Patent Description:
A gas turbine engine typically includes a turbomachinery core having a high pressure compressor, combustor, and high pressure turbine in serial flow relationship. The core is operable in a known manner to generate a primary gas flow. The high pressure compressor includes annular arrays ("rows") of stationary vanes that direct air entering the engine into downstream, rotating blades of the compressor. Collectively one row of compressor vanes and one row of compressor blades make up a "stage" of the compressor. Similarly, the high pressure turbine includes annular rows of stationary nozzle vanes that direct the gases exiting the combustor into downstream, rotating blades of the turbine. Collectively one row of nozzle vanes and one row of turbine blades make up a "stage" of the turbine. Typically, both the compressor and turbine include a plurality of successive stages.

With operation of a gas turbine engine, dust, debris and other materials can buildup onto the internal components of the engine over time, which can result in a reduction in the operating efficiency of such components. For example, dust layers and other materials often become baked onto the airfoils of the high pressure compressor. To remove such material deposits, current cleaning methods utilize a guided hose to inject water into the compressor inlet. Unfortunately, such conventional cleaning methods often provide insufficient cleansing of the compressor airfoils, particularly the airfoils located within the aft stages of the compressor.

<CIT> relates to an apparatus for injecting cleaning materials into the steam chest of a turbine and to methods for cleaning high pressure turbines using that apparatus and discloses a system according to the preamble of claim <NUM> and a method according to the preamble of claim <NUM>. Accordingly, an improved system and method for in situ cleaning of internal components of a gas turbine engine would be welcomed in the technology.

In one aspect, the invention is directed to a system for in situ cleaning of internal components of a gas turbine engine according to claim <NUM>. The system generally includes a plug assembly defining a fluid passageway extending lengthwise between an inlet end and an outlet end. The plug assembly is configured to be installed within an access port of the engine such that the fluid passageway defines a flow path between inner and outer casings of the engine for supplying a cleaning fluid within an interior of the engine. The plug assembly includes an inner sleeve at least partially defining the fluid passageway and an outer sleeve configured to receive a portion of the inner sleeve. The inner sleeve is configured to be coupled to the inner casing and the outer sleeve is configured to be coupled to the outer casing. The system also includes a fluid conduit configured to be coupled between a fluid source positioned external to the gas turbine engine and the inlet end of the plug assembly for supplying the cleaning fluid to the plug assembly. A cleaning fluid supplied from the fluid conduit may be directed through the fluid passageway from the inlet end to the outlet end and may then be expelled from the plug assembly into the interior of the gas turbine engine.

In another aspect, the invention is directed to an assembly comprising a gas turbine engine and a system according to any of the claims <NUM> to <NUM>.

The engine generally includes an outer casing and an inner casing spaced radially inwardly from the outer casing by a radial distance. The outer casing defines an outer portion of an access port of the engine and the inner casing may define an inner portion of the access port. The engine also includes a plug assembly defining a fluid passageway extending lengthwise between an inlet end and an outlet end. The plug assembly is installed within the inner and outer portions of the access port such that the fluid passageway defines a flow path between the inner and outer casings for supplying a cleaning fluid within an interior of the engine. The plug assembly includes an inner sleeve at least partially defining the fluid passageway and an outer sleeve configured to receive a portion of the inner sleeve. The inner sleeve is coupled to the inner casing and the outer sleeve is coupled to the outer casing. In addition, the engine includes a cap configured to be removably coupled to the outer sleeve at the outlet end of the plug assembly. The cap is configured to prevent fluid flow through the fluid passageway when the cap is installed onto the plug assembly.

In a further aspect, the invention is directed to a method for in situ cleaning of internal components of a gas turbine engine according to claim <NUM>. The method generally includes accessing a plug assembly installed within an access port defined through inner and outer casings of the gas turbine engine. The plug assembly defines a fluid passageway extending lengthwise between an inlet end and an outlet end such that the fluid passageway defines a flow path between the inner and outer casings. The plug assembly includes an inner sleeve at least partially defining the fluid passageway and an outer sleeve configured to receive a portion of the inner sleeve. The method also includes coupling a fluid conduit between a fluid source positioned external to the gas turbine engine and an inlet end of the plug assembly and supplying a cleaning fluid from the fluid source through the fluid conduit to the plug assembly such that the cleaning fluid is directed through the fluid passageway defined by the plug assembly and is expelled from an outlet end of the plug assembly into an interior of the gas turbine engine.

These and other features, aspects and advantages of the present invention will be 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 aspects of the invention and, together with the description, serve to explain the principles of the invention.

It is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

In general, the present subject matter is directed to a system and method for in situ cleaning of internal components of a gas turbine engine. Specifically, in several embodiments, the present disclosure is directed to a plug assembly that is configured to be installed within an access port of the gas turbine engine to allow a cleaning fluid to be injected into the interior of the engine to provide targeting cleaning of one or more internal components of the engine. For example, as will be described below, the plug assembly may define a fluid passageway that extends between an inlet end and an outlet end, with the inlet end being accessible to the exterior of the engine and the outlet end being in fluid communication with the interior of the engine. In such embodiments, by coupling a fluid hose or conduit to the inlet end of the plug assembly, a cleaning fluid may be supplied to the plug assembly from a location exterior to the engine and subsequently injected into the interior of the engine. Moreover, the plug assembly may also be configured to be capped or plugged when the assembly is not being used to provide access to the interior of the engine. As such, the plug assembly may remain installed within the access port during operation of the engine.

In a particular embodiment of the present subject matter, one or more of the disclosed plug assemblies may be installed within one or more of the access ports providing internal access to the high pressure compressor of a gas turbine engine to allow for targeted cleaning of the internal components of the compressor, such as the compressor blades and/or vanes. For example, the plug assembly(ies) may be installed within the access port(s) providing access to one or more of the aft stages of the compressor to allow baked-on dust layers and other material deposits to be removed from the airfoils located within such stage(s).

It should be appreciated that, for purposes of description, the disclosed system and method will be described herein with reference to providing targeted, in situ cleaning of internal components of the high pressure compressor of a gas turbine engine. However, in general, the system and method disclosed herein may be used to provide targeted, in situ cleaning within the interior of any other suitable component of a gas turbine engine. Additionally, it should be appreciated that the disclosed system and method may generally be used to provide in situ cleaning of internal components located within any suitable type of gas turbine engine, including aircraft-based turbine engines and land-based turbine engines, regardless of the engine's current assembly state (e.g., fully or partially assembled). Moreover, with reference to aircraft engines, it should be appreciated that the present subject matter may be implemented on wing or off wing.

Referring now to the drawings, <FIG> illustrates a cross-sectional view of one embodiment of a gas turbine engine <NUM> that may be utilized within an aircraft in accordance with aspects of the present subject matter, with the engine <NUM> being shown having a longitudinal or axial centerline axis <NUM> extending therethrough for reference purposes. 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 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) turbine <NUM> for driving the high pressure compressor <NUM> via a first (high pressure) drive shaft <NUM>, and then to a second (low pressure) turbine <NUM> for driving the booster compressor <NUM> and fan section <NUM> via a second (low pressure) 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.

Additionally, as shown in <FIG>, the fan section <NUM> of the engine <NUM> may generally include a rotatable, axial-flow fan rotor assembly <NUM> that is configured to be surrounded by an annular fan casing <NUM>. It should be appreciated by those of ordinary skill in the art that the fan casing <NUM> may be configured to 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 assembly <NUM> and 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> so as to define a secondary, or by-pass, airflow conduit <NUM> that provides additional propulsive jet thrust.

It should be appreciated that, in several embodiments, the second (low pressure) drive shaft <NUM> may be directly coupled to the fan rotor assembly <NUM> to provide a direct-drive configuration. Alternatively, the second drive shaft <NUM> may be coupled to the fan rotor assembly <NUM> via a speed reduction device <NUM> (e.g., a reduction gear or gearbox) to provide an indirect-drive or geared drive configuration. Such a speed reduction device(s) may also be provided between any other suitable shafts and/or spools within the engine <NUM> as desired or required.

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>.

The gas turbine engine <NUM> may also include a plurality of access ports defined through its casings and/or frames for providing access to the interior of the core engine <NUM>. For instance, as shown in <FIG>, the engine <NUM> may include a plurality of access ports <NUM> (only six of which are shown) defined through the outer casing <NUM> for providing internal access to one or both of the compressors <NUM>, <NUM> and/or for providing internal access to one or both of the turbines <NUM>, <NUM>. In several embodiments, the access ports <NUM> may be spaced apart axially along the core engine <NUM>. For instance, the access ports <NUM> may be spaced apart axially along each compressor <NUM>, <NUM> and/or each turbine <NUM>, <NUM> such that at least one access port <NUM> is located at each compressor stage and/or each turbine stage for providing access to the internal components located at such stage(s). In addition, the access ports <NUM> may also be spaced apart circumferentially around the core engine <NUM>. For instance, a plurality of access ports <NUM> may be spaced apart circumferentially around each compressor stage and/or turbine stage.

Referring now to <FIG>, a simplified, cross-sectional view of a portion of the high pressure compressor <NUM> described above with reference to <FIG> is illustrated in accordance with aspects of the present subject matter. As shown, the compressor <NUM> may include a plurality of compressor stages, with each stage including both an annular array of fixed compressor vanes <NUM> (only one of which is shown for each stage) and an annular array of rotatable compressor blades <NUM> (only one of which is shown for each stage). Each row of compressor vanes <NUM> is generally configured to direct air flowing through the compressor <NUM> to the row of compressor blades <NUM> immediately downstream thereof.

Additionally, the compressor <NUM> may include an inner casing <NUM> configured to encase the various compressor stages and an outer casing <NUM> spaced radially outwardly from the inner casing <NUM>. For example, as shown in <FIG>, the outer casing <NUM> may be spaced apart from the inner casing <NUM> by a radial distance <NUM>. The radial distance <NUM> defined between the inner and outer casings <NUM>, <NUM> may vary, by design, along the axial length of the compressor <NUM>. In addition, due to the differing rates of thermal expansion between the inner and outer casings <NUM>, <NUM>, the radial distance <NUM> at a given axial location along the compressor <NUM> may vary during operation of the gas turbine engine <NUM>. For instance, the inner casing <NUM> may expand at a faster rate than the outer casing <NUM>, thereby causing a reduction in the radial distance <NUM> defined between the inner and outer casings <NUM>, <NUM>.

Moreover, the compressor <NUM> may include a plurality of access ports <NUM> defined through the inner and outer casings <NUM>, <NUM>, with each access port <NUM> being configured to provide access to the interior of the compressor <NUM> at a different axial location. For example, as shown in <FIG>, each access port <NUM> may include an outer portion <NUM> defined through the outer casing <NUM> and an inner portion <NUM> defined through the inner casing <NUM>. As such, by inserting an optical probe, repair tool and/or other device through the inner and outer portions <NUM>, <NUM> of a given access port <NUM>, a service worker may gain access to the interior of the compressor <NUM>.

In several embodiments, the access ports <NUM> may be spaced apart axially such that each access port <NUM> is aligned with or otherwise provides interior access to a different stage of the compressor <NUM>. For instance, as shown in <FIG>, two separate access ports <NUM> are illustrated that provide access to two different stages of the compressor <NUM>. In other embodiments, it should be appreciated that similar access ports <NUM> may also be provided for any of the other stages of the compressor <NUM>. It should also be appreciated that, in addition to axially spaced access ports <NUM>, access ports <NUM> may be also provided at differing circumferentially spaced locations. For instance, in one embodiment, a plurality of circumferentially spaced access ports <NUM> may be defined through the compressor casings <NUM>, <NUM> at each compressor stage to provide interior access to the compressor <NUM> at multiple circumferential locations around the compressor stage.

Referring now to <FIG>, one embodiment of a system <NUM> for in situ cleaning of internal components of a gas turbine engine <NUM> is illustrated in accordance with aspects of the present subject matter. Specifically, <FIG> and <FIG> illustrate a portion of the cross-sectional view of the high pressure compressor <NUM> shown in <FIG> with a plug assembly <NUM> of the disclosed system <NUM> being installed within one of the compressor access ports <NUM>. In this regard, <FIG> illustrates the plug assembly <NUM> in an unplugged/uncapped state to allow a cleaning fluid to be injected through the plug assembly <NUM> and into the interior of the compressor <NUM> while <FIG> illustrates the plug assembly <NUM> in a plugged/capped state to prevent fluid flow through the assembly <NUM> during operation of the gas turbine engine <NUM>. Additionally, <FIG> and <FIG> illustrate cross-sectional views of the plug assembly <NUM> shown in <FIG> and <FIG> respectively, with <FIG> illustrating the plug assembly <NUM> in its unplugged/uncapped state and <FIG> illustrating the plug assembly <NUM> in its plugged/capped state.

In general, the system <NUM> will be described herein with reference to providing targeted, in situ cleaning of the internal components of the high pressure compressor <NUM> of the gas turbine engine <NUM> described above with reference to <FIG> and <FIG>, such as the vanes <NUM> and/or blades <NUM> of the compressor <NUM>. However, it should be appreciated that, in other embodiments, the system <NUM> may be similarly used to provide in situ cleaning of any other suitable internal engine components. For instance, as opposed to installing the disclosed system components relative to an access port <NUM> defined through the casing(s) <NUM>, <NUM> of the compressor <NUM>, the system components may be installed relative to an access port defined through the casing(s) of one of the turbines <NUM>, <NUM> to allow an in situ cleaning operation to be performed on the internal engine component(s) of the turbine(s) <NUM>, <NUM>, such as the turbine blades and/or nozzles.

As shown in <FIG>, the system <NUM> may generally include a plug assembly <NUM> configured to be installed within the inner and outer portions <NUM>, <NUM> of a given access port <NUM> of the compressor <NUM>. In several embodiments, the plug assembly <NUM> may define a fluid passageway <NUM> extending lengthwise between an inlet end <NUM> and an outlet end <NUM>, with the inlet end <NUM> being positioned at or adjacent to the outer casing <NUM> of the compressor <NUM> and the outlet end <NUM> being positioned at or adjacent to the inner casing <NUM> of the compressor <NUM>. As such, by installing the plug assembly <NUM> through the access port <NUM>, the fluid passageway <NUM> may provide a means for directing a cleaning fluid (indicated by arrows <NUM> in <FIG> and <FIG>) through the inner and outer casings <NUM>, <NUM> for subsequent delivery within the interior of the compressor <NUM>.

As shown <FIG>, in several embodiments, the plug assembly <NUM> may include an outer sleeve <NUM> configured to be coupled to the outer casing <NUM> of the compressor <NUM> and an inner sleeve <NUM> configured to be coupled to the inner casing <NUM> of the compressor <NUM>. Each sleeve <NUM>, <NUM> may generally define a through-hole or passageway extending along its length. For example, as particularly shown in <FIG>, the outer sleeve <NUM> may define an outer passageway <NUM> extending lengthwise between its outer end (e.g., the inlet end <NUM> of the plug assembly <NUM>) and its opposed inner end <NUM>. Similarly, the inner sleeve <NUM> may define an inner passageway <NUM> extending lengthwise between its outer end <NUM> and its opposed inner end (e.g., the outlet end <NUM> of the plug assembly <NUM>). Additionally, as shown in <FIG> and <FIG>, a portion of the inner sleeve <NUM> may be configured to be received within the outer sleeve <NUM> so that the outer passageway <NUM> defined by the outer sleeve <NUM> is in fluid communication with the inner passageway <NUM> defined by the inner sleeve <NUM>. As a result, the inner and outer sleeves <NUM>, <NUM> may collectively define the fluid passageway <NUM> extending between the inlet and outlet ends <NUM>, <NUM> of the plug assembly <NUM>.

Additionally, as shown in <FIG> and <FIG>, in several embodiments, the inner and outer sleeves <NUM>, <NUM> may be configured to be coupled to the inner and outer casings <NUM>, <NUM>, respectively, via a threaded connection. For example, the outer sleeve <NUM> may define an outer threaded area <NUM> around its outer perimeter that is configured to engage a corresponding threaded area <NUM> defined within the outer portion <NUM> of the access port <NUM>. Similarly, the inner sleeve <NUM> may define an inner threaded area <NUM> around its outer perimeter that is configured to engage a corresponding threaded area <NUM> defined within the inner portion <NUM> of the access port <NUM>. As such, when installing the plug assembly <NUM> within the access port <NUM>, the inner and outer threaded areas <NUM>, <NUM> of the sleeves <NUM>, <NUM> may be screwed into or otherwise engaged with the corresponding threaded areas <NUM>, <NUM> of the inner and outer portions <NUM>, <NUM> of the access port <NUM> to allow the assembly <NUM> to be coupled to the inner and outer casings <NUM>, <NUM>.

Moreover, in several embodiments, the inner sleeve <NUM> may be configured to move relative to the outer sleeve <NUM> to accommodate relative movement between the inner and outer casings <NUM>, <NUM>. For example, due to the temperature differential between the inner and casings <NUM>, <NUM> during operation of the gas turbine engine <NUM>, the casings <NUM>, <NUM> may have differing rates of thermal expansion. Such varied thermal expansion can lead to variations in the radial distance <NUM> defined between the inner and outer casings <NUM>, <NUM> at the location of the plug assembly <NUM>. Thus, by allowing the inner sleeve <NUM> to move relative to the outer sleeve <NUM>, the overall radial height of the plug assembly <NUM> may be automatically adjusted with variations in the radial distance <NUM> defined between the inner and outer casings <NUM>, <NUM> while still maintaining a rigid coupling between the sleeves <NUM>, <NUM> and the casings <NUM>, <NUM>.

As shown in <FIG> and <FIG>, in one embodiment, the inner sleeve <NUM> may be configured to slide relative to the outer sleeve <NUM> in a lengthwise direction of the plug assembly <NUM> (indicated by arrow <NUM> in <FIG> and <FIG>) such that the amount of the inner sleeve <NUM> that is received within the outer passageway <NUM> of the outer sleeve <NUM> increases or decreases as the radial distance <NUM> between the inner and outer casings <NUM>, <NUM> decreases or increases, respectively. In such an embodiment, the plug assembly <NUM> may include a biasing mechanism, such as a spring <NUM>, coupled between the inner and outer sleeves <NUM>, <NUM> to provide a biasing force against the inner sleeve <NUM> that biases in the inner sleeve <NUM> in the direction of the inner casing <NUM>. As such, when the radial distance <NUM> between the inner and outer casings <NUM>, <NUM> decreases, the compressive force applied through the plug assembly <NUM> may overcome the biasing force applied by the spring <NUM>, thereby compressing the spring <NUM> and allowing the inner sleeve <NUM> to move relative to the outer sleeve <NUM> in the direction of the inlet end <NUM> of the plug assembly <NUM>. Similarly, when the radial distance <NUM> between the inner and outer casings <NUM>, <NUM> increases, the biasing force applied by the spring <NUM> may bias the inner sleeve <NUM> in the direction of the outlet end <NUM> of the plug assembly <NUM>, thereby allowing the plug assembly <NUM> to span the increased radial gap between the casings <NUM>, <NUM>.

As shown in the illustrated embodiment, the spring <NUM> may be positioned within an enlarged portion <NUM> of the outer passageway <NUM> defined by the outer sleeve <NUM> such that the spring <NUM> extends around at least a portion of the section of the inner sleeve <NUM> received within the outer sleeve <NUM>. Specifically, as shown in <FIG> and <FIG>, the spring <NUM> may be engaged between an inner surface <NUM> of the enlarged portion <NUM> of the outer passageway <NUM> and a spring flange <NUM> extending outwardly from the inner sleeve <NUM>. As such, the biasing force provided by the spring <NUM> may be applied against the flange <NUM> to push the inner sleeve <NUM> away from the inlet end <NUM> of the plug assembly <NUM> when the radial distance <NUM> between the inner and outer casings <NUM>, <NUM> is increased.

Moreover, in several embodiments, the inner sleeve <NUM> may define a mounting flange <NUM> at or adjacent to its inner threaded area <NUM> that serves as a mechanical stop when installing the inner sleeve <NUM> relative to the inner casing <NUM>. For example, as shown in <FIG>, the mounting flange <NUM> may be positioned radially outwardly from the inner threaded area <NUM> such that the flange <NUM> contacts the inner casing <NUM> when the inner sleeve <NUM> has been properly installed relative to the casing <NUM>. In addition, such contact between the mounting flange <NUM> and the inner casing <NUM> may be used to provide an additional sealed interface between the plug assembly <NUM> and the inner casing <NUM>, thereby preventing the working fluid flowing through the compressor <NUM> from leaking through the inner portion <NUM> of the access port <NUM>.

Referring particularly to <FIG> and <FIG>, the plug assembly <NUM> may also include a removable cap <NUM> configured to close-off or otherwise cap the fluid passageway <NUM> defined by the plug assembly <NUM> during operation of the gas turbine engine <NUM>. As particularly shown in <FIG>, the cap <NUM> may generally include a cap portion <NUM> and a plug portion <NUM> extending outwardly from the cap portion <NUM>. The cap portion <NUM> may generally be configured to be removably coupled to the outer sleeve <NUM> at the inlet end <NUM> of the plug assembly <NUM>. For example, as shown in <FIG>, an end portion <NUM> of the outer sleeve <NUM> may be threaded at or adjacent to the inlet end <NUM> of the assembly <NUM>. In such an embodiment, the inner surface of the cap portion <NUM> may be similarly threaded to allow the cap portion <NUM> to be screwed onto the end portion <NUM> of the outer sleeve <NUM>, thereby providing a means to close-off or cover the inlet end <NUM> of the plug assembly <NUM>.

Additionally, as shown in <FIG>, the plug portion <NUM> of the cap <NUM> may be configured to be inserted within the fluid passageway <NUM> of the plug assembly <NUM> such that, when the cap portion <NUM> is coupled to the outer sleeve <NUM>, the plug portion <NUM> extends lengthwise within the plug assembly <NUM> and occupies a portion of the fluid passageway <NUM>. For example, as shown in the illustrated embodiment, the plug portion <NUM> generally defines a length <NUM> between the cap portion <NUM> and a plug end <NUM> of the cap <NUM>. In such an embodiment, the length <NUM> of the plug portion <NUM> may be selected such that the plug portion <NUM> occupies all or significant portion of the fluid passageway <NUM> when the plug portion <NUM> is inserted within the assembly <NUM>. For instance, as shown in <FIG>, the length <NUM> of the plug portion <NUM> may generally correspond to the overall length of the plug assembly <NUM> such that the plug end <NUM> of the cap <NUM> is generally aligned with and/or positioned at or adjacent to the outlet end <NUM> of the plug assembly <NUM>.

Referring particularly to <FIG> and <FIG>, the disclosed system <NUM> may also include a cleaning fluid source <NUM> (e.g., a mobile cleaning station, a fluid tank and/or any other suitable fluid source) and a fluid conduit <NUM> configured to be coupled between the fluid source <NUM> and the plug assembly <NUM>. Specifically, when it is desired to perform an in situ cleaning operation within the compressor <NUM>, the cap <NUM> may be removed from the plug assembly <NUM> and the fluid conduit <NUM> may be coupled to the plug assembly <NUM> to provide a flow path between the fluid source <NUM> and the plug assembly <NUM>. Cleaning fluid directed through the fluid conduit <NUM> from the fluid source <NUM> may then be supplied to the plug assembly <NUM> and may flow through the fluid passageway <NUM> to the outlet end <NUM> of the assembly <NUM>. The cleaning fluid may then be expelled from the plug assembly <NUM> into the interior of the compressor <NUM>.

It should be appreciated that the fluid conduit <NUM> may be configured to be coupled to the plug assembly <NUM> using any suitable coupling and/or connection means known in the art. For example, as shown in <FIG>, in one embodiment, a supply end <NUM> of the conduit <NUM> may be threaded to allow the end <NUM> to be coupled to the threaded end portion <NUM> of the outer sleeve <NUM>. In such an embodiment, when the cap <NUM> is removed from the plug assembly <NUM>, the supply end <NUM> of the conduit <NUM> may be screwed onto the threaded end portion <NUM> of the outer sleeve <NUM> to provide a continuous flow path between the conduit <NUM> and the fluid passageway <NUM> defined by the plug assembly <NUM>. Alternatively, the fluid conduit <NUM> may be configured to be coupled to the plug assembly <NUM> using any other suitable means. For instance, in another embodiment, the supply end <NUM> of the conduit <NUM> may be configured to be inserted into the outer passageway <NUM> of the outer sleeve <NUM> at the inlet end <NUM> of the assembly <NUM> (e.g., via a quick connect-type coupling) to allow cleaning fluid to be supplied through the plug assembly <NUM> from the conduit <NUM>.

It should also be appreciated that the cleaning fluid used within the system <NUM> may generally correspond to any suitable fluid. For instance, the cleaning fluid may correspond to a liquid, gas and/or any combination thereof (e.g., foam). In addition, the cleaning fluid may contain and/or may serve as a delivery means for solid materials, such as solid particulates and/or abrasive materials. For instance, a liquid cleaning fluid containing solid abrasives may be supplied through the plug assembly <NUM> and injected into the compressor <NUM> at a relatively high pressure to allow the abrasive materials to be used to wear down or abrade away any baked-on material deposits located on the compressor vanes <NUM> and/or blades <NUM>. Moreover, the cleaning fluid may be supplied through the plug assembly <NUM> at any suitable pressure and/or velocity. For example, the plug assembly <NUM> may be configured to accommodate injection of the cleaning fluid using a pulsing pressure technique and/or at ultrasonic velocities.

Additionally, it should be appreciated that the outlet end <NUM> of the plug assembly <NUM> may generally have any suitable shape and/or configuration that allows for cleaning fluid to be injected into the interior of the compressor <NUM>. For example, in one embodiment, the outlet end <NUM> of the plug assembly <NUM> may be configured or shaped to form a nozzle (e.g., a convergent nozzle or convergent-divergent nozzle), thereby allowing a high pressure stream or jet of cleaning fluid to be injected into the interior of the compressor <NUM> from the plug assembly <NUM>. Alternatively, the outlet end <NUM> of the plug assembly <NUM> may be configured to form any other suitable opening or outlet for expelling cleaning fluid into the interior of the compressor <NUM>.

It should also be appreciated that, although the system <NUM> has generally been described herein with reference to a single plug assembly <NUM> installed within a single access port <NUM> of the gas turbine engine <NUM>, the system <NUM> may include multiple plug assemblies <NUM> installed within various different access ports <NUM> of the engine <NUM>. For instance, plug assemblies <NUM> may be installed within access ports <NUM> spaced apart axially along the engine <NUM>, such as by installing a plug assembly <NUM> within an access port positioned at each compressor stage and/or turbine stage of the gas turbine engine <NUM>. Similarly, plug assemblies <NUM> may be installed within access ports <NUM> spaced apart circumferentially around the engine <NUM>, such as by installing a plurality of plug assemblies <NUM> within the access ports <NUM> spaced apart circumferentially around a given compressor stage(s) and turbine stage(s).

Moreover, it should be appreciated that the disclosed plug assembly <NUM> may also be configured to accommodate any tools, probes and/or devices desired to be inserted into the interior of the gas turbine engine <NUM> via one of its access ports <NUM>. For example, the fluid passageway <NUM> defined by the plug assembly <NUM> may be sized so as to accommodate an optical probe, such as a borescope, a fiberscope or a videoscope, used to perform a visual inspection of the interior of the engine <NUM>.

Referring now to <FIG>, a flow diagram of one embodiment of a method <NUM> for in situ cleaning of internal components of a gas turbine engine is illustrated in accordance with aspects of the present subject matter. In general, the method <NUM> will be discussed herein with reference to the gas turbine engine <NUM> and the system <NUM> described above with reference to <FIG>. However, it should be appreciated by those of ordinary skill in the art that the disclosed method <NUM> may generally be implemented with gas turbine engines having any other suitable engine configuration and/or with systems having any other suitable system configuration. In addition, although <FIG> depicts steps performed in a particular order for purposes of illustration and discussion, the methods discussed herein are not limited to any particular order or arrangement. One skilled in the art, using the disclosures provided herein, will appreciate that various steps of the methods disclosed herein can be omitted, rearranged, combined, and/or adapted in various ways without deviating from the scope of the present disclosure.

As shown in <FIG>, at (<NUM>), the method <NUM> includes accessing a plug assembly installed within an access port defined through inner and outer casings of the gas turbine engine. For example, as indicated above, the disclosed plug assembly <NUM> may be installed within a given access port <NUM> of the gas turbine engine <NUM> such that an outer sleeve <NUM> of the plug assembly <NUM> is coupled to the outer casing <NUM> (e.g., within an outer portion <NUM> of the access port <NUM> defined by the outer casing <NUM>) and an inner sleeve <NUM> of the plug assembly <NUM> is coupled to the inner casing <NUM> (e.g., within an inner portion <NUM> of the access port <NUM> defined by the inner casing <NUM>).

Additionally, at (<NUM>), the method <NUM> may include coupling a fluid conduit between a fluid source positioned external to the gas turbine engine and an inlet end of the plug assembly. For example, as indicated above, a supply end <NUM> of the fluid conduit <NUM> may be coupled to the inlet end <NUM> of the plug assembly <NUM> and an opposed end of the fluid conduit <NUM> may be in fluid communication with a suitable fluid source <NUM>. As such, the fluid conduit <NUM> may provide a flow path between the fluid source <NUM> and the plug assembly <NUM>.

Moreover, at (<NUM>), the method <NUM> may include supplying a cleaning fluid from the fluid source through the fluid conduit such that the cleaning fluid is directed through a fluid passageway defined by the plug assembly and is expelled from an outlet end of the plug assembly into an interior of the gas turbine engine. Specifically, as indicated above, the plug assembly <NUM> may define a fluid passageway <NUM> extending between its inlet and outlet ends <NUM>, <NUM>. Thus, by supplying a cleaning fluid to the inlet end <NUM> of the plug assembly <NUM>, the cleaning fluid may be directed through the fluid passageway <NUM> to the outlet end <NUM> of the plug assembly <NUM>. The cleaning fluid may then be expelled from the plug assembly <NUM> into the interior of the gas turbine engine <NUM> to allow one or more internal components of the engine <NUM> to be cleaned.

It should be appreciated that the disclosed method <NUM> may further include additional method elements. For example, in one embodiment, the method <NUM> may include removing a cap <NUM> from the plug assembly <NUM> prior to coupling the fluid conduit <NUM> to the inlet end <NUM> of the plug assembly <NUM>. In addition, the method <NUM> may include reinstalling the cap <NUM> relative to the plug assembly <NUM> after the cleaning fluid has been supplied through the plug assembly <NUM> such that a cap portion <NUM> of the cap <NUM> is coupled to the outer sleeve <NUM> and a plug portion <NUM> of the cap <NUM> extends lengthwise within the fluid passageway <NUM> defined by the plug assembly <NUM>.

Claim 1:
A system (<NUM>) for in situ cleaning of internal components of a gas turbine engine (<NUM>), the gas turbine engine including an outer casing (<NUM>) and an inner casing (<NUM>), the system comprising:
a plug assembly (<NUM>) defining a fluid passageway (<NUM>) extending lengthwise between an inlet end (<NUM>) and an outlet end (<NUM>), the plug assembly configured to be installed within an access port (<NUM>) of the gas turbine engine such that the fluid passageway defines a flow path between the inner and outer casings of the gas turbine engine for supplying a cleaning fluid within an interior of the gas turbine engine, the plug assembly including an inner sleeve (<NUM>) at least partially defining the fluid passageway and an outer sleeve (<NUM>) configured to receive a portion of the inner sleeve, the inner sleeve configured to be coupled to the inner casing and the outer sleeve configured to be coupled to the outer casing,
a fluid conduit (<NUM>) configured to be coupled between a fluid source (<NUM>) positioned external to the gas turbine engine and the inlet end of the plug assembly for supplying the cleaning fluid to the plug assembly,
whereby a cleaning fluid supplied from the fluid conduit is directed through the fluid passageway from the inlet end to the outlet end and is expelled from the plug assembly into the interior of the gas turbine engine, characterised in that the inner sleeve (<NUM>) defines an inner threaded (<NUM>) area around an outer perimeter of the inner sleeve, the inner threaded area configured to engage a corresponding threaded portion (<NUM>) of the access port (<NUM>) defined through the inner casing.