A high-temperature vibration fatigue test system for a gas turbine turbine blade

Abstract

This invention discloses a high-temperature vibration fatigue testing system for gas turbine blades, comprising a high-temperature chamber, an electromagnetic vibration table, a clamping fixture, two or more independently controllable heaters, and a thermal energy circulation unit. The blade sample is placed inside the high-temperature chamber and clamped onto the surface of the electromagnetic vibration table using the clamping fixture. The blade surface is divided into two or more independent temperature zones. The outlet of each heater is connected to the high-temperature chamber via an independent duct, and the outlet of each independent duct corresponds to a temperature zone on the blade sample. An electric valve is installed on each independent duct. This invention, by forming a matrix heater system with multiple independently controlled heaters corresponding to the temperature zones of the blade sample, and in conjunction with independently controllable ducts, creates a non-uniform temperature field distribution on the blade sample. The physical structure ensures the independence and accuracy of temperature control in each zone, thus obtaining the influence of the turbine blade temperature gradient on its high-cycle fatigue performance.

Description

Technical Field

[0001] This invention relates to the field of turbine blade testing technology. Specifically, it relates to a high-temperature vibration fatigue testing system for gas turbine blades. Background Technology

[0002] During long-term service, large turbine blades of heavy-duty gas turbines are continuously subjected to the coupled effects of multiple physical fields, including centrifugal loads from high-speed rotation, high-temperature thermal stress, and unsteady aerodynamic excitation. This can easily induce high-cycle fatigue failure, seriously affecting the safe operation of the unit. Therefore, designing and studying high-temperature vibration fatigue tests for turbine blades to accurately obtain their high-temperature vibration fatigue performance is of great significance for blade design, process evaluation, and safety assessment.

[0003] Existing testing systems typically employ steady-state heating systems such as high-temperature chambers, quartz lamps, and electromagnetic induction coils. During the test, the temperature fields inside and outside the blade are nearly identical. However, in actual operating conditions, there is a temperature gradient in the blade body, and there is no external airflow impact in the test environment. This differs significantly from the actual operating conditions of a gas turbine and cannot account for the impact of the temperature gradient in the blade body on high-cycle fatigue performance under actual operating conditions. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a high-temperature vibration fatigue testing system for gas turbine blades that accurately reproduces the non-uniform temperature field distribution of gas turbine blades under real service environment, so as to obtain the influence of the temperature gradient of the turbine blade on the high-cycle fatigue performance.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a high-temperature vibration fatigue testing system for gas turbine blades, comprising a high-temperature chamber, an electromagnetic vibration table, a clamping fixture, two or more independently adjustable heaters, and a thermal energy circulation unit; the blade sample is placed inside the high-temperature chamber, and the blade sample is clamped on the table surface of the electromagnetic vibration table by the clamping fixture; the blade surface of the blade sample is divided into two or more independent temperature zones; the air outlet of each heater is connected to the high-temperature chamber via an independent air duct, and the air outlet of each independent air duct corresponds to a temperature zone on the blade sample, and an electric valve is installed on the independent air duct; each heater and electric valve are electrically connected to an industrial control computer; the air inlet of the heater is connected to the air outlet of the thermal energy circulation unit, and the air inlet of the thermal energy circulation unit is connected to the high-temperature chamber; the thermal energy circulation unit sends air from the high-temperature chamber into each heater, and acts on the blade sample through the independent air duct. The blade sample was divided into multiple grid-like independent temperature zones. Based on these temperature zones, the specific positions of each heater and independent air duct were set to simulate a real non-uniform gas heating temperature field.

[0006] The aforementioned high-temperature vibration fatigue testing system for gas turbine blades also includes a measurement and control unit that is communicatively connected to an industrial control computer. The measurement and control unit includes a temperature detection component, which is used to detect the temperature data of each temperature zone of the blade sample and transmit the temperature data to the multivariable decoupling control algorithm built into the measurement and control unit to obtain the measured temperature field data. Based on the deviation between the measured temperature field data and the target temperature field data, the multivariable decoupling control algorithm outputs control parameters to the industrial control computer, which adjusts the heating power of each heater and the opening degree of each electric valve.

[0007] The aforementioned high-temperature vibration fatigue testing system for gas turbine blades includes a measurement and control unit that further comprises a laser displacement sensor, an accelerometer, and a strain gauge. The strain gauge is tightly fitted onto the surface of the blade sample. The accelerometer is mounted on the platform of the electromagnetic vibration table, and the laser displacement sensor is mounted on the wall of the high-temperature chamber. The detection laser beam emitted by the laser displacement sensor is projected onto the surface of the blade sample and received by the sensor receiver after reflection. The laser displacement sensor and the accelerometer are respectively connected to a power amplifier, and then communicate with the vibration control system through the power amplifier. The strain gauge is communicated with a multi-channel dynamic strain measurement system.

[0008] The above-mentioned high-temperature vibration fatigue testing system for gas turbine blades has an air inlet at the top and an air outlet at the bottom of the high-temperature chamber. The blade sample is clamped between the air inlet and the air outlet, with the pressure surface of the blade sample facing the air outlet. An independent air duct is connected to the high-temperature chamber through the air inlet, and the independent air duct is wrapped with a heat insulation layer.

[0009] The aforementioned high-temperature vibration fatigue testing system for gas turbine blades includes a thermal energy circulation unit comprising a circulating fan, a first air duct, and a second air duct. The air inlet of the first air duct is connected to the bottom of the high-temperature chamber, the air outlet of the first air duct is fluidly connected to the air inlet of the circulating fan, the air outlet of the circulating fan is fluidly connected to the air inlet of the second air duct, and the air outlet of the second air duct is fluidly connected to the air inlets of each heater.

[0010] The aforementioned high-temperature vibration fatigue testing system for gas turbine blades includes a control valve installed at the air inlet of the high-temperature chamber, a connecting pipe installed at the air inlet end of the control valve, and an independent air duct connected to the connecting pipe for fluid communication; the first end of the branch air duct is connected to the connecting pipe for fluid communication, and the second end of the branch air duct is connected to the air inlet of the circulating fan for fluid communication; an interlocking valve that is linked to the control valve is installed on the branch air duct near the first end.

[0011] The aforementioned high-temperature vibration fatigue testing system for gas turbine blades includes a control valve comprising a housing, a rotary valve plate, and a motor. A connecting pipe is fixedly connected to the housing. The rotary valve plate is coaxially rotatably mounted inside the housing, and a flow hole with the same diameter as the air inlet is provided on the rotary valve plate. The motor is mounted on the housing, and the output shaft of the motor is coaxially fixedly connected to the rotary valve plate. The motor drives the rotary valve plate to rotate, aligning the flow hole with the air inlet for conduction or offsetting it for cut-off. Protrusions are fixedly mounted on the surface of the rotary valve plate, and the protrusions are spaced apart from the flow holes. A groove is provided on one side of the housing, and the protrusions protrude from the groove on the housing. The end of the linkage valve extends into the groove. When the rotary valve plate rotates, it drives the protrusions to push the end of the linkage valve, thereby opening the linkage valve.

[0012] The aforementioned high-temperature vibration fatigue testing system for gas turbine blades includes a linkage valve comprising a fixed housing, a movable baffle, a pin, and a stop block. The fixed housing has a through hole, and the movable baffle is disposed inside the fixed housing and fits against the through hole. The area of ​​the fixed housing is larger than the area of ​​the movable baffle. The edge of the fixed housing is hinged to the movable baffle via the pin. The stop block is fixed to the side wall of the movable baffle and passes through the fixed housing. The free end of the stop block extends into a groove on the housing. A spring is installed on the stop block, and the other end of the spring is connected to the fixed housing.

[0013] The aforementioned high-temperature vibration fatigue testing system for gas turbine blades includes a clamping fixture comprising a clamping block, a toothed column, and a blade clamp. The clamping block has an internal toothed hole, the toothed column is inserted into the internal toothed hole, and the blade clamp is fixed to the end of the toothed column. The side wall of the blade clamp fits against the side wall of the clamping block, and the other end of the toothed column is pressed against the side wall of the clamping block by bolts. The blade root of the blade sample is fixed to the blade clamp. The clamping block is connected to an electromagnetic vibration table via a connecting column, and the connecting column is connected to a circulating water cooling system via a pipeline.

[0014] The technical solution of the present invention achieves the following beneficial technical effects:

[0015] This invention utilizes a matrix heater system composed of multiple independently controlled heaters, each corresponding to a specific temperature zone on the turbine blade sample. Combined with independently controllable air ducts, this creates a non-uniform temperature field distribution on the blade sample. The physical structure ensures the independence and precision of temperature control in each zone, allowing for the acquisition of the influence of turbine blade temperature gradients on high-cycle fatigue performance. By setting up a measurement and control unit with corresponding algorithms, the heating power of each heater and the opening of the corresponding independent air duct are dynamically adjusted, independently controlling the airflow velocity and mass flow rate in the corresponding area. This "airflow-heat" coupled regulation mechanism enables the system to simulate the complex non-uniform aerodynamic heating effect on the blade surface, overcoming the limitations of traditional thermal fatigue testing machines that can only provide a uniform temperature environment. This represents a leap from "static heating" to "dynamic thermal field simulation," while simultaneously simulating a realistic high-temperature airflow impact environment.

[0016] This invention employs a thermal energy circulation unit in conjunction with branch ducts, control valves, and linkage valves. The heater can first circulate and heat the air to a specified temperature. The preheated high-temperature air can then directly impact the turbine blades, simulating the instantaneous impact of high-temperature combustion gas on the turbine blades, rather than using gradually heated hot air to impact the turbine blades. The temperature change on the surface of the turbine blades matches the actual operating conditions, thereby obtaining accurate temperature data. Attached Figure Description

[0017] Figure 1 Front view cross-sectional structural schematic diagram of the present invention

[0018] Figure 2 A perspective three-dimensional schematic diagram of the high-temperature chamber of this invention;

[0019] Figure 3 A perspective three-dimensional schematic diagram of the clamping fixture of the present invention;

[0020] Figure 4 A top cross-sectional view of the control valve of this invention;

[0021] Figure 5 A top view cross-sectional schematic diagram of the linkage valve of the present invention.

[0022] The reference numerals in the figure are as follows:

[0023] 100 - High temperature chamber; 101 - Air inlet; 102 - Air outlet;

[0024] 200-Electromagnetic vibration table;

[0025] 300-Clamping fixture; 301-Clamping block; 302-Internal toothed hole; 303-Toothed post; 304-Blade clamp;

[0026] 400 - Measurement and control unit; 401 - Laser displacement sensor; 402 - Accelerometer; 403 - Temperature detection component; 404 - Strain gauge;

[0027] 500 - Heater; 501 - Independent air duct; 502 - Insulation layer; 503 - Industrial control computer;

[0028] 600 - Thermal energy circulation unit; 601 - Circulating fan; 602 - First air duct; 603 - Second air duct;

[0029] 700-blade sample;

[0030] 800-Branch duct; 801-Control valve; 802-Housing shell; 803-Rotary valve plate; 804-Flow hole; 805-Motor; 806-Protrusion; 807-Linkage valve; 808-Fixed shell; 809-Movable baffle; 810-Pin; 811-Stop. Detailed Implementation

[0031] This embodiment provides a high-temperature vibration fatigue testing system for gas turbine blades, such as... Figure 1 As shown, the system includes a high-temperature chamber 100, an electromagnetic vibration table 200, a clamping fixture 300, two or more independently adjustable heaters 500, and a thermal energy circulation unit 600. The table surface of the electromagnetic vibration table 200 is fixedly connected to the clamping fixture 300 via a connecting column extending into the high-temperature chamber 100. The connecting column and the high-temperature chamber 100 are sealed together using an internal high-temperature elastic material. The blade sample 700 is placed inside the high-temperature chamber 100 and clamped onto the clamping fixture 300. All components of the testing system that come into contact with high temperatures are made of high-temperature resistant materials and are covered with thermal insulation material.

[0032] The blade surface of the blade sample 700 is divided into two or more independent temperature zones. Specifically, the division is carried out along the length and width of the blade in a grid pattern. The area of ​​each temperature zone can be the same or different, and repeated adjustments can be made according to actual needs. The air outlet of each heater 500 is connected to the high-temperature chamber 100 through an independent air duct 501, and the air outlet of each independent air duct 501 corresponds to a temperature zone on the blade sample 700. An electric valve is installed on the independent air duct 501. Each heater 500 and electric valve are electrically connected to the industrial control computer 503. The industrial control computer 503 is used to adjust the heating power of the heater 500 and the opening degree of the electric valve.

[0033] like Figure 1 As shown, the air inlet of heater 500 is fluidly connected to the air outlet of thermal energy circulation unit 600, and the air inlet of thermal energy circulation unit 600 is fluidly connected to high temperature chamber 100; thermal energy circulation unit 600 sends air from high temperature chamber 100 into each heater 500, and acts on blade sample 700 through independent air duct 501.

[0034] like Figure 1 and Figure 2 As shown, the high-temperature chamber 100 has an air inlet 101 at the top, which is matched with a matrix of independent air ducts 501. The air inlet 101 protrudes upward to form a connecting pipe. The independent air ducts 501 are inserted into the connecting pipe and are in fluid communication with the air inlet 101. Each independent air duct 501 is wrapped with a heat insulation layer 502 to prevent heat from affecting each other laterally. The high-temperature chamber 100 has an air outlet 102 at the bottom. The blade sample 700 is clamped between the air inlet 101 and the air outlet 102, and the pressure surface of the blade sample 700 is set towards the air outlet 102.

[0035] like Figure 1As shown, the thermal energy circulation unit 600 includes a circulating fan 601, a first air duct 602, and a second air duct 603. The air inlet of the first air duct 602 is connected to the bottom of the high-temperature chamber 100, the air outlet of the first air duct 602 is fluidly connected to the air inlet of the circulating fan 601, the air outlet of the circulating fan 601 is fluidly connected to the air inlet of the second air duct 603, and the air outlet of the second air duct 603 is fluidly connected to the air inlet of each heater 500.

[0036] like Figure 1 As shown, a control valve 801 is installed on the air inlet 101 of the high-temperature chamber 100. A connecting pipe is provided on the air inlet end of the control valve 801. The independent air duct 501 is in fluid communication with the connecting pipe. The first end of the branch air duct 800 is in fluid communication with the connecting pipe, and the second end of the branch air duct 800 is in fluid communication with the air inlet of the circulating fan 601. An interlocking valve 807 that is linked with the control valve 801 is installed on the branch air duct 800 near the first end.

[0037] like Figure 4 As shown, the control valve 801 includes a housing 802, a rotary valve plate 803, and a motor 805. A connecting pipe is fixedly connected to the housing 802. The rotary valve plate 803 is coaxially rotatably installed inside the housing 802. A flow hole 804 with the same diameter as the air inlet 101 is opened on the rotary valve plate 803. The motor 805 is installed on the housing 802. The output shaft of the motor 805 is coaxially fixedly connected to the rotary valve plate 803. The motor 805 drives the rotary valve plate 803 to rotate, so that the flow hole 804 is aligned with the air inlet 101 for conduction or staggered for cut-off. A protrusion 806 is fixedly installed on the surface of the rotary valve plate 803. The protrusion 806 is arranged at intervals with the flow hole 804. A groove is opened on one side of the housing 802. The protrusion 806 protrudes from the groove position on the housing 802. The end of the linkage valve 807 extends into the groove. When the rotary valve plate 803 rotates, it drives the protrusion 806 to push the end of the linkage valve 807, so that the linkage valve 807 opens.

[0038] like Figure 5 As shown, the linkage valve 807 includes a fixed housing 808, a movable baffle 809, a pin 810, and a stop block 811. The fixed housing 808 has a through hole. The movable baffle 809 is disposed inside the fixed housing 808 and fits against the through hole. The area of ​​the fixed housing 808 is larger than the area of ​​the movable baffle 809. The edge of the fixed housing 808 is hinged to the movable baffle 809 by the pin 810. The stop block 811 is fixed on the side wall of the movable baffle 809 and passes through the fixed housing 808. The free end of the stop block 811 extends into a groove on the housing 802. A spring is installed on the stop block 811, and the other end of the spring is connected to the fixed housing 808.

[0039] The test system in this embodiment, such as Figure 1As shown, it also includes a measurement and control unit 400 that is communicatively connected to the industrial control computer 503. The measurement and control unit 400 includes a temperature detection component 403, which is used to detect the temperature data of each temperature zone of the blade sample 700. In this embodiment, the temperature detection component 403 is an infrared thermal imager with two infrared detection probes. To facilitate detection, light-transmitting glass plates are provided on the walls of the high-temperature chamber 100 at positions opposite to the pressure and suction surfaces of the blade sample 700. The light-transmitting glass plates are made of quartz glass, which can minimize the influence on the detection light. Other types of glass or light-transmitting materials can also be used to minimize the influence. The infrared detection probes are positioned one above the other. The infrared detection probes are fixed on both sides of the high-temperature chamber 100, and the detection beam is projected onto the surface of the blade sample 700 through the light-transmitting glass plate. Before the test, the infrared detection probes are tested and calibrated, and the test is carried out after they are stable. The temperature detection component 403 also includes a host and other structures to realize temperature detection, which is the same as the existing technology and will not be described in detail. The temperature detection component 403 transmits the temperature data to the multivariable decoupling control algorithm built into the measurement control unit 400 to obtain the measured temperature field data. The multivariable decoupling control algorithm outputs the control parameters to the industrial control computer 503 according to the deviation between the measured temperature field data and the target temperature field data. The industrial control computer 503 adjusts the heating power of each heater 500 and the opening degree of each electric valve.

[0040] like Figure 1 As shown, the measurement and control unit 400 also includes a laser displacement sensor 401, an acceleration sensor 402, and a strain gauge 404. The strain gauge 404 is tightly attached to the surface of the blade sample 700. The acceleration sensor 402 is mounted on the platform of the electromagnetic vibration table 200. The laser displacement sensor 401 is mounted on the wall of the high-temperature chamber 100. The laser displacement sensor 401 adopts the spectral confocal scheme in the prior art. The detection laser beam emitted by the laser displacement sensor 401 is projected onto the surface of the blade sample 700. The detection laser beam is reflected by the surface of the blade sample 700 to the receiving end of the laser displacement sensor 401. The laser displacement sensor 401 and the acceleration sensor 402 are respectively connected to a power amplifier, and then communicate with the vibration control system through the power amplifier. The strain gauge 404 communicates with the multi-channel dynamic strain measurement system. By actually measuring the amplitude and strain of the blade sample 700, the actual output power of the electromagnetic vibration table 200 is adjusted.

[0041] like Figure 3As shown, the clamping fixture 300 in this embodiment includes a clamping and fixing block 301, a toothed column 303, and a blade clamp 304. The clamping and fixing block 301 has an inner toothed hole 302. The toothed column 303 is inserted into the inner toothed hole 302. The blade clamp 304 is fixed on the end of the toothed column 303. The side wall of the blade clamp 304 fits against the side wall of the clamping and fixing block 301. The other end of the toothed column 303 is pressed onto the side wall of the clamping and fixing block 301 by bolts. The blade root of the blade sample 700 is fixed on the blade clamp 304. The clamping and fixing block 301 is connected to the electromagnetic vibration table 200 through a connecting column. The connecting column is connected to the circulating water cooling system through a pipeline.

[0042] During the specific test, the test system is first set up, and the heater 500 and the circulating fan 601 are turned on. At this time, the flow hole 804 and the independent air duct 501 are in a staggered state, that is, the independent air duct 501 is closed. Since the entire test system is in a relatively closed state, the protrusion 806 pushes the stop block 811, the movable baffle 809 is opened, and the branch air duct 800 is in a conductive state. The circulating fan 601 cannot continuously draw air from the high-temperature chamber 100 through the first air duct 602. At this time, a "small circulation" state is performed, that is, the gas blown by the circulating fan 601 is heated after passing through the heater 500. The heated gas enters the branch air duct 800 through the independent air duct 501, and then enters the air inlet of the circulating fan 601 again through the first air duct 602, so as to achieve the effect of circulating and heating the air, and at the same time, it can preheat some of the pipelines.

[0043] Once the air is preheated to the specified temperature, the electromagnetic vibration table 200 is activated. The electromagnetic vibration table 200 applies vibration to the blade sample 700 via the clamping fixture 300. The motor 805 drives the rotary valve 803 to rotate, connecting the flow hole 804 to the independent air duct 501. Simultaneously, the protrusion 806 and the stop block 811 are misaligned, and the movable baffle 809 is reset and closed under spring action. The branch air duct 800 is closed, and the high-temperature airflow directly enters the high-temperature chamber 100 through the independent air duct 501, impacting the cold blade sample. Sample 700 enters the "large circulation" state, which meets the working condition of high-temperature gas instantaneously impacting the cold blade sample 700; when periodic thermal shock testing is required, the motor 805 drives the rotary valve plate 803 to rotate, so that the flow hole 804 periodically connects with the independent air duct 501, realizing the periodic thermal shock of the blade sample 700 by the high-temperature airflow. When the independent air duct 501 is closed, the protrusion 806 pushes the stop block 811, the linkage valve 807 opens, and the high-temperature air undergoes "small circulation" to keep the air warm.

[0044] Two infrared temperature probes, one above and one below, measure the surface temperature of the blade sample 700. By adjusting the size of the detection spot of the infrared temperature probe, the detection spot covers the blade sample 700, thereby detecting the temperature change and temperature gradient on the surface of the blade sample 700.

[0045] The test system used in this implementation:

[0046] 1. Achieving accurate simulation of non-uniform temperature fields on blade surfaces, improving testing precision: Existing technologies typically only provide a uniform ambient temperature, ignoring the significant temperature gradient from the blade root to the tip during actual operation, leading to overly optimistic or unrealistic test results. This invention utilizes a matrix-style segmented heating module and a multi-channel airflow distributor to achieve independent spatial zone control. By adjusting the heating power and airflow rate (airflow-heat coupling) of different areas, a complex non-uniform temperature field consistent with actual operating conditions can be constructed on the blade surface. Combined with real-time feedback from an infrared thermal imager, errors caused by "temperature field mismatch" in traditional testing can be eliminated, making the test data closer to engineering reality.

[0047] 2. Mechanical linkage design ensures high reliability in high-temperature environments: In high-temperature environments, traditional electronic valves or independent actuators are prone to failure, and their control logic is complex and prone to malfunction. This invention adopts a mechanical linkage structure, using a single motor drive to achieve logical interlocking of "main circuit open, branch circuit closed". This completely avoids damage to electronic components caused by high temperatures, and the action response is absolutely synchronous, eliminating the need for complex high-temperature sensor feedback control, greatly improving the system's operational stability and safety in extreme environments.

[0048] 3. Realistically reproducing the "thermal shock" condition, solving the distortion problem of traditional static heating: Existing technologies mostly use constant temperature chambers or quartz lamps for static heating, where the blade temperature rises slowly and uniformly, failing to simulate the intense process of high-temperature gas impacting cold blades at the moment of gas turbine startup. This invention uses a "small loop-large loop" switching mechanism. The system first heats the air to the target temperature in a closed loop (small loop), then instantly switches to the impact mode (large loop) via a rotating valve. This allows the high-temperature airflow to directly impact the blades at an extremely high heating rate, accurately simulating the "thermal shock" process under real-world conditions, thus enabling accurate acquisition of fatigue life data for blades under drastic temperature changes.

[0049] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A high-temperature vibration fatigue testing system for gas turbine blades, characterized in that, It includes a high-temperature chamber (100), an electromagnetic vibration table (200), a clamping fixture (300), two or more independently adjustable heaters (500), and a thermal energy circulation unit (600). The blade sample (700) is placed inside the high temperature chamber (100), and the blade sample (700) is clamped on the table surface of the electromagnetic vibration table (200) by the clamping fixture (300). The blade surface of the blade sample (700) is divided into two or more independent temperature zones; the air outlet of each heater (500) is connected to the high temperature chamber (100) through an independent air duct (501), and the air outlet of each independent air duct (501) corresponds to a temperature zone on the blade sample (700). An electric valve is installed on the independent air duct (501); each heater (500) and electric valve are electrically connected to the industrial control computer (503). The air inlet of the heater (500) is fluidly connected to the air outlet of the thermal energy circulation unit (600), and the air inlet of the thermal energy circulation unit (600) is fluidly connected to the high temperature chamber (100); the thermal energy circulation unit (600) sends the air in the high temperature chamber (100) into each heater (500), and acts on the blade sample (700) through the independent air duct (501).

2. The high-temperature vibration fatigue testing system for gas turbine blades according to claim 1, characterized in that, It also includes a measurement control unit (400) that is connected to the industrial control computer (503). The measurement control unit (400) includes a temperature detection component (403). The temperature detection component (403) is used to detect the temperature data of each temperature zone of the blade sample (700) and transmit the temperature data to the multivariable decoupling control algorithm built into the measurement control unit (400) to obtain the measured temperature field data. The multivariable decoupling control algorithm outputs the control parameters to the industrial control computer (503) according to the deviation between the measured temperature field data and the target temperature field data. The industrial control computer (503) adjusts the heating power of each heater (500) and the opening degree of each electric valve.

3. The high-temperature vibration fatigue testing system for gas turbine blades according to claim 2, characterized in that, The measurement control unit (400) also includes a laser displacement sensor (401), an acceleration sensor (402), and a strain gauge (404). The strain gauge (404) is tightly attached to the surface of the blade sample (700). The acceleration sensor (402) is mounted on the table of the electromagnetic vibration table (200). The laser displacement sensor (401) is mounted on the wall of the high-temperature chamber (100). The detection laser beam emitted by the laser displacement sensor (401) is projected onto the surface of the blade sample (700). The detection laser beam is reflected by the surface of the blade sample (700) to the receiving end of the laser displacement sensor (401). The laser displacement sensor (401) and the acceleration sensor (402) are respectively connected to the power amplifier and then communicate with the vibration control system through the power amplifier. The strain gauge (404) is communicated with the multi-channel dynamic strain measurement system.

4. A high-temperature vibration fatigue testing system for gas turbine blades according to claim 1, characterized in that, The high-temperature chamber (100) has an air inlet (101) at the top and an air outlet (102) at the bottom. The blade sample (700) is clamped between the air inlet (101) and the air outlet (102), and the pressure surface of the blade sample (700) faces the air outlet (102). An independent air duct (501) is connected to the high-temperature chamber (100) through the air inlet (101), and the independent air duct (501) is wrapped with a heat insulation layer (502).

5. A high-temperature vibration fatigue testing system for gas turbine blades according to claim 1, characterized in that, The thermal energy circulation unit (600) includes a circulating fan (601), a first air duct (602) and a second air duct (603). The air inlet of the first air duct (602) is connected to the bottom of the high-temperature box (100). The air outlet of the first air duct (602) is fluidly connected to the air inlet of the circulating fan (601). The air outlet of the circulating fan (601) is fluidly connected to the air inlet of the second air duct (603). The air outlet of the second air duct (603) is fluidly connected to the air inlet of each heater (500).

6. A high-temperature vibration fatigue testing system for gas turbine blades according to claim 5, characterized in that, A control valve (801) is installed on the air inlet (101) of the high temperature chamber (100). A connecting pipe is provided on the air inlet end of the control valve (801). The independent air duct (501) is fluidly connected to the connecting pipe. The first end of the branch air duct (800) is fluidly connected to the connecting pipe, and the second end of the branch air duct (800) is fluidly connected to the air inlet of the circulating fan (601). A linkage valve (807) that is linked with the control valve (801) is installed on the branch air duct (800) near the first end.

7. A high-temperature vibration fatigue testing system for gas turbine blades according to claim 6, characterized in that, The control valve (801) includes a housing (802), a rotary valve plate (803), and a motor (805). The connecting pipe is fixedly connected to the housing (802). The rotary valve plate (803) is coaxially rotatably installed inside the housing (802). The rotary valve plate (803) has a flow hole (804) with the same diameter as the air inlet (101). The motor (805) is installed on the housing (802). The output shaft of the motor (805) is coaxially fixedly connected to the rotary valve plate (803). The motor (805) drives the rotary valve plate (803) to rotate, so that the flow hole (804) is aligned with the air inlet (101) for conduction or staggered cut-off.

8. A high-temperature vibration fatigue testing system for gas turbine blades according to claim 7, characterized in that, A protrusion (806) is fixedly installed on the surface of the rotary valve plate (803). The protrusion (806) and the flow hole (804) are arranged at intervals. A groove is provided on one side of the housing (802). The protrusion (806) protrudes from the groove on the housing (802). The end of the linkage valve (807) extends into the groove. When the rotary valve plate (803) rotates, it drives the protrusion (806) to push the end of the linkage valve (807) to open the linkage valve (807).

9. A high-temperature vibration fatigue testing system for gas turbine blades according to claim 8, characterized in that, The linkage valve (807) includes a fixed shell (808), a movable baffle (809), a pin (810), and a stop block (811). The fixed shell (808) has a through hole. The movable baffle (809) is disposed inside the fixed shell (808) and fits against the through hole. The area of ​​the fixed shell (808) is larger than the area of ​​the movable baffle (809). The edge of the fixed shell (808) is hinged to the movable baffle (809) through the pin (810). The stop block (811) is fixed on the side wall of the movable baffle (809) and passes through the fixed shell (808). The free end of the stop block (811) extends into the groove on the outer shell (802). A spring is installed on the stop block (811), and the other end of the spring is connected to the fixed shell (808).

10. A high-temperature vibration fatigue testing system for gas turbine blades according to claim 1, characterized in that, The clamping fixture (300) includes a clamping block (301), a toothed column (303), and a blade clamp (304). The clamping block (301) has an inner toothed hole (302). The toothed column (303) is inserted into the inner toothed hole (302). The blade clamp (304) is fixed on the end of the toothed column (303). The side wall of the blade clamp (304) fits against the side wall of the clamping block (301). The other end of the toothed column (303) is pressed onto the side wall of the clamping block (301) by bolts. The blade root of the blade sample (700) is fixed on the blade clamp (304). The clamping block (301) is connected to the electromagnetic vibration table (200) through a connecting column. The connecting column is connected to the circulating water cooling system through a pipeline.

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