Rotary sample temperature measuring method based on fluorescence arc length

Abstract

According to the rotating sample temperature measurement method based on the fluorescence arc length, the fluorescence service life of a material can be detected by measuring the fluorescence arc length, the function relation between the fluorescence service life and the temperature exists, temperature measurement is achieved by detecting the change of the fluorescence service life, high-precision temperature data can be provided, and in addition, the temperature measurement accuracy is improved. The high-speed rotating sample is adopted, the application scene in production and life is simulated, the feasibility is further improved, the limitation of the radiation temperature measurement technology is solved, an effective solution is provided for temperature monitoring in the high-speed rotating environment, and the high-speed rotating temperature measurement device has important significance for ensuring normal operation of components, improving safety and scientific research.

Description

Technical Field

[0001] This invention relates to the field of temperature monitoring under high-speed rotation, and to, but is not limited to, a method for measuring the temperature of a rotating sample based on the length of a fluorescence arc. Background Technology

[0002] Temperature measurement technology has a wide range of applications in scientific research, industry and daily life, especially in temperature measurement under high-speed rotation, such as engine turbine blades. Accurate temperature measurement is of great significance for ensuring the normal operation of components, avoiding safety problems and extending the service life of components.

[0003] Traditional temperature measurement methods, such as infrared radiation and fiber optic thermometry, can measure the temperature of components in high-speed rotating environments. However, radiation thermometry still faces many challenges in operating in environments with high background noise, and cannot meet the requirements of modern industry and scientific research for temperature information, especially in terms of accuracy and precision.

[0004] Therefore, a novel high-precision temperature measurement method is needed to achieve temperature measurement under high-speed rotation and provide high-precision temperature data. The present invention, a rotating sample temperature measurement method based on fluorescence arc length, is proposed to meet this need. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention proposes a method for measuring the temperature of a rotating sample based on the length of a fluorescence arc.

[0006] The technical method of this invention is implemented as follows:

[0007] In a first aspect, embodiments of the present invention provide a method for measuring the temperature of a rotating sample based on the length of a fluorescence arc, the method comprising:

[0008] The obtained nickel-based alloy was cut into blade shapes to obtain the alloy matrix;

[0009] A layer of fluorescent material was deposited on the alloy substrate using atmospheric plasma spraying technology;

[0010] A continuous laser is incident on the fluorescent material to excite fluorescence, and the fluorescence lifetime of the fluorescent material is determined by measuring the length of the fluorescence arc.

[0011] Based on the functional relationship between the fluorescence lifetime of the fluorescent material and temperature, the temperature of the fluorescent material, i.e., the sample temperature, is determined.

[0012] The relationship between fluorescence lifetime and temperature is expressed as follows: In the formula, ΔE is the activation energy, representing the sensitivity of fluorescence lifetime to temperature changes; k is the Boltzmann constant, which is 8.617 × 10⁻⁶.5 eV / K;R S R T These are constants related to the material.

[0013] In some embodiments, the fluorescent material includes, but is not limited to, YSZ:Eu.

[0014] In some embodiments, the step of incidenting a continuous laser beam onto the fluorescent material to excite fluorescence, and determining the fluorescence lifetime of the fluorescent material by measuring the fluorescence arc length, includes:

[0015] Assuming a wirelessly narrow pulse of light excitation Atoms are excited to their excited states. Atoms in the excited states will return to their ground states via either radiative or non-radiative transitions. Assume the decay rates of the two transitions are respectively... and Then the decay rate of the excited state can be expressed as: In the formula, Indicates the number of excited-state atoms at time t;

[0016] Based on this, the single-exponential decay equation for excited-state atoms is obtained, expressed as: In the formula, τ is the fluorescence lifetime, and the fluorescence intensity is proportional to the number of excited-state molecules that decay.

[0017] The single-exponential decay equation of the excited-state atom is rewritten as: In the formula, Indicates the fluorescence intensity at time 0;

[0018] Therefore, fluorescence lifetime is defined as the reciprocal of the total decay rate, that is, the formula for fluorescence lifetime is expressed as: .

[0019] The rotating sample temperature measurement method based on fluorescence arc length provided in this invention can detect the fluorescence lifetime of a material by measuring the length of the fluorescence arc. Since fluorescence lifetime has a functional relationship with temperature, temperature measurement is achieved by detecting changes in fluorescence lifetime, providing high-precision temperature data. Furthermore, the use of a high-speed rotating sample simulates application scenarios in production and daily life, further improving feasibility and overcoming the limitations of radiation thermometry. This provides an effective solution for temperature monitoring in high-speed rotating environments, which is of great significance for ensuring normal component operation, improving safety, and scientific research. On the other hand, this invention improves the accuracy of temperature measurement by spraying highly efficient fluorescent materials, overcoming the limitations of traditional temperature measurement techniques in high-speed rotating environments. Simultaneously, measuring the length of the fluorescence arc simplifies data acquisition and processing, providing the relationship between fluorescence intensity and temperature, facilitating temperature determination. Thirdly, the use of YSZ material to dope the fluorescent material also makes it suitable for high-temperature environments, ensuring the system's tolerance and stability at high temperatures. The fluorescence lifetime measurement using the lifetime decay method improves the accuracy and sensitivity of the system in high-temperature environments. Attached Figure Description

[0020] Figure 1 This is a schematic flowchart of a rotating sample temperature measurement method based on fluorescence arc length provided in an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the testing mechanism provided in the embodiments of the present invention;

[0022] Figure 3 This is a schematic diagram illustrating the definition of fluorescence lifetime provided in an embodiment of the present invention;

[0023] Figure 4 This is a graph showing the change in fluorescence lifetime with temperature, provided in an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the following description, references to "some embodiments" refer to a subset of all possible embodiments; however, it is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. Unless otherwise defined, all technical and scientific terms used in the embodiments of the invention have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of the invention pertain. The terminology used in the embodiments of the invention is for the purpose of describing the embodiments of the invention only and is not intended to limit the invention.

[0026] This invention provides a method for measuring the temperature of a rotating sample based on the length of a fluorescence arc. (See also...) Figure 1 , Figure 1 This is a schematic flowchart of the rotating sample temperature measurement method based on fluorescence arc length provided in an embodiment of the present invention, which will be combined with... Figure 1 The steps shown are explained.

[0027] Step S1: Cut the obtained nickel-based alloy into blade shapes to obtain the alloy matrix.

[0028] In some embodiments, when cutting the alloy substrate into blade shapes, care should be taken not to make too many or too few blades to ensure that when it rotates at high speed, the laser can hit the fluorescent material sprayed on the blade surface to excite it and generate fluorescence that can be captured by the camera. To be on the safe side, the alloy substrate can also be cut into a circle, so that the blades do not need to be cut. Then, a hole is drilled in the center of the circle to facilitate connection with the motor and gears.

[0029] In some embodiments, the alloy matrix refers to the matrix material used as the sample under test, which simulates the actual blade structure and provides an adhesion substrate for the fluorescent material.

[0030] In this invention, precision machining processes such as wire cutting and electrical discharge machining can be used to process nickel-based alloys into blade-shaped samples. The dimensions can be referenced from actual engine blades to simulate the geometry of real service components, making the temperature measurement results closer to actual operating conditions.

[0031] Step S2: An atmospheric plasma spraying technique is used to deposit a layer of fluorescent material on the alloy substrate.

[0032] In some embodiments, atmospheric plasma spraying is a thermal spraying process that uses a plasma arc to generate high temperatures (approximately 10,000-30,000°C) to melt powdered fluorescent materials and spray them at high speed onto the surface of an alloy substrate to form a uniform coating.

[0033] In some embodiments, the fluorescent material serves as a temperature-sensitive element, and its fluorescence lifetime is monotonic with temperature, thus being used for indirect temperature measurement.

[0034] Step S3: A continuous laser is incident on the fluorescent material to excite fluorescence, and the fluorescence lifetime of the fluorescent material is determined by measuring the length of the fluorescence arc.

[0035] In this invention, based on the photograph taken, the intensity is calculated using brightness. The intensity ratio of two points is found to be 1 / e. The angle between these two points is calculated. The rotation speed is known, and the time for one revolution is known. Therefore, the rotation time taken for the two points to rotate is calculated, which is the fluorescence lifetime.

[0036] In some embodiments, a continuous laser is used as the excitation source to continuously irradiate the fluorescent material to generate a stable fluorescence signal. The main principle of this measurement is to excite the sample with a laser, measure the decay of the fluorescence intensity after excitation, find the ratio of the intensities of two points in an image taken by a camera to be 1 / e, and calculate the angle between these two points. Based on the known rotation speed, the fluorescence lifetime of the sample can be obtained.

[0037] In practical applications, the fluorescence arc length and fluorescence lifetime vary depending on the material and temperature.

[0038] In some embodiments, an Eu-doped YSZ coating is sprayed onto the alloy substrate using APS (atmospheric plasma spraying technology). The fluorescent elements that can be used are not limited to Eu, but include other fluorescent elements. This coating has high-temperature stability and can be excited to produce fluorescence under continuous laser. Different fluorescent materials emit fluorescence at different wavelengths, and the excited fluorescence will dissipate at a certain rate.

[0039] In some embodiments, a continuous laser is incident on a fluorescent material to excite fluorescence. A time-correlated single-photon detector is used to measure the fluorescence lifetime. A photomultiplier tube with a high sampling frequency is used to collect the signal. The measurement system is less affected by light scattering or reflection, fluctuations in the intensity of the excitation light field, or uneven distribution of the coating. In particular, it exhibits higher temperature measurement accuracy and sensitivity in high-temperature environments. Compared with other measurement methods, the single-photon detector can detect light signals with extremely low intensity, which allows fluorescence lifetime measurement to be performed at extremely low photon count rates, thereby reducing the impact of environmental noise.

[0040] In some embodiments, the decay process of fluorescence intensity directly determines fluorescence lifetime and is a key intermediate parameter for temperature inversion. Fluorescence lifetime is a monotonic function of temperature. Because high temperatures increase the frequency of nonradiative transitions and intermolecular collisions, the probability of returning to the ground state via radiation is reduced. Different fluorescence lifetimes are obtained at different fluorescence arc lengths, and the temperature of the rotating sample is measured.

[0041] Step S4: Based on the functional relationship between the fluorescence lifetime of the fluorescent material and temperature, determine the temperature of the fluorescent material, i.e., the sample temperature;

[0042] The relationship between fluorescence lifetime and temperature is expressed as follows: In the formula, ΔE is the activation energy, representing the sensitivity of fluorescence lifetime to temperature changes; k is the Boltzmann constant, which is 8.617 × 10⁻⁶. -5 eV / K;R S R T These are constants related to the material.

[0043] The rotating sample temperature measurement method based on fluorescence arc length provided in this invention can detect the fluorescence lifetime of a material by measuring the change in fluorescence intensity through the measurement of the fluorescence arc length. Since fluorescence lifetime has a functional relationship with temperature, temperature measurement is achieved by detecting changes in fluorescence lifetime, providing high-precision temperature data. Furthermore, the use of a high-speed rotating sample simulates application scenarios in production and daily life, further improving feasibility and overcoming the limitations of radiation thermometry. This provides an effective solution for temperature monitoring in high-speed rotating environments, which is of great significance for ensuring normal component operation, improving safety, and scientific research. On the other hand, this invention improves the accuracy of temperature measurement by spraying highly efficient fluorescent materials, overcoming the limitations of traditional temperature measurement techniques in high-speed rotating environments. Simultaneously, measuring the length of the fluorescence arc simplifies data acquisition and processing, providing the relationship between fluorescence intensity and temperature, facilitating temperature determination. Thirdly, the use of YSZ material to dope the fluorescent material also makes it suitable for high-temperature environments, ensuring the system's tolerance and stability at high temperatures. The fluorescence lifetime measurement using the lifetime decay method improves the accuracy and sensitivity of the system in high-temperature environments.

[0044] In some preferred embodiments, the alloy center needs to be drilled to connect with gears and a motor, enabling it to achieve high-speed rotation.

[0045] In some preferred embodiments, the fluorescent material includes, but is not limited to, YSZ:Eu.

[0046] In some preferred embodiments, the step of incidenting a continuous laser beam onto the fluorescent material to excite fluorescence, and determining the fluorescence lifetime of the fluorescent material by measuring the length of the fluorescence arc, includes:

[0047] Assuming a wirelessly narrow pulse of light excitation Atoms are excited to their excited states. Atoms in the excited states will return to their ground states via either radiative or non-radiative transitions. Assume the decay rates of the two transitions are respectively... and Then the decay rate of the excited state can be expressed as: In the formula, Indicates the number of excited-state atoms at time t;

[0048] Based on this, the single-exponential decay equation for excited-state atoms is obtained, expressed as: In the formula, τ is the fluorescence lifetime, and the fluorescence intensity is proportional to the number of excited-state molecules that decay.

[0049] The single-exponential decay equation of the excited-state atom is rewritten as: In the formula, Indicates the fluorescence intensity at time 0;

[0050] Therefore, fluorescence lifetime is defined as the reciprocal of the total decay rate, that is, the formula for fluorescence lifetime is expressed as: .

[0051] This invention also discloses a method for determining the temperature of a rotating sample based on the length and rotation speed of a fluorescence arc. A device consisting of a continuous laser, a rotating sample, and a camera is constructed. The continuous laser beam is directed onto a high-speed rotating blade made of a fluorescent material sample. The rotation speed is fixed and known, generating fluorescence. When the fluorescence returns, some stray light is filtered out by a filter at the front of the camera, and the captured light is obtained. By measuring the length of the fluorescence arc, the fluorescence intensity can be obtained. Based on the relationship between fluorescence intensity and time, the fluorescence lifetime can be measured. Finally, based on the relationship between fluorescence lifetime and temperature, the temperature of the rotating sample can be determined. This method for determining the temperature of a rotating sample based on the length and rotation speed of a fluorescence arc, employing a time-correlated single-photon detector, improves measurement accuracy and precision. It is applicable to temperature measurement in high-speed rotating fields such as engine turbine blades and is of significant importance.

[0052] In addition, the present invention also provides a method for determining the temperature of a rotating sample based on the length and rotation speed of the fluorescence arc, comprising the following steps:

[0053] S1: Design and manufacture a set of blades: Take a piece of nickel-based alloy and cut it into blade shapes.

[0054] S2: A YSZ:Eu coating is deposited on the alloy substrate using APS (Atmospheric Plasma Spraying) technology.

[0055] S3: Fluorescent material deposited on an alloy substrate is excited by continuous laser to emit fluorescence.

[0056] S4: Allow the fluorescence to pass through the filter and return to the camera, where the camera takes a picture to obtain a photograph of the fluorescence arc length.

[0057] S5: The change in fluorescence intensity is obtained by measuring the length of the fluorescence arc. According to the definition of fluorescence lifetime, the time required for the fluorescence intensity of a molecule to drop to 1 / e of the maximum fluorescence intensity at excitation is the fluorescence lifetime τ of the material. , where τ is the fluorescence lifetime, θ is the angle between the two points, and ω is the blade rotation speed.

[0058] In this invention, a point with the strongest intensity is found, and another point with an intensity of 1 / e of the strongest intensity is found. The angle between these two points is calculated. Based on the known rotational speed, the time taken between these two points can be obtained, which is the fluorescence lifetime.

[0059] S6: Assuming an infinitely narrow pulse of light excitation An atom is excited to its excited state, and the excited atom will return to the ground state through radiation or non-radiation transition.

[0060] Assume the two decay transition rates are respectively and The decay rate of the excited state can then be expressed as: Formula 1: In the formula, n(t) represents the number of excited-state atoms at time t. From this, the single exponential decay equation for excited-state matter can be obtained: Formula 2: In the formula, τ represents the fluorescence lifetime, and the fluorescence intensity is proportional to the number of excited-state molecules that decay. Therefore, the above formula can be rewritten as: Formula 3: In the formula, The fluorescence intensity is at time 0. The fluorescence lifetime is defined as the reciprocal of the total decay rate: Formula 4: ;

[0061] That is, the time required for the fluorescence intensity to decay to 1 / e of the initial intensity is the fluorescence lifetime of the fluorescent substance under the measurement conditions.

[0062] S7: Temperature measurement is achieved based on the functional relationship between the lifetime of fluorescent materials and temperature. The formula for the relationship between the lifetime τ(T) of fluorescent materials and temperature T is: Formula 5: ;

[0063] Where ΔE is the activation energy, which determines the sensitivity of fluorescence lifetime to temperature changes; k is the Boltzmann constant, which is 8.617 × 10⁻⁶. -5 eV / K; RS and RT are material-related constants.

[0064] According to the appendix Figure 2 As can be seen, a pulsed laser emits laser light, which is filtered out by a filter to remove stray light, retaining only the laser of a specific wavelength. This laser light is then directed onto the sample for excitation. The sample is stored in a high-temperature furnace, where different temperatures can be selected for heating. The fluorescence emitted by the sample after excitation is captured by a lens through a filter, converted into photoelectric value by a PMT, and then converted into current by a resistance box before entering the oscilloscope.

[0065] According to the appendix Figure 3 It can be seen that the time required for the fluorescence emission intensity to drop to 1 / e of its initial intensity after optical pulse excitation is the fluorescence lifetime of the material.

[0066] According to the appendix Figure 4 It is known that as the temperature increases, the lattice vibration is enhanced, the number of phonons participating in absorption increases, which leads to a faster fluorescence quenching rate and a shorter fluorescence lifetime.

[0067] Therefore, through the above steps and methods, high-precision temperature measurement with a high signal-to-noise ratio is achieved under high temperature and high rotation speed conditions, effectively solving the limitations of traditional radiation thermometry under high background noise. The above specific implementation methods describe in detail the design principle and implementation method of the present invention, demonstrating the significant advantages of the present invention in temperature measurement under high-speed sample rotation.

[0068] This invention provides a high-precision, high-sensitivity, and high signal-to-noise ratio high-speed temperature measurement method by designing and utilizing the combination of rotating samples and fluorescent materials. It can effectively solve the problem that traditional radiation thermometry is difficult to measure under high background noise. This invention is of great significance for the normal operation of components, scientific research, and process equipment monitoring in high-speed and high-temperature environments.

[0069] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of the present invention are included within the scope of protection of the present invention.

[0070] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of the invention, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the invention. The sequence numbers of the above-described embodiments of the invention are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0071] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. In the several embodiments provided by this invention, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not performed.

[0072] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for measuring the temperature of a rotating sample based on the length of a fluorescence arc, characterized in that, The method includes: The obtained nickel-based alloy was cut into blade shapes to obtain the alloy matrix; A layer of fluorescent material was deposited on the alloy substrate using atmospheric plasma spraying technology; A continuous laser is incident on the fluorescent material to excite fluorescence, and the fluorescence lifetime of the fluorescent material is determined by measuring the length of the fluorescence arc. Based on the functional relationship between the fluorescence lifetime of the fluorescent material and temperature, the temperature of the fluorescent material, i.e., the sample temperature, is determined. The relationship between fluorescence lifetime and temperature is expressed as follows: In the formula, ΔE is the activation energy, representing the sensitivity of fluorescence lifetime to temperature changes; k is the Boltzmann constant, which is 8.617 × 10⁻⁶. -5 eV / K;R S R T These are constants related to the material.

2. The method according to claim 1, characterized in that, The fluorescent materials include, but are not limited to, YSZ:Eu.

3. The method according to claim 1, characterized in that, The step of incidenting a continuous laser beam onto the fluorescent material to excite fluorescence, and determining the fluorescence lifetime of the fluorescent material by measuring the length of the fluorescence arc, includes: Assuming a wirelessly narrow pulse of light excitation Atoms are excited to their excited states. Atoms in the excited states will return to the ground state through either radiative or non-radiative transitions. Assume that the two decay transition rates are respectively... and Then the decay rate of the excited state can be expressed as: In the formula, Indicates the number of excited-state atoms at time t; Based on this, the single-exponential decay equation for excited-state atoms is obtained, expressed as: In the formula, τ is the fluorescence lifetime, and the fluorescence intensity is proportional to the number of excited-state molecules that decay. The single-exponential decay equation of the excited-state atom is rewritten as: In the formula, represents the fluorescence intensity at time 0; Therefore, fluorescence lifetime is defined as the reciprocal of the total decay rate, that is, the formula for fluorescence lifetime is expressed as: .

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