The present invention relates generally to monitoring operating environments and in particular to instrumented components and telemetry systems enabled for wirelessly transmitting electronic data indicative of individual component condition within an operating environment such as that of a combustion turbine engine.
A wireless telemetry system for a turbine combustion is disclosed in U.S. application Ser. No. 11/936,936, which is incorporated herein by reference. As disclosed therein, a high temperature wireless telemetry system may be powered by induced RF energy generated by air gap transformers including a transformer primary induction coil assembly that is stationary and a secondary induction coil assembly that rotates. The telemetry system includes at least one sensor deposited on a component such as a turbine blade. A telemetry transmitter circuit is affixed to the turbine blade and a connecting material is deposited on the turbine blade for routing electronic data signals from the sensor to the telemetry transmitter circuit, the electronic data signals indicative of a condition of the turbine blade. An induction power system is provided for powering the telemetry transmitter circuit with a rotating data antenna affixed to the root of the turbine blade, such as the turbine blade; and a stationary data antenna affixed to a static seal segment adjacent to the turbine blade.
As shown in
A rotating data antenna assembly 308 is mounted to a face of the turbine root 301, and is in electrical communication with the transmitter assembly 300 via a second electrical 310. The antenna assembly 308 includes an induction coil and antenna secured within an RF transparent ceramic cover 311, which is mounted to the face of the blade root 309 using a bracket 313. The cover 311 includes flanges 312 secured in the bracket 313, and the flanges 312 are oriented on the root 309 parallel with, rather than perpendicular to, the centrifugal force direction (represented by the arrow labeled “C”) of the rotating blade 302, so the ceramic cover 311 is loaded in compression and not in bending.
While the above-described rotating antenna assembly 308 works for certain turbine engine designs, it may not be compatible with turbine blade sections that incorporate seal plates. Seal plates are often mounted to a turbine rotor disc on which the rotor blades are fixed to seal cooling fluid paths. However, the above-described rotating antenna assembly may not be used with seal plates. There is insufficient space between the seal plate and face of the root blade, and if the antenna assembly is capable of being mounted to the blade root face, the seal plate would interfere with transmission of signals from the antenna.
In use, air is drawn in through compressor 12, where it is compressed and driven towards combustor 14. Combustor 14 mixes the air with fuel and ignites it thereby forming a working gas. This working gas temperature will typically be above about 1300° C. This gas expands through turbine 16, being guided across blades 18 by vanes 22. As the gas passes through turbine 16, it rotates blades 18 and shaft 20, thereby transmitting usable mechanical work through shaft 20. Combustion turbine 10 may also include a cooling system (not shown), dimensioned and configured to supply a coolant, for example, steam or compressed air, to blades 18 and vanes 22.
The environment within which turbine blades 18 and vanes 22 operate is particularly harsh, subject to high operating temperatures and a corrosive atmosphere, which may result in serious deterioration of blades 18 and vanes 22. This is especially likely if TBC 26 should spall or otherwise deteriorate. Embodiments of the invention are advantageous because components may transmit real time or near real time data indicative of a component's condition during operation of combustion turbine 10.
U.S. Pat. No. 6,576,861, the disclosure of which is specifically incorporated herein by reference, discloses a method and apparatus that may be used to deposit embodiments of sensors and connectors for connecting sensors with transmitters or otherwise routing data signals. In this respect, methods and apparatus disclosed therein may be used for the patterning of fine sensor and/or connector features of between about 100 microns and 500 microns without the need of using masks. Multilayer electrical circuits and sensors may be formed by depositing features using conductive materials, resistive materials, dielectric materials, insulative materials and other application specific materials. Alternate methods may be used to deposit multilayer electrical circuits, sensors and connectors such as thermal spraying, vapor deposition, laser sintering and curing deposits of material sprayed at lower temperatures may be used as well as other suitable techniques.
Transmitters 54 may be multi-channel and have various specifications depending on their location within a casing of combustion turbine 10. Transmitters 54 may be configured to function within the early stages of compressor 12, which are subject to operating temperatures of between about 80° C. to 120° C. Transmitters 54 may be configured to function within later stages of compressor 12 and/or stages of turbine 16 subject to operating temperatures of greater than about 120° C. and up to about 300° C. Transmitters 54 may be fabricated using silicon-on-insulator (SOI) integrated circuit technology for wireless telemetry transmission circuits and other materials capable of operating in regions with temperatures greater than about 120° C.
One or more sensors 50 may be connected with one or more compressor blades 23 by fabricating or depositing sensors 50 and connectors 52 directly onto a surface of blade 23. Connector 52 may extend from sensor 50 to a termination location, such as the peripheral edge of blade 23 so that a distal end 53 of connector 52 is exposed for connection to transmitter 54. Sensor 50 and connector 52 may be positioned on blade 23 to minimize any adverse affect on the aerodynamics of blade 23. Embodiments allow for a distal end 53 of connectors 52 to be exposed at a termination location, which may be proximate a peripheral edge of a component or other suitable location. This allows a field technician to quickly and easily connect connector 52 to a transmitter 54 regardless of its location.
Type K thermocouple materials NiCr or NiAl may be used in sections of compressor 12 having an operating environment up to approximately 800° C. For example, NiCr(20) may be used to deposit a strain gage in compressor 12. Type N thermocouple material, such as alloys of NiCrSi and NiSi, for example, may be used for depositing sensors in sections of turbine 16 having an operating environment between approximately 800° C. to 1150° C.
Type S, B and R thermocouple materials may be used for depositing sensors in sections of turbine 16 having an operating environment between approximately 1150° C. to 1350° C. For example, Pt—Rh, Pt—Rh(10) and Pt—Rh(13) may be deposited to form sensors 50 within turbine 16 provided that the material generates an acceptable thermoelectric voltage for a particular application within combustion turbine 10. Ni alloys, for example NiCr, NiCrSi, NiSi and other oxidation-resistant Ni-based alloys such as MCrAlX, where M may be Fe, Ni or Co, and X may be Y, Ta, Si, Hf, Ti, and combinations thereof, may be used as sensing materials for high temperature applications in deeper sections of compressor 12 and throughout turbine 16. These alloys may be used as sensing material deposited in various sensing configurations to form sensors such as heat flux sensors, strain sensors, pressure sensors, chemical species sensors, and wear sensors.
Components within combustion turbine 10, such as blades 18, 19 and/or vanes 22, 23 may have application specific sensors 50 deposited to conform to a component's surface and/or embedded within a barrier or other coating deposited within combustion turbine 10. For example,
Silicon-based electronic semiconductors, such as those that may be used for transmitting data may have limited applications due to their operational temperature constraints. Temperature and performance properties of silicon and silicon-on-insulator (SOI) electronic chip technologies may limit their applications to operating environments of less than about 129° C. Aspects of the invention allow for such electronic systems to be deployed for wireless telemetry device 76 within compressor 12, which typically has an operating temperature of about 100-150° C.
Embodiments of wireless telemetry sensor systems may be configured to operate within higher temperature regions present in later stages of compressor 12, and within turbine 16. These regions may have operating temperatures of about 150-250° C. and higher. Materials having temperature and electrical properties capable of operation in these higher temperature regions may be used for depositing sensors 50, 74, connectors 52, 72 and fabricating wireless telemetry devices 76.
Sensors 50, 74 and high temperature interconnect lines or connectors 52, 72 may be deposited using known deposition processes such as plasma spraying, EB PVD, CVD, pulsed laser deposition, mini-plasma, direct-write, mini-HVOF or solution plasma spraying. Typically, dynamic pressure measurements, dynamic and static strain, and dynamic acceleration measurements are desired on both stationary and rotating components of combustion turbine 10 together with component surface temperature and heat flux measurements. Thus, embedded or surface mounted sensors 50, 74 may be configured as strain gages, thermocouples, heat-flux sensors, pressure transducers, micro-accelerometers as well as other desired sensors.
Wireless telemetry device 76 may include a board 80, an electronic circuit 90, an operational amplifier 92, a modulator 94 and an RF oscillator/transmitter 96 electrically connected with each other via interconnects 98. The embodiment of
Embodiments of the present invention provide components for use in combustion turbine 10 instrumented with telemetry systems that may include one or more sensors, lead lines connecting sensors with at least one telemetry transmitter circuit, at least one transmitting antenna, a power source and at least one receiving antenna. For example, embodiments of the present invention allow for transmitting sensor data from a rotating component, such as a turbine engine blade having certain electronic components located on a seal plate, which operates in an environment having a temperature of between about 300-500° C. For purposes of the disclosure herein, the term “high temperature” without additional qualification will refer to any operating environment, such as that within portions of combustion turbine 10, having a maximum operating temperature of between about 300-500° C.
With respect to
In an embodiment of the invention, one or more components of a wireless telemetry system, including the rotating data antenna assembly 116 and/or telemetry transmitter assembly 117, are affixed to the seal plate 115 providing ease of access to such components. With respect to the previously described prior art in which the transmitter assembly is mounted directly to the blade platform, the entire blade must be removed in order to access the transmitter assembly. In the below-described embodiments, the transmitter assembly 117 and other components are mounted to the seal plate 115 and are accessible without removing the blades 111, platforms 113 and roots 114. In addition, if necessary, the seal plates 115 are removable to access the wireless telemetry components.
In reference to
As shown, the first electrical connection 119 may include first lead lines or connectors 120 deposited on the blade 111 in connection with the sensor 118, and on areas of the platform 113. In addition, second lead lines 121 are secured to a surface of the seal plate 115 and connected to the transmitter assembly 117. The transmitter assembly 117 is in electrical communication with the rotating antenna assembly 116 via a second electrical connection 122 that includes electrical lead lines 123 secured to the surface of the seal plate 115. The lead lines 121 and 123 of the first 120 and second 122 electrical connection, respectively, may include electrical wires secured to the seal plate 115 with ceramic cement and/or tack welding techniques.
Embodiments of the invention may include a mounting bracket assembly including a first bracket 125 for affixing the rotating antenna assembly 116 to the seal plate 115 and a second bracket 126 for affixing the telemetry transmitter assembly 117 to the seal plate 115. The brackets 125 and 126 are preferably fabricated or forged from the same metal alloy as the seal plate 115. Accordingly, the seal plate 115 and bracket assembly 124 may be composed of a Ni-based superalloy or any other metal superalloy material that is suitable for components of a combustion turbine.
As shown in more detail in
The inventors of the present invention have determined that RF transparent cover 128 may be fabricated from an RF transparent, high toughness, structural ceramic materials. Ceramic matrix composites may be used to fabricate housing 128 as well as material selected from a family of materials known as toughened ceramics. Materials such as silicon carbide, silicon nitride, zirconia and alumina are available with increased toughness due to doping with additional elements and/or designed microstructures resulting from specific processing approaches.
One such material that is RF transparent, easy to form, and relatively inexpensive is a material selected from a ceramic family generally referred to as zirconia-toughened alumina (ZTA). Ceramic material selected from this family of aluminum oxide materials is considerably higher in strength and toughness than conventional pure aluminum oxide materials. This results from the stress-induced transformation toughening achieved by incorporating fine zirconium oxide particles uniformly throughout the aluminum oxide. Typical zirconium oxide content is between 10% and 20%. As a result, ZTA offers increased component life and performance relative to conventional pure aluminum oxide materials. Another exemplary material would be zirconia, partially stabilized with 3%-30% additions of oxides, such as magnesia (MSZ) and yttria (YSZ).
The designed microstructures of ZTA and YSZ are fracture-resistant when the ceramic is loaded in compression. However, if loaded sufficiently in tension, the ceramic will fail catastrophically, as with traditional ceramic materials. Consequently, RF transparent cover 128 is designed so that the tensile stresses in the ceramic material are minimized during operation of combustion turbine 10. This is accomplished by designing and fabricating such that (1) all corners, edges and bends of the ceramic components are machined to eliminate sharp corners and edges, in order to reduce the stress concentration factor at these locations, and (2) the orientation and fit of the ceramic component in a rotating antennae mounting bracket 125 is such that during operation the G-forces applied to the ceramic box do not generate significant bending stresses in the attachment flanges. This is accomplished by orienting the flanges parallel with the G-loading direction, rather than perpendicular to the G-loading direction, so the ceramic flange is loaded in compression and not in bending.
As shown in
Compared to the prior assembly shown in
In reference to
As shown in
The electronics package 133 may contain a high temperature circuit board. The main body of electronics package 133 may be fabricated from alloys such as Kovar, an alloy of Fe—Ni—Co. The thermal expansion coefficient of Kovar ranges from about 4.5−6.5×10−6/° C., depending on exact composition. The Ni-based alloys typically used for high temperature turbine components, such as turbine blade 130 have thermal expansion coefficients in the range of about 15.9−16.4×10−6/° C. Electronics package 133 may be affixed securely in place while allowing for relative movement between electronics package 133 and seal plate 115. This relative movement may result from their different thermal expansion rates, which occur over time during the high number of thermal cycles between ambient air temperature and the >450° C. operating temperature typically experienced proximate seal plate 115.
The thermal expansion coefficient of electronics package 133 may be less than that of mounting bracket 126 when the operating system within which these components reside is at a high temperature. Consequently, electronics package 133, including any circuit board contained therein, would expand less than mounting bracket 126, which may lead to damage caused by vibrational energy in the system. In order to secure electronics package 133 within mounting bracket 126 to accommodate the dimensional change differential between bracket 126 and electronics package 133, a layer of ceramic fiber woven fabric 135 may be placed between the electronic package 133 and the inside surface of mounting bracket 126. Fabric 135 may be fabricated from suitable ceramic fiber, including such fibers as silicon carbide, silicon nitride or aluminum oxide. For example, a quantity of Nextel™ aluminum oxide based fabric, manufactured by 3M, may be used for fabric 135. Although, the embodiment of the invention illustrates the use of the fabric 135, this fabric 135 is not required in all instances.
Cover plate 136 may be formed with a flange 146 oriented generally perpendicular to the direction of centrifugal forces (similar to that of the brackets members 138 and 139), to add structural support to the cover plate 136, which counters the centrifugal forces occurring when rotor disc 112 is operating at full speed. This relieves retention screws 118 from carry the load applied to cover plate 136 via centrifugal forces, and allows them to be made sufficiently small so that the telemetry transmitter assembly 117 fits in a relatively small recess 137 of the bracket member 126 with no interference with any adjacent components. If retention screws 118 were required to carry the load applied by the centrifugal forces, their required size would be too large to fit in the available space.
Embodiments of the present invention may be powered by various means such as induced RF energy and/or by harvesting thermal or vibrational power within the combustion turbine engine 10. In the energy harvested power model, either thermoelectric or vibro-electric power could be generated from the energy available in an operating combustion turbine engine 10. Thermopiles may be used to generate electricity from thermal energy, or piezoelectric materials may generate electricity from vibration of combustion turbine engine 10. Examples of these forms of power sources are described in U.S. Pat. No. 7,368,827, the entire disclosure of which is incorporated herein by reference.
Induced power modes are provided for powering components of wireless high temperature telemetry systems. Such systems may be configured as air-gap transformers where the transformer primary induction coil assembly 150 is stationary and the secondary induction coil assembly 127 rotates. For example, an induced RF power configuration is provided for powering a rotating telemetry transmitter circuit contained within telemetry transmitter assembly 117.
Primary induction coil assembly 150 and data transmission antenna holder 154 may be formed with lobes in the region of attachment to bracket 152. The associated regions of material in the bracket 152 are removed in the same lobe shape, with slightly larger size to accommodate installation. The lobe shape defines a radius of curvature that enables positive retention of induction coil assembly 150 and antenna and holder 153, 154, which may be placed into bracket 152 from an end and slid into position. The lobe shape enables positive retention to be maintained while simultaneously ensuring that tensile stresses are not generated in induction coil assembly 150 and antenna holder 154, both of which may be fabricated of relatively brittle materials subject to structural failure under tensile stresses.
The lobes may be positioned far enough from the front of induction coil assembly 150 and data transmission antenna 153 to ensure that metal bracket 152 does not interfere with electrical functionality. Ceramic cement may be applied between the surfaces of induction coil assembly 150 and antenna holder 154, and their respective pockets in bracket 152, in order to provide a secure fit and accommodate thermal expansion differences during heat up and cool down. A thin plate (not shown) may be attached on each end of bracket 152 that covers the lobed regions of the induction coil assembly 150 and the data antenna 153, ensuring retention during operation.
One or more brackets 152 may be fabricated of the same alloy as static seal segment 151, such as Inconel 625, and have an arcuate shape to conform to the interior surface of static seal segment 151. Bracket 152 may be affixed to the interior surface of static seal segment 151 using an interrupted weld 155 to minimize distortion of static seal segment 151. Induction coil assembly 150 may include at least one stationary core 156 and at least one stationary primary winding 157 with ‘H Cement’ 157 sold by JP Technologies, or any ceramic cement that is capable of electrically insulating and structurally protecting the windings, encasing portions of stationary core 156.
One or more stationary primary winding 157 may be energized by high frequency, high current power sources. The power can be supplied to each stationary induction coil assembly 150 individually, or a series of stationary induction coil assemblies 150 may be electrically connected and driven by a single power supply. In an exemplary embodiment there may be five adjacent, stationary induction coil assemblies 150 with each driven by its own power supply. The current flowing through each stationary primary winding 157 creates a magnetic field in the rotating secondary induction coil assembly 127 that in turn creates a current in the rotating secondary winding 130. The current from rotating secondary winding 130 supplies power to a wireless telemetry transmitter circuit contained within wireless telemetry transmitter assembly 150 as described more fully herein below.
Embodiments of induced power systems disclosed herein may employ multiple individual primary and secondary induction coil assemblies 150, 127 to accommodate various geometries with combustion turbine 10. For instance, stationary induction coil assembly 150 and data transmission primary antenna 153 may need to span a certain distance of static seal segment 151 in order to induce enough power to the, system components and transmit the required data. An embodiment of induction coil assembly 150 and data transmission antenna 153 may need to be approximately four feet in length. In this example, for ease of fabrication, four individual power/antenna assemblies each with a length of approximately one foot may be fabricated with respective brackets 152 and installed adjacent to one another on one or more static seal segments 151. If the end-to-end gap distance between the individual antennae is sufficiently small then the antenna assembly will function as if it were a single, four-foot long antenna. Such antenna assemblies may be formed from straight or curved elements thereby providing assemblies of varying lengths that are straight, curved or otherwise configured as required by the specific application. In an embodiment, a plurality of such antenna assemblies may span an arc of approximately 112 degrees in the top half of one or more static seal segments 151 within turbine 10.
The inventors of the present invention have determined that a particular class of magnetic core materials meets or exceeds the performance requirements of embodiments of the present invention. The general term for this class of materials is a nanocrystalline iron alloy. One composition of this class of material is sold under the trade name NAMGLASS® and has a composition of approximately 82% iron—with the balance being silicon, niobium, boron, copper, carbon, nickel and molybdenum. It has been determined that such nanocrystalline iron alloy material exhibits desirable characteristics such as a Curie temperature greater than 500° C., very low coercivity, low eddy-current loss, high saturation flux density and the permeability is very stable over the entire high temperature operating range.
This nanocrystalline iron alloy material is commercially available in tape-wound configurations in the form of toroids, or “C” core transformer cores. Embodiments of the present invention utilize this nanocrystalline iron alloy material to form an “I” core shape, which was used for the primary stationary core 156. The “I” shape was selected because this shape holds itself in place in the channel on stationary mounting bracket 152. The induction core 156 of each induction coil assembly 150 consists of a plurality of 0.007″ thick laminations of nanocrystalline iron alloy material built up into an arc of approximately eleven inches in length. The same nanocrystalline iron alloy material may be used for the rotating antenna 131 transformer core.
The strength of the magnetic field used to couple power between the stationary and rotating elements may be increased by increasing the frequency of the driving signal, i.e., the high frequency AC signal produced by an exemplary induction power driver circuit illustrated in
The wire used for winding cores 156, 129 may be made of a about 5% to about 40% nickel-clad copper with ceramic insulation in order to reduce oxidation and failure at high temperatures. The handling characteristics of this wire are significantly more challenging than standard organic-insulated bare copper, as a result of the protective, ceramic coating, and special techniques were developed for the processes of winding both the primary and rotating elements. Other wires may be insulated silver or anodized aluminum.
Two types of ceramic materials may be used in the construction of both the primary and rotating induction coil assemblies 150, 127. It is important to ensure the windings 157, 130 do not short (conduct) to the core elements 156, 129. In addition to ceramic insulation supplied on the wires, a compound, such as H cement, a ceramic cement with ultra fine particle size, may be used as an insulating base coat on the winding cores 156, 129. Once the winding cores 156, 129 are wound they may be potted with Cotronics 940, an aluminum oxide based ceramic cement. In an alternative embodiment, the insulating base coat and potting material may be Cotronics 940 or other ceramic cement material.
The voltage regulator of transmitter circuit 210 maintains a constant DC voltage output, even though the AC input voltage may vary. A constant voltage output is required to achieve better accuracy and stable operating frequency for the signal output. The voltage regulator also supplies a constant voltage, a strain gauge sensor 118 and a ballast resistor (not shown). The strain gauge sensor 118 and ballast resistor provide the sensor signal input to the transmitter circuit 210. As the surface where the strain gauge sensor 118 is mounted deflects, the strain gauge changes resistance, which causes the voltage at the transmitter circuit 210 input to change.
The varying voltage provided by the signal from the strain gauge sensor 118 is amplified first by a differential amplifier and then by a high gain AC amplifier. The resulting signal is applied to a varactor diode in the voltage controlled oscillator (VCO) section of transmitter circuit 210. The VCO oscillates at a high carrier frequency. This carrier frequency may be set in the band of 125 to 155 MHz with respect to transmitter circuit 210. The fixed carrier frequency is changed slightly by the changing voltage on the varactor. This change in frequency or deviation is directly related to the deflection or strain undergone by strain gauge sensor 118. The VCO carrier output is fed to a buffer stage and the buffer output connects to a transmitting antenna contained in the rotating antenna assembly 142 via lead wires 124 of
In a receiving device, such as transceiver 56 in
Various embodiments of wireless telemetry transmitter circuit 210 fabricated on a circuit board may be adapted for use within combustion turbine 10 at varying operating temperatures and with a range of sensor types. Elements of transmitter circuit 210 and alternate embodiments thereof may be fabricated using various temperature sensitive materials such as silicon-on-insulator (SOI) integrated circuits up to approximately 350° C.; polysilseqioxane, PFA, polyimide, Nomex, PBZT, PBO, PBI, and Voltex wound capacitors from approximately 300-350° C.; and PLZT, NPO, Ta2O5, BaTiO3 multilayer ceramic capacitors from approximately 450-500° C.
Various embodiments of resistors may be fabricated of Ta, TaN, Ti, SnO2, Ni—Cr, Cr—Si and Pd—Ag for operating environments of approximately up to 350° C. and Ru, RuO2, Ru—Ag and Si3N4 for operating environments of approximately 350° C. and greater. Individual high temperature electronic components, such as discrete transistor, diode or capacitor die made from SiC, AlN, GaN, AlGaN, GaAs, GaP, InP, AlGaAs, AlGaP, AlInGaP, and GaAsAlN, or other high temperature capable semiconducting material, may be replaced by a single SOI CMOS device for operation at temperatures not exceeding approximately 350° C.
While the preferred embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous variations, changes and substitutions will occur to those of skill in the art without departing from the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.
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Keyes et al., High Temperature Telemetry Systems for in Situ Monitoring of Gas Turbine Engine Components, 2009 IEEE, 15 pp. |
Number | Date | Country | |
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20120197597 A1 | Aug 2012 | US |