CN-116337243-B - Infrared temperature measurement correction method, device and system for three-dimensional curved surface

CN116337243BCN 116337243 BCN116337243 BCN 116337243BCN-116337243-B

Abstract

The invention discloses an infrared temperature measurement correction method, device and system for a three-dimensional curved surface, wherein the infrared temperature measurement correction method comprises the steps of dividing the surface of a blade into at least two emissivity measurement areas according to the surface types of the measured blade, obtaining the emissivity distribution of each emissivity measurement area of the surface of the blade at different temperatures, obtaining bidirectional reflection distribution functions of different surface types according to projection energy of an infrared light source at different incidence angles and reflection energy received by an infrared camera at different detection angles, and obtaining corrected measured temperatures according to the emissivity distribution of each emissivity measurement area of the surface of the blade at different temperatures and the bidirectional reflection distribution functions of different surface types. The invention has wide application range and high correction precision, can correct the infrared temperature measurement of the curved surface of the turbine blade of the aeroengine and the like in a complex environment, and can realize non-contact, multidimensional and online measurement of the curved surface.

Inventors

ZHANG BIAO
ZHANG TIANYU
WU JIAWEN
LI JIAN
XU CHUANLONG

Assignees

东南大学

Dates

Publication Date: 20260505
Application Date: 20230306

Claims (9)

1. An infrared temperature measurement correction method for a three-dimensional curved surface is characterized by comprising the following steps: Dividing the surface of the blade into at least two emissivity measurement areas according to the type of the surface of the blade to be measured; Acquiring emissivity distribution of each emissivity measurement area on the surface of the blade at different temperatures; obtaining bidirectional reflection distribution functions of different surface types according to projection energy of an infrared light source under different incidence angles and reflection energy received by an infrared camera under different detection angles; obtaining corrected measurement temperature according to the obtained emissivity distribution of each emissivity measurement area of the surface of the blade at different temperatures and the bidirectional reflection distribution functions of different surface types; According to the obtained emissivity distribution of each emissivity measuring area of the surface of the blade at different temperatures and the bidirectional reflection distribution functions of different surface types, the corrected measuring temperature is obtained as follows: In the formula, Is the space position Measuring the temperature after correction; a factory calibration curve for the infrared camera; Is wavelength; the integrated transmittance of the infrared measurement window; Is the influence coefficient of high-temperature fuel gas; the detection angle of the infrared camera; to measure the area in the emissivity The emissivity value at the internal temperature, 1-Q, Q is the number of divided emissivity measurement areas; 、 The upper and lower limits of the wavelength response of the infrared camera are respectively; black body spectral radiant force generated for real temperature; Blackbody spectrum radiation force generated for the high temperature background blade; Different spatial positions on the high temperature background blade; for different spatial positions on high temperature background blades For measuring blade space position Is used for the angular coefficient of (a), The micro-element area in the visible area of the position to be measured; A visual area for the position to be measured; Is a bi-directional reflection distribution function of a curved surface; representing an energy incident direction vector; the energy emission direction vector is represented.
2. The method for infrared thermometry correction of a three-dimensional curved surface according to claim 1, wherein acquiring emissivity profiles at different temperatures for each region of the blade surface comprises: Measuring the emissivity value of any one or more space positions in each emissivity measurement area at room temperature as the emissivity value of the corresponding emissivity measurement area, and when a plurality of space positions are adopted, taking the average value of the emissivity values of the plurality of positions as the emissivity value of the corresponding emissivity measurement area; Then the surface of the blade is heated to obtain each emissivity measuring area At different temperatures Emissivity value at 。
3. The method for infrared thermometry correction of a three-dimensional curved surface according to claim 2, wherein the calculated relation of emissivity is expressed as: The calculated relation of emissivity of any spatial position is expressed as: In the formula, For the measured temperature of the infrared camera, c 1 =3.7418×10 -6 W.m is the first Planck coefficient and c 2 =1.4388×10 -6 m.K is the second Planck coefficient.
4. The method for infrared thermometry correction of a three-dimensional curved surface according to claim 3, wherein in the step of dividing the surface of the blade into at least two emissivity measurement areas according to the type of surface of the blade being measured, the type of surface of the blade is divided according to the degree of grinding and corrosion.
5. The method of infrared thermometry modification of a three-dimensional curved surface according to claim 4, wherein the blade surface is classified into at least three surface types according to the degree of grinding and erosion, including a surface type free of wear and erosion, a surface type heavy in wear and erosion, and at least one surface type between the surface type free of wear and erosion and the surface type heavy in wear and erosion.
6. The method for infrared thermometry correction of a three-dimensional curved surface according to claim 2, characterized by different spatial locations on a high temperature background blade Visible area for measuring blade Angle coefficient between infinitesimal According to the set bending blade spacing And a surface shape function And (3) performing calculation: In the formula, As the angular coefficient between the visible area primitives, Is a spatial location.
7. The method for infrared thermometry correction of a three-dimensional curved surface according to claim 2, wherein the gas composition according to the environment in which the curved surface is set Concentration of Pressure and force Temperature (temperature) Calculating to obtain the influence coefficient of high-temperature fuel gas Carrying the temperature correction model to carry out temperature correction, comprising the following steps: According to the line-by-line method, HITEMP database and gas composition Concentration of Pressure and force Temperature (temperature) Calculating the emission line intensity of a gas ; Then the average spectrum absorption coefficient of the infrared camera detection wave band is calculated by using the accumulated K distribution method ; Calculating the influence coefficient of high-temperature fuel gas according to the radiation transfer equation, the fuel gas temperature, the fuel gas area size and the absorption coefficient 。
8. An infrared temperature measurement correction device for a three-dimensional curved surface, comprising: The temperature acquisition module is used for acquiring temperature data of the three-dimensional curved surface at high temperature; The processing module corrects the temperature data acquired by the temperature acquisition module according to the infrared temperature measurement correction method of any one of claims 1-7.
9. An infrared thermometry correction system for a three-dimensional curved surface in a complex background, comprising: A curved blade for use as an object to be measured and providing background radiation; The fixed bottom plate is used for fixing the three-dimensional bending blades and changing the spacing between the three-dimensional bending blades; The ceramic heating plate is used for heating the surface of the three-dimensional curved blade; The variable-voltage power supply is used for supplying power to the ceramic heating plate and controlling the temperature of the ceramic heating plate through the power supply voltage; the K-type thermocouple is used for measuring the actual temperature of the bent blade and the high-temperature fuel gas and providing reference data for emissivity measurement and infrared correction results; the temperature patrol instrument is used for recording the temperature obtained by the measurement of the thermocouple; the infrared light source is used for emitting infrared radiation energy and providing a light source for measuring the bidirectional reflection distribution of the surface; the infrared camera is used for measuring infrared radiation energy and temperature of the three-dimensional curved surface at high temperature and obtaining original temperature data needing to be corrected; the swirl premix burner is used for generating high-temperature fuel gas and simulating the environment of the high-temperature fuel gas; the smoke analyzer is used for measuring the components and the concentration of the high-temperature fuel gas; The pressure sensor is used for measuring the pressure of the high-temperature fuel gas; And The data processing unit corrects the original temperature data obtained by the infrared camera according to the infrared temperature measurement correction method of any one of claims 1 to 7.

Description

Infrared temperature measurement correction method, device and system for three-dimensional curved surface Technical Field The invention belongs to the technical field of aviation temperature measurement, and further relates to the technical field of infrared radiation temperature measurement, in particular to an infrared temperature measurement correction method and system for a three-dimensional curved surface under a complex background. Background In order to increase the specific impulse of an aeroengine, the most direct and efficient approach is to increase the turbine rotor inlet temperature. However, as inlet temperature increases, resulting in long-term operation of the turbine blade under greater thermal loading conditions, the failure rate of the turbine blade is increased. The working temperature of the turbine blade is accurately measured, and the method has great significance for prolonging the service life of the turbine blade and improving the safe operation of an aeroengine. At present, the main temperature measurement mode is divided into contact temperature measurement and non-contact temperature measurement. The contact type temperature measurement comprises a film thermocouple temperature measurement method, a temperature indicating paint temperature measurement method, a crystal temperature measurement method and the like, and the non-contact type temperature measurement comprises a fluorescence temperature measurement method and a radiation temperature measurement method. In the working state of the turbine blade, the thin film thermocouple temperature measuring method has the problem that wires are difficult to place, and the temperature indicating paint temperature measuring method and the crystal temperature measuring method cannot reflect the dynamic change of temperature. In the non-contact temperature measurement method, the fluorescence temperature measurement method has the advantages of wide temperature measurement range and high temperature measurement precision, but the difficulty of response signal acquisition is high, and the signal is very easy to fail along with the rise of the temperature. The infrared radiation temperature measurement method has a great deal of application in the temperature measurement process of the current domestic and foreign aeroengines, has the advantages of no damage to the surface of the measured object compared with the traditional temperature measurement method, short response time, capability of measuring continuously-changed temperature values in real time, wide temperature measurement range and high sensitivity. Radiation thermometry has a greater advantage in the operating environment of turbine blades. Radiation temperature measurement errors are affected by the emissivity of the blade surface, which is related to the blade surface characteristics, such as erosion of the coating, oxidation, etc., and all factors change the emissivity of the blade surface. Meanwhile, the surface emissivity of the blade is also related to factors such as temperature, wavelength, observation angle and surface condition, so that it is difficult to accurately measure the surface emissivity of the blade. When the angle between the observation line and the normal line of the surface of the measured piece is 0-60 degrees, the emissivity is basically kept unchanged. Besides the influence of the emissivity of the blade on the temperature measurement result, the radiation of the high-temperature environment around the blade can also influence the temperature measurement result, the reflection attribute of a certain point under the illumination condition is related to the position, the incidence direction, the emergent direction and the wavelength of the incident point, and the acquisition of the bidirectional reflection distribution function value has very important significance for effective radiation measurement. In the calculation of the radiation heat transfer, the angular coefficient between any two radiation heat exchange surface elements is also required to be calculated. Disclosure of Invention The invention aims to provide an infrared temperature measurement correction method, device and system for a three-dimensional curved surface. In order to solve the problems, the invention adopts the following technical scheme: the invention firstly provides an infrared temperature measurement correction method of a three-dimensional curved surface, which comprises the following steps: Dividing the surface of the blade into at least two emissivity measurement areas according to the type of the surface of the blade to be measured; Acquiring emissivity distribution of each emissivity measurement area on the surface of the blade at different temperatures; obtaining bidirectional reflection distribution functions of different surface types according to projection energy of an infrared light source under different incidence angles and reflection energy received by an infr