may be any system external to the fuel oxygen reduction unit, such as one or more of an environmental control system (ECS), a cabin air maintenance system, a cabin and / or crew oxygen delivery system, etc. In certain embodiments, the external system may be any system that uses and / or stores oxygen and is located external to the gas turbine engine utilizing or incorporating the fuel oxygen reduction unit, such as at a location external to the engine core cowling and / or nacelle.

[0135] Further aspects of the invention are provided by the subject matter of the following clauses:

[0136] A fuel oxygen reduction unit assembly for a fuel system, the fuel oxygen reduction unit assembly comprising: a fuel oxygen reduction unit, the fuel oxygen reduction unit being located downstream of a fuel source and defining a stripping gas flow path and a liquid fuel flow path, the fuel oxygen reduction unit comprising a device for transferring a certain amount of oxygen from a liquid fuel flow passing through the liquid fuel flow path to a gas flow passing through the stripping gas flow path; and an oxygen conversion unit, the oxygen conversion unit being in flow communication with the stripping gas flow path, the oxygen conversion unit being configured to extract an oxygen flow from the gas flow passing through the stripping gas flow path, the oxygen conversion unit defining an oxygen outlet, the oxygen outlet being configured to provide the extracted oxygen flow to an external system.

[0137] The fuel oxygen reduction unit assembly of one or more of these clauses, wherein the fuel system is a fuel system for an aircraft, and wherein the external system is an accessory system of the aircraft.

[0138] A fuel oxygen reduction unit assembly of one or more of these clauses, wherein the device for transferring a certain amount of oxygen from a liquid fuel flow to a gas flow includes: a contactor defining a liquid fuel inlet, a stripping gas inlet, and a fuel / gas mixture outlet; and a fuel / gas separator defining a fuel / gas mixture inlet, a liquid fuel outlet, and a stripping gas outlet that are flow-connected to the fuel / gas mixture outlet of the contactor.

[0139] The fuel oxygen reduction unit assembly of one or more of these clauses, wherein the means for transferring an amount of oxygen from the liquid fuel stream to the gas stream comprises a membrane fuel oxygen reduction unit.

[0140] A fuel oxygen reduction unit assembly as claimed in one or more of these clauses, wherein the oxygen conversion unit is a static component.

[0141] The fuel oxygen reduction unit assembly of one or more of these clauses, wherein the oxygen conversion unit includes a membrane defining a porous structure configured to filter oxygen from a gas stream passing through a stripping gas flow path.

[0142] The fuel oxygen reduction unit assembly of one or more of these clauses, wherein the oxygen conversion unit includes a catalyst, wherein the catalyst is configured to produce water from a gas stream passing through the stripping gas flow path.

[0143] The fuel oxygen reduction unit assembly of one or more of these clauses, wherein the oxygen conversion unit further comprises a water hydrolyzing device for generating an oxygen stream from water generated by the catalyst.

[0144] The fuel oxygen reduction unit assembly of one or more of these clauses, wherein the water hydrolyzer is a water electrolyzer.

[0145] The fuel oxygen reduction unit assembly of one or more of these clauses, wherein the oxygen conversion unit is in flow communication with the stripping gas flow path at a location downstream of a means for transferring an amount of oxygen from a liquid fuel flow through the liquid fuel flow path to a gas flow through the stripping gas flow path.

[0146] The fuel oxygen reduction unit assembly of one or more of these clauses, wherein the oxygen conversion unit is in flow communication with the stripping gas flow path at a location upstream of a means for transferring an amount of oxygen from a liquid fuel flow through the liquid fuel flow path to a gas flow through the stripping gas flow path.

[0147] The fuel oxygen reduction unit assembly of one or more of these clauses, further comprising: a sensor operable with the fuel oxygen reduction unit for sensing data indicative of a gas flow through the oxygen outlet of the oxygen conversion unit.

[0148] The fuel oxygen reduction unit assembly of one or more of these clauses, wherein the sensor is configured to sense data indicative of an oxygen content of the gas flow through the oxygen outlet, a fuel content of the gas flow through the oxygen outlet, or both.

[0149] A fuel oxygen reduction unit assembly according to one or more of these clauses, for use in an aircraft according to one or more of these clauses.

[0150] A fuel oxygen reduction unit assembly as claimed in one or more of these clauses, for use in a method as claimed in one or more of these clauses.

[0151] An aircraft comprises: an accessory system; and a fuel delivery system, the fuel delivery system comprising a fuel source and a fuel oxygen reduction unit located downstream of the fuel source and defining a stripping gas flow path and a liquid fuel flow path, the fuel oxygen reduction unit comprising a device for transferring a certain amount of oxygen from a liquid fuel flow passing through the liquid fuel flow path to an air flow passing through the stripping gas flow path; and an oxygen conversion unit, the oxygen conversion unit being in flow communication with the stripping gas flow path, the oxygen conversion unit being configured to extract an oxygen flow from the air flow passing therethrough, the oxygen conversion unit defining an oxygen outlet, the oxygen outlet being in flow communication with the accessory system air flow of the aircraft.

[0152] An aircraft of one or more of these clauses, wherein the device for transferring a certain amount of oxygen from a liquid fuel flow to an air flow includes: a contactor defining a liquid fuel inlet, a stripping gas inlet, and a fuel / gas mixture outlet; and a fuel / gas separator defining a fuel / gas mixture inlet, a liquid fuel outlet, and a stripping gas outlet that are flow-connected to the fuel / gas mixture outlet of the contactor.

[0153] An aircraft as claimed in one or more of these clauses, wherein the means for transferring an amount of oxygen from the liquid fuel flow to the air flow comprises a membrane fuel oxygen reduction unit.

[0154] An aircraft as claimed in one or more of these clauses, wherein the oxygen conversion unit is a static component.

[0155] The aircraft of one or more of these clauses, wherein the oxygen conversion unit comprises a membrane defining a porous structure configured to filter oxygen from a gas stream passing through the stripping gas flow path.

[0156] An aircraft of one or more of these clauses utilizing a fuel oxygen reduction unit of one or more of these clauses.

[0157] An aircraft as recited in one or more of these clauses, used in a method as recited in one or more of these clauses.

[0158] A method of operating a fuel oxygen reduction unit for a fuel system, the method comprising: providing a liquid fuel flow to the fuel oxygen reduction unit located downstream of a fuel source, the fuel oxygen reduction unit defining a stripping gas flow path and a liquid fuel flow path; transferring a portion of oxygen from the liquid fuel flow through the liquid fuel flow path to a stripping gas flow through the stripping gas flow path; extracting an oxygen flow from the stripping gas flow through the stripping gas flow path with an oxygen conversion unit; and providing the extracted oxygen flow from the oxygen conversion unit to a system external to the fuel oxygen reduction unit.

[0159] A method includes using a fuel oxygen reduction unit, wherein using the fuel oxygen reduction unit includes extracting oxygen from a liquid fuel and providing the extracted oxygen to an external system.

[0160] A method of one or more of these clauses, wherein the external system includes any one or more of the following: a system external to the fuel oxygen reduction unit; an environmental control system (ECS); a cabin air maintenance system; a cabin oxygen delivery system, a crew oxygen delivery system, or both; an oxygen consumption or storage system located external to the engine core cowling or engine nacelle of an engine incorporating or using a fuel oxygen reduction unit.

[0161] The method of one or more of these clauses, wherein the using step further comprises: receiving a liquid fuel stream with a fuel oxygen reduction unit; wherein extracting oxygen from the liquid fuel comprises transferring a certain amount of oxygen from the liquid fuel stream to a stripping gas stream, and extracting the oxygen stream from the stripping gas stream with an oxygen conversion unit.

[0162] The method of one or more of these clauses, wherein the fuel system is a fuel system for an aircraft, and wherein the system external to the fuel oxygen reduction unit is an accessory system of the aircraft.

[0163] A method as claimed in one or more of these clauses, utilizing a fuel oxygen reduction unit as claimed in one or more of these clauses.

[0164] A method as claimed in one or more of these clauses, and an aircraft utilizing one or more of these clauses.

Claims

1. A fuel oxygen reduction unit assembly for a fuel system, the fuel oxygen reduction unit assembly comprising: a fuel oxygen reduction unit located downstream of a fuel source and defining a stripping gas flow path and a liquid fuel flow path, the fuel oxygen reduction unit comprising means for transferring an amount of oxygen from a liquid fuel flow through said liquid fuel flow path to a gas flow through said stripping gas flow path; as well as an oxygen conversion unit in flow communication with the stripping gas flow path, the oxygen conversion unit configured to extract an oxygen stream from the gas stream passing through the stripping gas flow path, the oxygen conversion unit defining an oxygen outlet configured to provide the extracted oxygen stream to an external system; wherein the stripping gas flow path comprises a stripping gas supply path and a stripping gas return path, the stripping gas supply path being in gas flow communication with the fuel source and the fuel oxygen reduction unit to supply the gas flow from the fuel source to the fuel oxygen reduction unit, and the stripping gas return path being in gas flow communication with the fuel oxygen reduction unit and the fuel source to provide the gas flow from the fuel oxygen reduction unit back to the fuel source; and The oxygen conversion unit includes a catalyst configured to produce water from the gas flow passing through the stripping gas flow path, and a water hydrolysis device for producing an oxygen flow from the water produced by the catalyst.

2. The fuel oxygen reduction unit assembly according to claim 1, characterized in that: The fuel system is a fuel system for an aircraft, and wherein the external system is an accessory system of the aircraft.

3. The fuel oxygen reduction unit assembly according to claim 1, characterized in that: The means for transferring the amount of oxygen from the liquid fuel stream to the gas stream comprises: a contactor defining a liquid fuel inlet, a stripping gas inlet, and a fuel / gas mixture outlet; and A fuel / gas separator defines a fuel / gas mixture inlet in flow communication with the fuel / gas mixture outlet of the contactor, a liquid fuel outlet, and a stripping gas outlet.

4. The fuel oxygen reduction unit assembly according to claim 1, characterized in that: The means for transferring the amount of oxygen from the liquid fuel stream to the gas stream comprises a membrane fuel oxygen reduction unit.

5. The fuel oxygen reduction unit assembly according to claim 1, characterized in that: The oxygen conversion unit is a static component.

6. The fuel oxygen reduction unit assembly according to claim 5, characterized in that: The oxygen conversion unit includes a membrane defining a porous structure configured to filter oxygen from the gas stream passing through the stripping gas flow path.

7. The fuel oxygen reduction unit assembly according to claim 1, characterized in that: The water hydrolysis device is a water electrolysis device.

8. The fuel oxygen reduction unit assembly according to claim 1, characterized in that: The oxygen conversion unit is in flow communication with the stripping gas flow path at a location downstream of the means for transferring the amount of oxygen from the liquid fuel flow through the liquid fuel flow path to the gas flow through the stripping gas flow path.

9. The fuel oxygen reduction unit assembly according to claim 1, characterized in that: The oxygen conversion unit is in flow communication with the stripping gas flow path at a location upstream of the means for transferring the amount of oxygen from the liquid fuel flow through the liquid fuel flow path to the gas flow through the stripping gas flow path.

10. The fuel oxygen reduction unit assembly according to claim 1, characterized in that: The fuel oxygen reduction unit assembly further comprises: A sensor is operable with the fuel oxygen reduction unit for sensing data indicative of gas flow through the oxygen outlet of the oxygen conversion unit.

11. The fuel oxygen reduction unit assembly according to claim 10, characterized in that: The sensor is configured to sense data indicative of an oxygen content of the gas flow through the oxygen outlet, a fuel content of the gas flow through the oxygen outlet, or both.

12. An aircraft, comprising: Attachment system; as well as A fuel delivery system comprising a fuel source and a fuel oxygen reduction unit, wherein the fuel oxygen reduction unit is located downstream of the fuel source and defines a stripping gas flow path and a liquid fuel flow path, wherein the fuel oxygen reduction unit comprises means for transferring an amount of oxygen from a liquid fuel flow through said liquid fuel flow path to a gas flow through said stripping gas flow path; as well as an oxygen conversion unit in flow communication with the stripping gas flow path, the oxygen conversion unit being configured to extract oxygen from a gas flow therethrough, the oxygen conversion unit defining an oxygen outlet in flow communication with an accessory system of the aircraft; wherein the stripping gas flow path includes a stripping gas supply path and a stripping gas return path, the stripping gas supply path being in flow communication with the fuel source and the fuel oxygen reduction unit to supply the gas flow from the fuel source to the fuel oxygen reduction unit, the stripping gas return path being in flow communication with the fuel oxygen reduction unit and the fuel source to provide the gas flow from the fuel oxygen reduction unit back to the fuel source; and The oxygen conversion unit includes a catalyst configured to produce water from the gas flow passing through the stripping gas flow path, and a water hydrolysis device for producing an oxygen flow from the water produced by the catalyst.

13. The aircraft according to claim 12, characterized in that The means for transferring the amount of oxygen from the liquid fuel stream to the gas stream comprises: a contactor defining a liquid fuel inlet, a stripping gas inlet, and a fuel / gas mixture outlet; and A fuel / gas separator defines a fuel / gas mixture inlet in flow communication with the fuel / gas mixture outlet of the contactor, a liquid fuel outlet, and a stripping gas outlet.

14. The aircraft according to claim 12, characterized in that: The means for transferring the amount of oxygen from the liquid fuel stream to the gas stream comprises a membrane fuel oxygen reduction unit.

15. The aircraft according to claim 12, characterized in that The oxygen conversion unit is a static component.

16. A method of operating a fuel oxygen reduction unit for a fuel system, comprising: Use of a fuel oxygen reduction unit according to any one of claims 1 to 11, wherein using the fuel oxygen reduction unit comprises extracting oxygen from liquid fuel, and The extracted oxygen is provided to an external system.

17. The method according to claim 16, characterized in that The external system includes any one or more of the following: a system external to the fuel oxygen reduction unit; Environmental Control System (ECS); Cabin air maintenance system; cabin oxygen delivery system, crew oxygen delivery system, or both; and An oxygen consumption or storage system located external to the engine core cowl or nacelle of an engine incorporating or utilizing the fuel oxygen reduction unit.

18. The method according to claim 16, characterized in that The steps for use also include: receiving a liquid fuel stream with the fuel oxygen reduction unit; Extracting oxygen from liquid fuel includes transferring an amount of oxygen from the liquid fuel stream to the stripping gas stream, and An oxygen stream is extracted from the stripping gas stream using an oxygen conversion unit.

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