Patent Application
20180328215
The present disclosure relates generally to gas turbine engines, and more particularly to methods and devices for controlling gas turbine engine case clearance.
Turbine engines generally include fan, compressor, combustor and turbine sections positioned along an axial centerline. Each rotor assembly typically includes a plurality of blades extending out relative to the axial centerline. An outer case, including blade outer air seals (BOAS) can provide a radial surface along the flow path of the engine. Current clearance control systems in turbine engines use cooling air on the turbine case to control clearance for a case and blades. Conventional systems are slow acting and conservative because blade to outer seal rubs are bad for the engine. Advanced Clearance Control Systems are under investigation at engine manufacturer's facilities that use faster acting actuators and advanced sensor systems to give more control over the blade to seal clearance. Systems are large and bulky, containing so many sensors and actuators that benefits are not readily apparent.
There is a desire to provide a clearance control system that overcomes one or more of the aforementioned drawbacks.
Disclosed and claimed herein are a methods and devices for controlling blade outer air seal clearance. In one embodiment, a method for controlling blade outer air seal clearance includes receiving blade outer air seal clearance from an integrated sensor actuator, determining blade outer seal control by an electronic engine control unit, and controlling the blade outer air seal clearance by the electronic engine control unit, wherein an interleaved blade outer air seal is positioned by an integrated sensor actuator.
According to another embodiment, an integrated sensor actuator is provided for blade outer air seals. In one embodiment, the integrated sensor actuator includes an actuator, a sensor configured to detect blade outer air seal clearance, and a control unit configured to control blade outer air seal clearance for at least a portion of the blade outer air seal, wherein the blade outer air seal is positioned by integrated sensor actuators.
According to another embodiment, a blade outer air seal control system includes a plurality of integrated sensor actuators, segmented blade outer air seals, and a control unit. In one embodiment, the control unit is configured to receive blade outer air seal clearance from plurality of integrated sensor actuators, determine blade outer seal control by an electronic engine control unit, and control the blade outer air seal clearance by the electronic engine control unit, wherein interleaved blade out seals are positioned by integrated sensor actuators.
Other aspects, features, and techniques will be apparent to one skilled in the relevant art in view of the following detailed description of the embodiments.
The features, objects, and advantages of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify correspondingly throughout and wherein:
One aspect of the disclosure relates to control of blade outer air seal (BAOS), such as an interleaved blade outer air seal or quadrant blade outer air seal. According to one embodiment, a system, methods and device are provided to control a segmented blade outer air seal (BOAS) that is movable by one or more actuators. According to one embodiment, integrated sensor actuators may be employed to position a blade outer air seal quadrant. In this case, a linear actuator is used to press the blade outer air seal radially toward the center of the engine. According to another embodiment, the blade outer air seal may be interleaved to decrease the circumference of the casing. As such, the distance between the nearest rotating blade and the BOAS may be decreased. Individual quadrant control allows the system to compensate for variances in clearances at points around the circumference.
According to another embodiment, a gas turbine engine is provided including an engine control unit configured to control an engine based on blade clearance.
As used herein, the terms “a” or “an” shall mean one or more than one. The term “plurality” shall mean two or more than two. The term “another” is defined as a second or more. The terms “including” and/or “having” are open ended (e.g., comprising). The term “or” as used herein is to be interpreted as inclusive or meaning any one or any combination. Therefore, “A, B or C” means “any of the following: A; B; C; A and B; A and C; B and C; A, B and C”. An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive.
Reference throughout this document to “one embodiment,” “certain embodiments,” “an embodiment,” or similar term means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of such phrases in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner on one or more embodiments without limitation.
Referring now to the figures,
Integrated sensor actuators 110a-110d may each be configured to position (e.g, press and pull) one of the interleaved blade outer air seal elements 115a-115d. The actuator
Integrated sensor actuators 110a-110d may be one or more of a ball and screw, piezoelectric actuator, hydraulic actuator and actuator in general. Integrated sensor actuators 110a-110d may be configured to determine the blade outer air seal clearance, which may be the distance from a rotor element to a segment of a blade outer air seal. Each sensor may be configured to determine the nearest distance of a rotating blade to at least a portion of the blade outer air seal. Controller 105 may be configured to receive clearance data from each of integrated sensor actuators 110a-110d. Controller 105 may also control actuators of integrated sensor actuators 110a-110d to set clearance distances of one or more blade outer air seal elements 115a-115d. The blade outer air seal elements 115a-115d may be pushed to cause overlap at segment joints and to decreasing clearance gap.
At block 210, the control of the blade outer seal may be determined by an electronic engine control unit. Determining blade outer air seal control may include determining the nearest distance of a rotating blade to at least a portion of the blade outer air seal. The blade outer air seal component may be a segmented seal having four quadrants.
At block 215, the blade outer air seal clearance may be controlled by the electronic engine control unit. According to one embodiment, an interleaved blade outer air seal is positioned by an integrated sensor actuator at block 215. Controlling at block 215 may include outputting one or more control signals to control position of one or more integrated sensor actuators to position one or more blade outer air seal components.
According to one embodiment, integrated sensor actuator 305 may be coupled to an Electronic Engine control unit 315, Electric power generator 320, and RF generator 325. Integrated sensor actuator 305 may be configured to output clearance data to Electronic Engine Control unit 315, such as the nearest distance of a rotating blade to at least a portion of the blade outer air seal. Electronic Engine Control unit 315 may be configured to putput control data to integrated sensor actuator 305 to set clearance of a blade outer air seal. RF generator 325 may be employed to control an actuator of integrated sensor actuator 305. The actuator of integrated sensor actuator 305 may be coupled to blade outer air seal 330 in order to control clearance 340 between blade out air seal 330 and blade 345.
While this disclosure has been particularly shown and described with references to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the claimed embodiments.
This application claims priority to U.S. Provisional Application No. 61/922,355 filed on Dec. 31, 2013 and titled Method and Device for Controlling Blade Outer Air Seal, the disclosure of which is hereby incorporated by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US14/71598 | 12/19/2014 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61922355 | Dec 2013 | US |
