Gas turbine sensor assembly and associated shutter mechanism

A turbine engine including a stationary component having a probe opening, a plurality of rotor blades rotatable relative to the stationary component, and a sensor assembly disposed within the probe opening. The sensor assembly includes a sensor and a shutter mechanism having a shutter frame with a sensing window and at least one leaf member coupled to the shutter frame. The sensor assembly includes an actuator including a rotatable member having a receiving slot and a stator having a stopper member within the receiving slot. The rotatable member rotates relative to the stator over a range of motion defined relative to the stopper member, and the rotatable member is coupled to the at least one leaf member such that rotating the rotatable member in a first direction uncovers the sensing window, and such that counter-rotating the rotatable member in a second direction covers the sensing window with the at least one leaf member. Selectively covering the sensor when not in use protects the sensor from exposure to harsh conditions, extending its operative life.

BACKGROUND

The present disclosure relates generally to sensors for use in turbine engines and, more specifically, to a shutter mechanism for use in shielding sensors from operating conditions within gas turbine engines.

At least some known turbine engines include a compressor, a combustor, and a turbine coupled together in a serial flow relationship. Compressed air is discharged from the compressor, mixed with fuel, and ignited in the combustor to form a high energy gas stream. The high energy gas stream flows through the turbine, creating a high temperature environment within and downstream from the combustor and turbine, which is commonly referred to as the “hot gas path.”

In at least some known turbines, operating and environmental conditions are monitored with probes, such as non-contact type sensors based on optics, capacitance, inductance, reluctance, magnetism, and the like. To accurately measure the conditions of the environment, many known probes are positioned in exposure to the hot gas path of the turbine engine. Contaminants in the hot gas path, such as water, soot, sand, smoke, unburnt fuel, and/or other foreign debris can degrade signal quality and reduce the accuracy of any measurements to be taken. In addition, exposure to the hot gas path can induce thermal and/or mechanical stresses and strains into the probes that can damage the probe and/or reduce its useful service life. Such damage can result in costly replacement of the probe and/or increased downtime of the turbine engine. For example, if a probe must be replaced, recalibration of a replacement probe may be a time-consuming and/or difficult task.

BRIEF DESCRIPTION

In one aspect, a turbine engine is provided. The turbine engine includes a stationary component having a probe opening, a plurality of rotor blades, each of which is rotatable relative to the stationary component, and a sensor assembly within the probe opening. The sensor assembly includes a sensor and a shutter mechanism that includes a shutter frame having a sensing window. The sensor is configured to measure a target of interest within the turbine engine through the sensing window. At least one leaf member is disposed within the shutter frame and configured to selectively cover and uncover the sensing window. The sensor assembly also includes an actuator including a rotatable member having a receiving slot, and a stator having a stopper member disposed within the receiving slot. The rotatable member is rotatable relative to the stator over a range of motion defined relative to the stopper member, and the rotatable member is coupled to the at least one leaf member such that rotating the rotatable member in a first direction uncovers the sensing window, and such that counter-rotating the rotatable member in a second direction covers the sensing window with the at least one leaf member.

In another aspect, a shutter mechanism for use in shielding a sensor is provided. The shutter mechanism includes a shutter frame having a sensing window. At least one leaf member is disposed within the shutter frame and configured to selectively cover and uncover the sensing window. The sensor assembly also includes an actuator including a rotatable member having a receiving slot, and a stator having a stopper member disposed within the receiving slot. The rotatable member is rotatable relative to the stator over a range of motion defined relative to the stopper member, and the rotatable member is coupled to the at least one leaf member such that rotating the rotatable member in a first direction uncovers the sensing window, and such that counter-rotating the rotatable member in a second direction covers the sensing window with the at least one leaf member.

In yet another aspect, a sensor assembly having a sensor and a shutter frame having a sensing window. At least one leaf member is configured to selectively cover and uncover the sensing window. The sensor assembly also includes an actuator including a rotatable member having a receiving slot, and a stator having a stopper member disposed within the receiving slot. The rotatable member is rotatable relative to the stator over a range of motion defined relative to the stopper member, and the rotatable member is coupled to the at least one leaf member such that rotating the rotatable member in a first direction uncovers the sensing window, and such that counter-rotating the rotatable member in a second direction covers the sensing window with the at least one leaf member.

DETAILED DESCRIPTION

The embodiments described herein relate to a shutter mechanism that may be used to selectively shield sensors from operating conditions within gas turbine engines. The shutter mechanism is capable of selectively opening and closing to shield an optical sensor, for example, from exposure to foulants within a gas turbine engine. Optical and other sensor technologies require a clean path to the target of interest to be monitored by the sensor to facilitate obtaining accurate, meaningful, and useful data. Accordingly, the shutter mechanism may be closed when operating conditions within the gas turbine engine may degrade the optical sensor and/or its signal quality, or during periods when the sensor is not in use. When the operating conditions within the gas turbine engine are favorable and/or measurements are required to be taken, the shutter mechanism may be opened as-needed and for a limited duration to expose the optical sensor to the environment. The shutter mechanism facilitates shielding sensitive optical components of the sensor from fogging, overheating, fouling, or otherwise sustaining damage due to environmental conditions. Accordingly, the service life of the optical sensor assembly is increased, and calibration of the optical sensor is maintained.

Unless otherwise indicated, approximating language, such as “generally,” “substantially,” and “about,” as used herein indicates that the term so modified may apply to only an approximate degree, as would be recognized by one of ordinary skill in the art, rather than to an absolute or perfect degree. Accordingly, a value modified by a term or terms such as “about,” “approximately,” and “substantially” is not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Additionally, unless otherwise indicated, the terms “first,” “second,” etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to, for example, a “second” item does not require or preclude the existence of, for example, a “first” or lower-numbered item or a “third” or higher-numbered item.

FIG.1is a schematic illustration of an exemplary turbine engine assembly10. In the exemplary embodiment, turbine engine assembly10includes a gas turbine engine12that includes an inlet section13, a compressor section14disposed downstream from the inlet section13, a combustor section16(having a plurality of combustors17) positioned downstream from compressor section14, a turbine section18positioned downstream from combustor section16, and an exhaust section19disposed downstream from the turbine section18. Additionally, the gas turbine engine12may include one or more shafts22coupled between the compressor section14and the turbine section18.

The compressor section14may generally include a plurality of rotor disks24(one of which is shown) and a plurality of rotor blades26extending radially outward from and connected to each rotor disk24. Each rotor disk24in turn may be coupled to or form a portion of the shaft22that extends through the compressor section14. The compressor section14includes a plurality of compressor stages, each of which includes a circumferential array of rotor blades26and a corresponding circumferential array of stator blades (not shown) that are mounted to the casing of the compressor section14. The stator blades direct the incoming air into the rotor blades26, such that the air is progressively compressed through the compressor section14.

Turbine section18includes a plurality of rotor disks25(one of which is shown) and a plurality of rotor blades27extending radially outward from and being interconnected to each rotor disk25. Each rotor disk25in turn may be coupled to or form a portion of the shaft22that extends through the turbine section18. The turbine section18further includes a stationary component28such as, but not limited to, a heat shield, a shroud, or a casing that surrounds the rotor blades27and that at least partially defines a hot gas path20through the turbine section18. The stationary component28further includes a plurality of stator blades (not shown), which are arranged in one or more stages with the rotor blades27to expand a flow of combustion gas34.

Stationary component28also has a probe opening29defined therein. As will be described in more detail below, a sensor assembly30is within the probe opening29for monitoring the hot gas path20.

In operation, a flow of intake air32is channeled through the inlet section13and the compressor section14, and a flow of compressed air33is channeled towards combustor section16, where the air is mixed with fuel and combusted to form a flow of combustion gas34that is discharged towards turbine section18. The flow of combustion gas34discharged from combustor section16drives turbine section18about a centerline35of gas turbine engine12, and the flow of combustion gas34is channeled through turbine section18and then discharged from gas turbine engine12, via the exhaust section19, in the form of a flow of exhaust gas36.

Further, in some embodiments, compressor section14channels pressurization fluid38(e.g., bleed air) towards turbine section18and/or sensor assembly30. The bleed air38is channeled towards turbine section18to, for example, provide thermal management for the outer casing and hot gas path components therein. Additionally, the bleed air38can be used to actuate sensor assembly30, as will be described in more detail below. In an alternative embodiment, sensor assembly30may be provided with pressurized fluid from an external source.

FIGS.2-6illustrate various views of an exemplary sensor assembly30that may be used with turbine engine assembly10(shown inFIG.1). In the exemplary embodiment, sensor assembly30includes a sensor40and a shutter mechanism42. Shutter mechanism42includes a shutter frame44having a sensing window46, and a plurality of leaf members48coupled thereto. Sensor40is positioned within shutter mechanism42and is oriented to measure a target of interest within turbine engine assembly10through sensing window46. The target of interest may be, for example, the clearance between rotating and stationary parts of assembly10(e.g., between rotor blade27and stationary component28(e.g., the casing)), the time-of-arrival of the rotating part (e.g., rotor blade27), the temperature of the part, and/or characteristics (e.g., temperature, pressure, and emissions) of gas flowing that flows through the hot gas path20(shown inFIG.1) itself. Sensor40may be any non-contact type sensor, such as an optical sensor or a capacitance probe. Example optical sensors can include, but are not limited to, blade tip timing laser probes, blade tip clearance laser probes, pyrometers, interferometers, and infrared cameras.

As shown inFIG.3, leaf members48are rotatable relative to shutter frame44to selectively cover and uncover sensing window46. Accordingly, leaf members48are selectively positionable to uncover sensing window46to enable sensor40to take measurements and are selectively (re)positionable to cover sensing window46to shield sensor40from fouling and/or exposure to contaminants entrained in hot gas path20. In the exemplary embodiment, leaf members48are shaped to enable members48to “nest” (engage) with each other when in the covered position to facilitate substantially sealing sensing window46to inhibit the passage of foulants and/or contaminants therethrough. Leaf members48may or may not overlap one another.

Although illustrated as only including four leaf members48, it should be understood that shutter mechanism42may have any other number of leaf members48and that members48may be in any nestable configuration that enables sensor assembly30to function as described herein. For example, sensing window46may be selectively covered and uncovered by a single disc that rotates in/out of a desired position, by a plurality of discrete louvers that rotate open/closed, by flaps that selectively flip up and down, by a membrane or thin-walled member that is selectively movable under a force such as air pressure, by two or more leaves that selectively hinge open/closed like scissors, and/or by any combination of these mechanisms, or any other device that enables sensor40to function as described herein.

Leaf members48may be actuated between the covered and uncovered positions using any technology that enables shutter mechanism42to function as described herein. For example, leaf members48may be actuated via pneumatics, a piezoelectric device, a magnetic device, a hydraulic device, a mechanical linkage, a screw actuator, and/or a cable system. In the exemplary embodiment, leaf members48are actuated via pressurization fluid38received from compressor section14(both shown inFIG.1), as will be described in more detail below.

Referring again toFIGS.2-6, shutter mechanism42includes an actuator50that is coupled to leaf members48for moving leaf members48between the covered and uncovered positions. Referring toFIGS.2,4, and5, actuator50includes a rotatable member52and a stator54. Stator54includes an actuator housing56defined by a radial inner wall58, a radial outer wall60, and a front wall62, which together define an interior channel64. Rotatable member52is positionable within interior channel64with a clearance fit, for example. Thus, rotatable member52is movable within interior channel64. In one embodiment, movement of rotatable member52within interior channel64may be facilitated by ball bearings66that are between rotatable member52and stator54.

In the exemplary embodiment, leaf members48are coupled to rotatable member52with connector pins68. For example, front wall62has pin holes70defined therein, and connector pins68extend through pin holes70to physically connect leaf members48and rotatable member52. In addition, each leaf member48is coupled to shutter frame44with connector pins72, defining a respective pivot point therebetween. Thus, rotatable member52is movable within interior channel64to facilitate moving leaf members48between the covered and uncovered positions.

Rotatable member52includes a base frame74and a pair of arcuate side walls76extending from base frame74. Arcuate side walls76are spaced from each other circumferentially relative to a centerline78of sensor assembly30such that a receiving slot80is defined therebetween. Referring toFIG.5, when rotatable member52is positioned within interior channel64of stator54, radial inner wall58is disposed within receiving slot80, and radial outer wall60surrounds arcuate side walls76.

Referring again toFIGS.2,4, and5, stator54also includes a stopper insert82coupled to actuator housing56to enclose rotatable member52within interior channel64. Stopper insert82includes a shoulder base84and a pair of stopper members86extending from shoulder base84. Stopper members86are sized for insertion within receiving slot80. Thus, stopper members86are adapted to impede the range of motion of rotatable member52rotating relative to stator54. For example, when rotatable member52rotates in a first direction88(FIG.6), one arcuate side wall76abuts against a first of the stopper members86. When rotatable member52counter-rotates in a second direction90, the other arcuate side wall76abuts against a second of the stopper members86. Accordingly, the range of motion of rotatable member52is limited and defined relative to stopper members86, and the range of motion is correspondingly defined for leaf members48.

Actuation of shutter mechanism42may be performed manually by a technician, and/or automatically using pneumatics, a piezoelectric device, a magnetic device, a hydraulic device, a mechanical linkage, a screw actuator, and/or a cable system, as described above. Such operation may be controlled by a controller92(shown inFIG.1), including a memory and a processor adapted to execute programmed commands. For example, controller92may control covering and uncovering of sensing window46based on at least one of a temperature or a pressure of the hot gas path, and/or an operating status of turbine engine12(shown inFIG.1). For example, controller92may cover sensing window46when a temperature or pressure of hot gas path20(shown inFIG.1) is greater than a predefined threshold, and/or when operating conditions of turbine engine12are known to be harsh (e.g., startup, water wash, and liquid fuel operation). In addition, controller92may open/close sensing window46based on a schedule (time-based) or based on feedback received from other sensors. For example, if a sensor40in the hot gas path20detected conditions typical of a flame-out condition in the combustion section16, controller92could activate an idle sensor assembly30in the combustor (i.e., a sensor assembly with a closed shutter) to open the shutter mechanism42and expose the sensor40.

In the exemplary embodiment, bleed air (that is, pressurization fluid38) is channeled towards sensor assembly30for rotating rotatable member52in first and second directions88and90. More specifically, referring toFIGS.5and6, stopper insert82has a first port94and a second port96defined therein. A first pressurization line98is coupled to first port94, and a second pressurization line100is coupled to second port96. First and second pressurization lines98and100receive the bleed air directed toward turbine section18(shown inFIG.1), and the bleed air is selectively channeled through first and second ports94and94to facilitate rotation of rotatable member52.

For example, in one embodiment, first pressurization line98selectively (e.g., as determined by controller92(shown inFIG.1)) channels a first flow of pressurization fluid38through first port94and into a first receiving slot102of actuator50, and second pressurization line100selectively channels a second flow of pressurization fluid38through second port96and into a second receiving slot104of actuator50. First and second receiving slots102,104are circumferentially opposite one another. Channeling the first flow into first receiving slot102facilitates rotating rotatable member52in first direction88to open leaf members48and uncover sensing window46. Channeling the second flow into second receiving slot104facilitates rotating rotatable member52in second direction90to close leaf members48and cover sensing window46.

In one embodiment, only one of the first flow and the second flow are channeled into actuator50at a time to control the covering and uncovering of sensing window46. Alternatively, second pressurization line100continuously channels a passive flow of pressurization fluid38towards rotatable member52. The passive flow is channeled at a first pressure that is great enough to hold leaf members48in the covered position. When measurements need to be taken, the first flow is selectively channeled towards rotatable member52at a second pressure that is greater than the first pressure. Thus, the pressurization provided by the passive flow is overcome by the pressurization provided by the first flow, and leaf members48are held in the uncovered position. When the first flow is ceased, the passive flow enables the leaf members48to be automatically returned to the covered position (“fail close”). In an alternative embodiment, actuator50is configured to automatically return leaf members48to the uncovered position (“fail open”).

Referring again toFIGS.2,4, and5, sensor assembly30further includes a swirler plate106coupled to shutter frame44, and a deflector plate108coupled to swirler plate106. Swirler plate106and deflector plate108each include guide slots110defined therein that are sized to receive connector pins68therethrough and that define the range of motion of leaf members48. In addition, deflector plate108has bypass openings112defined therein, and swirler plate106has swirler vanes114that are in flow communication with bypass openings112. Bypass openings112are oriented to direct airflow in a generally radially outward direction relative to centerline78, and swirler vanes114are oriented to redirect the airflow received from bypass openings112generally radially inward and across the rear face of leaf members48. The bypass allows for continuous, uninterrupted cooling of the sensor40regardless of whether the shutter mechanism42is opened or closed. Without this feature, the flow of cooling air would stop when the shutter mechanism42closes, possibly causing the sensor40to overheat. Accordingly, the airflow acts as a cooling fluid for leaf members48that are exposed to hot gas path20(shown inFIG.1).

The embodiments described herein relate to a shutter mechanism for use in shielding sensors from harsh conditions within gas turbine engines. The shutter mechanism facilitates shielding an associated sensor from fouling or other harmful conditions, which in turn increases the useful service life and accuracy of the sensor. For example, the shutter mechanism includes a plurality of leaf members that work in concert to cover and uncover a sensing window of the shutter mechanism in which the sensor monitors the hot gas path therethrough. The shutter mechanism facilitates shielding sensitive optical components of the sensor from fogging, overheating, fouling, or otherwise sustaining damage due to environmental conditions.

Exemplary embodiments of gas turbine engines and associated sensor assemblies are described above in detail. The systems and methods described herein are not limited to the specific embodiments described herein, but rather, steps of the methods may be utilized independently and separately from other steps described herein. For example, the methods described herein are not limited to practice with industrial gas turbine engines as described herein. Rather, the exemplary embodiment can be implemented and utilized in connection with any application that implements non-contact type sensors.

Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only. Moreover, references to “one embodiment” in the above description are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. In accordance with the principles of the invention, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.

Exemplary clauses that describe the present sensor assembly, shutter mechanism, and gas turbine engine are as follows:

According to a first aspect, a turbine engine comprises: a stationary component comprising a probe opening; a plurality of rotor blades, each of which is rotatable relative to the stationary component; and a sensor assembly within the probe opening, the sensor assembly comprising a sensor and a shutter mechanism that comprises: a shutter frame comprising a sensing window, the sensor configured to measure a target of interest within the turbine engine through the sensing window; at least one leaf member disposed within the shutter frame and configured to selectively cover and uncover the sensing window; and an actuator comprising: a rotatable member comprising a receiving slot; and a stator comprising a stopper member disposed within the receiving slot, wherein the rotatable member is rotatable relative to the stator over a range of motion defined relative to the stopper member, and wherein the rotatable member is coupled to the at least one leaf member such that rotating the rotatable member in a first direction uncovers the sensing window, and such that counter-rotating the rotatable member in a second direction covers the sensing window with the at least one leaf member.

According to a previous aspect, the turbine engine further comprises a controller communicatively coupled to the actuator for selectively rotating the rotatable member, the controller configured to control covering and uncovering of the sensing window based on at least one of a temperature or a pressure of the hot gas path, or an operating status of the turbine engine.

According to any one or more previous aspects, the turbine engine further comprises a compressor section in flow communication with the stationary component and the actuator, the compressor section configured to provide bleed air to the actuator for selectively rotating the rotatable member.

According to any one or more previous aspects, the turbine engine further comprises at least one of a piezoelectric device, a magnetic device, a hydraulic device, a mechanical linkage, a screw actuator, or a cable system coupled to the actuator for selectively rotating the rotatable member.

According to any one or more previous aspects, the stationary component comprises at least one of a heat shield, a shroud, or a casing of the turbine engine.

According to any one or more previous aspects, the sensor is one of an optical sensor or a capacitance probe.

According to a second aspect of the present disclosure, a shutter mechanism for use in shielding a sensor comprises: a shutter frame comprising a sensing window; at least one leaf member disposed within the shutter frame and configured to selectively cover and uncover the sensing window; and an actuator comprising: a rotatable member comprising a receiving slot; and a stator comprising a stopper member disposed within the receiving slot, wherein the rotatable member is rotatable relative to the stator over a range of motion defined relative to the stopper member, and wherein the rotatable member is coupled to the at least one leaf member such that rotating the rotatable member in a first direction uncovers the sensing window, and such that counter-rotating the rotatable member in a second direction covers the sensing window with the at least one leaf member.

According to the second aspect, the shutter mechanism further comprises a first pressurization line configured to channel a first flow of pressurization fluid towards the rotatable member, the first flow configured to rotate the rotatable member in the first direction.

According to one or more previous aspects, the shutter mechanism further comprises a second pressurization line configured to channel a second flow of pressurization fluid towards the rotatable member, the second flow configured to counter-rotate the rotatable member in the second direction.

According to one or more previous aspects, the shutter mechanism further comprises the second pressurization line, which is configured to channel a passive flow of pressurization fluid towards the rotatable member, wherein the passive flow is configured to rotate the rotatable member in the second direction, and the passive pressurization fluid is channeled at a lower pressure than the first flow such that the rotatable member rotates in the first direction when the first flow is channeled towards the rotatable member.

According to one or more previous aspects, the shutter mechanism further comprises at least one plate coupled to the shutter frame, the at least one plate configured to channel cooling fluid across the at least one leaf member.

According to one or more previous aspects of the shutter mechanism, the at least one plate has a guide slot defined therein, and the shutter mechanism further comprises: a connector coupled between the at least one leaf member and the rotatable member, wherein the connector is translatable within the at least one guide slot to define a range of motion of the at least one leaf member.

According to one or more previous aspects of the shutter mechanism, the at least one leaf member comprises a plurality of leaf members that are nestable with each other when at least one of covering or uncovering the sensing window.

According to one or more previous aspects of the shutter mechanism, the shutter mechanism comprises at least one of a piezoelectric device, a magnetic device, a hydraulic device, a mechanical linkage, a screw actuator, or a cable system coupled to the actuator for selectively rotating the rotatable member.

According to a third aspect, a sensor assembly comprises: a sensor; a shutter frame comprising a sensing window; at least one leaf member configured to selectively cover and uncover the sensing window; and an actuator comprising: a rotatable member comprising a receiving slot; and a stator comprising a stopper member disposed within the receiving slot, wherein the rotatable member is rotatable relative to the stator over a range of motion defined relative to the stopper member, and wherein the rotatable member is coupled to the at least one leaf member such that rotating the rotatable member in a first direction uncovers the sensing window, and such that counter-rotating the rotatable member in a second direction covers the sensing window with the at least one leaf member.

According to any one or more previous aspects, the sensor assembly further comprises a first pressurization line configured to channel a first flow of pressurization fluid towards the rotatable member, the first flow configured to rotate the rotatable member in the first direction.

According to any one or more previous aspects, the sensor assembly further comprises a second pressurization line configured to channel a second flow of pressurization fluid towards the rotatable member, the second flow configured to counter-rotate the rotatable member in the second direction.

According to any one or more previous aspects of the sensor assembly, the second pressurization line is configured to channel a passive flow of pressurization fluid towards the rotatable member, wherein the passive flow is configured to rotate the rotatable member in the second direction, and the passive pressurization fluid is channeled at a lower pressure than the first flow such that the rotatable member rotates in the first direction when the first flow is channeled towards the rotatable member.

According to any one or more previous aspects, the sensor assembly further comprises at least one of a piezoelectric device, a magnetic device, a hydraulic device, a mechanical linkage, a screw actuator, or a cable system coupled to the actuator for selectively rotating the rotatable member.

According to any one or more previous aspects of the sensor assembly, the sensor is one of an optical sensor or a capacitance probe.