Patent Description:
A typical aircraft-mounted gas turbine engine includes gas turbine engine components having very fine cooling passages that allow for higher gas temperatures in the combustor and/or the high-pressure or low-pressure turbines. During operation, particularly in environments that contain fine-scale dust, environmental particulate accumulates on engine components and within the cooling passages of the engine. For example, dust (reacted or non-reacted), sand, or similar can build up on the flow path components and on the impingement cooled surfaces during turbine engine operation. In addition, particulate matter entrained in the air that enters the turbine engine and the cooling passages can contain sulfur-containing species that can corrode the components. Such accumulation can lead to reduced cooling effectiveness of the components and/or corrosive reaction with the metals and/or coatings of the engine components. Thus, particulate build-up can lead to premature distress and/or reduced engine life. Additionally, accumulations of environmental contaminants (e.g. dust-reacted and unreacted, sand, etc.) can degrade aerodynamic performance of the high-pressure components and lower fuel efficiency of the engine through changes in airfoil morphology.

Current approaches for treating fully assembled engines generally rely on foam or liquids. However, the physical characteristics of the treating medium impose limits on the engine surfaces which may be affected by the treating medium. For example, it is desirable to treat the cooling air passages of a jet engine. The cooling air passages have holes in the outer faces of combustors and turbines which have a diameter of approximately <NUM>. The known treatment foams have bubbles which are two to ten times larger than these openings. As such, the bubble diameter prevents the foam from entering the cooling air passages, and thus the foams are not suitable for treating the cooling air passages. Liquid-based treatments, on the other hand, may have components small enough to pass through the cooling holes, but have a different set of limitations. Liquid treatments are driven by rotational speeds or gravity. This tends to concentrate the liquid in the outer diameter when the gas turbine engine is rotating or near the bottom of a static engine. In neither case will the liquid tend to flow uniformly through all the circuits of the cooling air passages.

Accordingly, a need exists for an improved method to clean gas turbine engine components.

<CIT> discloses a system and a method for cleaning components of a gas turbine engine. The method includes introducing a working fluid into a gas flow path or a cooling circuit defined by the one or more components of the gas turbine engine such that the working fluid impinges upon a surface of the one or more components of the gas turbine engine, wherein the working fluid includes a plurality of detergent droplets entrained in a flow of steam. A system for cleaning components of a gas turbine engine are also presented.

<CIT> discloses a wash system for a gas turbine engine. The wash system may include a water source containing a volume of water therein, and a surface filming agent source containing a volume of a surface filming agent therein. The wash system also may include a mixing chamber in fluid communication with the water source and the surface filming agent source, wherein the mixing chamber is configured to mix the water and the surface filming agent therein to produce a film-forming mixture. The film-forming mixture may be a liquid-gas mixture of the surface filming agent in a liquid phase and the water in a gaseous phase. The wash system further may include a number of supply lines in fluid communication with the mixing chamber, wherein the supply lines are configured to direct the film-forming mixture into the gas turbine engine.

The invention is defined by a vapor-based system for treating one or more components of a gas turbine engine in accordance with claim <NUM>, and a method for treating one or more components of an aircraft-mounted gas turbine engine in accordance with claim <NUM>.

In accordance with one embodiment of the present disclosure, a vapor-based system for treating one or more components of a gas turbine engine is provided. The system includes a treatment compound having a delivery temperature for a corresponding delivery pressure. The delivery temperature is greater than an engine component surface temperature. The system includes a storage vessel containing the treatment compound. A delivery module is operably coupled to the storage vessel and to an engine access point. The delivery module is operable to deliver the treatment compound at one or more locations of the gas turbine engine such that the treatment compound is a vapor when exposed to an engine air-path so as to treat the engine component.

In accordance with another embodiment of the present disclosure, a method for treating one or more components of an aircraft-mounted gas turbine engine is provided. The method includes operably coupling a delivery module, which is coupled to a storage vessel, to an engine access point. The delivery module is activated to deliver a portion of a treatment compound to the engine access point. The treatment compound is a supersaturated vapor upon entering an engine air-path. The supersaturated vapor has a delivery temperature for a corresponding a delivery pressure. The delivery temperature is greater than a surface temperature of a component surface such that the vapor changes phase on the component surface.

In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention which is delimited by the appended claims.

As used herein, the terms "first" and "second" may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.

As used herein, the term "vapor" refers to a substance in the gaseous state, as distinguished from the liquid or solid state.

As used herein, the phrases "constructed of CMCs" and "comprised of CMCs" shall mean components substantially constructed of CMCs. More specifically, the CMC components shall include more CMC material than just a layer or coating of CMC materials. For example, the components constructed of CMCs may be comprised or constructed substantially or entirely of CMC materials, including greater than about <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> percent CMC material.

Methods and systems are generally provided for treating gas turbine engine components, even in an assembled, in-situ engine. The methods of the present disclosure generally provide for delivery of a treatment compound in a vapor form. Being in a vapor form, the treatment compound more thoroughly penetrates an assembled gas turbine engine (as compared to liquid or foam-based treatment systems), allowing the treatment compound to affect engine components not readily accessible using current in-situ engine cleaning approaches.

To achieve the desired effect, the treatment compound is heated to a delivery temperature and a delivery pressure prior to delivery to the gas turbine engine. For example, if the treatment compound is water based, it is generally heated to a delivery temperature from <NUM> to <NUM> and a delivery pressure from <NUM> kPa to <NUM>,<NUM> kPa. The gas turbine engine to be treated may be at a standard atmosphere of <NUM> at <NUM> kPa. Upon delivery to the gas turbine engine, the treatment compound encounters lower pressure and temperature conditions than the delivery pressure and temperature, such that the treatment compound vaporizes (if not already a vapor). Because the water-based treatment compound has a delivery pressure (partial pressure) from <NUM> kPa to <NUM>,<NUM> kPa, and the saturation pressure of a water-based compound at <NUM> is about <NUM> kPa, the resultant vapor may be supersaturated. The term "supersaturated," as used herein, refers to a vapor of a compound that has a higher partial pressure than the vapor pressure of the compound.

The vapor has a portion of suspended droplets having a range of diameters from <NUM> to <NUM> (e.g., from <NUM> to <NUM>). As the vapor (which may be supersaturated) is driven through the gas turbine engine by the delivery module, the vapor encounters engine surface components and begins to condense thereon. Because the diameter of the droplets formed in the vapor may be less than <NUM> (e.g., from <NUM> to <NUM>), the droplets are able to reach the targeted surfaces of the gas turbine engine unreachable by droplets having larger diameters.

Referring now to the drawings, <FIG> illustrates a cross-sectional view of one embodiment of a gas turbine engine <NUM> that may be utilized with an aircraft in accordance with aspects of the present subject matter, the engine <NUM> is shown having a longitudinal or axial centerline axis <NUM> extending therethrough for reference purposes. The engine <NUM> will be discussed in detail below. Although shown as a turbofan jet engine, the methods described herein may be used on any turbomachine including, but not limited to, high-bypass turbofan engines, low-bypass turbofan engines, turbojet engines, turboprop engines, turboshaft engines, propfan engines, and so forth.

<FIG> illustrates a schematic view of one embodiment of a vapor-based treatment system <NUM> for treating of one or more components of a gas turbine engine <NUM> in accordance with aspects of the present subject matter. In the illustrated embodiment, the treatment system <NUM> includes, a treatment compound <NUM> contained in a storage vessel <NUM>. The storage vessel <NUM> is operably coupled to a delivery module <NUM> via coupling <NUM>. In some embodiments, a controller <NUM> is communicatively coupled to the delivery module <NUM> and the storage vessel <NUM> via communications link <NUM> to manage the delivery of the treatment compound <NUM> to the gas turbine engine <NUM>. The delivery of the treatment compound <NUM> to the gas turbine engine <NUM>, even in-situ, is accomplished via a delivery passage <NUM> coupled to an engine access point <NUM>. It should be appreciated that the delivery passage <NUM> may be, but is not limited to, a hose, a pipe, a conduit, a duct, an encapsulation, or an atmospheric passage defined by a portion of moving air. In certain embodiments, a discharge collector <NUM> is positioned to collect a treatment system waste fluid <NUM>.

Referring still to <FIG>, the treatment compound <NUM> may be in any desirable phase of matter when stored in the storage vessel <NUM> but is a supersaturated vapor upon entry into the gas turbine engine <NUM>. Also, the treatment compound may be any compound designed to affect encountered gas turbine engine components. For example, the treatment compound may be a cleaning agent, a restorative agent, or a protective agent. Additionally, the treatment compound may be specifically formulated to affect the encountered gas turbine engine component based on the material makeup of the component. For example, in an embodiment in accordance with aspects of the present disclosure, the treatment compound may be formulated as a restorative compound compatible with an outer coating of a CMC composite. In still other embodiments, the treatment compound may be a protective compound compatible with an outer coating of a flow path component.

In an exemplary embodiment in accordance with aspects of the present disclosure, the treatment compound <NUM> may be a liquid at room temperature and is heated to a delivery temperature from <NUM> to <NUM> and a delivery pressure from <NUM> kPa to <NUM>,<NUM> kPa prior to introduction into the gas turbine engine <NUM>. For example, the gas turbine engine <NUM> may be at a standard atmospheric temperature and pressure of <NUM> at <NUM> kPa and the liquid treatment compound <NUM> may be brought to about <NUM>° C and held at about <NUM> kPa. As the treatment compound <NUM> is introduced to the gas turbine engine <NUM> by the delivery module <NUM> (which is liquid delivery module in this exemplary embodiment), the stepdown to a lower pressure causes the treatment compound <NUM> to vaporize or "flash," resulting in a supersaturated vapor. In such an example, the liquid treatment compound <NUM> at about <NUM> and about <NUM> kPa would experience about a <NUM> kPa pressure differential at the instant of introduction, instantly vaporize, yet remain at about <NUM>. As the vapor begins to cool, the vapor develops droplets having a diameter of less than <NUM> (e.g., from <NUM> to <NUM>). Because of this small droplet diameter, the vapor is able to permeate the engine, especially the plurality of cooling passages. As the vapor encounters gas turbine engine <NUM> components, a portion of the treatment compound changes phase and condenses on the encountered surface. In some embodiments, this condensed treatment compound <NUM>, may be further dispersed by motoring (i.e., rotating without fuel) the gas turbine engine <NUM>.

In an additional exemplary embodiment in accordance with aspects of the present disclosure, the treatment compound <NUM>, unlike the exemplary embodiment above, may be a vapor which is brought to a delivery temperature from <NUM> to <NUM> and a delivery pressure from <NUM> kPa to <NUM>,<NUM> kPa prior to introduction into the gas turbine engine <NUM>. As the treatment compound <NUM> is already a vapor in this embodiment, the introduction into the gas turbine engine <NUM> does not drive a phase change.

However, as the vapor begins to cool, the vapor develops droplets having a diameter of less than <NUM> (e.g., from <NUM> to <NUM>). Because of this small droplet diameter, the vapor is able to permeate the engine, especially the plurality of cooling passages. As the vapor encounters gas turbine engine <NUM> components, a portion of the treatment compound changes phase and condenses on the encountered surface.

It should be appreciated that delivering the treatment compound <NUM> in a vapor form in accordance with an aspect of the present disclosure may be particularly advantageous, ensuring the treatment compound <NUM> reaches the desired engine components. For example, the utilization of a vapor allows the treatment compound <NUM> to reach engine components which are unreachable by traditional solution or slurry approaches due to the absence of a line of sight to the component. Additionally, by employing a vapor, the engine access point <NUM> may be any engine orifice including, but not limited to, an inlet <NUM> (<FIG>) of the fan casing <NUM> (<FIG>), a borescope inspection port, a component of the fuel system <NUM> (<FIG>) or an exhaust nozzle <NUM> (<FIG>). It should also be recognized that composition of the treatment compound determines the range of temperatures and pressures required to drive a supersaturation condition within the compound. For example, while water-based compounds have a temperature range from <NUM> to <NUM>, alcohol-based solutions may have a delivery temperature from <NUM> to <NUM> at the same delivery pressures.

<FIG> illustrates a schematic view of one embodiment of a treatment system <NUM> for treating one or more components of a gas turbine engine <NUM> in accordance with aspects of the present subject matter. In the depicted embodiment, the delivery module <NUM> is fluidly coupled via a hose <NUM> to a fuel system coupler <NUM>. The fuel system coupler <NUM> is operably coupled to the gas turbine engine's <NUM> fuel system <NUM>. The fuel system <NUM> includes a plurality of hoses <NUM> and fuel injector nozzles <NUM> coupled to the gas turbine engine <NUM>. In such an embodiment, the delivery module <NUM> delivers a portion of the treatment compound <NUM> through the fuel system <NUM> to be dispersed by the fuel injector nozzles <NUM> into the combustors <NUM> (<FIG>) of the gas turbine engine <NUM>.

<FIG> illustrates a schematic view of one embodiment of a treatment system <NUM> for treating one or more components of a gas turbine engine <NUM> in accordance with aspects of the present subject matter. As illustrated, the treatment system <NUM> includes, a first storage vessel <NUM> and a second storage vessel <NUM>, and the treatment compound <NUM> includes a first active ingredient <NUM> and a second active ingredient <NUM>. The first active ingredient is contained in the first storage vessel <NUM>, and the second active ingredient <NUM> is contained in the second storage vessel <NUM>. As shown in <FIG>, the delivery module <NUM> of this embodiment also includes a mixing chamber <NUM>. At the direction of the controller <NUM>, the mixing chamber <NUM> mixes a portion of the first active ingredient <NUM> with a portion of the second active ingredient <NUM> to produce the treatment compound <NUM>.

<FIG> illustrates a schematic view of one embodiment of a treatment system <NUM> for treating one or more components of a gas turbine engine <NUM> in accordance with aspects of the present subject matter. In the illustrated embodiment, the treatment system <NUM> includes a storage vessel (<FIG>, <NUM>), which is a pressure vessel <NUM>. The pressure vessel <NUM> holds a portion of the treatment compound <NUM> in a vapor phase. To maintain the treatment compound <NUM> as a vapor, a pressure control mechanism <NUM> and a temperature control mechanism <NUM> are coupled to the pressure vessel <NUM>. In the exemplary embodiment, the treatment compound <NUM> is delivered as a vapor to the gas turbine engine <NUM> by the delivery module <NUM>.

<FIG> illustrates a schematic view of one embodiment of a treatment system <NUM> for treating one or more components of a gas turbine engine <NUM> in accordance with aspects of the present subject matter. In the illustrated embodiment, the treatment system <NUM> includes a storage vessel (<FIG>, <NUM>), which is a pressure vessel <NUM>. The pressure vessel <NUM> holds a portion of the treatment compound <NUM> in a liquid form. To maintain the treatment compound <NUM> as a liquid, a first pressure control mechanism <NUM> and a first temperature control mechanism <NUM> are coupled to the pressure vessel <NUM>. A vaporizer <NUM> is operably coupled between the pressure vessel <NUM> and the delivery module <NUM>. A second pressure control mechanism <NUM> and a second temperature control mechanism <NUM> are operably coupled to the vaporizer <NUM> to establish vaporizations conditions therein. In the depicted embodiment, the vaporizer <NUM> converts a portion of liquid treatment compound <NUM> to a vapor and delivers the vapor to the delivery module <NUM>.

Referring now to <FIG>, a flow diagram of a method <NUM> is shown for treating one or more components of an aircraft-mounted gas turbine engine. The exemplary method <NUM> includes at <NUM> operably coupling the delivery module to an engine access point. The delivery module is also coupled to a storage vessel. The exemplary method <NUM> includes at <NUM> activating the delivery module to deliver a portion of a treatment compound to the engine access point. The treatment compound is a supersaturated vapor upon entering an engine air-path. The supersaturated vapor may have a delivery temperature for a corresponding a delivery pressure. The delivery temperature is greater than a surface temperature of a component surface such that the vapor changes phase on the component surface.

Referring again to <FIG>, in general, the engine <NUM> may include a core gas turbine engine (indicated generally by reference character <NUM>) and a fan section <NUM> positioned upstream thereof. The core engine <NUM> may generally include a substantially tubular outer casing <NUM> that defines an annular inlet <NUM>. In addition, the outer casing <NUM> may further enclose and support a booster compressor <NUM> for increasing the pressure of the air that enters the core engine <NUM> to a first pressure level. A high pressure, multi-stage, axial-flow compressor <NUM> may then receive the pressurized air from the booster compressor <NUM> and further increase the pressure of such air. The pressurized air exiting the high-pressure compressor <NUM> may then flow to a combustor <NUM> within which fuel is injected by a fuel system <NUM> into the flow of pressurized air, with the resulting mixture being combusted within the combustor <NUM>. The high energy combustion products are directed from the combustor <NUM> along the hot gas path of the engine <NUM> to a first (high pressure, HP) turbine <NUM> for driving the high pressure compressor <NUM> via a first (high pressure, HP) drive shaft <NUM>, and then to a second (low pressure, LP) turbine <NUM> for driving the booster compressor <NUM> and fan section <NUM> via a second (low pressure, LP) drive shaft <NUM> that is generally coaxial with first drive shaft <NUM>. After driving each of turbines <NUM> and <NUM>, the combustion products may be expelled from the core engine <NUM> via an exhaust nozzle <NUM> to provide propulsive jet thrust.

It should be appreciated that each turbine may generally include one or more turbine stages, with each stage including a turbine nozzle and a downstream turbine rotor. As will be described below, the turbine nozzle may include a plurality of vanes disposed in an annular array about the centerline axis <NUM> of the engine <NUM> for turning or otherwise directing the flow of combustion products through the turbine stage towards a corresponding annular array of rotor blades forming part of the turbine rotor. As is generally understood, the rotor blades may be coupled to a rotor disk of the turbine rotor, which is, in turn, rotationally coupled to the turbine's drive shafts <NUM>, <NUM>.

Additionally, as shown in <FIG>, the fan section <NUM> of the engine <NUM> may generally include a rotatable, axial-flow fan rotor <NUM> surrounded by an annular fan casing <NUM>. In particular embodiments, the (LP) drive shaft <NUM> may be connected directly to the fan rotor <NUM> such as in a direct-drive configuration. In alternative configurations, the (LP) drive shaft <NUM> may be connected to the fan rotor <NUM> via a speed reduction device <NUM> such as a reduction gear gearbox in an indirect-drive or geared-drive configuration. Such speed reduction devices may be included between any suitable shafts / spools within engine <NUM> as desired or required.

It should be appreciated by those of ordinary skill in the art that the fan casing <NUM> may be supported relative to the core engine <NUM> by a plurality of substantially radially-extending, circumferentially-spaced outlet guide vanes <NUM>. As such, the fan casing <NUM> may enclose the fan rotor <NUM> band its corresponding fan rotor blades <NUM>. Moreover, a downstream section <NUM> of the fan casing <NUM> may extend over an outer portion of the core engine <NUM> to define a secondary, or by-pass, airflow conduit <NUM> that provides additional propulsive jet thrust.

During operation of the engine <NUM>, it should be appreciated that an initial air flow (indicated by arrow <NUM>) may enter the engine <NUM> through an associated inlet <NUM> of the fan casing <NUM>. The air flow <NUM> then passes through the fan blades <NUM> and splits into a first compressed air flow (indicated by arrow <NUM>) that moves through conduit <NUM> and a second compressed air flow (indicated by arrow <NUM>) which enters the booster compressor <NUM>. The pressure of the second compressed air flow <NUM> is then increased and enters the high-pressure compressor <NUM> (as indicated by arrow <NUM>). After mixing with fuel and being combusted within the combustor <NUM>, the combustion products <NUM> exit the combustor <NUM> and flow through the first turbine <NUM>. Thereafter, the combustion products <NUM> flow through the second turbine <NUM> and exit the exhaust nozzle <NUM> to provide thrust for the engine <NUM>.

<FIG> provides a block diagram of an exemplary computing system <NUM> that is representative of an embodiment of controller <NUM> that may be used to implement the methods and systems described herein according to exemplary embodiments of the present disclosure. Though described below as a computing system, it should be appreciated that in some embodiments, the controller may be an analog system or an electrical system that does not include a computing device. As shown, the computing system <NUM> may include one or more computing device(s) <NUM>. The one or more computing device(s) <NUM> may include one or more processor(s) <NUM> and one or more memory device(s) <NUM>. The one or more processor(s) <NUM> may include any suitable processing device, such as a microprocessor, microcontroller, integrated circuit, logic device, or other suitable processing device. The one or more memory device(s) <NUM> may include one or more computer-readable media, including, but not limited to, non-transitory computer-readable media, RAM, ROM, hard drives, flash drives, or other memory devices.

The one or more memory device(s) <NUM> may store information accessible by the one or more processor(s) <NUM>, including computer-readable instructions <NUM> that may be executed by the one or more processor(s) <NUM>. The instructions <NUM> may be any set of instructions that when executed by the one or more processor(s) <NUM>, cause the one or more processor(s) <NUM> to perform operations. The instructions <NUM> may be software written in any suitable programming language or may be implemented in hardware. In some embodiments, the instructions <NUM> may be executed by the one or more processor(s) <NUM> to cause the one or more processor(s) <NUM> to perform operations, such as implementing one or more of the processes mentioned above.

The memory device(s) <NUM> may further store data <NUM> that may be accessed by the processor(s) <NUM>. For example, the data <NUM> may include a third instance of shared data for a gas turbine engine, as described herein. The data <NUM> may include one or more table(s), function(s), algorithm(s), model(s), equation(s), etc. according to example embodiments of the present disclosure.

The one or more computing device(s) <NUM> may also include a communication interface <NUM> used to communicate, for example, with the other components of system. The communication interface <NUM> may include any suitable components for interfacing with one or more network(s), including for example, transmitters, receivers, ports, controllers, antennas, or other suitable components.

For instance, processes discussed herein may be implemented using a single computing device or multiple computing devices working in combination. Databases, memory, instructions, and applications may be implemented on a single system or distributed across multiple systems. Distributed components may operate sequentially or in parallel.

Claim 1:
A vapor-based system (<NUM>) for treating one or more components of a gas turbine engine (<NUM>), the system (<NUM>) comprising:
a treatment compound (<NUM>) having a delivery temperature for a corresponding delivery pressure;
a storage vessel (<NUM>) containing the treatment compound (<NUM>); and
a delivery module (<NUM>) operably coupled to the storage vessel (<NUM>) and to an engine access point (<NUM>), wherein the delivery module (<NUM>) is operable to deliver the treatment compound (<NUM>) at one or more locations of the gas turbine engine (<NUM>);
a controller (<NUM>) communicatively coupled to the delivery module (<NUM>) and the storage vessel (<NUM>) via a communications link (<NUM>) to manage the delivery of the treatment compound (<NUM>) to the gas turbine engine (<NUM>) such that the treatment compound (<NUM>) is a vapor in an engine air-path and is supersaturated when exposed to an engine component that is to be treated and condenses thereon;
wherein the engine component that is to be treated has an engine component surface temperature and wherein the system is configured so that the delivery temperature of the vapor is greater than the engine component surface temperature,
wherein the treatment compound comprises a cleaning agent, a restorative agent, or a protective agent.