Thermal measurement system

Abstract

An apparatus and method for determining temperature in a system having an object, an optical sensor, and a gas flow passing between the object and the optical sensor, the method comprising: sensing a wavelength emitted from the object and indicating attenuation using the optical sensor; sensing a wavelength emitted from the object and indicating the temperature of at least one of the object or a gas using the optical sensor; and calculating the temperature of the gas using the wavelength.

Description

Technical Field

[0001] This disclosure generally relates to thermal measurement systems, and more specifically, to multi-wavelength thermometers. Background Technology

[0002] Temperature measurements are performed in a variety of environments, including industrial, scientific, and commercial processes. One technique utilizes a pyrometer (also known as an infrared thermometer) for estimating the temperature of an object. For example, multi-wavelength pyrometric measurements may involve sampling and combining radiation emitted by an object at multiple wavelengths. Other techniques utilize optical spectroscopy to measure the temperature or concentration of gases. Summary of the Invention

[0003] Aspects and advantages of the invention will be set forth in part in the description which follows, or may be apparent from the description or may be learned by practicing the invention.

[0004] In one aspect, this disclosure relates to a method for determining temperature in a system having an object, an optical sensor, and a gas flow passing between the object and the optical sensor, the method comprising: sensing an attenuation wavelength with the optical sensor, the attenuation wavelength being emitted from the object and indicating attenuation associated with the optical sensor; sensing at least one temperature wavelength with the optical sensor, the at least one temperature wavelength being emitted from the object and indicating the temperature of at least one of the object or the gas; and calculating the temperature of the gas using the at least one temperature wavelength and the attenuation wavelength.

[0005] On the other hand, this disclosure relates to a method for determining the temperature of a gas, the method comprising: flowing a gas between an object and a thermal measurement system, the thermal measurement system including at least an optical sensor and a processor; filtering light waves emitted from the surface of the object and having various wavelengths using the optical sensor; sensing a gas wavelength associated with high gas absorption and an attenuation wavelength indicating attenuation of the optical sensor using the optical sensor; calculating a first gas temperature using the gas wavelength by the processor; determining the temperature of the object; retrieving at least one parameter indicating gas absorption and associated with the object temperature and the first gas temperature from a database provided in the processor; determining gas absorption; calculating the attenuation of the optical sensor using the attenuation wavelength by the processor; and calculating the actual gas temperature using the attenuation and gas absorption.

[0006] In another aspect, this disclosure relates to a thermal measurement system for determining the temperature of a gas disposed around an object, the thermal measurement system comprising: an optical sensor spaced at a predetermined distance from the object, the optical sensor including an attenuation filter associated with attenuation of the optical sensor determined by an attenuated wavelength that has passed through the gas to reach the object; an optical detector for converting the attenuated wavelength into a transmitted signal; and a processor configured to receive the transmitted signal, the processor including a storage device for storing a set of parameters and a computer for determining at least one parameter from the set of parameters associated with the transmitted signal, and calculating the gas temperature using the transmitted signal and the at least one parameter.

[0007] These and other features, aspects, and advantages of this disclosure will become better understood with reference to the following description. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate aspects of this disclosure and, together with the description, serve to explain the principles of this disclosure. Attached Figure Description

[0008] The complete and feasible disclosure of this disclosure, including its best mode, is set forth in the specification with reference to the accompanying drawings, for those skilled in the art, wherein:

[0009] Figure 1 This is a schematic diagram of a thermal measurement system that is spaced apart from the object and has an optical sensor.

[0010] Figure 2 It includes those from Figure 1 An enlarged view of a portion of the thermal measurement system of the optical sensor.

[0011] Figure 3 It is a description from Figure 1 An exemplary emission / absorption emissivity diagram of light emitted by an object.

[0012] Figure 4 It indicates a specific wavelength. Figure 3 Emission rate diagram.

[0013] Figure 5 It is used for depiction Figure 1 A flowchart illustrating the method for measuring gas temperature in a thermal management system.

[0014] Figure 6 It is used for depiction Figure 1 A flowchart illustrating another method for measuring gas temperature in a thermal management system. Detailed Implementation

[0015] The aspects of this disclosure described herein relate to thermal measurement systems and methods for determining the temperature of a gas. More specifically, this disclosure generally relates to using attenuation to more accurately determine the temperature of a gas positioned around an object (as a non-limiting example, turbine blades). For illustrative purposes, this disclosure will be described with respect to determining the temperature of the gas around turbine blades for use in an aircraft gas turbine engine. It should be understood that the aspects of this disclosure described herein are not limited thereto and have general applicability in engines, including compressors, as well as in non-aircraft applications such as other mobile applications and non-mobile industrial, commercial, and residential applications.

[0016] The aspects of the thermal measurement system described herein can be implemented in a turbine engine, for example, as a product supply, a standalone product, a service supply, and / or a component of a service supply. The aspects of this disclosure can even be located remotely from the actual gas and object. For example, a computer system employing the aspects of this disclosure can be located at a remote location, stored remotely, and / or accessible via the Internet.

[0017] In aerospace applications, particularly in gas or combustion turbine engines where combustion gases flow through the engine to reach multiple rotating turbine blades, monitoring the temperature of components within the turbine engine and the combustion gases passing through it is essential for turbine engine maintenance and optimal performance. Thermocouples located in the exhaust section can be used to measure the exhaust temperature, which can then be modeled to estimate the temperature of upstream components. The reliability of thermocouples is limited as combustion temperatures increase. Similarly, pyrometers can be used to directly measure component temperatures, which can then be used to estimate the exhaust temperature based on the component temperatures as the components rotate through the exhaust. The reliability of pyrometer measurement techniques is also limited by the accuracy of changes in environmental conditions.

[0018] Another complicating factor in measuring temperature in certain harsh environments is that the addition of any kind of device in certain combustion zones (e.g., aircraft engines) is highly regulated. Therefore, there is a constant need to improve temperature measurement.

[0019] Typical multi-wavelength pyrometers, combined with modeling, have traditionally been used to estimate the temperature of gases within cooled turbine engine components. For example, engine components with integrated cooling can have an object temperature that is a function of both the temperature of combustion products (referred to herein as gas temperature) and the cooling efficiency. In the example where the cooled turbine engine component includes cooling orifices, this estimation would need to account for the cooling effect of gas movement through and out of the component.

[0020] Other techniques, such as Tunable Diode Laser Absorption Spectroscopy (TDLAS), utilize narrow diode lasers at specific wavelengths and detect the absorption of certain gases at those wavelengths. In environments where dust or other particulate matter may be present in the airflow, one approach is to consider passive systems where an active laser or other light source is not required in the particulate-containing environment. For example, to meet performance, power, or reliability requirements, the high temperatures around the burner and exhaust can hinder laser positioning and cooling to a set temperature.

[0021] This disclosure combines the use of a pyrometer and an optical sensor. The pyrometer can be used to directly and non-invasively measure the temperature of an uncooled component at any combustion temperature, regardless of the presence of particulate material in the gas flow. The optical sensor provides the benefit of improved temperature detection, which can explain the cooling effect of the gas discharged through cooling holes in the component.

[0022] As discussed herein, this disclosure includes a thermal measurement system having an optical sensor and its components, the optical sensor used to sense wavelengths indicating attenuation caused by the optical sensor. The thermal measurement system provides a non-contact measurement of the relative high temperature of a gas by sensing the wavelength of emitted light passing through a gas from an object surface, including sampling the wavelength of light that is also partially or completely absorbed by the gas and re-emitted based on the gas's temperature and its relative emissivity. It is well known that attenuation is related to a gradual loss of flux intensity. The temperature sensing system of this invention can compensate for attenuation variations throughout the sensor. Typically, the optical sensor can consist of an optical window, lenses, and other optical components. Because the optical sensor is located in a combustion environment, soot, carbon, and other contaminants can cover the optical components and alter their transmission characteristics. This change in transmission characteristics affects the attenuation of the light signal received by the optical detector in the temperature sensing system from the gas and the blades.

[0023] The apparatus and method described herein for determining gas temperature provide a more accurate reading of the gas temperature within an engine by taking attenuation into account. Uncertainty may arise in determining the gas temperature when optical attenuation occurs and the emission of a gas at a known specific temperature. This uncertainty arises because there is difficulty in discerning whether a temperature change has actually occurred or whether the sensed change originates from attenuation changes. Therefore, as described herein, deconvolution of optical attenuation is beneficial. A solution for determining optical attenuation involves sensing the wavelength of light emitted from an object surface that is completely absorbed and re-emitted at a gas temperature that closely matches blackbody emission (i.e., the effective emissivity of the gas equals 1).

[0024] The optical sensor described herein for sensing wavelengths can be positioned in a predetermined aperture and permanently attached to the engine. Exhaust measurements are commonly used to control the engine and also to perform predictive health estimates to understand engine lifespan. The thermal measurement system described herein provides fundamental measurements of the operating engine. It is further envisioned that the optical sensor could be positioned in an existing duct mirror port located within a turbine engine. Obtaining actual and accurate gas temperatures will aid in monitoring and validating performance (e.g., blade / bucket performance) and in optimizing combustor performance. Steady-state and transient temperature data can be obtained and used to track and measure local combustor performance and component health.

[0025] As used herein, the term "upstream" refers to the direction opposite to the direction of fluid flow, while the term "downstream" refers to the direction in the same direction as the fluid flow. The terms "front" or "forward" indicate what is in front of something, and "back" or "rear" indicate what is behind something. For example, when used for fluid flow, front / forward can indicate upstream, and back / rear can indicate downstream.

[0026] Furthermore, as used herein, the term "radial" or "radially" refers to a direction away from a common center. For example, in the overall context of a turbine engine, radial refers to the direction of a ray extending between the engine's central longitudinal axis and the outer circumference of the engine. Additionally, as used herein, the term "group" or a "set" of elements can refer to any number of elements, including only one element.

[0027] All directional references (e.g., radial, axial, proximal, distal, up, down, upward, downward, left, right, lateral, front, rear, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, backward, etc.) are used for identification purposes only to aid the reader's understanding of this disclosure and do not impose limitations, particularly regarding the location, orientation, or use of aspects of this disclosure described herein. Unless otherwise stated, connection references (e.g., attachment, coupling, connection, and joining) are to be interpreted broadly and may include intermediate members between sets of elements and relative movement between elements. Therefore, a connection reference does not necessarily imply that two elements are directly connected and have a fixed relationship with each other. Exemplary figures are for illustrative purposes only, and the dimensions, positions, order, and relative sizes reflected in the accompanying figures may vary.

[0028] Turning Figure 1 The diagram shows a block diagram representation of a thermal measurement system (TMS) 10 according to the disclosure herein. The TMS 10 includes an object 12 that emits emitted light 14. The emitted light 14 passes through a gas 16 toward the TMS 10. The TMS 10 can be used to measure the temperature of the gas 16 (referred to herein as gas temperature (T)) in various environments. g )) and / or measure the temperature of the object's surface (referred to as object temperature (T in this article)o As a non-limiting example, object 12 can be any stationary or moving object, or some combination thereof. For example, object 12 can be any one or more hot gas path components of a gas turbine, such as a combustion liner, turbine nozzle, turbine stator, turbine afterburner, etc. Similarly, in the case where the object is a moving object, object 12 can be any traversing or rotating object typically located in a harsh environment, such as turbine blades or a set of pistons. The aspects disclosed herein provide solutions and benefits for measuring temperature in harsh environments (e.g., high temperatures), where the object temperature (T) o It can be within the range of 500°F to 3000°F and / or gas temperature (T). g It can be in the range of 500°F to 4000°F.

[0029] The TMS 10 described herein can be used to measure the temperature of various gases 16. In a typical combustion environment, the TMS 10 can be used when the gas 16 is, for example, carbon dioxide (CO2), vapor (H2O), hydrocarbons (e.g., natural gas, vaporized jet fuel, diesel, etc.), or some combination thereof. The TMS 10 can also measure other types of gases. Similarly, the TMS 10 can be used in various pressurized environments; as a non-limiting example, the pressure of the environment in which the gas 16 is present (e.g., a combustion chamber) can be 3 atmospheres or at least 5 atmospheres, and up to 6 atmospheres. Pressures can also be as low as atmospheric pressure or in a vacuum.

[0030] Emitted light 14 passes through gas 16 to define injected light 18. Injected light 18 is defined as a total emitted light wave that propagates from and interacts with the object 12 and is altered by gas 16. Optical system 20 is spaced from object 12 at a measurable distance (L). Optical system 20 may include optical sensor 22, which may include optical instruments 24, such as, as a non-limiting example, optical window 26, lens 28, at least one filter 30, and at least one detector 32. At least one filter 30 may be a plurality of filters for filtering injected light 18, and at least one detector 32 may be a plurality of detectors for measuring injected light 18, so that filter 30 may be positioned in front of detector 32. However, it is contemplated that filter 30 and detector 32 are integrated with each other, or that filter 30 is integrated with or part of other optical instruments 24 located in front of detector 32. Filter 30 may be a bandpass filter that allows light to pass through at a specific wavelength (near-infrared (NIR) wavelength or long-infrared (LIR) wavelength). As a non-limiting example, detector 32 may be a photodiode, such as one with a responsivity of standard or extended ranges of InGaAs, GaP, Si, Ge, or a combination of Si / InGaAs. For sensing wavelengths exceeding 2.6 μm, a thermopile is an option for at least one detector 32. Other optical instruments 24 (as a non-limiting example, at least one of a prism, mirror, fiber optic cable, or combination thereof) may also be provided in optical sensor 22. Optical instruments 24 are constructed within optical sensor 22 to provide a current signal 34 between optical sensor 22 and a conversion device (as a non-limiting example, amplifier 36). Assuming the current signal 34 is large compared to any noise associated with a particular optical sensor 22, sensing NIR wavelengths will be more sensitive than sensing LIR wavelengths.

[0031] Amplifier 36 can be configured to convert the current signal 34 into a transmission signal 38, as a non-limiting example, into a voltage associated with the current and / or optical power from each detector 32, for transmission to processor 40. It is envisioned that the detectors and amplifiers together define an optical detector capable of converting light into current using a single instrument, and then converting the current into voltage. Processor 40 may include functions for calculating the object temperature (T0). o ) and gas temperature (T) g The computer processing unit (CPU) 42. As a non-limiting example, the CPU 42 may be configured to use an algorithm to process the transmission signal 38 to provide the gas temperature (T). g The processor 40 may also include a storage device (as a non-limiting example, lookup table 46) for storing a set of parameters 44, more specifically, a set of spectral parameters. This set of parameters 44 can indicate the temperature at which the gas is determined (T). g Other required variables when ( ).

[0032] The set of parameters 44 stored in lookup table 46 may include, but is not limited to, various filter transmittance (f) values ​​associated with the installed filter 30, distance (L) related to the measurable distance between the optical sensor 22 and the object 12, various emissivity (ε) values ​​associated with the object 12, various absorption factors (X), and / or pressure values ​​(p). Lookup table 46 may also include ratio values ​​associated with any given parameter or set of parameters, object temperature (T... o ), gas temperature (T) g The filter transmittance (f) and the distance (L) are known variables. The filter transmittance (f) is based on the design and specifications of the detector 32 and the wavelength selection, and the distance (L) is based on the measurement between the optical sensor 22 and the object 12.

[0033] Sensor 48 can be placed in the surrounding environment of TMS 10 or in any other suitable location within the engine in which TMS 10 is provided. Pressure sensor 48 p It can sense the pressure (p) of the environment in which object 12 and gas 16 are located. Gas absorption sensor 48 X It can sense the absorption factor (X) corresponding to water concentration, carbon dioxide concentration, or any other suitable gas concentration. The absorption factor (A) is the known behavior of a particular gas's absorption at a specific wavelength, which depends on the gas's mole fraction (A / B), and is referred to herein as the absorption factor (X). The temperature sensor 48T can directly measure the temperature of an object (T). o ).

[0034] In this way, the TMS 10 is able to filter the injected light 18 and ultimately measure the gas temperature (T). g ) and / or object temperature (T o It should be noted that the disclosure herein is not limited to any particular processor used to perform the processing tasks described herein. The term "processor" is intended to mean any machine capable of performing computations or operations necessary for performing the tasks described herein. The term "processor" is also intended to mean any machine capable of accepting structured input and processing it according to prescribed rules to produce output. It should also be noted that the phrase "constructed as" as used herein indicates that the processor is equipped with a combination of hardware and software for performing the tasks described herein, as will be understood by those skilled in the art.

[0035] Turning Figure 2This is an enlarged schematic diagram of the optical system 20, showing six filters 30, each filter 30 used to distinguish specific wavelengths (λ1, λ2, λ3, λ4, λ5, λ6) from the injected light 18. Although six filters are illustrated, more or fewer filters 30 are contemplated. One or more filters 30 can be selected with specific detection wavelengths (λ1, λ2) or wavelength ranges corresponding to light directly emitted from the object 12, where the gas absorbs / emits light 14 with minimal absorption; these filters 30 will be simply referred to herein as object filters 50. Each object filter 50 is configured to collect light, particularly at temperatures related to the object temperature (T). o The first and second wavelengths (λ1, λ2) are associated with each other.

[0036] Similarly, one or more filters 30 may be selected to have specific detection wavelengths, third, fourth, fifth, and sixth wavelengths (λ3, λ4, λ5, λ6), or wavelength ranges corresponding to the case where gas 16 significantly absorbs / emits light 14; these filters will be simply referred to herein as gas filters 52. At least one of the gas filters 52 may be specifically associated with attenuation and is referred to herein as attenuation filter 52a. It is conceivable that any of the gas filters 52 can be used as attenuation filter 52a. As mentioned earlier herein, attenuation is due to environmental factors, such as contaminants 54, which, as a non-limiting example, can cover optical instruments and alter their transmission characteristics. The processor can use the wavelength (λ4) characteristic associated with attenuation filter 52a to determine a wavelength-independent fouling factor (F). Each of the other filters 30 configured to collect the third, fifth, and sixth wavelengths (λ3, λ5, λ6) may be specifically associated with variables including, but not limited to, gas absorption factor (X), pressure (p), and gas temperature (T). g The method for determining the scaling factor (F), which represents the degradation that equally affects all filters 30, will be described in more detail herein.

[0037] Figure 3Curve 56 is shown, depicting the emission of light as light passes from an object (object 12, as a non-limiting example) through a gas (gas 16, as a non-limiting example) compared to the wavelength of the light. The emission of the object or gas is governed by Planck's law, illustrated at two different temperatures. Object 12 is at a lower temperature than gas 16 (shown by the larger curve 56g) (shown by the smaller curve 56o). Curve 56 represents the behavior of H2O at a specific pressure (p) and gas absorption factor (X) and distance (L), which may appear different for other gases or even H2O at different specific pressures (p) and gas absorption factors (X). However, it should be understood that H2O still has the same transport and absorption regions; only the magnitude of gas interactions changes. The aspects disclosed herein utilize the information on curve 56. As shown by curve 56, light of certain wavelengths or intensities passes through gas 16, where gas 16 absorbs / emits minimally or almost nothing. Some minimal absorption / emission regions are depicted by the circled region "A". Similarly, light of certain wavelengths or intensities passes through gas 16 and is significantly or highly absorbed / emitted by gas 16, as depicted by gas absorption peak 58. This is due to the higher temperature of the gas and the absorption and subsequent re-emission of light from the gas at that higher temperature. Some significant regions are depicted by the circular region “B”. Furthermore, the circular region “C” includes wavelengths from approximately 4 μm to approximately 5 μm, where gas 16 absorbs and re-emits light to closely match blackbody emission at the gas temperature, where the effective emissivity of the gas is equal to 1. While the wavelengths in regions “A” and “B” are affected by object 12 and gas 16, the wavelengths measured in region “C” are not affected by the solid object. The wavelength signal is expressed via Planck's equation, the ideal gas equation, and the temperature dependence of gas absorption peak 58.

[0038] Figure 4 Curve 56 is shown again, with circular regions A, B, and C removed for clarity. As previously stated, TMS 10 processes information from collected light initially emitted from the surface of object 12. These wavelengths range from 0.5 μm to 10 μm. Depending on the specific gas 16, the filter 30 used in TMS 10 has at least one circular region “A” (… Figure 2 ), at least one circular area "B" Figure 2 ) and at least one circular area "C" ( Figure 2The detection range is aligned. Two vertical dashed lines along the first and second wavelengths (λ1, λ2) correspond to an object filter 50 that can be used to detect light minimally absorbed / emitted by a specific gas 16. The first wavelength (λ1) can be between 1200 and 1300 nm; as a non-limiting example, the first wavelength (λ1) can be equal to 1240 nm. The second wavelength (λ2) can be between 1550 and 1700 nm; as a non-limiting example, the second wavelength (λ1) can be equal to 1625 nm. Four vertical dashed lines along the third, fourth, fifth, and sixth wavelengths (λ3, λ4, λ5, λ6) correspond to a gas filter 52 that can be used to detect light significantly absorbed / emitted by a specific gas 16.

[0039] The vertical dashed line along the fourth wavelength (λ4) can specifically correspond to the attenuation filter 52a. The fourth wavelength (λ4), or the attenuation wavelength, can correspond to a wavelength range between 4100 and 4700 nm; as a non-limiting example, the attenuation wavelength (λ4) can be equal to 4500 nm. An exemplary attenuation filter 52a can be configured to detect light closely matched to gas emission, wherein all light emitted by object 12 is absorbed by gas 16 and emitted by the gas at a gas temperature (Tg) with an effective emissivity of 1.

[0040] The six wavelengths (λ1, λ2, λ3, λ4, λ5, λ6) described herein can be the center wavelength associated with each filter 30. As a non-limiting example, when the filter 30 is a bandpass filter as described herein, the bandpass width of the filter 30 can be 2-100 nm wide, depending on the filter 30. Therefore, each filter 30 can have a center wavelength and a wavelength range. In this example, a wider width is associated with more signal, while a narrower width is associated with higher sensitivity.

[0041] Turning Figure 5 The flowchart illustrates the determination of the gas temperature (T). g Method 100. At 102, gas 16 flows between object 12 and optical sensor 22. At 104, emitted light wave 14, which has passed through gas 16 to define injected light 18, is filtered. At 106, object temperature is determined. In one exemplary determination, object filter 50 may be configured to sense first and second wavelengths (λ1, λ2) both associated with low gas absorption at 108 to determine object temperature (T) using a first equation. o ):

[0042]

[0043] The first equation is a wavelength-independent scaling factor (F) related to attenuation, filter transmittance (f), object emissivity (ε), and the filtration wavelength (first or second (λ)).l (λ2) and object temperature (T) o The function of P(λ). 1,2 ,T o Simply put, this represents the application of Planck's law. For I1 or I2, the scaling factor (F), emissivity (ε), and object temperature (T) are independent of wavelength. o The parameters are the same, and for both filters 30, the filter transmittance (f) is known; therefore, there are two equations and two unknowns (T). o These equations (F×ε) can be used to calculate the temperature of an object at 110°C (T). o Further hypothesize the object's temperature (T). o The alternative techniques were determined by using a method at 112 that allows for direct measurement of the object's temperature (T). o ) sensor 48 T Sensing object temperature (T) o ).

[0044] Gas filter 52 can be configured to sense a third wavelength (λ3) associated with high gas absorption at 114 to determine the gas temperature (T) using the second equation. g ):

[0045]

[0046] Using calculated or sensed object temperature (T) o Now we can determine the product (F×ε) of the fouling factor (F) and emissivity (ε) of the object, but neither the fouling factor (F) nor the emissivity (ε) is known. The second equation is the wavelength-independent fouling factor (F), the filter factor (f) associated with the gas filter 52, the object emissivity (ε), the third wavelength (λ3), and the object temperature (T). o ), gas temperature (T) g The absorptivity (A) is a function of the third wavelength (λ3) and the gas temperature (T). g The first equation (I) is a function of distance (L), absorption factor (X), and pressure (p). It is related to either the first wavelength (λ1) or the second wavelength (λ2). 1，2 The ratio between equation (I) and equation (I3) can be used to calculate the temperature of the first gas (T). g For two equations and three unknowns (F, A, and T) g This can be done through multiple iterations. To calculate the gas temperature (T) g This requires determining the attenuation of the scaling factor (F) or the gas absorption rate (A).

[0047] Using the calculated value of (F×ε), an estimate of the attenuation can be determined by calculating the first fouling factor (F') at 116 using the emissivity (ε) value based on the material used for object 12, which is retrieved from lookup table 46 as a non-limiting example at 118. This material-based approximate emissivity (ε') will vary with engine operation, but it is a reasonable value for calculating the first fouling factor (F'). Using the first fouling factor (F'), two equations, and two unknowns (A, T) g The temperature of the first gas (T) can now be calculated at 120. g The gas temperature at this time (T) g This is only an approximation, because it has been found that when using the ratio method (I3 / I1), the error is approximately -20K at a gas temperature of 1500K (~2200F), and at T g =1800K (~2700F) increases to -50K. Even ignoring the uncertainty of the first scaling factor (F'), unless the object temperature (T) o The temperature is very small; otherwise, using I3 would directly generate a gas temperature (T). g The error is relatively large. It should be understood that the gas absorption rate (A) can now be determined at 122 using the first scaling factor (F'), although it should be understood that the gas absorption rate (A) also depends on the gas temperature (T). g The solution is nonlinear because it can be repeated at 118.

[0048] To account for attenuation, the attenuation wavelength (λ4) at 124 can be sensed and used to determine attenuation at 126 by finding the actual fouling factor (F). In region "C", where the gas absorptivity (A) is very high compared to the distance (L) from the object 12 to the optical sensor 22 from the emitted wavelength, the wavelength signal becomes independent of the object temperature (T). o ) and gas absorption rate (A). Therefore, the second equation simplifies to:

[0049]

[0050] Using a simplified second equation with a decay wavelength (λ4), the actual fouling factor (F) can be determined without the gas absorption rate (A) and more specifically, without either the absorption factor (X) or the pressure (p). The ratio of (I4 / I1) can be used with the two equations and the two unknowns (F, T). g Together, they are used to calculate the scaling factor (F). It is further envisioned that the irradiance (I4) can be directly calculated by measuring the flux and utilizing the attenuation wavelength (λ4). Using the equations and calculated values ​​described herein, the algorithm executed by processor 40 can then more accurately calculate the corrected gas temperature (T) at 128.g ).

[0051] The gas absorptivity (A) determined at 122 can also be used in the algorithm. The gas absorptivity (A) depends on the wavelength (λ) value, the absorption factor (X), the pressure (p), and the gas temperature (T). g It is envisioned that the absorption factor (X) and / or pressure (p) can be directly determined at 130 using real-time measurements from sensors 48X and 48p. Further envisioning, one of the absorption factor (X) or pressure (p) (whichever is sensed in real time) and any other calculated or known variables can be retrieved from lookup table 46 at 118. Other calculated or known variables required to retrieve the absorption factor (X) or pressure (p) from the lookup table include the ratio values ​​calculated herein, the first gas temperature (T... g ') and object temperature (T) o Algorithms can be applied to retrieve either the desired absorption factor (X) and / or pressure (p) value. Although the absorption factor (X) and / or pressure (p) determined here are based on the first gas temperature (T). g However, in cases where this method has been implemented in multiple iterations, the first gas temperature (T) g ') Approaching the actual gas temperature (T) over time g ), and in some iterations equals the actual gas temperature (T) g The use of the 52a attenuation sensor improved accuracy and reduced iteration requirements.

[0052] Further, we envision fifth and sixth detectors used to filter the fifth and sixth wavelengths (λ5, λ6). At position 132, the fifth wavelength (λ5) can be filtered and sensed by optical sensor 22. A table associated with the fifth wavelength (λ5) and the corresponding second equation (I5), along with other parameters described herein, can be stored in lookup table 46. At position 132, the sixth wavelength (λ6) can be filtered and sensed by optical sensor 22. Another table associated with the sixth wavelength (λ6) and the corresponding second equation (I6), along with other parameters described herein, can be stored in lookup table 46. The ratios (I5 / I1) and (I6 / I1) between the first and second equations both produce three unknowns (F, A, and T). g Using the ratio (I3 / I1), an algorithm can be applied to find T that satisfies all three ratios (I3 / I1, I5 / I1, and I6 / I1). g X and p, and extract the unknown variables (absorption factor (X) or stress (p)) from the table.

[0053] It should be understood that the methods described herein can occur in multiple sequences to achieve accurate temperature values. Multiple iterations of the method described herein can track changes in emissivity (ε) and fouling factor (F) over time. While many factors change during operation, emissivity (ε) and fouling factor (F) typically change slowly over time. These values ​​can also be used to inform subsequent iterations of calculations. Taking these slower changes into account allows for more accurate real-time data. Furthermore, detecting changes in emissivity (ε) and / or fouling factor (F) that are drastic over relatively short time periods can improve engine maintenance functionality.

[0054] Turning Figure 6 The flowchart depicts a method 200 for determining the temperature of gas 16 in a system having an object 12, an optical sensor 22, and gas 16 passing between the object 12 and the optical sensor 22. At 210, the optical sensor 22 is configured to sense an attenuating wavelength, referred to herein as a fourth wavelength (λ4), wherein the attenuating wavelength is emitted from the object 12 and indicates attenuation, as a non-limiting example, the fouling factor (F) described herein. At 212, the optical sensor 22 is configured to sense and indicate the object temperature (T) emitted from the object 12. o ) or the temperature of the first gas (T) g At least one temperature wavelength, wherein the first, second, and third wavelengths (λ1, λ2, λ3) are used. At 214, the method includes using a CPU 42, as a non-limiting example, to calculate a corrected gas temperature (T) of at least one of the gases 16 using at least one temperature wavelength (λ1, λ2, λ3) and an attenuation wavelength (λ4). g ).

[0055] Benefits associated with the apparatus and method described herein include maintaining the accuracy of temperature measurements. During engine operation, the emissivity of an object on any given component changes due to material aging or buildup. This alters the system's readings under specific operating conditions. The emissivity of any object scales the signal level received by the detector. Attenuation has a similar effect on the signal because buildup (optical degradation) exists on optical components or any source of signal level variation, thus reducing the signal level at all wavelengths of interest for both light originating from an object and light from a gas. The method described herein allows the system to account for variations in signal levels over the system's lifetime and whether these variations originate from changes in emissivity or attenuation. Taking this information into account improves measurement accuracy because attenuation affects all light passing through the optical system, while object emissivity only affects light originating from the object and does not affect gas emission.

[0056] It should be understood that the disclosed design is not limited to turbine engines with fan and supercharger sections, but is also applicable to turbojet engines and turboprop engines.

[0057] This written description uses examples to illustrate aspects of the present disclosure described herein, including best practices, and also enables any person skilled in the art to practice aspects of the present disclosure, including making and using any apparatus or system and performing any combined methods. The patentable scope of aspects of the present disclosure is defined by the claims, but may include other examples that would occur to a person skilled in the art. Such other examples are intended to fall within the scope of the claims if they have structural elements that are not indistinguishable from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

[0058] The various features, aspects, and advantages of this disclosure can also be implemented in the technical solutions defined in the following clauses:

[0059] A method for determining temperature in a system having an object, an optical sensor, and a gas flow passing between the object and the optical sensor, the method comprising: sensing an attenuation wavelength with the optical sensor, the attenuation wavelength being emitted from the object and indicating attenuation associated with the optical sensor; sensing at least one temperature wavelength with the optical sensor, the at least one temperature wavelength being emitted from the object and indicating the temperature of at least one of the object or the gas; and calculating the temperature of the gas using the at least one temperature wavelength and the attenuation wavelength.

[0060] According to any of the foregoing provisions, sensing the attenuated wavelength includes sensing the gas absorbing and re-emitting light to closely match the wavelength emitted by a blackbody having an effective emissivity equal to 1.

[0061] According to any of the foregoing descriptions, sensing the attenuation wavelength includes sensing a wavelength between 4100 and 4700 nm.

[0062] The method according to any of the foregoing clauses further includes sensing at least one wavelength associated with high gas absorption.

[0063] According to any of the foregoing provisions, sensing the at least one temperature wavelength includes sensing a first wavelength between 1200 nm and 1300 nm and sensing a second wavelength between 1550 nm and 1700 nm.

[0064] The method according to any of the foregoing clauses further includes using the optical sensor to sense a gas absorption wavelength that indicates the gas absorption factor of the gas.

[0065] The method according to any of the foregoing clauses further includes using the optical sensor to sense a pressure wavelength that indicates the pressure of the gas.

[0066] A method for determining the temperature of a gas, the method comprising: flowing the gas between an object and a thermal measurement system, the thermal measurement system including at least an optical sensor and a processor; filtering light waves of various wavelengths emitted from the surface of the object using the optical sensor; sensing a gas wavelength associated with high gas absorption and an attenuation wavelength indicating attenuation of the optical sensor using the optical sensor; calculating a first gas temperature using the gas wavelength by the processor; determining the temperature of the object; retrieving at least one parameter indicating gas absorption and associated with the object temperature and the first gas temperature from a database provided in the processor; determining the gas absorption; calculating the attenuation of the optical sensor using the attenuation wavelength by the processor; and calculating the actual gas temperature using the attenuation and the gas absorption.

[0067] According to any of the preceding clauses of the method, determining the temperature of the object includes one of: directly sensing the temperature of the object with a sensor; or sensing a first wavelength and a second wavelength different from the first wavelength with the optical sensor and calculating the object temperature using the first wavelength and the second wavelength by the processor, each of the first wavelength and the second wavelength being associated with low gas absorption.

[0068] According to any of the foregoing provisions, sensing the first wavelength includes sensing a wavelength between 1200 nm and 1300 nm.

[0069] According to any of the foregoing provisions, sensing the second wavelength includes sensing a wavelength between 1550 nm and 1700 nm.

[0070] According to any of the foregoing provisions, sensing the attenuated wavelength includes sensing the emitted and absorbed light from the gas to closely match the wavelength emitted by a blackbody having an effective emissivity equal to 1.

[0071] According to any of the foregoing descriptions, sensing the attenuation wavelength includes sensing a wavelength between 4100 and 4700 nm.

[0072] The method according to any of the foregoing clauses further includes sensing at least one of a gas absorption factor or pressure associated with the gas.

[0073] The method according to any of the foregoing clauses further includes using the optical sensor to sense another associated additional wavelength of the gas absorption factor or the pressure associated with the gas.

[0074] A thermal measurement system for determining the temperature of a gas disposed around an object, the thermal measurement system comprising: an optical sensor spaced at a predetermined distance from the object, the optical sensor including an attenuation filter associated with wavelength attenuation that has passed through the gas to reach the object; an optical detector for converting the attenuated wavelength signal into a transmitted signal; and a processor configured to receive the transmitted signal, the processor including a storage device for storing a set of parameters and a computer for determining at least one parameter from the set of parameters associated with the transmitted signal, and calculating the gas temperature using the transmitted signal and the at least one parameter.

[0075] According to any of the preceding clauses, the thermal measurement system wherein the optical sensor further includes at least one object temperature filter associated with the temperature of the object.

[0076] According to any of the preceding clauses, the thermal measurement system wherein the optical sensor further includes at least one gas temperature filter associated with the temperature of the gas.

[0077] The thermal measurement system according to any of the foregoing clauses further includes at least one of a pressure sensor for sensing pressure variables or a gas absorption sensor for sensing gas absorption.

[0078] The thermal measurement system according to any of the foregoing clauses further includes at least one additional filter for capturing an additional wavelength associated with another in the pressure variable or the gas absorption.

Claims

1. A thermal measurement system for determining the temperature of a gas disposed around an object, characterized in that, The thermal measurement system includes: An optical sensor spaced at a predetermined distance from the object, the optical sensor including an attenuation filter associated with the attenuation of the optical sensor, the attenuation being determined by the attenuated wavelength reaching the optical sensor after passing from the object through the gas; An optical detector for converting a wavelength signal, including the attenuated wavelength, into a transmission signal; Storage device, the storage device being used to store a set of parameters, the set of parameters including at least an emissivity value associated with the object; and Processor, the processor being configured as follows: Receive the transmitted signal, Determine at least one parameter associated with the transmitted signal from the set of parameters. The scaling factor is determined based on the attenuation wavelength, and The gas temperature is calculated using at least the scaling factor and the at least one parameter.

2. The thermal measurement system according to claim 1, characterized in that, The optical sensor further includes at least one object temperature filter associated with the temperature of the object.

3. The thermal measurement system according to claim 1, characterized in that, The optical sensor further includes at least one gas temperature filter associated with the temperature of the gas.

4. The thermal measurement system according to claim 1, characterized in that, It further includes at least one of a pressure sensor for sensing a pressure variable or a gas absorption sensor for sensing gas absorption, wherein the pressure variable or the gas absorption is part of the set of parameters.

5. The thermal measurement system according to claim 4, characterized in that, It further includes at least one additional filter for capturing an additional wavelength associated with the pressure variable or another in the gas absorption.

6. A method for determining temperature using the thermal measurement system according to claim 1, characterized in that, The method includes: The optical sensor senses an attenuation wavelength emitted from the object and indicates the attenuation associated with the optical sensor. The optical sensor senses at least one temperature wavelength, said at least one temperature wavelength being emitted from the object and indicating the temperature of at least one of the object or the gas; and The processor calculates the temperature of the gas using the at least one temperature wavelength and the attenuation wavelength.

7. The method according to claim 6, characterized in that, Sensing the attenuation wavelength includes sensing the absorption and re-emission of light by the gas to closely match the wavelength emitted by a blackbody having an effective emissivity equal to 1.

8. The method according to claim 6, characterized in that, The sensing of the attenuation wavelength includes sensing wavelengths between 4100 and 4700 nm.

9. The method according to claim 6, characterized in that, The sensing of at least one temperature wavelength includes sensing a first wavelength between 1200 nm and 1300 nm and sensing a second wavelength between 1550 nm and 1700 nm.

10. A method for determining the temperature of a gas using the thermal measurement system according to claim 1, characterized in that, The method includes: The gas is allowed to flow between the object and the thermal measurement system; The optical sensor is used to filter light waves of various wavelengths emitted from the surface of the object; The optical sensor is used to sense the gas wavelength and the attenuation wavelength, which indicates the attenuation of the optical sensor, wherein the gas wavelength is associated with high gas absorption; The processor calculates the temperature of the first gas using the gas wavelength; The temperature of the object is determined by the processor; The processor retrieves at least one parameter from the database that indicates gas absorption and is associated with the temperature of the object and the temperature of the first gas. The processor determines the gas absorption based on the at least one parameter; The processor calculates the attenuation of the optical sensor using the attenuation wavelength; and The processor calculates the actual gas temperature using the attenuation and the gas absorption.

11. The method according to claim 10, characterized in that, Sensing the attenuation wavelength includes sensing the emitted and absorbed light from the gas to closely match the wavelength emitted by a blackbody having an effective emissivity equal to 1.

12. The method according to claim 10, characterized in that, The sensing of the attenuation wavelength includes sensing wavelengths between 4100 and 4700 nm.

13. The method according to claim 10, characterized in that, The method further includes using the optical sensor to sense an additional wavelength associated with either the gas absorption factor or the pressure wavelength indicating the pressure of the gas, in order to calculate the actual gas temperature by the processor.

14. The method according to claim 10, characterized in that, Determining the temperature of the object includes one of the following: directly sensing the temperature of the object using a sensor; or sensing a first wavelength and a second wavelength different from the first wavelength using the optical sensor and calculating the object temperature using the first wavelength and the second wavelength by the processor, each of the first wavelength and the second wavelength being associated with low gas absorption.

15. The method according to claim 14, characterized in that, Sensing the first wavelength includes sensing wavelengths between 1200 nm and 1300 nm.

16. The method according to claim 15, characterized in that, Sensing the second wavelength includes sensing wavelengths between 1550 nm and 1700 nm.

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