Strain and temperature synchronous measurement comprehensive probe system

Abstract

The invention relates to the technical field of acquisition and measurement of key parameters of engine blades, and discloses a strain and temperature synchronous measurement comprehensive probe system which comprises a front-end probe system, a temperature acquisition module, an image acquisition module and a synchronous phase lock trigger device. The synchronous phase locking trigger device is used for transmitting the synchronous pulse to the image acquisition module and the temperature acquisition module to realize a synchronous phase locking function, so that a plurality of detection modules can be triggered at the same time, a delay error can be minimized, and the temperature acquisition module and the image acquisition module can operate simultaneously; temperature and image information at the same moment are collected, synchronous measurement of surface temperature and strain of an object to be measured is achieved, and technical support is provided for synchronous measurement of strain and temperature of engine turbine blades.

Description

Technical Field

[0001] The invention relates to the technical field of key parameter acquisition and measurement of engine blades, and discloses a strain-temperature synchronous measurement integrated probe system. Background Art

[0002] The turbine blades of aircraft engines are in a multi-field coupled extreme environment of high temperature and high pressure for a long time. They are the core of the engine and one of the most prone to failures. For example, the WS-15 engine has a combustion chamber outlet temperature close to 1700°C, a turbine blade speed of 15,000 rpm, and a surface temperature of over 1000°C. At the same time, they also have to withstand aerodynamic loads, vibration loads, centrifugal loads, thermal shock loads, etc., with an average load of about 300 to 400 MPa. At present, the turbine blades of aircraft engines face the problem of difficult detection, especially how to solve the problem of measuring temperature field and strain field.

[0003] For structures such as engine turbine blades, the strain field and temperature field are not independent relationships, but coupled superpositions under the multiple influences of temperature and various loads. Therefore, they need to be considered comprehensively in order to obtain a more accurate structural response. Thermal-strain coupling is first caused by the uneven distribution of the structural temperature field, which causes thermal strain and thermal deformation of the structure. The thermal strain and thermal deformation will affect the morphology of the structure and then cause uneven heating of the structure, resulting in temperature redistribution. In this way, they interact with each other. A typical example is that the surface morphology of a specific structure will change under the influence of the external radiation boundary. When the surface morphology changes, it will affect the radiation conditions of the structure on the boundary. Therefore, the two are related, and one aspect cannot be studied independently, and the whole needs to be analyzed.

[0004] As for the detection means, the current traditional single-point, single-parameter or peak measurement cannot describe the steady-state and transient distribution of blade strain and temperature field during service and the coupling effect between the two. The non-contact testing technology based on optical principles overcomes the shortcomings of contact testing such as interfering with the flow field and damaging the tested parts, and has high research value. The commonly used method for strain measurement is the digital image correlation DIC method, which is a non-contact, full-field morphology deformation optical measurement method based on digital image processing and computer vision. By comparing the digital images of the sample before and after deformation, the relative position difference information between the black and white pixels between the prefabricated speckles is identified, and the required strain information is obtained through relevant calculations. The advantage of DIC lies in the visualization of the local surface strain of the object and the customizable strain representation at different times during the loading process, which can effectively measure the deformation evolution of the turbine blade surface.

[0005] Radiation temperature measurement is a non-contact temperature measurement method based on Planck radiation theory. Since the radiation temperature measurement principle was proposed, radiation temperature measurement has developed into a relatively mature temperature measurement method and is widely used in temperature measurement in various fields. Radiation temperature measurement technology measures the thermal radiation of the target surface through a radiation pyrometer and then calculates its temperature. It does not affect the temperature field distribution of the blade and is not limited by the number of measurement points. It is suitable for temperature measurement of high-speed moving targets and has the characteristics of high resolution, high sensitivity, response time period, and wide temperature measurement range. In addition, by selecting a suitable characteristic wavelength for temperature measurement and designing an optical path system based on the characteristics of the grating reflection spectrometer and the dichroic spectrometer combined spectrometer structure on the spectral transmission efficiency of different bands, non-contact large-span radiation temperature measurement can be performed on engine turbine blades.

[0006] For the transmission of the optical path, the optical fiber transmission bundle is very suitable for the high temperature, high vibration and narrow harsh working environment of aircraft engine turbine blades due to its small mass, high temperature resistance, arbitrary bending, effective vibration resistance and good stability. It also makes the structure of the entire optical system more flexible and reasonable, and can effectively solve the problem of difficult probe assembly and testing.

[0007] However, some existing non-contact measurement devices cannot meet the requirements of synchronous strain and temperature measurement, or cannot work properly in extreme environments such as those inside the engine, making it difficult to carry out measurement work. Therefore, the measurement of engine turbine blades urgently needs to design a more stable and accurate measurement system and measurement solution. Summary of the invention

[0008] The purpose of the present invention is to provide a strain-temperature synchronous measurement integrated probe system, which can minimize the delay error to ensure that the temperature acquisition module and the image acquisition module can operate simultaneously, collect temperature and image information at the same time, and realize the synchronous measurement of the surface temperature and strain of the object to be measured.

[0009] In order to achieve the above technical effects, the technical solution adopted by the present invention is:

[0010] A strain-temperature synchronous measurement integrated probe system, comprising:

[0011] Front-end probe system, used to extend into the engine for detection and capture temperature and strain information on the blade surface;

[0012] A temperature acquisition module, used for transmitting and processing the temperature information of the front-end probe system;

[0013] An image acquisition module, used for transmitting and processing image information of the front-end probe system;

[0014] The synchronous phase-locked trigger device is used to synchronously trigger the temperature acquisition module and the image acquisition module to acquire the temperature and image information at the same time.

[0015] Furthermore, the synchronous phase-locked trigger device comprises:

[0016] A tone wheel structure, the tone wheel structure is coaxially arranged on the engine turbine shaft, and a protrusion is arranged on the tone wheel structure;

[0017] An electromagnetic sensor, the electromagnetic sensor comprising a magnet and an induction coil, the magnet being fixedly mounted on the aircraft engine at a position close to the protrusion; the induction coil being used to sense changes in magnetic flux in the magnetic circuit of the magnet and convert the changes in magnetic flux into electrical signals;

[0018] The synchronous reference device is used to receive the electrical signal transmitted by the induction coil and convert the electrical signal into a TTL level signal. The TTL level signal is used to trigger the synchronous pulse so that the temperature acquisition module and the image acquisition module trigger acquisition at the same time.

[0019] Furthermore, the front-end probe system comprises:

[0020] A probe lens barrel, which is used to collect temperature spectrum and strain spectrum information of the surface of the object to be measured, and integrate and transmit the collected temperature spectrum and strain spectrum;

[0021] A semi-transparent and semi-reflective mirror, which is used to receive the temperature spectrum and strain spectrum information integrated and transmitted by the probe barrel, and separate the temperature spectrum information of the first band and import it into the temperature acquisition module;

[0022] A beam splitter is used to receive the remaining spectral information passing through the semi-transparent and semi-reflective mirror, separate the second-band spectral information and the third-band spectral information, and import the second-band spectral information and the third-band spectral information into the image acquisition module respectively.

[0023] Furthermore, the probe lens barrel includes a shell, which is fixed to the aircraft engine stator structure through a mounting flange; a first reflector, a second reflector, and a front end lens group structure are sequentially arranged in the barrel along the spectral information transmission path.

[0024] Furthermore, the temperature acquisition module includes a temperature photoelectric detector, which receives the first band spectral information separated by the semi-transparent and semi-reflective mirror through a near-infrared optical fiber. The temperature photoelectric detector is used to convert the first band spectral information into an electrical signal and amplify it. A high-frequency data acquisition system is used to collect and process the amplified electrical signal to obtain the surface temperature information of the object to be measured.

[0025] Furthermore, in the temperature photoelectric detector, after limiting the first band spectral information transmitted by the near-infrared optical fiber through an aperture, it is collimated into parallel light through a collimator, and then incident on a first two-way beam splitter placed at an angle of 45° to obtain a reflection spectrum I and a transmission spectrum I. The reflection spectrum I is focused by a first focusing lens and then passed through a first filter to obtain a temperature measurement working spectrum I with a working wavelength of about 1050nm, and then incident on the sensitive surface of the first photoelectric detector to obtain a corresponding electrical signal and enter the first receiving circuit; the transmission spectrum I passes through a second two-way beam splitter placed at an angle of 45° to obtain a reflection spectrum II and a transmission spectrum II, and the reflection spectrum II After being focused by the second focusing lens, a temperature measurement working spectrum II with a working wavelength near 1650nm is obtained through the second filter, and then it is incident on the sensitive surface of the second photodetector to obtain a corresponding electrical signal and enter the second receiving circuit; the transmission spectrum II is focused by the third focusing lens and then passed through the third filter to obtain a temperature measurement working spectrum III with a working wavelength near 2200nm, and then it is incident on the sensitive surface of the third photodetector to obtain a corresponding electrical signal and enter the third receiving circuit; the three electrical signals converted from the temperature measurement working spectrum I, the temperature measurement working spectrum II, and the temperature measurement working spectrum III are respectively amplified by operational amplifier circuits.

[0026] Furthermore, the image acquisition system comprises:

[0027] The first optical fiber image transmission bundle, the first rear lens group and the first high-speed camera are used to transmit the second band spectrum information separated by the beam splitter through the first optical fiber image transmission bundle and the first rear lens group to the first high-speed camera for signal processing and imaging.

[0028] The second optical fiber image transmission bundle, the second rear lens group and the second high-speed camera are used to transmit the third band spectrum information separated by the beam splitter through the second optical fiber image transmission bundle and the second rear lens group to the second high-speed camera for signal processing and imaging.

[0029] Furthermore, it also includes a stroboscopic light source module, which is used to provide instantaneous illumination for the surface of the object to be measured through the pulsed laser of the stroboscopic light source.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention utilizes a synchronous phase-locked trigger device to transmit synchronous pulses to an image acquisition module and a temperature acquisition module to realize the function of synchronous phase-locking, thereby ensuring that multiple detection modules can be triggered at the same time, and minimizing the delay error, thereby ensuring that the temperature acquisition module and the image acquisition module can operate simultaneously, collecting temperature and image information at the same time, and realizing synchronous measurement of the surface temperature and strain of the object to be measured, thereby providing technical support for the synchronous measurement of the strain and temperature of the engine turbine blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the structure of the integrated probe system for synchronous measurement of strain and temperature in Example 1 or 2;

[0032] Figure 2 Schematic diagram of the structure of the overall experimental device in Example 1 or 2

[0033] Figure 3 is a schematic structural diagram of the liquid fuel supply subsystem in Example 2;

[0034] Among them, 1. the surface of the object to be measured; 2. the first reflector; 3. the second reflector; 4. the probe lens barrel; 5. the front end lens group structure; 6. the mounting flange; 7. the semi-transparent and semi-reflective mirror; 8. the near-infrared optical fiber; 9. the temperature photoelectric detector; 10. the beam splitter; 11. the first optical fiber image bundle; 12. the first rear lens group; 13. the first high-speed camera; 14. the second optical fiber image bundle; 15. the second rear lens group; 16. the second high-speed camera; 901. the aperture; 902. the collimator; 903. the first two-way beam splitter; 904. the first focusing lens; 905. the first filter; 906. A photodetector; 907, a first receiving circuit; 908, a second dichroic mirror; 909, a second focusing lens; 910, a second filter; 911, a second photodetector; 912, a second receiving circuit; 913, a third focusing lens; 914, a third filter; 915, a third photodetector; 916, a third receiving circuit; 917, an operational amplifier circuit; 918, a high-frequency data acquisition and processing system; 17, a tone wheel structure; 18, a magnet; 19, an induction coil; 20, a ferromagnetic core; 21, a synchronization reference device; 22, a synchronization pulse; 23, a stroboscopic light source module. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the embodiments and drawings. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0036] Example 1

[0037] See also Figure 1 and Figure 2 , a strain temperature synchronous measurement integrated probe system, comprising:

[0038] Front-end probe system, used to extend into the engine for detection and capture temperature and strain information on the blade surface;

[0039] A temperature acquisition module, used for transmitting and processing the temperature information of the front-end probe system;

[0040] An image acquisition module, used for transmitting and processing image information of the front-end probe system;

[0041] The synchronous phase-locked trigger device is used to synchronously trigger the temperature acquisition module and the image acquisition module to acquire the temperature and image information at the same time.

[0042] In this embodiment, a synchronous phase-locked trigger device is used to transmit synchronous pulses to the image acquisition module and the temperature acquisition module to realize the synchronous phase-locked function, ensuring that multiple detection modules can be triggered at the same time, minimizing the delay error, ensuring that the temperature acquisition module and the image acquisition module can operate simultaneously, and collecting the temperature and image information at the same time, thereby realizing the synchronous measurement of the temperature and strain of the surface 1 of the object to be measured.

[0043] Example 2

[0044] The embodiment of the present invention provides a strain-temperature synchronous measurement integrated probe system based on an optical fiber bundle, including a front-end probe system, a temperature acquisition module, an image acquisition module and a synchronous phase-locked trigger device. The front-end probe system is used to extend into the interior of the engine for detection and capture the temperature and strain information on the blade surface; the temperature acquisition module is used to transmit and process the temperature information of the front-end probe system; the image acquisition module is used to transmit and process the image information of the front-end probe system; and it also includes a stroboscopic light source module 23, which is used to provide instantaneous illumination for the surface 1 of the object to be measured through the pulsed laser of the stroboscopic light source, so as to facilitate clear and high-precision image capture of the image acquisition module. The synchronous phase-locked trigger device is used to synchronously trigger the temperature acquisition module, the image acquisition module and the stroboscopic light source module 23 to collect temperature and image information at the same time.

[0045] The front-end probe system includes an external probe lens barrel 4 and a mounting flange 6, and the probe lens barrel 4 is internally mounted with a first reflector 2, a second reflector 3, a front-end lens group structure 5, a semi-transparent mirror 7 and a beam splitter 10. The probe lens barrel 4 and the mounting flange 6 are made of high-temperature alloy, and the outer surface of the probe lens barrel 4 is plated with a ceramic-based thermal insulation coating; the mounting flange 6 is used for connection and sealing between the engine and the probe system; the temperature and strain spectral information of the surface 1 of the object to be measured is reflected, transmitted, integrated and processed in turn through the first reflector 2, the second reflector 3 and the front-end lens group structure 5, and after passing through the semi-transparent mirror 7, the temperature spectral information of the near-infrared band (the first band spectral information) is separated and extracted and introduced into the temperature acquisition module, and the remaining spectral information enters the beam splitter 10 through the semi-transparent mirror 7, and the blue light band (the second band spectral information) and the green light band (the third band spectral information) are separated again by the beam splitter 10, and enter the image acquisition module respectively.

[0046] The image acquisition system in this embodiment includes:

[0047] First fiber optic imaging bundle 11, first rear lens group 12 and first high-speed camera 13. The blue light spectrum information separated by the beam splitter 10 enters the first high-speed camera 13 through the first fiber optic imaging bundle 11 and the first rear lens group 12 for signal processing and imaging.

[0048] Second fiber optic imaging bundle 14, second rear lens group 15 and second high-speed camera 16. The green light spectrum information separated by the beam splitter 10 enters the second high-speed camera 16 through the second fiber optic imaging bundle 14 and the second rear lens group 15 for signal processing and imaging.

[0049] Figure 2 The structure shown is a temperature acquisition module, which adopts a three-channel spectrum acquisition scheme to determine the radiation emitted by different temperature intervals by collecting near-infrared spectra of different bands, thereby realizing temperature measurement over a wide range. The near-infrared band spectrum information is transmitted to the temperature acquisition module through the near-infrared optical fiber 8, and the near-infrared band thermal radiation energy is split by a spectroscopic scheme to obtain three different wavelengths of spectrum energy, and the spectrum information is converted into an electrical signal by a temperature photoelectric detector, and then the electrical signal is amplified by operation, and the electrical signal is collected and processed by a high-frequency data acquisition system to obtain temperature information.

[0050] Specifically, after the near-infrared band spectral information transmitted by the near-infrared optical fiber 8 is limited by the aperture 901, it is collimated into parallel light by the collimator 902, and then incident on the first two-way beam splitter 903 placed at an angle of 45° to obtain a reflection spectrum I and a transmission spectrum I. The reflection spectrum I is focused by the first focusing lens 904 and then passes through the first filter 905 to obtain a temperature measurement working spectrum I with a working wavelength of about 1050nm, and then is incident on the sensitive surface of the first photodetector 906 to obtain a corresponding electrical signal and enter the first receiving circuit 907; the transmission spectrum I passes through the second two-way beam splitter 908 placed at an angle of 45° to obtain a reflection spectrum II and a transmission spectrum II, and the reflection spectrum II is focused by the second focusing lens 909 and then passes through the second filter 910 to obtain a working wavelength The transmission spectrum II is focused by the third focusing lens 913 and then passes through the third filter 914 to obtain the temperature measurement working spectrum III with a working wavelength of about 2200nm, and then is incident on the sensitive surface of the third photodetector 915 to obtain the corresponding electrical signal and enter the third receiving circuit 916; the temperature measurement working spectrum I, the temperature measurement working spectrum II and the temperature measurement working spectrum III are respectively processed by the operational amplifier circuit for operational amplification of the three electrical signals, and finally the electrical signal transmitted by the operational amplifier circuit 917 is collected and processed by the high-frequency data acquisition and processing system 918, so as to visualize and analyze the temperature data.

[0051] Figure 3 The structure shown is a synchronous phase-locked trigger device, which includes a trigger end and a receiving end. The trigger end is a sound wheel structure 17 installed on the engine turbine shaft. The receiving end is equipped with a magnetoelectric sensor for sensing and receiving the rotation signal of the sound wheel structure 17. The magnetoelectric sensor is composed of a permanent magnet 18, an induction coil 19 and a ferromagnetic core 20. The sound wheel structure 17 is installed on the turbine rotor and rotates with the shaft. Every time the turbine rotor rotates one circle, the protrusion of the sound wheel structure 17 will cut the magnetic field, thereby causing the magnetic flux in the magnetic circuit composed of the permanent magnet 18 of the magnetoelectric sensor at the receiving end to change, and generating an induced electromotive force in the induction coil 19, which is converted into an electrical signal and input into the synchronous reference device 21. The phase-locked system provides a TTL level with a high time resolution, and the trigger synchronization pulse 22 is provided to the temperature photoelectric detector 9, the first high-speed camera 13, the second high-speed camera 16 and the stroboscopic light source module 23, so that multiple detection systems can be triggered and collected at the same time.

[0052] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A strain-temperature synchronous measurement integrated probe system, characterized in that: include: Front-end probe system, used to extend into the engine for detection and capture temperature and strain information on the blade surface; A temperature acquisition module, used for transmitting and processing the temperature information of the front-end probe system; An image acquisition module, used for transmitting and processing image information of the front-end probe system; The synchronous phase-locked trigger device is used to synchronously trigger the temperature acquisition module and the image acquisition module to acquire the temperature and image information at the same time.

2. The strain-temperature synchronous measurement integrated probe system according to claim 1 is characterized in that: The synchronous phase-locked trigger device comprises: A tone wheel structure, the tone wheel structure is coaxially arranged on the engine turbine shaft, and a protrusion is arranged on the tone wheel structure; An electromagnetic sensor, the electromagnetic sensor comprising a magnet and an induction coil, the magnet being fixedly mounted on the aircraft engine at a position close to the protrusion; the induction coil being used to sense changes in magnetic flux in the magnetic circuit of the magnet and convert the changes in magnetic flux into electrical signals; The synchronous reference device is used to receive the electrical signal transmitted by the induction coil and convert the electrical signal into a TTL level signal. The TTL level signal is used to trigger the synchronous pulse so that the temperature acquisition module and the image acquisition module trigger acquisition at the same time.

3. The strain-temperature synchronous measurement integrated probe system according to claim 1 is characterized in that: The front-end probe system comprises: A probe lens barrel, which is used to collect temperature spectrum and strain spectrum information of the surface of the object to be measured, and integrate and transmit the collected temperature spectrum and strain spectrum; A semi-transparent and semi-reflective mirror, which is used to receive the temperature spectrum and strain spectrum information integrated and transmitted by the probe barrel, and separate the temperature spectrum information of the first band and import it into the temperature acquisition module; A beam splitter is used to receive the remaining spectral information passing through the semi-transparent and semi-reflective mirror, separate the second-band spectral information and the third-band spectral information, and import the second-band spectral information and the third-band spectral information into the image acquisition module respectively.

4. The strain-temperature synchronous measurement integrated probe system according to claim 3 is characterized in that: The probe lens barrel comprises a shell, which is fixed on the aircraft engine stator structure through a mounting flange; a first reflector, a second reflector, and a front mirror group structure are sequentially arranged in the barrel along the spectral information transmission path.

5. The strain-temperature synchronous measurement integrated probe system according to claim 3 is characterized in that: The temperature acquisition module includes a temperature photoelectric detector, which receives the first band spectral information separated by the semi-transparent and semi-reflective mirror through a near-infrared optical fiber. The temperature photoelectric detector is used to convert the first band spectral information into an electrical signal and amplify it. A high-frequency data acquisition system is used to collect and process the amplified electrical signal to obtain the surface temperature information of the object to be measured.

6. The strain-temperature synchronous measurement integrated probe system according to claim 5 is characterized in that: In the temperature photoelectric detector, after limiting the first band spectral information transmitted by the near-infrared optical fiber through an aperture, it is collimated into parallel light through a collimator, and then incident on a first two-way beam splitter placed at an angle of 45° to obtain a reflection spectrum I and a transmission spectrum I. The reflection spectrum I is focused by a first focusing lens and then passes through a first filter to obtain a temperature measurement working spectrum I with a working wavelength of about 1050nm, and then is incident on the sensitive surface of the first photodetector to obtain a corresponding electrical signal and enter the first receiving circuit; the transmission spectrum I passes through a second two-way beam splitter placed at an angle of 45° to obtain a reflection spectrum II and a transmission spectrum II, and the reflection spectrum II passes through the first two-way beam splitter placed at an angle of 45° to obtain a reflection spectrum II and a transmission spectrum II. After being focused by the second focusing lens, a temperature measurement working spectrum II with a working wavelength near 1650nm is obtained through the second filter, and then it is incident on the sensitive surface of the second photodetector to obtain the corresponding electrical signal and enter the second receiving circuit; the transmission spectrum II is focused by the third focusing lens and then passed through the third filter to obtain a temperature measurement working spectrum III with a working wavelength near 2200nm, and then it is incident on the sensitive surface of the third photodetector to obtain the corresponding electrical signal and enter the third receiving circuit; the three electrical signals converted from the temperature measurement working spectrum I, the temperature measurement working spectrum II, and the temperature measurement working spectrum III are respectively amplified by operational amplifier circuits.

7. The strain-temperature synchronous measurement integrated probe system according to claim 3 is characterized in that: The image acquisition system comprises: The first optical fiber image transmission bundle, the first rear lens group and the first high-speed camera are used to transmit the second band spectrum information separated by the beam splitter through the first optical fiber image transmission bundle and the first rear lens group to the first high-speed camera for signal processing and imaging. The second optical fiber image transmission bundle, the second rear lens group and the second high-speed camera are used to transmit the third band spectrum information separated by the beam splitter through the second optical fiber image transmission bundle and the second rear lens group to the second high-speed camera for signal processing and imaging.

8. The strain-temperature synchronous measurement integrated probe system according to claim 7 is characterized in that: It also includes a stroboscopic light source module, which is used to provide instantaneous illumination for the surface of the object to be measured through the pulsed laser of the stroboscopic light source.

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