A method for measuring the surface temperature of a turbine blade with a thermal barrier coating using a crystal

Abstract

The present application provides a method for measuring the surface wall temperature of a turbine blade with a thermal barrier coating by using a crystal, which belongs to the technical field of engine temperature measurement, and comprises: opening a crystal hole on the outer wall surface of the turbine blade; burying a crystal in the crystal hole and encapsulating it with a high-temperature adhesive; cleaning the position on the surface of the turbine blade where the thermal barrier coating is to be sprayed; spraying a bottom layer and a surface layer on the surface of the turbine blade in sequence, wherein, for an APS coating, a hole is opened first, the crystal is buried, and then the coating is sprayed; for an EB-PVD coating, the surface is cleaned first, the coating is sprayed, and then a hole is opened and a crystal is buried; assembling the turbine blade with the buried crystal and the thermal barrier coating on a test engine for engine testing; decomposing the turbine blade into a single-piece state and taking out the crystal; measuring the lattice parameters of the crystal, and judging the crystal measurement temperature at each installation position of the turbine blade according to the lattice parameters and in combination with the engine test state, to obtain the surface wall temperature of the turbine blade with the thermal barrier coating.

Description

Technical Field

[0001] The present application belongs to the technical field of engine temperature measurement, and in particular, relates to a method for measuring the surface wall temperature of a turbine blade with a thermal barrier coating by using a crystal. Background Art

[0002] The wall temperature test of turbine blades in the complete state has always been a difficult point because they are in an environment of high temperature, high pressure and high-speed airflow. Crystal temperature measurement technology is widely used in the field of aero-engine temperature measurement due to its small crystal size, light weight, no leads and high precision. Since turbine blades have the need for thermal insulation, thermal barrier coatings need to be sprayed on the outer wall of the turbine blades. The most common thermal barrier coating methods include APS (atmospheric plasma spraying) and EB-PVD (electron beam physical vapor deposition). However, the current turbine blade crystal measurements are all based on the state without thermal barrier coating, and cannot reflect the wall temperature of turbine blades with thermal barrier coatings. Summary of the invention

[0003] The purpose of the present application is to provide a method for measuring the surface wall temperature of a turbine blade with a thermal barrier coating using a crystal, so as to solve or alleviate at least one problem in the background technology.

[0004] The technical solution of the present application is: a method for measuring the surface wall temperature of a turbine blade with a thermal barrier coating using a crystal, comprising:

[0005] Step S10, a crystal hole is formed on the outer wall of the turbine blade to embed a crystal for measuring temperature;

[0006] Step S20, after cleaning the surface of the turbine blade with a cleaning agent, burying the crystal in the crystal hole, and welding a metal cover sheet on the surface of the turbine blade after packaging with a high-temperature adhesive, wherein when the turbine blade is a turbine guide blade, the metal cover sheet is welded as needed, and when the turbine blade is a turbine rotor blade, the metal cover sheet must be welded;

[0007] Step S30, cleaning the position on the surface of the turbine blade where the thermal barrier coating is to be sprayed;

[0008] Step S40, spraying the bottom layer and the surface layer on the surface of the turbine blade in sequence, wherein when the thermal barrier coating is an APS coating, the steps are performed in the order of step S10, step S20, step S30 and step S40, and when the thermal barrier coating is an EB-PVD coating, the steps are performed in the order of step S30, step S40, step S10 and step S20;

[0009] Step S50, assembling the turbine blade with the embedded crystal and thermal barrier coating on the engine to be tested, and performing engine test according to the temperature state to be tested, ensuring that the temperature state to be tested is the highest test state and is maintained for a predetermined time;

[0010] Step S60, disassembling the turbine blades in the engine with the crystal embedded therein into a single piece state, taking out the crystal, and numbering them according to the installation position;

[0011] Step S70, measuring the lattice parameters of the crystal, judging the crystal measurement temperature at each installation position of the turbine blade according to the lattice parameters and in combination with the engine test state parameters, thereby determining the surface wall temperature of the turbine blade with the thermal barrier coating.

[0012] In a preferred embodiment of the present application, the crystal hole is a cylindrical hole, the bottom hole area of ​​the crystal hole is not less than the inlet area of ​​the crystal hole, and the bottom surface is flat;

[0013] The opening position of the crystal hole meets the following requirements: there is a temperature measurement requirement, the wall thickness is greater than the depth requirement, the position meets the strength requirement after the hole is opened, and the surface of the opening position is flat;

[0014] The aperture and depth of the crystal hole are required to meet the requirements for embedding the crystal, and the opening angle is perpendicular to the outer wall of the turbine blade.

[0015] In a preferred embodiment of the present application, in the state without thermal barrier coating, the method of opening the crystal hole includes electric spark drilling, electro-hydraulic beam drilling, and laser drilling; in the state with thermal barrier coating surface layer, the method of opening the crystal hole includes femtosecond laser drilling.

[0016] In a preferred embodiment of the present application, the cleaning agent is acetone.

[0017] In a preferred embodiment of the present application, the predetermined time length for maintaining the highest test state is 3 minutes to 7 minutes.

[0018] In a preferred embodiment of the present application, the measurement of the lattice parameters of the crystal includes: X-ray diffraction, high-resolution transmission electron microscopy, absorption spectroscopy, and Raman spectroscopy.

[0019] In a preferred embodiment of the present application, the present invention further includes: correcting the surface wall temperature of the turbine blade with thermal barrier coating measured by crystal, and the correction method is:

[0020] ;

[0021] In the formula, is the gas heat transfer coefficient;

[0022] is the cooling air heat transfer coefficient;

[0023] is the gas heat exchange temperature;

[0024] Heat exchange temperature for cold air;

[0025] is the measured temperature of the crystal;

[0026] is the blade wall temperature at the position corresponding to the corrected crystal;

[0027] is the thermal conductivity of the blade wall;

[0028] is the thermal conductivity of the crystal;

[0029] is the thermal conductivity of high temperature adhesive;

[0030] is the thermal conductivity of the cover sheet;

[0031] is the thermal conductivity of the thermal barrier coating;

[0032] is the total thickness of the blade wall;

[0033] It is the remaining wall thickness of the blade after the crystal is buried;

[0034] is the crystal thickness;

[0035] is the thickness of the high temperature adhesive;

[0036] is the thickness of the metal cover;

[0037] is the thickness of the thermal barrier coating surface layer.

[0038] The method provided in the present application of using crystal to measure the surface wall temperature of a turbine blade with a thermal barrier coating overcomes the existing technology of crystal measurement of turbine blades without thermal barrier coating, and can accurately reflect the wall temperature of turbine blades with thermal barrier coating, and the measurement results are more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0040] Figure 1 This is a schematic diagram of the crystal wall temperature measurement method of the present application.

[0041] Figure 2 Schematic diagram of the crystal wall temperature measurement with thermal barrier coating in this application.

[0042] Reference numerals:

[0043] 1-Turbine blades

[0044] 2-Crystal

[0045] 3-High temperature adhesive

[0046] 4-Metal cover

[0047] 5- Thermal barrier coating DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0049] like Figure 1 As shown, the present invention proposes a method for measuring the surface wall temperature of a turbine blade with a thermal barrier coating using a crystal, comprising the following steps:

[0050] Step S10: opening a crystal hole on the outer wall surface of the turbine blade.

[0051] The crystal hole is a cylindrical hole or a quasi-cylindrical hole. The bottom hole area should not be less than the hole inlet area, and the bottom surface should be flat. The opening position of the crystal hole should meet the following requirements: there is a temperature measurement requirement, the wall thickness is greater than the depth requirement, the position meets the strength requirement after the hole is opened (especially the rotating parts), and the surface of the opening position is as flat as possible. The hole diameter and depth requirements should meet the requirements for crystal burial. The opening angle is perpendicular to the outer wall of the blade.

[0052] In the absence of thermal barrier coating, the crystal hole can be opened by electric spark, electro-hydraulic beam, laser, etc. In the state with thermal barrier coating surface layer, the crystal hole opening method is femtosecond laser drilling.

[0053] For example, in this embodiment of the present application, the size of the micro-crystal is 0.2 mm×0.3 mm×0.3 mm, the aperture of the crystal hole is required to be φ0.6 (+0.10) mm, and the depth is required to be 0.5 (+0.10) mm.

[0054] Step S20, burying the crystal and filling with glue.

[0055] like Figure 2As shown, after cleaning the installation surface of the turbine blade 1 with acetone, the irradiated crystal 2 is embedded with the help of a stereo microscope, and is encapsulated with a high-temperature adhesive 3. After the high-temperature adhesive 3 is dried for 17 to 24 hours, a metal cover sheet 4 is welded on the surface of the turbine blade 1. The turbine guide blades are set as required, and the metal cover sheet 4 may or may not be welded; the turbine rotor blades should be welded with a metal cover sheet 4. The welding requirements are: the curvature of the welded surface should not be too large, there should be sufficient welding space, and the cooling outlet structures such as the air film holes and seams of the turbine blade 1 should not be blocked after welding.

[0056] For example, in the embodiment of the present application, the process of crystal embedding is as follows:

[0057] 1) Clean the mounting surface of the turbine blade 1 with acetone;

[0058] 2) Use a greased needle to place crystal 2 in the middle of the crystal hole;

[0059] 3) Pour the solid agent into the high temperature glue to form a high temperature adhesive 3;

[0060] 4) Inject high-temperature adhesive 3 into the hole, press lightly to expel the air in the hole, fine-tune the position of the crystal again so that it is placed in the middle of the crystal hole, and inject high-temperature adhesive 3 again until it is filled;

[0061] 5) After the surface of the high-temperature glue is dry, clean the high-temperature adhesive 3 on the protruding surface, so that the surface of the high-temperature adhesive 3 in the crystal hole is flush with the surface of the turbine blade 1;

[0062] 6) After natural drying for 20 hours, heat in a high-temperature furnace.

[0063] 7) The high-pressure turbine guide blades are no longer welded with metal cover plates 4. Instead, the surface of the high-pressure turbine rotor blades is welded with a circular metal cover plate 4 made of 1Cr18Ni9Ti material, 0.1mm thick and 3mm in diameter.

[0064] Step S30: cleaning the surface of the turbine blades.

[0065] Acetone is used to clean the surface of the turbine blade 1 where the thermal barrier coating 5 is to be sprayed. If the turbine blade 1 has a buried crystal 2, it should be avoided from contacting water and the cleaning liquid cannot flow into the buried crystal.

[0066] Step S40: spraying a thermal barrier coating on the surface of the turbine blade.

[0067] When spraying the thermal barrier coating 5, the base layer and the surface layer are sprayed in sequence as required. For the turbine blade 1 sprayed with the thermal barrier coating by APS, the steps S10, S20, S30, and S40 can be followed, or the base layer can be sprayed first and then the steps S10, S20, S30, and S40 (spraying the surface layer) can be followed. For the turbine blade 1 sprayed with the thermal barrier coating by EB-PVD, the steps S30, S40, S10, and S20 should be followed.

[0068] For example, in one example of the present application, the bottom layer of the thermal barrier coating of the high-pressure turbine guide blade is NiCrAlY coating, and the surface layer is nano ZrO2•Y2O3 coating. The bottom layer is sprayed by supersonic flame spraying, and the surface layer is sprayed by APS. The bottom layer is sprayed first, and then the process of steps S10, S20, S30, and S40 (spraying the surface layer) is carried out, and the crystal holes are opened by electric spark. The bottom layer of the thermal barrier coating of the high-pressure turbine rotor blade is NiCrAlYSi material, which is sprayed by supersonic flame spraying, and the surface layer is ZrO2•Y2O3 material, which is sprayed by EB-PVD method, and the process of steps S30, S40, S10, and S20 is carried out, and femtosecond laser drilling is used.

[0069] Step S50: testing the crystal wall temperature.

[0070] The turbine blade 1 with the thermal barrier coating and embedded crystals is mounted on the engine to be tested, and the engine is tested according to the temperature state to be tested, ensuring that the temperature state to be tested is the highest test state and is maintained for 3 minutes to 7 minutes. For example, in this example of the present application, the highest test state of the turbine blade 1 is maintained for 5 minutes.

[0071] Step S60: disassembling the crystal.

[0072] Disassemble the turbine blades with embedded crystals in the engine into individual pieces, remove the crystals, and number them according to their installation positions.

[0073] Removal steps:

[0074] 1) After removing the metal cover (limited to high-pressure turbine rotor blades), use a dropper to drop clean water on the surface of the high-temperature adhesive 3 and soak it for 30 minutes;

[0075] 2) Use a fine needle to peel off and soften the high-temperature adhesive 3 with water. After the crystal 2 is loosened, use a needle with grease to remove it;

[0076] 3) Place the crystal into the label and stick it to the tape;

[0077] 4) Number them according to the installation position.

[0078] Step S70: crystal data interpretation.

[0079] The lattice parameters of the crystal 2 are measured to provide input parameters for the final temperature judgment, and combined with the engine test state parameters, the crystal measurement temperature of each installation position of the turbine blade 1 is determined.

[0080] Among them, the methods for measuring crystal parameters of a crystal include: X-ray diffraction, high-resolution projection electron microscopy, absorption spectroscopy, Raman spectroscopy, etc. In this example of the present application, the X-ray diffraction method is used to judge the crystal measurement temperature.

[0081] Step S80: data correction.

[0082] Since the crystal is installed in the crystal hole on the surface of the turbine blade 1 and is encapsulated with a high-temperature adhesive, there is still a certain distance from the surface of the turbine blade 1. The temperature measured by the crystal is not the surface wall temperature of the turbine blade. Therefore, the temperature measured by the crystal is corrected in this application. The correction method is shown in the following formula:

[0083] ;

[0084] In the formula, is the gas heat transfer coefficient;

[0085] is the cooling air heat transfer coefficient;

[0086] is the gas heat exchange temperature;

[0087] Heat exchange temperature for cold air;

[0088] is the measured temperature of the crystal;

[0089] is the blade wall temperature at the position corresponding to the corrected crystal;

[0090] is the thermal conductivity of the blade wall;

[0091] is the thermal conductivity of the crystal;

[0092] is the thermal conductivity of high temperature adhesive;

[0093] is the thermal conductivity of the cover sheet;

[0094] is the thermal conductivity of the thermal barrier coating;

[0095] is the total thickness of the blade wall;

[0096] It is the remaining wall thickness of the blade after the crystal is buried;

[0097] is the crystal thickness;

[0098] is the thickness of the high temperature adhesive;

[0099] is the thickness of the metal cover;

[0100] is the thickness of the thermal barrier coating surface layer.

[0101] In calculation, if there is no metal cover =0; if there is no thermal barrier coating surface =0.

[0102] The method provided in the present application of using crystal to measure the surface wall temperature of a turbine blade with a thermal barrier coating overcomes the existing technology of crystal measurement of turbine blades without thermal barrier coating, and can accurately reflect the wall temperature of turbine blades with thermal barrier coating, and the measurement results are more accurate.

[0103] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for measuring the surface temperature of a turbine blade with a thermal barrier coating using a crystal, characterized in that: include: Step S10, a crystal hole is formed on the outer wall of the turbine blade to embed a crystal for measuring temperature; Step S20, after cleaning the surface of the turbine blade with a cleaning agent, burying the crystal in the crystal hole, and welding a metal cover sheet on the surface of the turbine blade after packaging with a high-temperature adhesive, wherein when the turbine blade is a turbine guide blade, the metal cover sheet is welded as needed, and when the turbine blade is a turbine rotor blade, the metal cover sheet must be welded; Step S30, cleaning the position on the surface of the turbine blade where the thermal barrier coating is to be sprayed; Step S40, spraying the bottom layer and the surface layer on the surface of the turbine blade in sequence, wherein when the thermal barrier coating is an APS coating, the steps are performed in the order of step S10, step S20, step S30 and step S40, and when the thermal barrier coating is an EB-PVD coating, the steps are performed in the order of step S30, step S40, step S10 and step S20; Step S50, assembling the turbine blade with the embedded crystal and thermal barrier coating on the engine to be tested, and performing engine test according to the temperature state to be tested, ensuring that the temperature state to be tested is the highest test state and is maintained for a predetermined time; Step S60, disassembling the turbine blades in the engine with the crystal embedded therein into a single piece state, taking out the crystal, and numbering them according to the installation position; Step S70, measuring the lattice parameters of the crystal, judging the crystal measurement temperature at each installation position of the turbine blade according to the lattice parameters and in combination with the engine test state parameters, thereby determining the surface wall temperature of the turbine blade with the thermal barrier coating.

2. The method for measuring the surface temperature of a turbine blade with a thermal barrier coating using a crystal according to claim 1, characterized in that: The crystal hole is a cylindrical hole, the bottom hole area of ​​the crystal hole is not less than the inlet area of ​​the crystal hole, and the bottom surface is flat; The opening position of the crystal hole meets the following requirements: there is a temperature measurement requirement, the wall thickness is greater than the depth requirement, the position meets the strength requirement after the hole is opened, and the surface of the opening position is flat; The aperture and depth of the crystal hole are required to meet the requirements for embedding the crystal, and the opening angle is perpendicular to the outer wall of the turbine blade.

3. The method for measuring the surface temperature of a turbine blade with a thermal barrier coating using a crystal according to claim 2, characterized in that: In the state without thermal barrier coating, the method of opening the crystal hole includes electric spark drilling, electro-hydraulic beam drilling, and laser drilling; in the state with thermal barrier coating surface layer, the method of opening the crystal hole includes femtosecond laser drilling.

4. The method for measuring the surface temperature of a turbine blade with a thermal barrier coating using a crystal according to claim 1, characterized in that: The cleaning agent is acetone.

5. The method for measuring the surface temperature of a turbine blade with a thermal barrier coating using a crystal according to claim 1, characterized in that: The scheduled time for maintaining the highest test state is 3 minutes to 7 minutes.

6. The method for measuring the surface temperature of a turbine blade with a thermal barrier coating using a crystal according to claim 1, characterized in that: Methods for measuring the lattice parameters of crystals include: X-ray diffraction, high-resolution projection electron microscopy, absorption spectroscopy, and Raman spectroscopy.

7. The method for measuring the surface temperature of a turbine blade with a thermal barrier coating using a crystal according to any one of claims 1 to 6, characterized in that: Also includes: The surface temperature of the turbine blade with thermal barrier coating measured by crystal is corrected by: In the formula, is the gas heat transfer coefficient; is the cooling air heat transfer coefficient; is the gas heat exchange temperature; Heat exchange temperature for cold air; is the measured temperature of the crystal; is the blade wall temperature at the position corresponding to the corrected crystal; is the thermal conductivity of the blade wall; is the thermal conductivity of the crystal; is the thermal conductivity of high temperature adhesive; is the thermal conductivity of the cover sheet; is the thermal conductivity of the thermal barrier coating; is the total thickness of the blade wall; It is the remaining wall thickness of the blade after the crystal is buried; is the crystal thickness; is the thickness of the high temperature adhesive; is the thickness of the metal cover; is the thickness of the thermal barrier coating surface layer.

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