Patent ID: 12258874

DETAILED DESCRIPTION

Compressors of a gas turbine engine include several airfoil types. An airfoil refers to a stationary or moving blade-like component that is used to control the flow of fluid or gas within the compressor, and they play a crucial role in directing the fluid or gas flow. There are two primary types of airfoils used in compressors: vanes, which remain stationary, and rotor blades, which spin.

Inlet guide vanes (IGVs) are typically located at the compressor inlet and are used to control the flow of fluid or gas as it enters the compressor. They may have an adjustable angle such that the inlet flow can be regulated, which helps in achieving optimal compressor performance.

In some operational conditions (e.g., certain atmospheric moisture and temperature conditions of engine intake air), non-heated inlet guide vanes may experience ice buildup. The accumulation of ice is problematic, as can cause compressor performance and/or operability loss or may be shed in large pieces that cause damage to downstream blades or vanes or other compressor hardware. To address this issue, inlet guide vanes may be heated. For example, the inlet guide vanes may be hollow and/or have fluid pathways for receiving hot air, where the associated heat prevents ice formation.

In modern inlet guide vanes, this hot air (or anti-ice air) is routed from a compressor's inter-stage or discharge bleed. The inlet guide vanes typically then release the air into the compressor flowpath/core flow (via one or more outlet openings, often via many holes in the IGV surface). While this arrangement is currently used and successful for preventing ice, it has certain drawbacks. For example, adding hot air to the compressor's flowpath may cause temperature distortion which leads to loss of stability margin. It may also increase certain turbine temperatures which reduces turbine life. Overall engine performance may also suffer. The embodiments discussed in this description provide improved structures and methods that address these drawbacks.

FIG.1shows a schematic arrangement of a gas turbine engine for a typical aerospace application. The gas turbine engine100comprises in flow series an intake110, a fan120, an intermediate pressure compressor130, a high pressure compressor140, a combustion chamber150, a high pressure turbine160, an intermediate pressure turbine162, a low pressure turbine164and an exhaust168. The high pressure turbine160is arranged to drive the high pressure compressor140via a first shaft180. The intermediate pressure turbine162is arranged to drive the intermediate pressure compressor130via a second shaft184and the low pressure turbine164is arranged to drive the fan120via a third shaft188. In operation air flows into the intake110and is compressed by the fan120. A first portion of the air flows through, and is compressed by, the intermediate pressure compressor130and the high pressure compressor140and is supplied to the combustion chamber150. Fuel is injected into the combustion chamber150and is burned in the air to produce hot exhaust gases which flow through, and drive, the high pressure turbine160, the intermediate pressure turbine162and the low pressure turbine164. The hot exhaust gases leave the low pressure turbine164and flow through the exhaust168to provide propulsive thrust. A second portion of the air bypasses the main engine to provide propulsive thrust.

Typically, the intermediate pressure compressor130will include multiple stages of airflow control in the form of variable inlet guide vanes200for the first stage together with variable stator vanes200for the succeeding stages. Other configurations of the intermediate pressure compressor130may include a single stage of inlet guide vanes200without the succeeding stages of variable stator vanes200. In this way, as the compressor speed is reduced from its design value these static vanes200are progressively closed in order to maintain an acceptable air angle value onto the following rotor blades.

FIGS.2-4show an example of a compressor300having an anti-ice system. An inlet guide vane302of the compressor300is arranged to receive hot air, or anti-ice air304. The inlet guide vane302may receive hot air (e.g., routed from a location downstream within the compressor's flowpath and/or downstream of the compressor's discharge) to prevent ice buildup. Once circulated through the inlet guide vane302(as discussed in more detail below), the anti-ice air304may flow through an outlet channel306where it is ultimately dumped overboard via an outlet port308. Advantageously, dumping the air overboard from the engine rather than back into the engine flowpath prevents the hot air from affecting compressor performance, prevents or substantially reduces temperature distortion, and may generally increase the engine's life via overall reduced temperatures.

As shown inFIGS.2-4, the anti-ice air304is circulated through a flowpath within the inlet guide vane302, where the inlet guide vane302has a stem310that includes an IGV inlet312and an IGV outlet314. The anti-ice air reaches the IGV inlet312via an inlet channel316, which may be formed integrally within other components and/or plumbed via tubing. The inlet channel316may receive hot air routed from a location downstream within the compressor's flowpath and/or downstream of the compressor's discharge.

The IGV inlet312may communicate with the inlet channel316at a stem manifold318located at a terminus of the inlet channel316. The stem manifold318may be a generally cylindrical cavity and may receive a stem310of the inlet guide vane302. The stem manifold318may have a manifold inlet (i.e., at a junction with the inlet channel316) and also a manifold outlet (i.e., at a junction with the outlet channel306). In the depicted embodiment, the manifold318has an inner diameter that is larger than an outer diameter of the stem310, which allows the stem310to rotate within the manifold318while maintaining fluid communication with the inlet channel316and the outlet channel306(e.g., to accommodate adjustability of the inlet guide vane302). To partition the manifold318between an inlet portion and an outlet portion (and also ensure the anti-ice air cannot bypass the inlet guide vane302by direct flow through the manifold), one or more seals323may be included, where the seals323generally contact the inner diameter of the manifold318and the outer diameter of the stem310.

The stem310of the inlet guide vane302may be fixed to, and extend from, a main body324(or “airfoil”) of the inlet guide vane302. In the depicted embodiment, the stem310extends radially outward from the main body324. As mentioned above, the stem310may extend into the manifold318, and it may function to receive the anti-ice air304from the inlet channel316(via the IGV inlet312of the stem310) and then discharge the anti-ice air304to the outlet channel306(via the IGV outlet314of the stem310). The stem310may also function to secure the inlet guide vane302in place.

The stem310, which may be hollow, may allow airflow to a corresponding hollow portion of the main body324of the inlet guide vane302. Collectively, the hollow portion(s) of the inlet guide vane302that receive airflow are referred to as the anti-ice cavity326.

The anti-ice cavity326may include a directed airflow path such that the anti-ice air304is directed along a particular route from the IGV inlet312to the IGV outlet314. As shown, a center barrier328may generally distinguish the anti-ice cavity326between an inlet side322and an outlet side330. The center barrier328may extend through the stem310and a portion of the main body324, and it may terminate within the main body324(and/or have an opening within the main body324) to allow airflow between the two sides. E,g, as shown inFIG.2, a transition opening334is located at the radial-inner portion of the inlet guide vane302to allow the anti-ice air to flow from the inlet side322to the outlet side330. This ensures that the entirety or majority of the inlet guide vane's airfoil is heated via the anti-ice air304flowing therein.

In the depicted embodiment, the inlet side322is located adjacent to a leading edge336and the outlet side330is located adjacent to a trailing edge338. This may be desirable where a significant temperature loss is experienced by the anti-ice air as it flows through the inlet guide vane302. However, this is not a required feature, and the opposite orientation may also be used.

FIGS.3-4depict a feature provided by the stem310and the manifold318that accounts for adjustability of the inlet guide vane302. As shown inFIG.3(where the main body324is in a first position), the IGV inlet312is within the inlet portion342of the manifold318and similarly the IGV outlet314is within the outlet portion344of the manifold318. InFIG.4, the stem310has rotated relative to its position inFIG.3(to allow for adjustability of the main body324). However, due to the shape and size of the manifold318(e.g., cylindrical surrounding the stem, and larger than the O.D. of the stem) and the position of the seals323, the IGV inlet312remains within the inlet portion342of the manifold318and the IGV outlet314remains within the outlet portion344of the manifold318. Up to 180 degrees of rotation of the stem310can be handled in this arrangement.

FIGS.5-6show another embodiment of an anti-ice system, where up to 360 degrees of IGV rotation may be accommodated. As shown, an inlet channel416of the device leads to an inlet manifold419, where the inlet manifold419is distinct from an outlet manifold421. The inlet manifold419is associated with, and fluidly communicated with, an IGV inlet412located on a stem410of an inlet guide vane402. The stem410may have multiple concentric cavities: an outer cavity460and an inner cavity462. In the depicted embodiment, the outer cavity460is included as part of an inlet portion of the anti-ice cavity426, and the inner cavity462may be included as part of an outlet portion of the anti-ice cavity426. As such, the outer cavity460may be accessible via the IGV inlet412, and the inner cavity462may be accessible via an IGV outlet414.

As shown inFIG.5, the stem410may have multiple segments with different diameters (where the segments are positionally-fixed to each other). For example, a first segment464, which may generally define the outer boundary of the outer cavity460within the stem410and may be located within the inlet manifold419, may extend directly from a main body424of the inlet guide vane402. A second segment466, which may extend from the first segment464radially outward within the compressor, may generally define the outer boundary of the inner cavity462within the stem410and may be located within the outlet manifold421.

In this embodiment, since the inlet manifold419and the outlet manifold421are distinct and may completely surround their respective stem portions, the stem410may rotate 360 degrees about the stem's longitudinal axis without preventing airflow. Advantageously, this embodiment therefore provides enhanced IGV adjustability.

To direct airflow, an anti-ice cavity426within the main body424of the inlet guide vane402may generally have an inlet portion430(or outer portion) and an outlet portion432(or inner portion). This structure may be formed via including a center tube470within a generally hollow cavity of the main body424, where the center tube470leads to the outlet inner cavity460of the stem410, and where the outer portion of the anti-ice cavity426is directly in communication with the IGV inlet412. Herein, a tube may be considered a “barrier” given that it separates inlet and outlet portions of an anti-ice cavity. As such, anti-ice air404flowing during normal operation will first flow from out-to-in through the outer portion of the anti-ice cavity until it reaches a terminus472of the center tube470. The anti-ice air404will then flow in-to-out (or upward from the perspective ofFIG.4) through the center tube470to the IGV outlet414.

Notably, the outlet channel406and the inlet channel416shown inFIG.4are coextensive and parallel, but this is not required. The outlet channel406may extend the opposite direction, as it does in the prior embodiment. As in the embodiment discussed above, the outlet channel406may flow towards an outlet port that ultimately dumps the anti-ice air overboard.

FIG.7shows another embodiment of an anti-ice system. In this embodiment, anti-ice air504flows from a compressor discharge through tubes (much like the embodiments discussed above), and then into a 360 degree manifold arrangement580. The manifold arrangement580may be integrally cast into an air inlet housing, for example, which may generally surround a plurality of inlet guide vanes502.

The manifold arrangement580may be generally divided into manifolds of two types: a set of inlet manifolds582and a set of outlet manifolds584. As shown, the inlet manifolds582may alternate with the outlet manifolds584along the perimeter of the manifold arrangement580. Each of the inlet manifolds582may receive the anti-ice air from a location downstream within the compressor, and each of the outlet manifolds584may lead to an outlet port508for dumping the anti-ice air504overboard.

A unique aspect of this embodiment is the sequence of airflow of the anti-ice air504as it flows from an inlet manifold582, through one or more inlet guide vanes502, and then out via the outlet manifold584. In particular, the anti-ice air504may arrive at a first inlet guide vane502avia a first inlet manifold582a. The first inlet manifold may also be associated with, and provide hot air to, a second inlet guide vane502b. This is advantageous as associating each manifold with two inlet guide vanes (instead of one) may decrease the complexity of the system and the number of components needed.

The first inlet guide vane502a(as well as the other inlet guide vanes) may include a main body524that is hollow, but without particular partitions (which may be distinct relative to the embodiments above). As such, air flowing through the first inlet guide vane502amay flow radially-inwardly in a generally-linear motion to an inner crossover duct586. The first inner crossover duct586amay be located at the inner terminus of the first inlet guide vane502a. Like each inlet and outlet duct, the inner crossover duct586may fluidly communicate with two inlet guide vanes. The first inner crossover duct586a, for example, may be a generally hollow body that allows flow from the first inlet guide vane502ato a third inlet guide vane502c. Similarly, a second inner crossover duct586bmay allow flow of the anti-ice air from the second inlet guide vane502bto a fourth inlet guide vane502d.

Once air enters the third inlet guide vane502cand the fourth inlet guide vane502d, the anti-ice air flows radially outward towards, and into, respective outlet manifolds584(particularly the first outlet manifold584aand the second outlet manifold584b). Uniquely, anti-ice air entering an inlet manifold is ultimately split and flows into two different outlet manifolds, and each outlet manifold receives anti-ice air originating at two different inlet manifolds. As a result of this embodiment, two consecutive inlet guide vanes502with inward airflow alternate with two consecutive inlet guide vanes502with outward air flow around the perimeter of the system.

FIG.8shows another embodiment of an anti-ice system610. In this embodiment, the anti-ice air604is bled off from within a hub690of the compressor600. The anti-ice air604is directed through holes or inlet openings694in a high pressure compressor shaft692and then flows through an elongated cavity696of the compressor shaft692. The anti-ice air604then flows out through outlet openings698in the shaft and into a cavity700under (or radially inside) the compressor's main flowpath702.

The anti-ice air604then enters into an inner manifold618, which leads into each of the inlet guide vanes602via hollow inner stems704(which extend from respective main bodies606of the inlet guide vanes602). The anti-ice air604then travels radially outward through hollow cavities of the inlet guide vanes602, providing heating for prevention of ice, before being collected in an outer manifold619via an outer stem611of the inlet guide vane602. Ultimately, the anti-ice air flows outward via an outlet channel606until being dumped overboard. A unique aspect of this embodiment is that the inlet guide vanes602receive airflow in an “in-to-out” flow path, which is advantageous since external piping and/or cast inlet channeling are not required to direct air at the compressor's discharge to the inlet guide vanes602.

As shown in this embodiment, a valve708may regulate the flow of anti-ice air604, turning it on and off and/or regulating the flow rate as is needed or desired. The valve in this embodiment is located in the outlet channel606, but it may be located in other suitable locations. Further, a similar valve may be included in any other embodiment described herein, particularly either within an inlet channel or outlet channel. Other valve locations are also contemplated.

To clarify the use of and to hereby provide notice to the public, the phrases “at least one of <A>, <B>, . . . and <N>” or “at least one of <A>, <B>, . . . or <N>” or “at least one of <A>, <B>, . . . <N>, or combinations thereof” or “<A>, <B>, . . . and/or <N>” are defined by the Applicant in the broadest sense, superseding any other implied definitions hereinbefore or hereinafter unless expressly asserted by the Applicant to the contrary, to mean one or more elements selected from the group comprising A, B, . . . and N. In other words, the phrases mean any combination of one or more of the elements A, B, . . . or N including any one element alone or the one element in combination with one or more of the other elements which may also include, in combination, additional elements not listed. Unless otherwise indicated or the context suggests otherwise, as used herein, “a” or “an” means “at least one” or “one or more.”

While various embodiments have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible. Accordingly, the embodiments described herein are examples, not the only possible embodiments and implementations.

The subject-matter of the disclosure may also relate, among others, to the following aspects:

A first aspect includes a gas turbine engine that includes: an inlet guide vane; an inlet channel extending from a location downstream of the inlet guide vane to a stem manifold; and an outlet channel extending to an outlet port, the outlet port configured to dump anti-ice air overboard, wherein the inlet guide vane includes an anti-ice cavity in fluid communication with the inlet channel and the outlet channel such that anti-ice air, flowing from a downstream location within a core flow of the gas turbine, flows from the inlet channel, through the inlet guide vane, and to the outlet channel.

A second aspect includes the first aspect, and further includes wherein the inlet guide vane includes a stem, the stem having an inlet for receiving the anti-ice air from the inlet channel and an outlet for discharging the anti-ice air to the outlet channel.

A third aspect includes the second aspect, and further includes wherein the stem extends from an airfoil of the inlet guide vane.

A fourth aspect includes any of the second or third aspects, and further includes wherein the stem is located in a manifold, the manifold being located at a terminus of the inlet channel.

A fifth aspect includes the fourth aspect, and further includes wherein at least one seal is located between the stem and an inner diameter surface of the manifold.

A sixth aspect includes any of the second through fifth aspects, and further includes wherein the stem includes an outer cavity and an inner cavity that is concentric with the outer cavity, wherein one of the inner cavity and the outer cavity receives anti-ice air from the inlet channel, and wherein the other of the inner cavity and the outer cavity discharges the anti-ice air to the outlet channel.

A seventh aspect includes the sixth aspect, and further includes wherein the outer cavity and the inner cavity are located in first stem segment, wherein the inner cavity is located in a second stem segment, and wherein the first stem segment terminates adjacent to the second stem segment.

An eighth aspect includes any of the first through seventh aspects, and further includes wherein a barrier is located in the anti-ice cavity of the inlet guide vane such that the anti-ice cavity is separated between an inlet side and an outlet side.

A ninth aspect includes any of the first through eighth aspects, and further includes wherein a tube is located within the anti-ice cavity, the tube separating an inlet portion of the anti-ice cavity and an outlet portion of the anti-ice cavity.

A tenth aspect includes any of the first through ninth aspects, and further includes wherein the inlet guide vane is rotatable without ceasing fluid communication between the inlet channel and the outlet channel.

An eleventh aspect includes an inlet guide vane for a gas turbine engine, comprising: a main body at least partially forming an airfoil; a stem extending from the main body, wherein the stem includes an inlet configured for receiving an anti-ice air and an outlet configured for discharging an anti-ice air from the inlet guide vane; an anti-ice cavity at least partially within the main body; and a barrier separating an inlet portion of the anti-ice cavity and an outlet-portion of the anti-ice cavity.

A twelfth aspect includes the eleventh aspect, and further includes wherein the stem extends radially outward from the main body.

A thirteenth aspect includes any of the eleventh or twelfth aspects, and further includes wherein the barrier is configured to direct the anti-ice air through a predetermined flow path within the anti-ice cavity.

A fourteenth aspect includes any of the eleventh through thirteenth aspects, and further includes wherein the barrier includes a tube.

A fifteenth aspect includes any of the eleventh through fourteenth aspects, and further includes wherein the barrier separates an inlet side of the anti-ice cavity from an outlet side of the anti-ice cavity, and wherein the barrier forms an opening providing fluid communication between the inlet side and the outlet side.

A sixteenth aspect includes any of the eleventh through fifteenth aspects, and further includes wherein the stem includes an outer cavity and an inner cavity that are concentric, wherein one of the inner cavity and the outer cavity includes the inlet, and the other of the inner cavity and the outer cavity includes the outlet.

A seventeenth aspect includes any of the eleventh through sixteenth aspects, and further includes wherein the stem is configured for receipt within a manifold that receives the anti-ice air.

An eighteenth aspect includes the seventeenth aspect, and further includes wherein when received by the manifold, a seal is located between an inner diameter surface of the manifold and the stem.

A nineteenth aspect includes an anti-ice system for a gas turbine engine, comprising: an inlet guide vane; an inlet channel extending from a location downstream of the inlet guide vane to a stem manifold; and an outlet channel extending to an outlet port, the outlet port configured to dump anti-ice air overboard, wherein the inlet guide vane includes an anti-ice cavity in fluid communication with the inlet channel and the outlet channel such that anti-ice air, flowing from a downstream location within a core flow of the gas turbine, flows from the inlet channel, through the inlet guide vane, and to the outlet channel.

A twentieth aspect includes the nineteenth aspect, and further includes wherein the inlet guide vane includes a stem, the stem having an inlet for receiving the anti-ice air from the inlet channel and an outlet for discharging the anti-ice air to the outlet channel.