Patent Description:
In a gas turbine engine, air is pressurized in a compressor, mixed with fuel in a combustor, and ignited such that hot combustion gas is generated. In at least some known turbine engines, ignition of the air and fuel can result in oxidation and partial decomposition of the mixture, thereby resulting in coking within the turbine engine. More specifically, coking is a process that forms hard deposits within a fuel supply system of the turbine engine, for example. The hard deposits also form from other hydrocarbon-based substances in other areas of the turbine engine, such as in a fan assembly of the turbine engine. Excess buildup of the hard deposits in the turbine engine can clog the components of the turbine engine, and necessitate service of the turbine engine after prolonged use. For example, servicing the fuel supply system generally includes detaching the turbine engine from an airframe, removing fuel nozzles of the fuel supply system from the turbine engine, replacing the fuel nozzles with different fuel nozzles, transferring the removed fuel nozzles to another location for cleaning, and reattaching the turbine engine to the airframe. As such, a stockpile of unused turbine engine components is maintained in the event a turbine engine is scheduled for service. In addition, removing and replacing fuel nozzles in the fuel supply system can be a time-consuming and laborious task. Moreover, if combusted engine oil is trapped outside of the fuel supply system, such as in the fan assembly, critical ventilation can be blocked, resulting in unscheduled engine removal and significant disassembly to service the components at a piece-part level.

<CIT> relates to a method of cleaning a workpiece. <CIT> relates to a method of introducing a foam-like or foam forming cleaning agent into parts of a power train where the cleaning agent remains in the power train for a preset time.

<CIT> teaches that coking can occur in a fan midshaft.

A method of cleaning a component within a turbine engine is provided according to claim <NUM>. The method includes disassembling the turbine engine to provide a flow path to an interior passageway of the component from an access point, wherein the component has coked hydrocarbons formed thereon, and filling a volume of the interior passageway with an amount of cleaning solution. The cleaning solution is configured to remove the coked hydrocarbons from the component. The method further includes holding the amount of cleaning solution within the interior passageway for a predetermined residence time.

Disassembling the turbine engine includes disassembling a fan assembly of the turbine engine to define a first open end of a fan midshaft of the turbine engine by removing a center body from a fan midshaft to define a first open end and removing center vent tube from fan midshaft to provide access to an interior of fan midshaft, wherein the first open end defines the access point to an interior passageway of the fan midshaft which has coked hydrocarbons formed therein.

In one aspect, which may include at least a portion of the subject matter of any of the preceding and/or following examples and aspects, the fan midshaft includes a second open end, and the method further includes sealing the second open end prior to discharging the flow of cleaning solution towards the interior passageway.

In one aspect, which may include at least a portion of the subject matter of any of the preceding and/or following examples and aspects, sealing the second open end includes positioning a plug within the interior passageway of the component proximate the second open end, wherein the plug is insertable through the first open end of the fan midshaft when in a first operational mode, and actuating the plug into a second operational mode from the first operational mode, wherein the plug is configured to seal the second open end when in the second operational mode.

In one aspect, which may include at least a portion of the subject matter of any of the preceding and/or following examples and aspects, filling a volume of the interior passageway includes filling the volume with the cleaning solution including a foaming agent.

In one aspect, which may include at least a portion of the subject matter of any of the preceding and/or following examples and aspects, holding the amount of cleaning solution comprises holding the amount of cleaning solution for the predetermined residence time defined within a range between about <NUM> minutes and about <NUM> hours.

Here and throughout the specification and claims, range limitations may be combined and/or interchanged. Such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise.

As used herein, the terms "axial" and "axially" refer to directions and orientations that extend substantially parallel to a centerline of the turbine engine. Moreover, the terms "radial" and "radially" refer to directions and orientations that extend substantially perpendicular to the centerline of the turbine engine. In addition, as used herein, the terms "circumferential" and "circumferentially" refer to directions and orientations that extend arcuately about the centerline of the turbine engine.

Embodiments of the present disclosure relate to cleaning coked hydrocarbons from a component within a turbine engine. More specifically, the systems and methods described herein facilitate cleaning the turbine engine without, for example, having to detach the turbine engine from the airframe, and without having to remove the component to be cleaned from the turbine engine. In contrast, the systems and methods described herein provide a cleaning solution to the turbine engine via an access point, which is defined by disassembling a portion of the turbine engine while still coupled to the airframe. For example, in one embodiment, fuel nozzles of the turbine engine have coked hydrocarbons formed thereon, and the turbine engine is disassembled such that cleaning fluid may be provided to the fuel nozzles from a single access point. As such, the time and effort for disassembling and cleaning components of the turbine engine are reduced, thereby reducing the amount of time for returning a refurbished turbine engine to service.

While the following embodiments are described in the context of a turbofan engine, it should be understood that the systems and methods described herein are also applicable to turboprop engines, turboshaft engines, turbojet engines, and ground-based turbine engines, for example.

<FIG> is a schematic diagram of an exemplary turbine engine <NUM> coupled to an airframe <NUM>. Turbine engine <NUM> includes a fan assembly <NUM>, a low-pressure or booster compressor assembly <NUM>, a high-pressure compressor assembly <NUM>, and a combustor assembly <NUM>. Fan assembly <NUM>, booster compressor assembly <NUM>, high-pressure compressor assembly <NUM>, and combustor assembly <NUM> are coupled in flow communication. Turbine engine <NUM> also includes a high-pressure turbine assembly <NUM> coupled in flow communication with combustor assembly <NUM> and a low-pressure turbine assembly <NUM>. Fan assembly <NUM> includes an array of fan blades <NUM> extending radially outward from a rotor disk <NUM>. Low-pressure turbine assembly <NUM> is coupled to fan assembly <NUM> and booster compressor assembly <NUM> through a first drive shaft <NUM>, and high-pressure turbine assembly <NUM> is coupled to high-pressure compressor assembly <NUM> through a second drive shaft <NUM>. Turbine engine <NUM> has an intake <NUM> and an exhaust <NUM>. Turbine engine <NUM> further includes a centerline <NUM> about which fan assembly <NUM>, booster compressor assembly <NUM>, high-pressure compressor assembly <NUM>, and turbine assemblies <NUM> and <NUM> rotate.

In operation, air entering turbine engine <NUM> through intake <NUM> is channeled through fan assembly <NUM> towards booster compressor assembly <NUM>. Compressed air is discharged from booster compressor assembly <NUM> towards high-pressure compressor assembly <NUM>. Highly compressed air is channeled from high-pressure compressor assembly <NUM> towards combustor assembly <NUM>, mixed with fuel, and the mixture is combusted within combustor assembly <NUM>. High temperature combustion gas generated by combustor assembly <NUM> is channeled towards turbine assemblies <NUM> and <NUM>. Combustion gas is subsequently discharged from turbine engine <NUM> via exhaust <NUM>.

<FIG> is a schematic illustration of an exemplary fluid delivery system <NUM> that may be used to clean turbine engine <NUM> (shown in <FIG>). In the exemplary embodiment, fluid delivery system <NUM> is embodied as a mobile flight line cart including a plurality of components that, when used in combination, facilitate providing a flow of cleaning solution to turbine engine <NUM>. Fluid delivery system <NUM> includes a cleaning tank <NUM> that stores the cleaning solution therein, and a rinse tank <NUM> that stores a rinsing solution therein, such as deionized water. Cleaning tank <NUM> includes a heater <NUM> positioned therein for heating the cleaning solution to a predetermined temperature. Heater <NUM> facilitates heating the cleaning solution to any temperature that enables the systems and methods to function as described herein. In one embodiment, heater <NUM> heats the cleaning solution to a temperature defined within a range between about <NUM> and about <NUM> before being discharged towards turbine engine <NUM>.

Cleaning tank <NUM> and rinse tank <NUM> are coupled in flow communication with a first valve assembly <NUM> that is selectively operable to provide either the cleaning solution or the rinsing solution to turbine engine <NUM>. More specifically, fluid delivery system <NUM> includes a first pump <NUM> coupled in flow communication with first valve assembly <NUM>. First pump <NUM> discharges either the cleaning solution or the rinsing solution towards a second valve assembly <NUM>, which is selectively operable to discharge the selected solution towards turbine engine <NUM> via a discharge line <NUM>. In some embodiments, fluid delivery system <NUM> includes a compressor <NUM> coupled in flow communication with discharge line <NUM>, and compressor <NUM> is selectively operable to facilitate providing purge air through discharge line <NUM> when draining solution from turbine engine <NUM>. Fluid delivery system <NUM> also includes an accumulator <NUM> coupled between first pump <NUM> and second valve assembly <NUM>. Accumulator <NUM> modulates the flow pulses discharged from first pump <NUM> to provide a steady flow to second valve assembly <NUM>.

In one embodiment, fluid delivery system <NUM> further includes a receiving line <NUM> coupled in flow communication with turbine engine <NUM>. As will be explained in more detail below, receiving line <NUM> receives fluid that has been channeled towards turbine engine <NUM> through discharge line <NUM>, circulated through turbine engine <NUM>, and subsequently drained from turbine engine <NUM>. In the exemplary embodiment, fluid delivery system <NUM> includes a second pump <NUM> coupled in flow communication with receiving line <NUM>. When used cleaning solution is channeled through receiving line <NUM>, second pump <NUM> induces flow of the used cleaning solution from turbine engine <NUM> and discharges the used cleaning solution towards a filter <NUM>. In some embodiments, filter <NUM> removes contaminants from the used cleaning solution, thereby forming reconditioned cleaning solution, which is then discharged into cleaning tank <NUM> for further use.

Fluid delivery system <NUM> may use any cleaning solution to clean turbine engine <NUM> that enables the systems and methods to function as described herein. In the exemplary embodiment, the cleaning solution is formed a cleaning detergent and water. In one embodiment, the cleaning solution includes cleaning detergent of up to about <NUM> percent by weight of the composition. Moreover, the cleaning solution includes any cleaning detergent that enables the systems and methods to function as described herein. In one embodiment, the cleaning detergent is generally effective at degreasing and decoking, and contains an organic and alkaline solution of up to about <NUM> percent by weight of the detergent. In some embodiments, the organic and alkaline solution includes alkyl and aromatic amines, non-ionic, anionic, and cationic surfactants, and either a polycyclic aromatic hydrocarbon or di-propylene glycol methyl ether.

In an alternative example which does not form part of the claimed invention, the cleaning solution includes at least one of citric acid or glycolic acid. An example cleaning solution that includes at least one of citric acid or glycolic acid includes, but is not limited to, Citranox® ("Citranox" is a registered trademark of Alconox, Inc. , of White Plains, NY). In some examples, the cleaning solution also includes at least one of a foaming agent, surfactants, or other suitable additives. In a further alternative example, the cleaning solution includes an organic solvent, such as a Turco® <NUM> cleaning solution.

<FIG> are box diagrams illustrating fluid delivery system <NUM> (shown in <FIG>) providing solution to a component of turbine engine <NUM> from an access point. In the exemplary embodiment, turbine engine <NUM> includes a fuel supply system <NUM> including a component <NUM>, such as at least one fuel nozzle <NUM>. Fuel supply system <NUM> also includes a fuel circuit <NUM>, a split control unit (SCU) <NUM> coupled in selective flow communication with fuel circuit <NUM>, and a fuel manifold <NUM> coupled in flow communication SCU <NUM>. In operation, fuel is channeled towards fuel nozzle <NUM> from fuel circuit <NUM>, through SCU <NUM>, through fuel manifold <NUM>, and towards an interior passageway <NUM> of fuel nozzle <NUM>. As noted above, coked hydrocarbons sometimes form on a component within turbine engine <NUM> after prolonged use. In the exemplary embodiment, the component is a component of fuel supply system <NUM> or a fan midshaft, as will be described in more detail below.

Referring to <FIG>, a method of cleaning a component, which is not part of the claimed invention, such as fuel nozzle <NUM>, within turbine engine <NUM> is described herein. In the exemplary embodiment, fuel nozzle <NUM> has coked hydrocarbons formed thereon, such as within interior passageway <NUM> or on an outer surface of fuel nozzle <NUM>. The method includes disassembling a first portion of turbine engine <NUM> to provide a flow path <NUM> to interior passageway <NUM> of fuel nozzle <NUM> from an access point <NUM>. More specifically, fuel manifold <NUM> is disassembled by disconnecting SCU <NUM> from fuel manifold <NUM> to define inlet port <NUM> and access point <NUM> at fuel manifold <NUM>. A flow of cleaning solution is then discharged towards interior passageway <NUM> from access point <NUM>, where the cleaning solution is configured to remove the coked hydrocarbons from fuel nozzle <NUM>. For example, in the exemplary embodiment, discharge line <NUM> of fluid delivery system <NUM> (shown in <FIG>) is connected to fuel manifold <NUM> at inlet port <NUM>, and fluid delivery system <NUM> is actuated to discharge cleaning solution towards turbine engine <NUM>.

In one embodiment, the flow of cleaning solution is discharged in at least one pulsed interval having a predetermined discharge time. For example, the flow of cleaning solution is discharged in at least a first pulsed interval and a second pulsed interval, where a predetermined residence time is defined between the first pulsed interval and the second pulsed interval. Introducing the cleaning solution into turbine engine <NUM> in the first pulsed interval and then allowing a predetermined residence time to elapse before discharging the second pulsed interval facilitates allowing the cleaning solution of the first pulsed interval to settle and interact with the coked hydrocarbons formed on fuel nozzle <NUM>. The second pulsed interval is then discharged after the predetermined residence time has elapsed such that the cleaning solution within turbine engine <NUM> is refreshed. Alternatively, a flow of rinsing solution is discharged into turbine engine <NUM> after the predetermined residence time has elapsed after the first pulsed interval.

The predetermined discharge time and the predetermined residence time may be of any duration that enables the systems and methods to function as described herein. In one embodiment, the predetermined discharge time is defined within a range between about <NUM> seconds and about <NUM> seconds. In addition, in one embodiment, the predetermined residence time is defined within a range between about <NUM> minutes and about <NUM> minutes.

In the exemplary embodiment, the flow of cleaning solution is channeled through inlet port <NUM>, through fuel manifold <NUM>, through interior passageway <NUM> of fuel nozzle <NUM>, and is then discharged from fuel nozzle <NUM>. The method further includes disassembling a second portion of turbine engine <NUM> to define a drainage port <NUM> therein. Drainage port <NUM> is coupled in flow communication with fuel nozzle <NUM> such that the solution channeled into turbine engine <NUM> is drained from turbine engine <NUM> through drainage port <NUM>. In one embodiment, drainage port <NUM> is defined by uninstalling at least one ignitor plug (not shown) from turbine engine <NUM>, where the at least one ignitor plug is located at about a <NUM> o'clock position within turbine engine <NUM>. As such, the solution is gravity drained from turbine engine <NUM>. More specifically, the solution is discharged from fuel nozzle <NUM> and into a combustor dome, is drained through air holes in the combustor dome into a combustor case, and is then drained from the combustor case through drainage port <NUM>. Moreover, in the exemplary embodiment, receiving line <NUM> of fluid delivery system <NUM> is coupled to turbine engine <NUM> at drainage port <NUM> such that used cleaning solution is recycled to fluid delivery system <NUM>, as described above.

The method further includes discharging a flow of rinsing solution towards interior passageway <NUM> of fuel nozzle <NUM> from access point <NUM>. More specifically, fluid delivery system <NUM> is actuated as described above to facilitate discharging the flow of rinsing solution through discharge line <NUM> rather than the flow of cleaning solution. The rinsing solution is then drained through drainage port <NUM>.

Referring to <FIG>, the method includes disassembling a portion of turbine engine <NUM> to provide direct access to fuel nozzle <NUM> having coked hydrocarbons formed thereon.

More specifically, turbine engine <NUM> is disassembled to define an access point <NUM> at an inlet port <NUM> of turbine engine <NUM>. For example, inlet port <NUM> is defined by uninstalling at least one ignitor plug from turbine engine <NUM>, or by uninstalling a borescope cover from turbine engine <NUM>. The flow of cleaning solution is then discharged towards fuel nozzle <NUM> from access point <NUM>, such that the cleaning solution impinges against an outer surface <NUM> of fuel nozzle <NUM>. In some embodiments, the cleaning solution enters fuel nozzle <NUM> through an opening defined therein such that coked hydrocarbons are also removed the interior of fuel nozzle <NUM>.

Referring to <FIG>, the method includes disassembling fan assembly <NUM> of turbine engine <NUM> to provide access to component <NUM> installed therein. For example, in the exemplary embodiment, fan assembly <NUM> includes a fan midshaft <NUM> and a center body <NUM> and a center vent tube <NUM> coupled to fan midshaft <NUM>. Disassembling fan assembly <NUM> includes removing center body <NUM> from fan midshaft <NUM> to define a first open end <NUM> in fan midshaft <NUM>, and removing center vent tube <NUM> from fan midshaft <NUM> to provide access to an interior of fan midshaft <NUM>. More specifically, first open end <NUM> defines an access point <NUM> to an interior passageway <NUM> of fan midshaft <NUM>, which has coked hydrocarbons formed therein. The cleaning solution is then discharged into interior passageway <NUM>, and a volume of interior passageway <NUM> is filled with an amount of cleaning solution in the form of an aerated foam. Interior passageway <NUM> is filled with the amount of cleaning solution for a predetermined residence time that facilitates allowing the cleaning solution to interact with the coked hydrocarbons formed therein, ranging effectively from <NUM> minutes to <NUM> hours. The cleaning solution is then drained through first open end <NUM> and rinsing solution is discharged into interior passageway <NUM> followed by mechanical removal of additional coking products lifted from the fan mid shaft inner diameter employing an articulating brush comprised of nylon.

<FIG> is a schematic illustration of an exemplary sealing and discharge assembly <NUM> in a first operational mode that may be used when delivering fluid to fan midshaft <NUM>, and <FIG> is a schematic illustration of sealing and discharge assembly <NUM> in a second operational mode. In the exemplary embodiment, sealing and discharge assembly <NUM> includes a discharge shaft <NUM>, an inflatable plug <NUM>, and a supply line <NUM> coupled in flow communication with inflatable plug <NUM>. Discharge shaft <NUM> includes a first end <NUM> and a second end <NUM>. Inflatable plug <NUM> is coupled to discharge shaft <NUM> at first end <NUM>, and a sealing cap <NUM> is coupled to discharge shaft <NUM> at second end <NUM>.

Referring to <FIG>, fan midshaft <NUM> includes first open end <NUM> and a second open end <NUM>. When in the first operational mode, inflatable plug <NUM> is deflated to a size such that sealing and discharge assembly <NUM> is insertable through first open end <NUM>, and such that inflatable plug <NUM> is positionable within interior passageway <NUM> proximate second open end <NUM>. Referring to <FIG>, the inflatable plug <NUM> is then actuated from the first operational mode to the second operational mode, where the inflatable plug <NUM> seals second open end <NUM> when in the second operational mode. More specifically, fluid is supplied to inflatable plug <NUM> via supply line <NUM> to inflate inflatable plug <NUM> to a size that facilitates sealing second open end <NUM>. Second open end <NUM> is sealed prior to discharging the flow of cleaning solution towards interior passageway <NUM>.

When sealing and discharge assembly <NUM> is fully inserted within interior passageway <NUM>, sealing cap <NUM> couples to fan midshaft <NUM> with an interference fit to facilitate sealing first open end <NUM>. Discharge shaft <NUM> is coupled in flow communication with discharge line <NUM> (shown in <FIG>), for example, and includes at least one discharge outlet <NUM> defined therein. As such, when sealed, interior passageway <NUM> is provided with cleaning solution discharged from discharge outlet <NUM> to facilitate removing coked hydrocarbons formed therein.

In one embodiment, a volume of interior passageway <NUM> is filled with an amount of the cleaning solution, and the amount of cleaning solution is held within interior passageway <NUM> for a predetermined residence time. The predetermined residence time is defined within a range between about <NUM> minutes and about <NUM> hours. In some embodiments, the cleaning solution includes a foaming agent, which facilitates filling the volume of interior passageway <NUM> and enabling the cleaning solution to interact with coked hydrocarbons on the surface of fan midshaft <NUM> without being directly applied thereto.

After the predetermined residence time has elapsed, interior passageway <NUM> is drained through at least one of first open end <NUM> and second open end <NUM>. In some embodiments, the method includes suctioning the cleaning solution from interior passageway <NUM>. Moreover, in the exemplary embodiment, fan midshaft <NUM> includes at least one annular member <NUM> positioned within interior passageway <NUM>. When draining solution from interior passageway <NUM>, the solution may pool in a space defined between adjacent annular members <NUM>. As such, in one embodiment, suctioning solution from interior passageway <NUM> includes providing a directed suction force to the space defined between adjacent annular members <NUM> to facilitate removing pooled solution from interior passageway <NUM>. Fan midshaft <NUM> is then cleaned mechanically and rinsed, or a second application of cleaning solution is provided.

<FIG> are flow diagrams illustrating exemplary methods of cleaning a component within turbine engine <NUM>. Referring to <FIG>, a method <NUM>, which is not part of the claimed invention, includes disassembling <NUM> turbine engine <NUM> to provide a flow path <NUM> to interior passageway <NUM> of component <NUM> from access point <NUM> in turbine engine <NUM>. Component <NUM> has coked hydrocarbons formed thereon. Method <NUM> further includes discharging <NUM> a flow of cleaning solution towards interior passageway <NUM> from access point <NUM>. The cleaning solution is configured to remove the coked hydrocarbons from component <NUM>.

Referring to <FIG>, a method <NUM> includes disassembling <NUM> turbine engine <NUM> to provide a flow path to interior passageway <NUM> of component <NUM> from access point <NUM> in turbine engine <NUM>. Component <NUM> has coked hydrocarbons formed thereon. Method <NUM> further includes filling <NUM> a volume of interior passageway <NUM> with an amount of cleaning solution, wherein the cleaning solution is configured to remove the coked hydrocarbon from the component, and holding <NUM> the amount of cleaning solution within interior passageway <NUM> for a predetermined residence time.

Referring to <FIG>, a method <NUM>, which is not part of the claimed invention, includes disassembling <NUM> turbine engine <NUM> to define access point <NUM> to component <NUM>. Component <NUM> has coked hydrocarbons formed thereon. Method <NUM> further includes discharging <NUM> a flow of cleaning solution towards component <NUM> from access point <NUM>. The cleaning solution is configured to remove the coked hydrocarbons from component <NUM>, and the cleaning solution includes at least one of citric acid or glycolic acid.

An exemplary technical effect of the assembly and methods described herein includes at least one of: (a) cleaning internal components of a turbine engine while coupled to an airframe; (b) cleaning internal components of the turbine engine in a quick and efficient manner; and (c) reducing an amount of time for cleaning and returning a cleaned turbine engine to service.

Exemplary embodiments of a cleaning system for use with a turbine engine and related components are described above in detail. The system is not limited to the specific embodiments described herein, but rather, components of systems and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. For example, the configuration of components described herein may also be used in combination with other processes, and is not limited to practice with a fuel nozzles or a fan section of a turbine engine. Rather, the exemplary embodiment can be implemented and utilized in connection with many applications where removing coked hydrocarbons from an object is desired.

Although specific features of various embodiments of the present disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of embodiments of the present disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.

Claim 1:
A method of cleaning a component (<NUM>) within a turbine engine (<NUM>), said method comprising:
disassembling the turbine engine (<NUM>) to provide a flow path (<NUM>) to an interior passageway (<NUM>) of the component (<NUM>) from an access point (<NUM>) in the turbine engine (<NUM>), wherein the component (<NUM>) has coked hydrocarbons formed thereon;
filling a volume of the interior passageway (<NUM>) with an amount of cleaning solution, wherein the cleaning solution is configured to remove the coked hydrocarbons from the component (<NUM>); and
holding the amount of cleaning solution within the interior passageway (<NUM>) for a predetermined residence time, characterized in that
disassembling the turbine engine (<NUM>) comprises disassembling a fan assembly (<NUM>) of the turbine engine (<NUM>) by removing a center body (<NUM>) from a fan midshaft (<NUM>) to define a first open end (<NUM>) of the fan midshaft (<NUM>) of the turbine engine (<NUM>) and removing center vent tube (<NUM>) from the fan midshaft (<NUM>) to provide access to an interior of fan midshaft (<NUM>), wherein the first open end (<NUM>) defines the access point (<NUM>) to an interior passageway (<NUM>) of the fan midshaft (<NUM>) which has coked hydrocarbons formed therein.