System and method for evaluating thermal insulation effect of thermal barrier coating of turbine blade in rotating state

Abstract

The invention discloses a system and a method for evaluating the thermal insulation effect of a thermal barrier coating of a turbine blade in a rotating state, the system comprises a service environment simulation unit, a temperature field measurement unit and an evaluation unit, and the service environment simulation unit comprises a turbine blade test piece and a gas spray gun; the temperature field measuring unit comprises an infrared thermal imaging module and a thermocouple module, the thermocouple module comprises a thin film thermocouple and a miniature thermocouple, and the thin film thermocouple is arranged between the blade and the thermal barrier coating and used for obtaining a temperature field of an interface; the micro thermocouple is arranged on the surface, away from the blade, of the thermal barrier coating and used for obtaining a temperature field of the surface of the thermal barrier coating; the evaluation unit evaluates the thermal insulation effect of the thermal barrier coating according to the temperature measurement result. The real service environment of high-temperature and high-speed rotation of the thermal barrier coating of the turbine blade can be simulated, the surface of the thermal barrier coating is heated in an annular gas flame mode, the high-power and high-speed motor is adopted to drive the turbine blade to rotate at a high speed, and real-time temperature measurement in the high-speed rotation state is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-pressure turbine blades, and relates to performance evaluation of thermal barrier coatings on turbine blades, and in particular to a system and method for evaluating the heat insulation effect of thermal barrier coatings on turbine blades in a rotating state. Background Art

[0002] High-pressure turbine blades are the core components of aircraft engines that bear temperature and load, and the accurate design and evaluation of the blade's temperature bearing capacity is crucial. However, in the environment of rotation, especially high-speed rotation, and interaction with gas and cold air, it is extremely difficult to test the temperature field of turbine blades. There is no mature turbine blade surface temperature field testing technology in engineering, nor is there any confirmed turbine blade temperature field data.

[0003] In addition, in order to improve the temperature-bearing capacity of turbine blades, some aircraft engines use thermal barrier coatings. Testing the surface and interface temperature field of the thermal barrier coating on turbine blades is the premise and basis for evaluating the thermal insulation effect of the thermal barrier coating, but there is currently no definite data, let alone evaluation means.

[0004] In the prior art, the temperature test and evaluation of turbine blades mainly use fluorescence thermometry and high-temperature multi-color irreversible temperature-indicating paint. Fluorescence thermometry has the advantages of high temperature measurement accuracy, wide range, and no influence from the surrounding environment. However, when using fluorescence thermometry to test the temperature of turbine blades, it is necessary to pre-mix and add fluorescent substances to the thermal barrier coating material of the turbine blades. The preparation process has high requirements and the structure of the temperature measuring device is complex. Temperature-indicating paint has great advantages in temperature testing of high-speed motion and complex-shaped surfaces, but its accuracy is low, and the measured components need to be disassembled to judge the temperature, and real-time temperature monitoring and evaluation cannot be performed. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a system and method for evaluating the thermal insulation effect of thermal barrier coatings on turbine blades in a rotating state, so as to solve the problem that the surface and interface temperatures of thermal barrier coatings on turbine blades in a rotating state cannot be measured or measured inaccurately, accurately obtain the surface temperature field of rotating turbine blades in a high-temperature gas environment, and evaluate the thermal insulation effect of the thermal barrier coating based on this, thereby providing a basis for the design of the temperature bearing capacity of turbine blades.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a system for evaluating the thermal insulation effect of thermal barrier coatings on turbine blades in a rotating state, comprising a service environment simulation unit, a temperature field measurement unit, and an evaluation unit;

[0008] The service environment simulation unit is mainly used to simulate the actual working environment and state of the turbine blade, and includes a turbine blade test piece and a gas spray gun. The turbine blade test piece is installed on a turbine disk with a rotating shaft, and is driven to rotate by the rotating shaft and the turbine disk. The turbine blade test piece includes a blade and a thermal barrier coating coated on the surface of the blade, which is consistent with the turbine blade in actual work; the gas spray gun is directed toward the turbine blade test piece, and is mainly used to provide a load to the turbine blade test piece in a rotating state, and the load simulates the force and thermal shock in actual work;

[0009] The temperature field measurement unit is mainly used to measure the temperature of several key positions in the experiment in real time, and includes an infrared thermal imaging module and a thermocouple module. The probe of the infrared thermal imaging module is facing the turbine blade test piece, and is used to obtain the temperature field of the surface of the thermal barrier coating; the thermocouple module includes a thin film thermocouple and a micro thermocouple. The thin film thermocouple is arranged between the blade and the thermal barrier coating, and is used to obtain the temperature field of the interface; the micro thermocouple is arranged on the surface of the thermal barrier coating away from the blade, and is used to obtain the temperature field of the surface of the thermal barrier coating.

[0010] The evaluation unit is mainly used to evaluate the heat insulation effect of the thermal barrier coating according to the results of the infrared thermal imaging module, the thin film thermocouple and the micro thermocouple.

[0011] The temperature field of the thermal barrier coating surface obtained by the infrared thermal imaging module is mainly used to verify the temperature field of the thermal barrier coating surface obtained by the micro-thermocouple.

[0012] In one embodiment, there are multiple gas spray guns evenly distributed along the circumference of the combustion platform. The gas spray guns generate a high-temperature and high-speed flame with a temperature of 1000°C-1700°C and a speed of 1-2 Mach through combustion. The high-temperature and high-speed flame acts on the leading edge of the turbine blade test piece and can provide loads including centrifugal force, aerodynamic force and hot spot.

[0013] In one embodiment, an adhesive layer, an insulating layer and a protective layer are sequentially arranged between the blade and the thermal barrier coating, wherein the adhesive layer is arranged on one side of the blade, and the protective layer is arranged on one side of the thermal barrier coating. The thin-film thermocouple is arranged between the insulating layer and the protective layer. The material of the thin-film thermocouple is an iridium-rhodium alloy, and its positive and negative cold ends can be led out to an area not covered by the thermal barrier coating using electrodes. The material of the micro-thermocouple is a platinum-rhodium alloy.

[0014] In one embodiment, the thin film thermocouple is connected to the temperature collection device via lead 1, and the micro thermocouple is connected to the temperature collection device via lead 2. Lead 1 and lead 2 constitute the signal line of the thermocouple module. The signal line is fixed on the blade and connected to the conductive slip ring in turn through the turbine disk and the central channel of the rotating shaft. The rotating signal line is converted into a stationary signal line through the conductive slip ring.

[0015] In one embodiment, the conductive slip ring includes a rotor and a stator, the rotor is assembled and connected to the rotating shaft, a circuit board and a gold pin are provided at one end of the rotor close to the stator, and the signal line passes through the central channel of the rotating shaft into the axial through hole of the rotor and is connected to the rotor.

[0016] In one embodiment, the conductive slip ring receives the temperature signal and converts it into a current signal or a differential voltage signal, and utilizes the contact between the rotor and the stator, specifically mainly utilizes the connection between the circuit board and the gold pin, to transmit the current signal or the differential voltage signal to a remotely connected temperature acquisition device through a static signal line.

[0017] In one embodiment, a Hall test module is installed on the rotor or the rotating shaft. The Hall test module converts the mechanical geometric displacement on the rotor or the rotating shaft into pulses or digital quantities through magneto-electric conversion, thereby obtaining the position and direction of the rotating shaft, outputting pulse signals with the same time interval, and using the leading edge signal of the pulse signal to trigger the infrared thermal imaging module to take pictures and perform infrared thermal imaging.

[0018] In one embodiment, the infrared thermal imaging module selects a short wave band of 1.5-1.6 microns or a medium wave band of 3.8-4.05 microns for infrared thermal imaging, and sets a filter in front of the infrared thermal imaging lens to reduce the influence of the gas flame on the temperature measurement.

[0019] A second aspect of the present invention further provides a method for evaluating the thermal insulation effect of a thermal barrier coating on a turbine blade under a rotating state, which is implemented based on the thermal insulation effect evaluation system for a thermal barrier coating on a turbine blade under a rotating state described in the first aspect, and comprises the following steps:

[0020] Start the motor to drive the turbine disk to rotate, and turn on the gas spray gun to provide load to the rotating turbine blade test piece;

[0021] The temperature field of the thermal barrier coating surface is collected by infrared thermal imaging module, the temperature field of the interface between the blade and the thermal barrier coating is collected by thin film thermocouple, and the temperature field of the thermal barrier coating surface is collected by micro thermocouple;

[0022] The thermal insulation effect of the thermal barrier coating is evaluated, wherein the thermal insulation effect is the difference between the surface temperature of the thermal barrier coating and the interface temperature between the blade and the thermal barrier coating.

[0023] In one embodiment, the rotation speed of the turbine disk is 10000-20000 rpm.

[0024] Compared with the prior art, the present invention can simulate the real service environment of high-temperature and high-speed rotation of the thermal barrier coating of turbine blades, heat the surface of the thermal barrier coating by means of an annular gas flame, and use a high-power high-speed motor to drive the turbine blades to rotate at high speed, thereby realizing real-time temperature measurement under high-speed rotation state.

[0025] The present invention adopts three temperature measurement technologies, including contact and non-contact temperature measurement methods, which can verify each other. The present invention can simultaneously measure the temperature field of the surface and interface of the thermal barrier coating, thereby calculating a particularly important performance of the thermal barrier coating, namely the thermal insulation effect.

[0026] In addition, the present invention is applicable to flat parts, curved parts and complex real turbine blades, which proves that the method has a wide range of applications. The device has a simple structure, and when the device is used to measure the thermal insulation temperature, the temperature test response is fast, the test process is simple, and the practicability is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the thermal insulation effect evaluation system of the thermal barrier coating of turbine blades in a rotating state of the present invention.

[0028] Figure 2 It is a plan view of the arrangement structure of the thermocouple of the present invention in the thermal barrier coating of the turbine blade.

[0029] Figure 3 It is a cross-sectional view of the arrangement structure of the thermocouple of the present invention in the thermal barrier coating of the turbine blade.

[0030] Figure 4 It is a schematic diagram of the structure of converting a signal line into a stationary signal line through a conductive slip ring in the present invention.

[0031] Figure 5 It is the temperature measurement result of the thermocouple module in the embodiment of the present invention.

[0032] Figure 6 It is the temperature measurement result of the infrared thermal imaging module in the embodiment of the present invention. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below with reference to the accompanying drawings and examples.

[0034] In addition to the impact of high-speed gas and the complex airflow of the cooling air film, the turbine blades in the rotating state also need to withstand the centrifugal force of high-speed rotation, making the test of the temperature field of the turbine blades extremely difficult. The layout of the temperature sensor, the interference of the airflow, the connection of the sensor under high-speed rotation, and the transmission of the signal are all very difficult during contact temperature measurement. If contact temperature measurement technology, such as micro-thermocouples and thin-film thermocouples, is used, how to install the thermocouples, how to achieve real-time transmission of test data, and how to calibrate the test results are all huge challenges. If non-contact temperature measurement technology, such as infrared temperature measurement, is used, how to filter out high-temperature flames, how to eliminate temperature interference from adjacent blades, how to achieve detection and calibration of curved surface structures, and how to ensure the credibility of the results are all great problems. More importantly, the surface of the turbine blade is not only affected by high-temperature and high-speed gas and cold air, but also by high-speed rotating loads. When combined, hot spots, turbulence, wakes, and other phenomena will occur, affecting the test results. Therefore, how to achieve the test of gas and load, especially the temperature field of rotating loads, is a factor that needs to be considered and is also a greater challenge.

[0035] like Figure 1 As shown, the present invention provides a thermal insulation effect evaluation system for thermal barrier coatings on turbine blades in a rotating state, which mainly includes three parts: a service environment simulation unit, a temperature field measurement unit and an evaluation unit.

[0036] Among them, the service environment simulation unit mainly includes a turbine blade test piece 1 and a gas spray gun 4. The turbine blade test piece 1 is a detection and evaluation object, including a blade 6 and a thermal barrier coating 64 coated on the surface of the blade 6. The turbine blade test piece 1 is installed on a turbine disk 2 with a rotating shaft 3. The present invention can use a high-power high-speed motor to drive the rotating shaft 3 to rotate at high speed to design a rotor module, including a power drive motor, a gearbox, a multi-stage rotating shaft and a lubrication system. The rotating shaft 3 is fixedly connected to the turbine disk 2, thereby driving the turbine disk 2 to rotate, and then driving the turbine blade test piece 1 to rotate. Obviously, the number of blades 6 is multiple, and they are installed symmetrically around the center. The gas spray gun 4 is fixedly arranged and faces each turbine blade test piece 1. Its function is to provide a load to the turbine blade test piece 1 in a rotating state, including centrifugal force, aerodynamic force and hot spot. Therefore, the service environment simulation unit of the present invention can simulate the real service environment of high-temperature and high-speed rotation of the thermal barrier coating of the turbine blade.

[0037] The temperature field measurement unit mainly includes an infrared thermal imaging module 7 and a thermocouple module 8, wherein the probe of the infrared thermal imaging module 7 faces the turbine blade test piece 1, and obtains the temperature field of the surface of the thermal barrier coating 64 based on the infrared thermal imaging technology. The thermocouple module 8 is used to realize contact measurement, which includes a thin film thermocouple 81 and a micro thermocouple 82, such as Figure 2The thin film thermocouple 81 is arranged between the blade 6 and the thermal barrier coating 64 to obtain the temperature field of the interface, and the micro thermocouple 82 is arranged on the surface of the thermal barrier coating 64 away from the blade 6 to obtain the temperature field of the surface of the thermal barrier coating 64.

[0038] The evaluation unit evaluates the thermal insulation effect of the thermal barrier coating 64 according to the results of the infrared thermal imaging module 7, the thin film thermocouple 81 and the micro thermocouple 82. For example, the evaluation unit can be any processor with a computing function. The present invention can realize the thermal insulation effect evaluation of the thermal barrier coating 64 of the turbine blade under the high-speed rotation of 10000-20000rpm.

[0039] When testing the heat insulation effects of different thermal barrier coatings 64 , the existing blade 6 is used as a substrate and coated with different thermal barrier coatings 64 . Compared with the processing technology in actual applications, basically no additional process steps or special materials are required.

[0040] In some embodiments of the present invention, Figure 1 As shown, there are four gas spray guns 4, which are evenly distributed on the circumference of the combustion platform 5. The combustion of fuel, oxygen and air generates a high-temperature and high-speed flame with a temperature of 1000℃-1700℃ and a speed of 1-2 Mach, which acts on the leading edge of the turbine blade test piece 1, generating centrifugal force, aerodynamic force, hot spot and other loads. Through this structure, the present invention can heat the surface of the thermal barrier coating 64 by means of an annular gas flame, and restore the real service environment to the maximum extent. For example, the fuel can be kerosene.

[0041] In some embodiments of the present invention, the thermocouple module 8 performs contact measurement, and a signal line 9 is required to connect the temperature acquisition device. Figure 2 As shown, the thin film thermocouple 81 is connected to the temperature acquisition device through the lead 1 91, the micro thermocouple 82 is connected to the temperature acquisition device through the lead 2 92, and the signal line 9 is composed of the lead 1 91 and the lead 2 92. Figure 1 As shown, the signal line 9 is fixed on the blade 6, and is connected to the conductive slip ring 10 through the turbine disk 2 and the central channel of the rotating shaft 3 in sequence, and the rotating signal line 9 is converted into a stationary signal line 11 through the conductive slip ring 10.

[0042] In some embodiments of the present invention, Figure 3As shown, between the blade 6 and the thermal barrier coating 64, along the direction of the blade 6 toward the thermal barrier coating 64, a bonding layer 61, an insulating layer 62 and a protective layer 63 are sequentially arranged. The thin film thermocouple 81 is arranged between the insulating layer 62 and the protective layer 63. For example, the material of the blade 6 of the present invention is a nickel-based high-temperature alloy; the material of the bonding layer 61 is NiCrAlY or NiCoCrAlY; the insulating layer 62 is an aluminum oxide layer or an amorphous YSZ layer or an Al2O3 layer, the protective layer 63 is an Al2O3 layer or a YZrAlO layer, and the material of the thermal barrier coating 64 is generally YSZ.

[0043] In some embodiments of the present invention, the material of the thin film thermocouple 81 is conventional thin film thermocouple materials such as iridium rhodium, NiCr / NiSi, or other electrode materials with high temperature resistance, oxidation resistance and good electrical conductivity, and the material of the micro thermocouple 82 is platinum rhodium alloy, and specifically, double platinum rhodium couple wire can be directly selected. The positive and negative cold ends of the thin film thermocouple 81 are led out to the area not covered by the thermal barrier coating 64, that is, the blade tenon, through the lead 91 to realize signal collection.

[0044] In some embodiments of the present invention, Figure 4 As shown, the conductive slip ring 10 includes a rotor 101 and a stator 102, and the dynamic and static conversion of the lead wire of the contact temperature measurement is mainly realized by the rotor 101 and the stator 102. The rotor 101 is assembled and fixedly connected with the rotating shaft 3. The rotor 101 is provided with a circuit board 103 and a gold pin 104 at one end close to the stator 102. The signal line 9 passes through the axial through hole of the rotor 101 through the central channel of the rotating shaft 3 and is connected to the rotor 101. The rotor 101 has a signal acquisition component, which can obtain the temperature signal transmitted by the signal line 9. Specifically, the rotor 101 is first connected with the lead wire 1 91 of the thin film thermocouple 81 and the lead wire 2 92 of the micro thermocouple 82 that rotate with the rotating shaft 3, and the two leads are passed through the through hole of the conductive slip ring 10. At the same time, the flange structure 105 is used to fix the rotor 101 at the tail end of the rotating shaft 3 so that it rotates with the shaft.

[0045] The thin film thermocouple 81 and the micro thermocouple 82 both use two conductors of different materials to form a closed loop. When there is a temperature gradient at both ends, current will flow through the loop, and an electromotive force will exist between the two ends. Therefore, based on the contact temperature measurement method, the present invention distributes the thin film thermocouple 81 and the micro thermocouple 82 at the interface between the blade 6 and the thermal barrier coating 64 and the surface of the thermal barrier coating 64, respectively, fixes their respective leads on the turbine disk 2, passes through the central channel of the rotating shaft 3, and makes it rotate with the shaft, and then connects their respective leads to the rotor 101 of the conductive slip ring, uses the conductive slip ring 10 to receive the temperature signal and convert it into a current signal or a differential voltage signal, uses the contact between the rotor 101 and the stator 102, mainly uses the connection between the circuit board 103 and the gold needle 104, and transmits the current signal or differential voltage signal to the temperature acquisition device connected at the remote end through the static signal line 11, thereby realizing the temperature field detection of the surface and interface of the thermal barrier coating 64 of the turbine blade under high-speed rotation.

[0046] The circuit board 103 is a ring piece or circuit structure in a conductive slip ring product, and has a pinhole thereon. The gold needle 104 is arranged in the pinhole to form a gold-gold superconducting self-lubricating contact.

[0047] In some embodiments of the present invention, a Hall test module 12 is installed on the rotor 101 or the rotating shaft 3, and a pulse signal is generated when the rotating shaft 3 rotates one circle and reaches the Hall test module 12. Thus, the Hall test module 12 converts the mechanical geometric displacement on the rotor 101 or the rotating shaft 3 into a pulse or digital quantity through magnetoelectric conversion, so that the position and direction of the rotating shaft 3, the turbine disk 2, and the blade 6 can be obtained, and the infrared thermal imaging module 7 is triggered to take pictures by outputting pulse signals with the same time interval, and infrared thermal imaging is performed by using the leading edge signal of the pulse signal, where the leading edge signal specifically refers to the front rising edge of the pulse signal waveform. For example, according to the flame spectrum characteristics, the present invention selects infrared thermal imaging in the short wave of 1.5-1.6 microns or the medium wave band of 3.8-4.05 microns, and at the same time sets a filter in front of the infrared thermal imaging lens to reduce the influence of the gas flame on the temperature measurement, so that the infrared thermal imaging can penetrate the flame to measure the temperature of the thermal barrier coating 64, thereby realizing the data collection and recording of the temperature field of the thermal barrier coating of the turbine blade under high-speed rotation.

[0048] Through this structure, the present invention measures the temperature field on the surface of the thermal barrier coating 64 based on the infrared thermal imaging temperature measurement technology in the non-contact temperature measurement method. Only when the temperature field collected by the infrared thermal imaging module 7 and the temperature field collected by the micro-thermocouple 82 are within the allowable error range, it is considered to be an effective surface temperature collection, and the temperature field collected by the micro-thermocouple 82 is used as the basis for evaluating the thermal insulation effect.

[0049] According to the above system, a method for evaluating the thermal insulation effect of a thermal barrier coating on a turbine blade in a rotating state of the present invention comprises the following steps:

[0050] The starter motor drives the turbine disk 2 to rotate, and the gas spray gun 4 is turned on to provide a load to the rotating turbine blade test piece 1;

[0051] The temperature field of the surface of the thermal barrier coating 64 is collected by the infrared thermal imaging module 7, the temperature field of the interface between the blade 6 and the thermal barrier coating 64 is collected by the thin film thermocouple 81, and the temperature field of the surface of the thermal barrier coating 64 is collected by the micro thermocouple 82;

[0052] The thermal insulation effect of the thermal barrier coating 64 is evaluated, and the thermal insulation effect is the difference between the surface temperature of the thermal barrier coating 64 and the interface temperature between the blade 6 and the thermal barrier coating 64 .

[0053] The present invention can provide technical support for the temperature field measurement and thermal insulation effect evaluation of thermal barrier coatings on turbine blades under high-speed rotation, which is beneficial to the design of turbine blade components and the application of thermal barrier coatings.

[0054] To verify the effect of the present invention, a specific thermal insulation effect evaluation embodiment of the present invention has the following steps:

[0055] Step 1: A thin film thermocouple 81 and a micro thermocouple 82 are respectively attached to the surface and interface of the thermal barrier coating 64 of the turbine blade.

[0056] First, NiCrAlY as a bonding layer 61 and Al2O3 as an insulating layer 62 are sprayed on the surface of the blade 6 in sequence, and then a thin film thermocouple 81 made of iridium-rhodium alloy is prepared on the surface of the insulating layer 62 by a magnetron sputtering method, and a protective layer 63 is sprayed for reinforcement. Finally, a certain thickness of YSZ is deposited as a thermal barrier coating 64 by an electron beam physical vapor deposition method, and a micro thermocouple 82 made of double platinum-rhodium material is pasted on the surface of the thermal barrier coating 64 by flame spraying.

[0057] Step 2, connecting the signal leads of the thin film thermocouple 81 and the micro thermocouple 82 to achieve dynamic-static conversion.

[0058] First, the lead 1 91 of the thin film thermocouple 81 is fixed on the turbine disk and the high-speed shaft, and the lead 2 92 of the micro thermocouple 82 is fixed on the turbine disk and the high-speed shaft, and then connected to the rotor 101 of the conductive slip ring 10. At the same time, the stator 102 of the conductive slip ring 10 is also connected to the temperature acquisition device through the static signal line 11.

[0059] Step 3, connect the infrared thermal imaging module 7 and the synchronous trigger of the rotating shaft 3, and set the corresponding parameters.

[0060] First, the infrared thermal imaging module 7 is connected to the Hall test module 12 on the conductive slip ring 10, and the rotating shaft 3 is started to test whether the synchronous triggering is stable. In this embodiment, the infrared emissivity is set to 0.85.

[0061] Step 4, start the service environment simulation unit. In this embodiment, the rotation speed is set to 10000 rpm, the temperature is set to 1150° C., and the experimental time is 60 s.

[0062] Step 5, by exporting the data of the thin film thermocouple 81, the micro thermocouple 82, and the infrared thermal imaging module 7, the surface and interface temperature values ​​of the thermal barrier coating 64 are obtained, and the heat insulation effect of the thermal barrier coating 64 is obtained by calculation.

[0063] The results of the thin film thermocouple 81 and the micro thermocouple 82 of this embodiment are as follows Figure 5 As shown, it can be found that when the surface temperature of the thermal barrier coating 64 is 1150°C, the temperature at the interface is 1140°C. The results of infrared thermal imaging are as follows Figure 6 As shown, the surface temperature of the thermal barrier coating 64 is 1154° C., which is basically consistent with the data of the micro-thermocouple 82 . From this, it can be calculated that the thermal insulation effect of the thermal barrier coating 64 in this service environment is approximately 110° C.

Claims

1. A system for evaluating the thermal insulation effect of thermal barrier coatings on rotating turbine blades, characterized in that: It includes service environment simulation unit, temperature field measurement unit and evaluation unit; The service environment simulation unit comprises a turbine blade test piece (1) and a gas spray gun (4); the turbine blade test piece (1) is mounted on a turbine disk (2) with a rotating shaft (3), and comprises a blade (6) and a thermal barrier coating (64) coated on the surface of the blade (6); the gas spray gun (4) faces the turbine blade test piece (1) to provide a load to the turbine blade test piece (1) in a rotating state; The temperature field measurement unit comprises an infrared thermal imaging module (7) and a thermocouple module (8), wherein a probe of the infrared thermal imaging module (7) faces the turbine blade test piece (1) to obtain the temperature field on the surface of the thermal barrier coating (64); the thermocouple module (8) comprises a thin film thermocouple (81) and a micro thermocouple (82), wherein the thin film thermocouple (81) is arranged between the blade (6) and the thermal barrier coating (64) to obtain the temperature field of the interface; The micro thermocouple (82) is arranged on a surface of the thermal barrier coating (64) away from the blade (6) to obtain a temperature field on the surface of the thermal barrier coating (64); The evaluation unit evaluates the heat insulation effect of the thermal barrier coating (64) based on the results of the infrared thermal imaging module (7), the thin film thermocouple (81) and the micro thermocouple (82).

2. The thermal insulation effect evaluation system of thermal barrier coating on rotating turbine blades according to claim 1, characterized in that: There are multiple gas spray guns (4) evenly distributed along the circumference of the combustion platform (5), and combustion produces a high-temperature and high-speed flame with a temperature of 1000°C-1700°C and a speed of 1-2 Mach. The high-temperature and high-speed flame acts on the leading edge of the turbine blade test piece (1), and the loads provided include centrifugal force, aerodynamic force and hot spot.

3. The thermal insulation effect evaluation system of thermal barrier coating on rotating turbine blades according to claim 1, characterized in that: An adhesive layer (61), an insulating layer (62) and a protective layer (63) are sequentially arranged between the blade (6) and the thermal barrier coating (64), wherein the adhesive layer (61) is arranged on one side of the blade (6), and the protective layer (63) is arranged on one side of the thermal barrier coating (64); the thin-film thermocouple (81) is arranged between the insulating layer (62) and the protective layer (63); the material of the thin-film thermocouple (81) is an iridium-rhodium alloy, and the material of the micro-thermocouple (82) is a platinum-rhodium alloy.

4. The thermal insulation effect evaluation system of thermal barrier coatings for rotating turbine blades according to claim 1, characterized in that: The thin film thermocouple (81) is connected to a temperature acquisition device via a first lead (91), and the micro thermocouple (82) is connected to a temperature acquisition device via a second lead (92). The first lead (91) and the second lead (92) constitute a signal line (9) of the thermocouple module (8). The signal line (9) is fixed on the blade (6), connected to a conductive slip ring (10) through a turbine disk (2) and a central channel of a rotating shaft (3) in sequence, and converted into a stationary signal line (11) via the conductive slip ring (10).

5. The thermal insulation effect evaluation system of thermal barrier coatings for rotating turbine blades according to claim 4, characterized in that: The conductive slip ring (10) comprises a rotor (101) and a stator (102); the rotor (101) is assembled and connected to the rotating shaft (3); a circuit board (103) and a gold pin (104) are provided at one end of the rotor (101) close to the stator (102); the signal line (9) penetrates into the axial through hole of the rotor (101) via the central channel of the rotating shaft (3) and is connected to the rotor (101).

6. The thermal insulation effect evaluation system of thermal barrier coatings for rotating turbine blades according to claim 5, characterized in that: The conductive slip ring (10) receives the temperature signal and converts it into a current signal or a differential voltage signal, and transmits the current signal or the differential voltage signal to a remotely connected temperature acquisition device through a static signal line (11) by utilizing the contact between the rotor (101) and the stator (102).

7. The thermal insulation effect evaluation system of thermal barrier coatings for rotating turbine blades according to claim 5, characterized in that: A Hall test module (12) is installed on the rotor (101) or the rotating shaft (3). The Hall test module (12) converts the mechanical geometric displacement on the rotor (101) or the rotating shaft (3) into a pulse or a digital quantity through magnetoelectric conversion, thereby obtaining the position and direction of the rotating shaft (3), outputting pulse signals with the same time interval, and using the leading edge signal of the pulse signal to trigger the infrared thermal imaging module (7) to take pictures, thereby performing infrared thermal imaging.

8. The thermal insulation effect evaluation system of thermal barrier coatings for rotating turbine blades according to claim 5, characterized in that: The infrared thermal imaging module (7) selects a short wave of 1.5-1.6 microns or a medium wave of 3.8-4.05 microns for infrared thermal imaging, and a filter is arranged in front of the infrared thermal imaging lens to reduce the influence of the gas flame on the temperature measurement.

9. A method for evaluating the thermal insulation effect of thermal barrier coatings on rotating turbine blades, which is implemented based on the thermal insulation effect evaluation system for thermal barrier coatings on rotating turbine blades as claimed in claim 1, characterized in that: The steps include: The motor is started to drive the turbine disk (2) to rotate, and the gas spray gun (4) is turned on to provide a load to the turbine blade test piece (1) in a rotating state; The temperature field on the surface of the thermal barrier coating (64) is collected by an infrared thermal imaging module (7), the temperature field on the interface between the blade (6) and the thermal barrier coating (64) is collected by a thin film thermocouple (81), and the temperature field on the surface of the thermal barrier coating (64) is collected by a micro thermocouple (82); The thermal insulation effect of the thermal barrier coating (64) is evaluated, wherein the thermal insulation effect is the difference between the surface temperature of the thermal barrier coating (64) and the interface temperature between the blade (6) and the thermal barrier coating (64).

10. The method for evaluating the thermal insulation effect of thermal barrier coatings on rotating turbine blades according to claim 9, characterized in that: The rotation speed of the turbine disc (2) is 10000-20000 rpm.

Images