Sacrificial temperature coupon for turbomachinery

Abstract

To provide a method of determining a temperature to which a component within a turbomachine was exposed.SOLUTION: A method and a system enable a temperature (408) to which a component (200) within a turbomachine (100) was exposed to be determined. The method includes operating the turbomachine (100) including the component (200) for an elapsed period of time, determining a thickness (410) of an oxide layer (302) that has been formed on a coupon (300) attached to the component (200), and determining a temperature offset based on the thickness measurement (410) of the oxide layer (302). The method also includes determining the temperature (408) to which the component (200) was exposed using the temperature offset, and outputting the temperature (408) to which the component was exposed.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The field of the disclosure relates generally to gas temperature measurement, and more particularly to methods and systems for use in measuring gas temperature in various operating environments. [Background technology]

[0002] Combustion turbines, such as gas turbine engines, typically include a compressor section, a combustor section, a turbine section, and an exhaust section. During operation, the compressor section draws in and compresses ambient air. The combustor section typically includes multiple combustors that receive compressed air and mix it with fuel to form a fuel / air mixture. The mixture is combusted in the combustors to form hot working gases that may be channeled to the turbine section, where they are expanded through alternating rows of stationary and rotating airfoils and used to generate power that can drive a rotor. The expanded gases exiting the turbine section may be exhausted from the engine via the exhaust section.

[0003] Combustion anomalies within a turbine can cause undesirable damage and even destroy combustion engine components, potentially necessitating repair or replacement of such components. The fuel / air mixture channeled through individual combustors is controlled during operation to facilitate maintaining one or more operating characteristics within predetermined ranges, such as, for example, to maintain desired efficiency and power output, control emissions levels, prevent pressure oscillations, and / or prevent flameout. In at least some control systems, hard-wired thermocouples may be used to measure temperatures. However, such thermocouples can only measure temperatures near their installed locations. In other words, thermocouples suffer from relatively low spatial resolution. As a result, components located far from the thermocouples are generally exposed to temperatures different from those measured by the thermocouples. In the event of a component failure, knowing the temperature to which the failed component was exposed is a key factor in improving the accuracy of root cause analysis. Therefore, there is a need for a system and method for measuring the gas operating temperatures of various components at their installed locations without using hard-wired thermocouples. Summary of the Invention

[0004] In one aspect, a method for determining a temperature to which a component in a turbomachine is exposed is provided. The method includes operating the turbomachine including the component over an elapsed time, determining a thickness of an oxide layer formed on a coupon attached to the component, and determining a temperature offset based on the oxide layer thickness measurements. The method also includes determining a temperature to which the component was exposed using the temperature offset and outputting the temperature to which the component was exposed.

[0005] In another aspect, a measurement device for use in determining an operating temperature within a turbomachine is provided. The measurement device includes at least one coupon coupled to a component within the turbomachine and a processor. The processor is configured to receive measurements of a thickness of an oxide layer formed on the coupon after the turbomachine has operated with the component for a predetermined period of time and to determine a temperature offset based on the thickness of the oxide layer. The processor is further configured to apply the temperature offset to measured temperatures obtained within the turbomachine during operation and use the temperature offset to determine an actual temperature to which the component was exposed during operation of the turbomachine.

[0006] In a further aspect, at least one non-transitory computer-readable storage medium having stored thereon instructions, which, when executed by at least one processor, cause the at least one processor to receive measurements of a thickness of an oxide layer formed on a coupon attached to a component of a turbine machine that has been operated for a predetermined period of time and determine a temperature offset based on the measured thickness of the oxide. The instructions also cause the at least one processor to apply the temperature offset to a historical operating temperature of the turbomachine to determine an actual temperature to which the component was exposed during operation of the turbomachine, and output the actual temperature to which the component was exposed during operation of the turbomachine.

[0007] The above description is provided only as a summary of some implementations disclosed herein. These and other implementations are described in more detail herein. In addition, some implementations include one or more processors of one or more computing devices, the one or more processors operable to execute instructions stored in associated memory, the instructions configured to cause the performance of any of the methods described herein. Some implementations also include one or more non-transitory computer-readable storage media that store computer instructions executable by the one or more processors to perform any of the methods described herein.

[0008] It should be understood that all combinations of the foregoing concepts and additional concepts described in more detail herein are considered to be part of the subject matter disclosed herein, for example, all combinations of claimed subject matter appearing at the end of this disclosure are considered to be part of the subject matter disclosed herein.

[0009] The above-described system and method, as well as other features of the present invention, will become more apparent, and the invention itself will be better understood, by reference to the following description of embodiments of the invention in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective cross-sectional view of an exemplary gas turbine engine; [Figure 2] FIG. 2 is a perspective view of an exemplary component that may be used with the turbine shown in FIG. 1 and includes a sacrificial coupon attached to the component. [Figure 3] 3 is a cross-sectional view of an exemplary coupon, such as the coupon shown in FIG. 2, after a layer of oxide has built up on the coupon. [Figure 4] FIG. 1 is a block diagram of an exemplary system that may be used to determine the thermal history of a gas turbine component by analyzing oxides formed on coupons attached to the component. [Figure 5] 5 illustrates an exemplary user interface screen that may be used with the system shown in FIG. 4 to input values ​​used to determine the offset temperature. [Figure 6] 5 is an exemplary set of temperature data that may be output from the system shown in FIG. 4 showing the actual operating temperature of a given component based on an offset applied to the thermal history data. [Figure 7] FIG. 1 is a flow diagram of an exemplary method for determining the thermal history of a gas turbine component by analyzing oxides formed on coupons attached to the component. DETAILED DESCRIPTION OF THE INVENTION

[0011] Although the embodiments of the present disclosure have been described with reference to these specific preferred embodiments, it will be understood that the present invention is not limited to these preferred embodiments. On the contrary, however, the present invention includes numerous alternatives, modifications, and equivalents, and it is apparent that many alternatives, combinations, modifications, and variations will be apparent to those skilled in the art. Accordingly, the preferred embodiments of the present invention as set forth above are intended to be illustrative only and not limiting. Various changes can be made without departing from the spirit and scope of the present invention.

[0012] In the following specification and claims, reference will be made to a number of terms that shall be defined to have the following meanings.

[0013] The singular forms "a," "an," "the," and "said" include plural referents unless the context clearly dictates otherwise.

[0014] The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0015] "Optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes cases where the event occurs and cases where the event does not occur.

[0016] References to "one embodiment" are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, although particular features of various embodiments described herein may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the present disclosure, any feature of any drawing and / or embodiment described herein may be referenced and / or claimed in combination with any feature of any other drawing and / or embodiment described herein. Furthermore, unless expressly stated to the contrary, an embodiment "including" or "having" one or more elements having a particular characteristic may also include additional such elements that do not have that characteristic.

[0017] As used herein, the term "real-time" refers to any of the time when relevant events occur, the time when certain data are measured and collected, the time when the data is processed, and the time when the system responds to events and environments. In the embodiments described herein, these activities and events occur substantially simultaneously.

[0018] As used herein, the terms "processor" and "computer," as well as related terms such as "processing device," "computing device," and "controller," are not limited to those integrated circuits commonly referred to in the art as computers, but broadly refer to microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits, and / or other programmable circuits, and these terms are used interchangeably herein. In the embodiments described herein, memory may include, but is not limited to, computer-readable media such as random access memory (RAM) and computer-readable non-volatile media such as flash memory. Alternatively, floppy disks, compact disk read-only memories (CD-ROMs), magneto-optical disks (MODs), and / or digital versatile disks (DVDs) may also be used. Also, in the embodiments described herein, additional input channels may be, but are not limited to, computer peripherals associated with an operator interface, such as a mouse and keyboard. Alternatively, other computer peripherals, such as, for example, but not limited to, a scanner, may also be used. Furthermore, in the embodiments described herein, additional output channels may include, but are not limited to, an operator interface monitor.

[0019] Unless otherwise indicated, approximation language such as "generally," "substantially," and "about" used herein indicates that the modified term may apply only to an approximate degree, as recognized by one of ordinary skill in the art, rather than to an absolute or complete degree. Thus, values ​​modified by one or more terms such as "about," "approximately," and "substantially" are not limited to the exact value specified. In at least some cases, approximation language may correspond to the precision of an instrument for measuring the value. Additionally, unless otherwise indicated, terms such as "first," "second," and the like are used herein merely as labels and are not intended to impose any order, position, or hierarchy on the items they refer to. Furthermore, for example, a reference to a "second" item does not require or exclude the presence of, for example, a "first" or lower-numbered item, or a "third" or higher-numbered item.

[0020] In one embodiment, a system may be used to determine the thermal history of a gas turbine component by analyzing oxides formed on coupons attached to the component. More specifically, in one embodiment, an offset for the temperature component may be determined based on the relative distance of the coupon from the temperature sensor. The offset may be added or subtracted, as appropriate, from the temperatures contained in the thermal history to determine the true, actual temperature to which the component was exposed during operation.

[0021] In one implementation, at least one sacrificial coupon is attached to each target component to determine the actual thermal limits of the components in a turbine configuration. The coupons may be attached to the components using spot welding, adhesives, mechanical fasteners, and / or any other known joining method that allows the coupon to function as described herein and does not adversely affect the operation of the component. As described herein, the coupons may be used to monitor and / or determine the thermal history of the component. More specifically, the thickness of the oxide present on the extracted coupon may be measured. The measured oxide thickness may be input into a calculation tool, such as a summer module or other computing device, to enable the determination of the temperature to which the component was actually exposed.

[0022] In one embodiment, the database maintains and stores test results and associated oxidation data for a wide variety of steel alloys. Steel alloys have different known oxidation rates based on their specific chemical composition. The oxidation data may include oxide layer measurements in addition to corresponding recorded temperatures, pressures, and moisture levels. Generally, higher temperature exposures correspond to thicker oxide layers.

[0023] A cross-sectional examination may be performed on the coupon to reveal the thickness of the oxide layer or coating. The layer thickness may be correlated to the temperature it was exposed to. While different components within a turbine have different chemical compositions, the chemical compositions of different coupons may be consistent and known. For example, a steel alloy may have a known chromium content. The chromium content affects the rate of change of oxide thickness in a known manner.

[0024] In one illustrative example, the low-temperature components positioned within the compressor section may operate at approximately 500°F to approximately 900°F. In other embodiments, the system may be used with components operating at different temperature ranges, such as approximately 1000°F to approximately 2000°F. One or more steel coupons may be affixed to the compressor section. In other embodiments, the coupons may be fabricated from other materials, such as, but not limited to, nickel, chromium, platinum, Rene 77, and / or any other material that enables the coupon to function as described herein, including precious metals. After a predetermined number of operating hours, the coupons may be removed from the components. The coupons have known chemistries, including a designed chromium content. A cross-sectional analysis may be performed on the coupons, and the thickness of the oxide layer may be measured.

[0025] The thermal history of the turbine may be retrieved and input into a calculation tool, such as a summer or computing device. For example, the thermal history may be input into the system by the turbine operator and / or may be determined by empirical data collected from laboratory results. The thermal history may include temperatures measured with hard-wired thermocouples and operational data. The operational data may include, but is not limited to, start-up, shutdown, ramp rates, and cool-down rates.

[0026] The thermal history may reflect temperatures only within certain sections of the turbine, i.e., measured by sensors (e.g., measured by hard-wired thermocouples). More specifically, the temperature sensors may be positioned only within those specific sections. For example, the thermal history temperatures of an implementation may include compressor discharge readings. As described herein, temperatures at components may vary depending on their relative distance from the temperature sensors. Other factors that may cause variations may include surrounding components, radiation, and / or gas flow, among other environmental variables.

[0027] Despite variations, temperatures from the thermal history can be useful in determining the rise and fall of temperatures throughout the turbine. More specifically, temperatures at components of interest will generally rise or fall in agreement with or in coordination with temperatures captured in the thermal history. Thus, the temperature changes can be used in conjunction with the determined offset to calculate the temperature at a particular component.

[0028] Because the component of interest may be several degrees cooler or hotter than the temperature measured by the sensor (e.g., depending on the distance of the coupon from the sensor), the temperature reading may not reflect the actual temperature present at the component. To this end, the system may determine an offset for the temperature component based on the relative distance of the coupon from the temperature sensor. The offset may be added or subtracted, as appropriate, from the temperature contained within the thermal history to determine the true, actual temperature to which the component was exposed during operation.

[0029] As described herein, the offset can be determined by measuring the oxide thickness formed on the coupon. More specifically, the actual temperature to which the coupon was exposed can then be determined by the system based on the measured thickness of the oxide formed on the coupon. The determined coupon temperature at the time the coupon was extracted can be compared to temperatures in the thermal history histogram data based on the elapsed time of the coupon's operation on the component. The calculated difference between the coupon temperature and the listed (i.e., temperature sensor) thermal history temperature can comprise an offset for the coupon's location. The determined offset can then be applied to any temperature measurements in the thermal history to determine the temperature of each coupon on the component at any given time registered in the thermal history.

[0030] Once the offset is known, the system may add or subtract the offset from all of the stored temperature measurements included in the turbine's thermal history. Thus, the system can determine the temperature at the component at each time included in the thermal history. Additionally, the system may be able to determine how long the component was exposed to a given temperature and / or determine the time frame when a failure occurred and the temperature of the component at the time of failure.

[0031] In one embodiment, the complete thermal history of the component is performed. Due to the relatively small size of the coupons, multiple coupons can be placed on or within a wide range of components at a relatively low cost. Furthermore, each coupon may be destroyed or otherwise oxidized before any harm occurs to the actual component to which it is attached. The offset temperature may increase the accuracy of temperature monitoring and / or component failure analysis.

[0032] Referring more particularly to the drawings, Figure 1 illustrates a perspective cross-sectional view of an exemplary gas turbine engine 100. In the exemplary embodiment, engine 100 includes a compressor section 112, a combustor section 114, a turbine section 116, and an exhaust section or system 118. Combustor section 114 includes multiple combustors 120, each including a combustion shell and a cover plate. Combustor liners or baskets 126 and transition ducts define a passage for channeling hot working gases flowing downstream toward turbine section 116 before being exhausted through exhaust section 118. The present invention is operable with any other known combustor geometries and / or gas turbine engine designs, including, but not limited to, can, can-annular, or annular configuration combustors in stationary land and / or vehicle applications.

[0033] During operation of the engine 100, compressed air from the compressor section 112 is provided to the combustor section 114, where it is combined with fuel supplied by a fuel injection system 128. The fuel / air mixture is ignited to form combustion products that make up hot working gases. It can be appreciated that combustion of the fuel and air can occur at various axial locations along its path through the combustor liner or basket 126 and transition duct 127 and into the turbine section 116. The hot working gases expand through the turbine section 116 and are exhausted through the exhaust section / system 118.

[0034] In the example combustion turbine 100, a temperature sensor 130 (e.g., a hard-wired thermocouple) may be positioned immediately upstream of the component 132 of interest, as shown. For example, an engineer may want to check the temperature of the component 132 to determine the temperature to which the component 132 was actually exposed and / or the actual temperature at which the component 132 failed. However, the temperature surrounding the component 132 may vary within the turbine 100 depending on the distance between the temperature sensor 130 and the component 132. Other possible variables may include, but are not limited to, exposure to radiation, proximity to other components, and / or ambient airflow, among other conditions. Thus, the component 132 may be several degrees cooler or warmer than the temperature of the installed temperature sensor 130, and thus the temperature reading at the sensor 130 may not reflect the actual temperature to which the component 132 was exposed.

[0035] FIG. 2 is a perspective view of an example component 200 such as may be included in the turbine 100 shown in FIG. 1 . A sacrificial coupon 202 is coupled to the component 200. The coupon 202 may be spot welded, glued, bolted, or otherwise fastened to the component 200 by another known method that enables the coupon 202 to function as described herein. As described herein, the coupon 202 may be used to monitor the thermal history of the component 200. More specifically, the coupon 202 may be attached to the component 200, and the turbine 100 may operate normally. Although the coupon 202 is depicted as a disk, the coupon 202 may have any other shape or size that enables the coupon 202 to function as described herein. After a predetermined time during operation, a layer of oxide may appear and grow in depth on the exposed surface of the coupon 202. The coupons may be removed after turbine operation has ceased, and the thickness of the oxide present on each extracted coupon 202 may be measured. The measured thickness may be input into a system to enable the temperature to which the component 200 was exposed to be determined. A replacement coupon may then be attached to component 200 to allow for continued analysis.

[0036] 3 shows an enlarged cross-sectional view of a coupon 300 including a layer of accumulated oxide 302. The thickness of the oxide layer 302 may be measured after the coupon 300 is separated or cut from the component 200 and cross-sectioned. In one embodiment, an average of multiple measurements of the thickness of the oxide layer 302 may be calculated and input into the system. In general, higher temperature exposure generally corresponds to a thicker oxide layer. Besides operating temperature, other factors that may affect the thickness of the oxide growth on the surface 304 of the coupon 300 may include, but are not limited to, the pressure and / or moisture to which the component 200, and therefore the coupon 300, is exposed.

[0037] 4 is a block diagram of an example system 400 that may be used to determine the thermal history 402 of a gas turbine component, such as component 200 (shown in FIG. 2), by analyzing oxides formed on coupons attached to the component during operation. As shown, an offset determination module 404 may determine an offset for a temperature component based on the relative distance of the coupon from a temperature sensor. The offset may be determined using a measured thickness 410 of an oxide layer formed on the coupon after it has been removed from the component. The offset may be added or subtracted, as appropriate, from temperatures included in the turbine's thermal history 406 to determine the true actual temperature 408 to which the component was exposed.

[0038] The turbine thermal history 406 may be retrieved as input to a calculation tool, such as an adder module 412. The thermal history 406 may be provided by the turbine operator or may be input using empirical data collected from laboratory results. The thermal history 406 may include, but is not limited to, temperatures as well as operational data. The operational data may include, but is not limited to, records of start-ups, shutdowns, ramp rates, cool-down rates, and / or any other operational data related to turbine operation.

[0039] The adder module 412 may include digital circuitry that performs the addition of numbers. In an exemplary embodiment, the adder module 412 includes a component temperature determination 414, which may include a computing device that performs the addition using one or more processors 422 and performs the various functions of the exemplary modules 404, 412, and / or 416 in memory 424. The oxide thickness and temperature correlation module 416 may correlate the thermal history data 406 with operating pressure and moisture level. The system 400 may further consider the chromium level and / or time of exposure data.

[0040] FIG. 5 illustrates an exemplary user interface screen 500 that may be used to input exemplary values ​​502, 504, 506, 508, 510, 512, and / or 514 into system 400 (shown in FIG. 4 ), which may be used to determine an offset temperature. More specifically, a user may input elapsed operating time 502 of the coupon's thermal exposure in hours. Another field may include the percentage of chromium in the coupon 504. Another input may include the operating temperature 506 from histogram data. Additionally, operating pressure 508 and moisture percentage or content 510 may also be input into interface 500. Other inputs may include measured values ​​of wall thickness 512 loss and / or measured values ​​of oxide thickness 514. As described herein, in one embodiment, a database may be accessed and maintained with test results associated with a wide variety of steel alloys and / or other materials, as well as associated oxidation data. The oxidation data may include, for example, oxide layer measurements in addition to corresponding recorded temperatures, pressures, and moisture levels.

[0041] FIG. 6 is an example set of temperature data columns 602, 604, 606, and 608 that may be output from system 400 and show the actual temperature 608 of a given component based on an offset 606 applied to thermal history data 602. For example, in an example embodiment, the offset 606 of 17.5385°F may have been determined from an analysis of an oxide layer formed on a coupon positioned in close proximity to the component of interest. As shown in first row 610, the offset 606 of 17.5385°F may be added to the temperature in thermal history 602 (i.e., 602°F) to arrive at the actual temperature 608 to which the component (i.e., 619.53847°F) was exposed during operation. A user may also view column 604 to see the percentage, or amount of time, the component was actually exposed to the temperature. This data may be useful in determining the time frame when the component failed and the operating temperature at which the component failed.

[0042] 7 is a flow diagram of an example method 700 that may be implemented to determine the thermal history of a gas turbine component by analyzing oxides formed on a coupon bonded to the component. To do so, generally, the method 700 may determine an offset to the temperature component based on the relative distance of the coupon from the temperature sensor. The offset may be added or subtracted, as appropriate, from the temperatures included in the thermal history to determine the actual temperature to which the component was exposed.

[0043] Referring more particularly to the flow diagram, the method 700 may include attaching 702 one or more sacrificial coupons to components of interest within the turbine configuration to determine their actual thermal limits. As described herein, the coupons may function to track the thermal history of the components. The turbine may then be operated normally 704. A log of the thermal history of the turbine's operation may be recorded 706.

[0044] The coupon may be extracted 708 during a turbine shutdown, and the thickness of its accumulated oxide layer may be measured 710. A cross-sectional analysis may be performed on the coupon to determine the thickness of the oxide layer formed on the outer surface of the coupon 710. The thickness of the layer may be correlated to the temperature it was exposed to. While different components within the turbine may have different chemical compositions, the chemical composition of the coupon may be consistent and known. For example, a steel alloy may have a known chromium content. The chromium content affects the rate of change of oxide thickness in a known manner.

[0045] The measured thickness may be input 712 into a calculation tool, such as an adder module or other computing device. The thermal history of the turbine may be retrieved 714 as an additional input to the calculation tool. For example, the thermal history may be provided by a turbine operator or by empirical data from laboratory results. The thermal history may include temperature and operating data. The operating data may include records of start-up, shutdown, ramp rates, and cool-down rates. As described herein, the temperature changes reflected in the thermal history may be used in conjunction with determined offsets to calculate the temperature of specific components.

[0046] The system may determine an offset for the temperature component based on the relative distance of the coupon from the temperature sensor 716. As described herein, the offset may be determined by measuring the oxide thickness formed on the coupon 716. More specifically, the temperature to which the coupon was exposed may then be looked up by the system based on the measured thickness. The determined coupon temperature at the time the coupon was extracted may be compared to the temperature at that time in the thermal history histogram data. The calculated difference between the coupon temperature and the listed (i.e., temperature sensor) thermal history temperature may include an offset for the coupon's location.

[0047] The offset may be added or subtracted as appropriate to the temperature contained within the thermal history to determine the true actual temperature to which the component was exposed 718. The determined offset may then be applied to any temperature measurement within the thermal history to output the temperature of the coupon for the component at any given time registered within the thermal history 720.

[0048] In this manner, method 700 may be used to determine the temperature of a component at each point in time included in the thermal history. Thus, method 700 may be used to determine how long a component was exposed to a given temperature. The system may also be able to determine when a failure occurred and the temperature of the component at the time of the failure.

[0049] Certain embodiments described herein may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment containing both hardware and software elements. In particular embodiments, the disclosed methods are implemented in software executed by a processor, including but not limited to firmware, resident software, microcode, etc., embodied in a processor-readable storage medium.

[0050] Furthermore, embodiments of the present disclosure, such as one or more embodiments, may take the form of a computer program product accessible from a computer-usable or computer-readable storage medium that provides program code for use by or in connection with a computer or any instruction execution system. For purposes of this description, a non-transitory computer-usable or computer-readable storage medium may be any apparatus that may tangibly embody a computer program and that may contain, store, communicate, propagate, or transport the program for use by or in connection with an instruction execution system, apparatus, or device.

[0051] In various embodiments, the medium may include an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or propagation medium. Examples of computer-readable storage media include semiconductor or solid-state memory, magnetic tape, removable computer diskettes, random access memory (RAM), read-only memory (ROM), rigid magnetic disks, and optical disks. Current examples of optical disks include compact disc-read-only memory (CD-ROM), compact disc-read / write (CD-R / W), and digital versatile disc (DVD).

[0052] A data processing system suitable for storing and / or executing program code may include at least one processor coupled directly or indirectly to memory elements via a system bus. The memory elements may include local memory employed during the actual execution of the program code, bulk storage, and cache memory that provides temporary storage of at least some program code to reduce the number of times the code must be retrieved from bulk storage during execution.

[0053] Input / output or I / O devices (including but not limited to keyboards, displays, pointing devices, etc.) may be coupled to a data processing system either directly or through intervening I / O controllers. Network adapters may also be coupled to the system to enable the data processing system to become coupled to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modems, and Ethernet cards are just a few of the currently available types of network adapters.

[0054] Advantages of the implementation may include generating a complete thermal history of a component. Because the coupons are relatively small in size, multiple coupons may be placed on or within a wide range of components at a relatively low cost. Furthermore, each coupon may be destroyed or otherwise oxidized before any harm occurs to the actual component to which it is affixed. The offset temperature may increase the accuracy of temperature monitoring and / or component failure analysis.

[0055] Further aspects of the invention are provided by the subject matter of the following clauses.

[0056] 1. A method for determining a temperature to which a component in a turbomachine is exposed, the method comprising: operating the turbomachine including the component over an elapsed time; determining a thickness of an oxide layer formed on a coupon attached to the component; determining a temperature offset based on the oxide layer thickness measurements; determining a temperature to which the component is exposed using the temperature offset; and outputting the temperature to which the component is exposed.

[0057] The method of any preceding clause, wherein the method further includes receiving a thermal history of operation of the turbomachine, the thermal history including recorded temperatures.

[0058] The method of any preceding clause, wherein the method further includes determining the thickness of the oxide layer further includes cross-sectioning the coupon after it is removed from the component.

[0059] The method of any of the preceding clauses, wherein the method further comprises attaching a coupon having a known oxidation rate to the component.

[0060] The method of any of the preceding clauses, wherein the method further comprises attaching a plurality of coupons to the component.

[0061] The method of any of the preceding clauses, wherein the method further includes extracting the coupon from the turbomachine after a predetermined period of operation of the turbomachine has elapsed.

[0062] The method of any preceding clause, wherein the method further includes determining the temperature offset includes correlating the measured oxide layer thickness to a history temperature associated with the thickness, the history temperature being one of a plurality of temperatures maintained in the thermal history, each temperature correlating to a plurality of history thickness measurements.

[0063] The method of any preceding clause, wherein the method further comprises determining a temperature difference between the measured temperature and a historical temperature.

[0064] The method of any preceding clause, wherein the method further includes determining at least one of a water content and an operating pressure to which the component is exposed during turbomachine operation.

[0065] The method of any of the preceding clauses, wherein the method further includes bonding the replacement coupon to the component at the same location previously occupied by the oxidized coupon within the turbomachine.

[0066] 1. A measurement device for use in determining an operating temperature within a turbomachine, the measurement device comprising: at least one coupon coupled to a component within the turbomachine; and a processor configured to receive measurements of a thickness of an oxide layer formed on the coupon after the turbomachine has operated with the component for a predetermined period of time, determine a temperature offset based on the thickness of the oxide layer, apply the temperature offset to measured temperatures obtained within the turbomachine during operation, and use the temperature offset to determine an actual temperature to which the component was exposed during operation of the turbomachine.

[0067] 10. The apparatus of any preceding clause, wherein the apparatus further includes receiving a thermal history of operation of the turbomachine, the thermal history including a plurality of temperature data obtained during turbomachine operation.

[0068] The apparatus of any preceding clause, wherein the apparatus further comprises at least one coupon having a known oxidation rate.

[0069] The apparatus of any preceding clause, wherein the apparatus further includes at least one coupon fastened to the component using at least one of a weld, an adhesive, and a mechanical fastener.

[0070] The apparatus of any preceding clause, wherein the coupon is extracted from the turbomachine after the turbomachine has been in operation with components therein for a period of time.

[0071] 10. The apparatus of any preceding clause, wherein the processor is further configured to correlate the measured thickness of the oxide layer to temperatures stored in a thermal history of the turbomachine, each temperature stored in the thermal history being associated with a thickness.

[0072] 10. The apparatus of any preceding clause, wherein the processor is further configured to determine a temperature difference between the measured temperature and the stored temperature.

[0073] 10. The apparatus of any preceding clause, wherein the processor is further configured to receive at least one input related to at least one of a water content near the component and an operating pressure during operation of the turbomachine.

[0074] At least one non-transitory computer-readable storage medium having stored thereon instructions that, when executed by the at least one processor, cause the at least one processor to: receive measurements of a thickness of an oxide layer formed on a coupon attached to a component of a turbine machine that has been operated for a predetermined period of time; determine a temperature offset based on the measured thickness of the oxide; apply the temperature offset to a historical operating temperature of the turbomachine to determine an actual temperature to which the component was exposed during operation of the turbomachine; and output the actual temperature to which the component was exposed during operation of the turbomachine.

[0075] 10. The method of claim 1, wherein the at least one processor is further configured to correlate the measured thickness to at least one historical temperature associated with the thickness, each historical temperature being correlated to a thickness measurement.

[0076] The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the disclosed embodiments. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest possible scope consistent with the principles and features defined by the following claims.

[0077] The methods and systems described herein are not limited to the specific embodiments described herein. For example, each system component and / or each method step may be utilized separately and independently of other components and / or steps described herein. For example, the methods and systems may also be used in combination with other combustion systems and are not limited to being practiced solely with gas turbine engines as described herein. Rather, the exemplary embodiments may be implemented and utilized in connection with many other rotary machines and combustion applications.

[0078] This specification uses examples to disclose the invention, including the best mode, and also to enable those skilled in the art to practice the invention, including making and using any device or system and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims. [Explanation of symbols]

[0079] 100 Gas turbine engine, combustion turbine 112 Compressor Section 114 Combustor Section 116 Turbine Section 118 Exhaust section or system, Exhaust section / system 120 Multiple Combustors 126 Combustor liner or basket 127 Transition Duct 128 Fuel injection system 130 Temperature Sensor 132 Components 200 components 202 Sacrifice Coupon 300 coupons 302 oxide layer, oxide layer 304 Surface 400 System 402 Thermal History 404 Offset Determination Module 406 Thermal history, thermal history data 408 True Actual Temperature 410 Thickness 412 Adder Module 414 Component Temperature Determination 416 Correlation Module 422 processor 424 memory 500 User Interface Screen, Interface 502 value, elapsed operating time 504 value, chromium percentage 506 value, operating temperature 508 Value, Operating Pressure 510 value, moisture percentage or water content 512 value, wall thickness 514 value, oxide thickness 602 Thermal History Data, Column, Thermal History Column 604 606 offset, column 608 Actual Temperature, Column 610 First Line 700 methods

Claims

1. 1. A method for determining a temperature (408) to which a component (200) in a turbomachine (100) has been exposed, the method comprising: operating the turbomachine (100) including the component (200) for an elapsed time; determining a thickness (410) of an oxide layer (302) formed on a coupon (300) attached to the component (200); determining a temperature offset based on thickness measurements (410) of the oxide layer (302); determining the temperature (408) to which the component (200) was exposed using the temperature offset; outputting the temperature (408) to which the component (200) was exposed; A method comprising:

2. The method of any preceding claim, further comprising receiving a thermal history (402) of operation of the turbomachine (100), the thermal history (402) comprising recorded temperatures.

3. 2. The method of claim 1, wherein the determining the thickness of the oxide layer further comprises cross-sectioning the coupon after the coupon is removed from the component.

4. The method of claim 1, further comprising attaching at least one coupon (300) having a known oxidation rate to the component (200).

5. The method of any preceding claim, further comprising extracting the coupon from the turbomachine after a predetermined period of operation of the turbomachine.

6. determining the temperature offset correlating the measured thickness (410) of the oxide layer (302) to a history temperature associated with the thickness (410), the history temperature being one of a plurality of temperatures maintained within the thermal history (402), each of which correlates to a plurality of history thickness measurements; determining a temperature difference between the measured temperature and the historical temperature; The method of claim 2 , comprising:

7. 2. The method of claim 1, wherein the determining the temperature offset further comprises determining at least one of a water content and an operating pressure to which the component is exposed during operation of the turbomachine.

8. 1. A measurement device (400) for use in determining an operating temperature (408) within a turbomachine (100), said measurement device (400) comprising: at least one coupon (300) coupled to a component (200) within said turbomachine (100); receiving a measurement of a thickness (410) of an oxide layer (302) formed on the coupon (300) after the turbomachine (100) has operated with the component (200) for a predetermined period of time; determining a temperature offset based on the thickness (410) of the oxide layer (302); applying the temperature offset to measured temperatures obtained within the turbomachine (100) during operation; and Using the temperature offset to determine the actual temperature (408) to which the component (200) is exposed during operation of the turbomachine (100). a processor (422) configured to: A measuring device (400) comprising:

9. The processor (422): receiving a thermal history (402) of operation of the turbomachine (100), the thermal history (402) including a plurality of temperature data acquired during operation of the turbomachine (100); correlating the measured thickness of the oxide layer (302) to temperatures stored in the thermal history (402) of the turbomachine (100), wherein each temperature stored in the thermal history (402) is associated with a thickness; determining a temperature difference between the measured temperature and the stored temperature; The apparatus of claim 8 , further configured to:

10. 10. The apparatus of claim 9, wherein the at least one coupon has a known oxidation rate, and the processor is further configured to receive at least one input related to at least one of a water content and an operating pressure in the vicinity of the component during operation of the turbomachine.

Images