A kind of identification test device and identification method of gas turbine squeeze film damper dynamic coefficient based on simple harmonic excitation principle

Abstract

The present application relates to the technical field of gas turbine, and particularly relates to a kind of identification test device and identification method of gas turbine extrusion oil film damper dynamics coefficient based on simple harmonic excitation principle, including test bench module, the test bench module includes SYT test system test bench, PC control machine, PC data collector system, YX lubricating oil tank, LE electric heater, TE thermocouple, YW liquid level meter, LM lubricating oil supply pump, LM lubricating oil return pump, LQ lubricating oil supply filter, LQ lubricating oil return filter, LL flowmeter, wherein, SYT test system test bench is used to install and drive gas turbine extrusion oil film damper.The test device relied on by the present application is simple in structure, convenient for testing, and is suitable for the dynamics coefficient identification of the extrusion oil film damper of the gas turbine, so that the dynamics coefficient identification of the extrusion oil film damper of the gas turbine can be tested on site, without the need for testing in a professional place, making the dynamics coefficient identification of the extrusion oil film damper of the gas turbine more convenient.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, and specifically to a test device and method for identifying the dynamic coefficient of a gas turbine squeeze film damper based on the principle of simple harmonic excitation. Background Technology

[0002] A gas turbine is an internal combustion power machine that uses a continuously flowing gas as a working fluid to drive a high-speed rotating impeller, converting the energy of fuel into useful work. It is a type of rotating impeller thermal engine. The use of gas turbines in the energy and power fields is increasing day by day. The rotor operating speed of new gas turbines is mostly transcritical speed. The rotor operating speed is higher and the gap between the rotor and the casing is smaller, which puts forward higher requirements for vibration and reliability.

[0003] The vibration suppression design of the rotor-support system of a gas turbine directly affects the reliability of the entire machine. As an important structure in the rotor-support system, the squeeze film damper effectively suppresses rotor vibration by utilizing the dissipation effect generated by the viscous fluid in the squeeze flow.

[0004] The dynamic coefficient of the extrusion film damper plays an important role in the design of the gas turbine rotor-support structure. However, most existing test equipment is difficult to test the dynamic coefficient of the extrusion film damper on-site. The extrusion film damper needs to be sent to the test site to test the dynamic coefficient, which makes the testing and identification of the dynamic coefficient of the extrusion film damper inconvenient.

[0005] Therefore, the present invention provides a test device and method for identifying the dynamic coefficient of a gas turbine extrusion film damper based on the principle of simple harmonic excitation, in order to solve the above-mentioned problems. Summary of the Invention

[0006] This invention addresses the technical problems existing in the prior art by providing a test device and method for identifying the dynamic coefficient of a gas turbine extrusion film damper based on the principle of simple harmonic excitation.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a test device for identifying the dynamic coefficient of a gas turbine squeeze film damper based on the principle of simple harmonic excitation, including a test bench module; The test bench module includes a SYT test system test bench, a PC controller, a PC data acquisition system, a YX lubricating oil tank, an LE electric heater, a TE thermocouple, a YW level gauge, an LM lubricating oil supply pump, an LM lubricating oil return pump, an LQ lubricating oil supply filter, an LQ lubricating oil return filter, and an LL flow meter. Among them, the SYT test system test bench is used to install and drive the gas turbine squeeze film damper; Based on the collaboration of multiple components in the test bench module, the dynamic coefficients of the gas turbine extrusion film damper on the SYT test system test bench are identified.

[0008] In a preferred embodiment, the SYT test system test bench includes a transmission assembly and a damper assembly; The transmission assembly includes a connecting screw, a dynamic force sensor, a vibrator, and a base. Among them, the connecting screw is used to achieve rigid connection and position fixation of each key structural component of the test bench; Among them, the dynamic force sensor is used to collect the excitation force data applied by the exciter in real time, providing key force parameters for the calculation of dynamic coefficients; Among them, the exciter is used to apply simple harmonic excitation according to set parameters to simulate the vibration condition of the gas turbine rotor when it is working, and to provide an excitation source for the test of the dynamic characteristics of the damper. The base serves as the foundational support structure for the test bench.

[0009] In a preferred embodiment, the dynamic force sensor is fixedly mounted on the surface of the connecting screw, and one end of the connecting screw is fixedly connected to the vibrator, which is rotatably mounted inside the base via a lead screw.

[0010] In a preferred embodiment, the damper assembly includes an elastic squirrel cage support, an outer ring of a squeeze film damper, an oil supply nozzle, a pressure gauge, an end seal of the squeeze film damper, an oil discharge nozzle, an elastic squirrel cage support seat, and an outer ring support seat of the squeeze film damper. The connecting screw is fixedly connected to the elastic squirrel cage support and is used to transmit the force generated by the vibrator to the elastic squirrel cage support.

[0011] In a preferred embodiment, the damper assembly further includes a drain nozzle, a displacement sensor clamp, a displacement sensor, and a lubricating oil collection plate. The drain nozzle is disposed on the lubricating oil collection plate. The displacement sensor clamp is fixedly disposed inside the elastic squirrel cage support by bolts, and the displacement sensor is disposed on the surface of the displacement sensor clamp by bolts. The lubricating oil collection plate is fixedly disposed on the surface of the elastic squirrel cage support and the outer ring support of the squeeze oil film damper.

[0012] In a preferred embodiment, the outer ring of the extrusion oil film damper is sleeved on the surface of the elastic squirrel cage support, the oil supply nozzle is disposed on the surface of the outer ring of the extrusion oil film damper and one end is connected to the elastic squirrel cage support, the pressure gauge is fixedly disposed on the surface of the oil supply nozzle, and the end cap of the extrusion oil film damper is sleeved between the inner arc surface of the outer ring of the extrusion oil film damper and the outer arc surface of the elastic squirrel cage support.

[0013] In a preferred embodiment, the oil drain nozzle is fixedly disposed below the outer ring of the extrusion oil film damper, and one end of the oil drain nozzle passes through the outer ring of the extrusion oil film damper and communicates with the elastic squirrel cage support. The elastic squirrel cage support and the outer ring support of the extrusion oil film damper are fixedly connected to the elastic squirrel cage support and the outer ring of the extrusion oil film damper, respectively. The elastic squirrel cage support and the outer ring of the extrusion oil film damper are fixedly connected to the base.

[0014] A method for identifying the dynamic coefficient of a gas turbine extrusion film damper based on the principle of simple harmonic excitation, applied to any one of the above-mentioned identification test devices for the dynamic coefficient of a gas turbine extrusion film damper based on the principle of simple harmonic excitation, includes the following specific steps: S1: Based on the design requirements of the gas turbine, determine the core parameters under different operating conditions, including rotor speed n (unit: r / min), target lubricating oil temperature T (unit: ℃), target lubricating oil supply pressure P (unit: Pa), and calculate the excitation frequency corresponding to the speed. S2: Complete the overall construction of the test bench and the connection of each system, ensuring that core components such as the elastic squirrel cage support, the extrusion oil film damper, the vibrator, and the sensor are installed in place, and that the lubrication system and the control and data acquisition system are connected smoothly. S3: The electric heater LE1 is started by the control unit PC1 to heat the lubricating oil in the lubricating oil tank YX1. The oil temperature is monitored in real time by the thermocouple TE1 until the lubricating oil temperature reaches the set value T. After the oil temperature reaches the target, the control unit PC1 first starts the lubricating oil return pump LM2, and then starts the lubricating oil supply pump LM1. The lubricating oil is filtered by the lubricating oil supply filter LQ1 and enters the squeezing oil film damper through the oil supply nozzle to form an effective internal oil film. The output of the lubricating oil supply pump LM1 is adjusted to stabilize the oil supply pressure displayed by the pressure gauge at the set value P. S4: The exciter in the X direction is triggered only by the controller PC1. The excitation output power is set to P1, the excitation frequency is υ, and the trigger signal is a sine signal. The original excitation force data OF1x and OF1y in the X and Y directions are collected by the dynamic force sensor, and the original displacement data OD1x and OD1y in the X and Y directions are collected by the displacement sensor. All the original data are transmitted to the data acquisition system PC2 for storage in real time. The exciter in the Y direction is triggered only by the controller PC1. The excitation output power is set to P2 (P1=P2 is required), the excitation frequency is still υ, and the trigger signal is a cosine signal (forming a 90° phase difference with the X direction excitation). The above data acquisition process is repeated. The original excitation force data OF2x and OF2y are acquired by the dynamic force sensor, and the original displacement data OD2x and OD2y are acquired by the displacement sensor. The data is then transmitted to PC2 for storage. S5: The data is filtered, Fourier transformed and parameters are extracted, and unit calibration is performed. Then, the matrix equation is established, the matrix is ​​determined to be invertible, the dynamic coefficients are solved, the dynamic coefficients are identified, and finally the dynamic coefficients of the gas turbine extrusion oil film damper are obtained based on the principle of simple harmonic excitation.

[0015] The beneficial effects of this invention are as follows: The method for identifying the dynamic coefficient of a gas turbine extrusion film damper based on the principle of simple harmonic excitation provided by this invention has a simple test device structure, is convenient for testing, and is suitable for identifying the dynamic coefficient of a gas turbine extrusion film damper. This allows the identification of the dynamic coefficient of the gas turbine extrusion film damper to be tested on-site without the need for testing in a professional location, making the identification of the dynamic coefficient of the gas turbine extrusion film damper more convenient. This invention provides a method for identifying the dynamic coefficients of a gas turbine extrusion film damper based on the principle of simple harmonic excitation. It can identify the dynamic coefficients of the gas turbine under different operating conditions such as rotor frequency, oil supply pressure, and oil supply temperature, providing support for the design of gas turbine rotors. This invention provides a method for identifying the dynamic coefficients of a gas turbine extrusion film damper based on the principle of simple harmonic excitation. It has strong engineering applicability and relies on a test bench device to obtain force, displacement and phase data, thereby realizing the identification of the dynamic coefficients of the gas turbine extrusion film damper. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the test bench structure of the SYT1 test system of the present invention; Figure 2 This is a schematic cross-sectional view of the test bench of the SYT1 test system of the present invention; Figure 3 This is a schematic diagram of the elastic squirrel cage support, displacement sensor fixture, and displacement sensor structure of the present invention. Figure 4 This is a flowchart of the dynamic coefficient identification method for the extrusion oil film damper of the present invention; Figure 5 This is a diagram of the test system of the present invention; Figure 6 This is a schematic diagram of the test system of the present invention.

[0017] In the diagram: 1. Connecting screw; 2. Dynamic force sensor; 3. Vibrator; 4. Base; 5. Elastic squirrel cage support; 6. Outer ring of the extrusion oil film damper; 7. Oil supply nozzle; 8. Pressure gauge; 9. End seal of the extrusion oil film damper; 10. Oil drain nozzle; 11. Elastic squirrel cage support seat; 12. Outer ring support seat of the extrusion oil film damper; 13. Drain nozzle; 14. Displacement sensor fixture; 15. Displacement sensor; 16. Lubricating oil collection plate. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] Reference Figure 1 - Figure 6 This application provides a test device for identifying the dynamic coefficient of a gas turbine squeeze film damper based on the principle of simple harmonic excitation, including a test bench module; The test bench module includes the SYT1 test system test bench, PC1 control computer, PC2 data acquisition system, YX1 lubricating oil tank, LE1 electric heater, TE1 thermocouple, YW1 level gauge, LM1 lubricating oil supply pump, LM2 lubricating oil return pump, LQ1 lubricating oil supply filter, LQ2 lubricating oil return filter, and LL1 flow meter. Among them, the SYT1 test system test bench is used to install and drive the gas turbine squeeze film damper; Based on the collaboration of multiple components in the test bench module, the dynamic coefficients of the gas turbine extrusion oil film damper on the SYT1 test system test bench are identified; The SYT1 test system test bench includes a transmission assembly and a damper assembly; The PC1 controller has a pre-set database of mainstream gas turbine rotor speed-frequency correspondences. After the user inputs the speed n, the recommended excitation frequency combination is automatically generated without manual calculation, which improves the ease of operation. The transmission assembly includes a connecting screw 1, a dynamic force sensor 2, a vibrator 3, and a base 4; Before the test, a frequency sweep test was conducted, and the frequency range was set to 0.5υ-2υ to identify the damper's natural frequency. The excitation frequency was automatically set to avoid the range of ±10% of the natural frequency to prevent resonance from causing data distortion. An insulation layer was added to the outside of the oil tank YX1, and thermocouple TE1 was added to the oil film inlet, outlet and inside the cavity. The actual oil film temperature was calculated by weighted average to compensate for the influence of ambient temperature fluctuations. Among them, the connecting screw 1 is used to achieve rigid connection and position fixation of each key structural component of the SYT1 test system test bench, and connect the core load-bearing components such as the elastic squirrel cage support 11 and the outer ring support 12 of the extrusion oil film damper, to ensure that the components do not undergo relative displacement during the test, maintain installation accuracy, enhance the rigidity of the overall structure of the SYT1 test system test bench, and avoid structural deformation caused by excitation force, which would affect the accuracy of excitation force transmission and displacement measurement. Among them, the dynamic force sensor 2 is used to collect the excitation force data applied by the exciter 3 in real time, providing key force parameters for the calculation of dynamic coefficients. It is installed between the exciter 3 and the elastic squirrel cage support 5, directly sensing the excitation force output by the exciter 3 in the X and Y directions, including raw data such as OF1x, OF1y, OF2x, and OF2y, and converting the mechanical signal into an electrical signal and transmitting it to the data acquisition system PC2 to ensure the real-time performance and accuracy of the excitation force data. Its measurement accuracy directly affects the reliability of the subsequent Fourier transform results and the solution of the dynamic equation, and is one of the core sensing components for identifying the dynamic coefficients of the damper. Among them, the exciter 3 is used to apply simple harmonic excitation according to the set parameters to simulate the vibration condition of the gas turbine rotor when it is working, and to provide an excitation source for the test of the damper dynamic characteristics. It is controlled by the controller PC1 and applies excitation force along the X and Y orthogonal directions respectively: the first test outputs power P1 and a sine signal, and the second test outputs power P2 (P1≠P2) and a cosine signal. The excitation frequency is υ, which is the frequency corresponding to the speed of the gas turbine, forming a simple harmonic excitation with a phase difference of 90°. By exciting the elastic squirrel cage support 5, the outer ring 6 of the extrusion oil film damper is driven to vibrate at the same frequency, which causes the oil film inside the damper to form an extrusion flow. Then, the vibration response data is collected by the sensor to create test conditions for the identification of dynamic coefficients. Among them, the base 4 is used as the basic load-bearing component of the SYT1 test system test bench, bearing all components of the SYT1 test system test bench, distributing the weight of each component and the load generated by the excitation force, and preventing the test bench from shifting or shaking as a whole. The dynamic force sensor 2 is fixedly mounted on the surface of the connecting screw 1, and one end of the connecting screw 1 is fixedly connected to the vibrator 3. The vibrator 3 is rotatably mounted inside the base 4 via a lead screw. The damper assembly includes an elastic squirrel cage support 5, an outer ring of an extrusion oil film damper 6, an oil supply nozzle 7, a pressure gauge 8, an end seal of the extrusion oil film damper 9, an oil discharge nozzle 10, an elastic squirrel cage support seat 11, and an outer ring support seat of the extrusion oil film damper 12. The connecting screw 1 is fixedly connected to the elastic squirrel cage support 5 and is used to transmit the force generated by the vibrator 3 to the elastic squirrel cage support 5. Among them, the elastic squirrel cage support 5 is the core support component of the damper, which has both support and vibration transmission functions. It directly bears the weight of the outer ring 6 of the squeeze oil film damper, and at the same time transmits the simple harmonic excitation applied by the exciter 3 to the inside of the damper, causing the oil film to squeeze and flow. Its elastic properties can simulate the support stiffness of the gas turbine rotor-support system, ensuring that the test conditions are consistent with the actual working scenario, and providing a real vibration response basis for the identification of dynamic coefficients; Among them, the outer ring 6 of the extrusion oil film damper constitutes the outer cavity of the extrusion oil film, providing space for oil film formation and extrusion flow, and cooperates with the internal rotor to form a closed oil film gap. After the lubricating oil is injected, a stable oil film is formed in this cavity. When subjected to vibration transmitted by the elastic squirrel cage support 5, the oil film generates a squeezing flow inside the cavity, thereby suppressing the vibration through the viscous dissipation effect. It is the core structural carrier for realizing the damping function. Among them, the oil supply nozzle 7 is used to accurately deliver lubricating oil to the oil film cavity of the damper, connects to the oil supply pipeline of the lubrication system, and injects the filtered and heated lubricating oil into the gap formed between the outer ring 6 and the internal components of the extrusion oil film damper, ensuring that the lubricating oil is evenly distributed, providing a guarantee for the formation of a stable and effective extrusion oil film, which directly affects the load-bearing capacity and damping effect of the oil film. Among them, pressure gauge 8 is used to monitor the lubricating oil supply pressure in real time to ensure the stability of the oil film. During the test, the oil supply pump needs to be adjusted to make the value displayed by pressure gauge 8 stable at the set target pressure P, so as to ensure that the oil film thickness and stiffness meet the test conditions. Among them, the squeeze oil film damper end seal 9 is used to seal the end of the damper to prevent lubricating oil leakage; Among them, the oil drain nozzle 10 is used to discharge the lubricating oil that has participated in the squeezing flow in the damper, so as to realize the oil circulation; Among them, the elastic squirrel cage support 11 and the outer ring support 12 of the extrusion oil film damper are used to fix the elastic squirrel cage support 5 and the outer ring 6 of the extrusion oil film damper, so as to ensure the installation accuracy and structural stability and ensure the accurate position of the cavity. The outer ring 6 of the extrusion oil film damper is sleeved on the surface of the elastic squirrel cage support 5. The oil supply nozzle 7 is set on the surface of the outer ring 6 of the extrusion oil film damper, and one end is connected to the elastic squirrel cage support 5. The pressure gauge 8 is fixedly set on the surface of the oil supply nozzle 7. The end seal 9 of the extrusion oil film damper is sleeved between the inner arc surface of the outer ring 6 of the extrusion oil film damper and the outer arc surface of the elastic squirrel cage support 5. The oil drain nozzle 10 is fixedly installed below the outer ring 6 of the extrusion oil film damper, and one end of the oil drain nozzle 10 passes through the outer ring 6 of the extrusion oil film damper and communicates with the elastic squirrel cage support 5. The elastic squirrel cage support 11 and the outer ring support 12 of the extrusion oil film damper are fixedly connected to the elastic squirrel cage support 5 and the outer ring 6 of the extrusion oil film damper, respectively. The elastic squirrel cage support 5 and the outer ring 6 of the extrusion oil film damper are fixedly connected to the base 4. The damper assembly also includes a drain nozzle 13, a displacement sensor clamp 14, a displacement sensor 15, and an oil collection plate 16. The drain nozzle 13 is disposed on the oil collection plate 16. The displacement sensor clamp 14 is fixedly disposed inside the elastic squirrel cage support 5 by bolts, and the displacement sensor 15 is disposed on the surface of the displacement sensor clamp 14 by bolts. The oil collection plate 16 is fixedly disposed on the surface of the elastic squirrel cage support 11 and the outer ring support 12 of the squeeze oil film damper. The drain nozzle 13 is used to guide the discharged lubricating oil to the lubricating oil collection plate 16 to avoid oil splashing. The displacement sensor clamp 14 is used to fix the displacement sensor 15 to ensure the accuracy of displacement measurement. Among them, the displacement sensor 15 is used to collect vibration displacement data, providing key response parameters for dynamic coefficient calculation. After being fixed by the clamp, it monitors the vibration displacement of the elastic squirrel cage support 5 in the X and Y directions in real time, and converts the mechanical displacement signal into an electrical signal and transmits it to the data acquisition unit PC2. A shielding cover is installed at the sensor end, and a differential signal transmission method is adopted to reduce electromagnetic interference on site; During the data acquisition phase, a 50Hz notch filter and a low-pass filter are added, with the cutoff frequency being 5 times the excitation frequency to filter out environmental vibration noise. The collected data includes raw data such as OD1x (X-direction displacement), OD1y (Y-direction displacement), OD2x, and OD2y from the two experiments. These data are the core source for extracting vibration characteristic parameters and solving dynamic equations through Fourier transform. Among them, the lubricating oil collection plate 16 is used to collect and recycle lubricating oil to realize the closed-loop circulation of the lubrication system.

[0020] A method for identifying the dynamic coefficient of a gas turbine extrusion film damper based on the principle of simple harmonic excitation, applied to any one of the above-mentioned identification test devices for the dynamic coefficient of a gas turbine extrusion film damper based on the principle of simple harmonic excitation, includes the following specific steps: S1: Reference Figure 2 and Figure 5 The test bench setup and test system connection were completed using this method; Based on the design requirements of the gas turbine, the core parameters under different operating conditions are determined, including rotor speed n (unit: r / min), target lubricating oil temperature T (unit: ℃), target lubricating oil supply pressure P (unit: Pa), and the frequency corresponding to the speed υ=n / 60 (Hz). Furthermore, frequency doubling and frequency division excitation options were added to S1, and excitation frequencies were set to υ, 2υ, and 0.5υ (υ=n / 60). Tests were conducted to identify the dynamic coefficients at different frequencies, thus comprehensively reflecting the actual working characteristics of the damper. S2: Complete the overall construction of the test bench and the connection of each system, ensuring that core components such as the elastic squirrel cage support 5, the extrusion oil film damper, the vibrator 3, and the sensor are installed in place, and that the lubrication system and the control and data acquisition system are connected smoothly. S3: The electric heater LE1 is started by the control unit PC1 to heat the lubricating oil in the lubricating oil tank YX1. The oil temperature is monitored in real time by the thermocouple TE1 until the lubricating oil temperature reaches the set value T. After the oil temperature reaches the standard, the control unit PC1 first starts the lubricating oil return pump LM2, and then starts the lubricating oil supply pump LM1. The lubricating oil is filtered by the lubricating oil supply filter LQ1 and enters the squeezing oil film damper through the oil supply nozzle 7 to form an effective internal oil film. The output of the lubricating oil supply pump LM1 is adjusted so that the oil supply pressure displayed by the pressure gauge 8 is stabilized at the set value P before triggering the vibrator 3. S4: The exciter in the X direction is triggered only by the controller PC1. The excitation output power is set to P1 and the excitation frequency is υ. A sinusoidal signal is triggered to excite the excitation. The dynamic force sensor 2 collects the raw data OF1x and OF1y of the X and Y excitation forces. The displacement sensor 15 collects the raw data OD1x and OD1y of the X and Y displacements. All raw data are transmitted to the data acquisition system PC2 for storage in real time. The controller PC1 triggers only the Y-direction exciter, sets the excitation output power to P2 (P1≠P2), and the excitation frequency remains υ. It triggers a cosine signal for excitation and repeats the above data acquisition process. The dynamic force sensor 2 collects the original excitation force data OF2x and OF2y, and the displacement sensor 15 collects the original displacement data OD2x and OD2y. The data is then transmitted to PC2 for storage. Simultaneously, multiple orthogonal excitation extensions are achieved through the controller PC1, using different excitation powers, such as P1, P2, P3...PN, which are not equal to each other and have phase differences of 90°, 180°, and 270°, to obtain an overdetermined set of equations. The dynamic coefficients are solved by the least squares method to avoid matrix singularity caused by a single data error. Limit the excitation power difference (e.g., |P1-P2|≥10%P1) and the phase difference error ≤±5°. Preset parameter verification logic in the controller PC1 to avoid the matrix determinant approaching zero due to the small difference in excitation parameters. S5: The data is filtered, Fourier transformed and parameters are extracted, and unit calibration is performed. Then, the matrix equation is established, the matrix is ​​determined to be invertible, the dynamic coefficients are solved, the dynamic coefficients are identified, and finally the dynamic coefficients of the gas turbine extrusion oil film damper are obtained based on the principle of simple harmonic excitation. If the absolute value of the coupling coefficient is less than 10% of the principal coefficient, the model can be simplified to an uncoupled form, retaining only the principal coefficient, thereby improving the adaptability of different types of dampers. Add matrix condition number verification to the matrix: Add condition number calculation to matrix M in S5. If the condition number is greater than the set threshold, the matrix is ​​determined to be close to singular, and an additional set of excitation tests is automatically triggered until the condition number meets the requirements to ensure the solution accuracy. The threshold is set to 1000; Based on the installation of the SYT1 test system test bench, it can be determined that a simple harmonic excitation force with a frequency of υ and a phase difference of 90° is applied in the x and y directions: ; in: υ is the excitation frequency, in Hz; ω is the angular frequency, measured in Hz; The maximum excitation force in the i-direction, in N; Let be the excitation force in the i-direction at time t, in N; At the same time, the simple harmonic model of the mouse cage performing simple harmonic motion at the same frequency can be measured as follows: ; in: The maximum displacement in the i-direction, in meters (m). Let be the displacement in the i-direction at time t, in meters. Substituting the above excitation force and harmonic model into the following damping model: ; in: m is the mass of the rat cage, in kg; Here, the principal stiffness is in the i-direction, in N / m. Coupled stiffness, in N / m; Damping in direction i, in Ns / m; For coupling damping, the unit is Ns / m; First, based on the sensitivity of the principal stiffness or damping coefficients to the data, solve for the principal coefficients separately. , , , Then, using the principal coefficients as known quantities, the coupling coefficients are solved iteratively through multiple sets of data. , , , This reduces the impact of the coupling coefficient on the overall error. Expanding the above damping model, we obtain the following four sub-models: ; To avoid interference from unstable factors at the beginning and end of the experiment, the first and last 1 / 3 of the data in the data strips were excluded, and only the middle 1 / 3 of the data in the data strips were retained for processing. The data segments F1x, F1y, D1x, D1y, F2x, F2y, D2x, and D2y were obtained sequentially from the original data OF1x, OF1y, OD1x, OD1y, OF2x, OF2y, OD2y. Fourier transform is performed on the experimental data segments F1x, F1y, D1x, and D1y under X-direction excitation. At the same time, the units of the parameters are processed to ensure that the unit of force is N and the unit of displacement is m, resulting in data FTF1x, FTF1y, FTD1x, and FTD1y respectively. Selecting the data group corresponding to the first maximum value in the FTD1x data, we obtain the following: , , , , , ; Fourier transform was performed on the experimental data segments F2x, F2y, D2x, and D2y under Y-direction excitation. At the same time, the units of the parameters were processed to ensure that the unit of force was N and the unit of displacement was m, resulting in data FTF2x, FTF2y, FTD2x, and FTD2y respectively. Selecting the data group corresponding to the first maximum value in the FTD2y data, we obtain the following: , , , , , ; Substituting the two sets of data into the sub-model, we obtain: ; in: ; ; ; By determining the non-invertibility of matrix M, i.e., det(M) ≠ 0, we can obtain: ; The excitation power was inconsistent in the two tests, and the excitation directions were orthogonal, indicating that matrix M is non-invertible. Therefore, the dynamic coefficient of the extrusion film damper can be obtained. ; After the solution is completed, the dynamic coefficients are substituted into the original damping model, and the theoretical excitation force or displacement is calculated in reverse. The error is compared with the actual collected data. If the error exceeds 5%, the abnormal data group is automatically removed and the solution is recalculated.

Claims

1. A test device for identifying the dynamic coefficient of a gas turbine squeeze film damper based on the principle of simple harmonic excitation, characterized in that, Includes a test bench module; The test bench module includes a SYT1 test system test bench, a PC1 control computer, a PC2 data acquisition system, a YX1 lubricating oil tank, a LE1 electric heater, a TE1 thermocouple, a YW1 level gauge, an LM1 lubricating oil supply pump, an LM2 lubricating oil return pump, an LQ1 lubricating oil supply filter, an LQ2 lubricating oil return filter, and an LL1 flow meter. Among them, the SYT1 test system test bench is used to install and drive the gas turbine squeeze film damper; Based on the collaboration of multiple components in the test bench module, the dynamic coefficients of the gas turbine extrusion oil film damper on the SYT1 test system test bench are identified.

2. The identification test device for the dynamic coefficient of a gas turbine squeeze film damper based on the principle of simple harmonic excitation according to claim 1, characterized in that, The SYT1 test system test bench includes a transmission assembly and a damper assembly; The transmission assembly includes a connecting screw (1), a dynamic force sensor (2), a vibrator (3), and a base (4).

3. The identification test device for the dynamic coefficient of a gas turbine squeeze film damper based on the principle of simple harmonic excitation according to claim 2, characterized in that, The dynamic force sensor (2) is fixedly mounted on the surface of the connecting screw (1), and one end of the connecting screw (1) is fixedly connected to the vibrator (3). The vibrator (3) is rotatably mounted inside the base (4) via a lead screw.

4. The identification test device for the dynamic coefficient of a gas turbine squeeze film damper based on the principle of simple harmonic excitation according to claim 2, characterized in that, The damper assembly includes an elastic squirrel cage support (5), an outer ring of an extrusion oil film damper (6), an oil supply nozzle (7), a pressure gauge (8), an end seal of the extrusion oil film damper (9), an oil discharge nozzle (10), an elastic squirrel cage support seat (11), and an outer ring support seat of the extrusion oil film damper (12). The connecting screw (1) is fixedly connected to the elastic squirrel cage support (5) and is used to transmit the force generated by the vibrator (3) to the elastic squirrel cage support (5).

5. The identification test device for the dynamic coefficient of a gas turbine squeeze film damper based on the principle of simple harmonic excitation according to claim 4, characterized in that, The damper assembly also includes a drain nozzle (13), a displacement sensor fixture (14), a displacement sensor (15), and an oil collection plate (16). The drain nozzle (13) is disposed on the oil collection plate (16). The displacement sensor fixture (14) is fixedly disposed inside the elastic squirrel cage support (5) by bolts, and the displacement sensor (15) is disposed on the surface of the displacement sensor fixture (14) by bolts. The oil collection plate (16) is fixedly disposed on the surface of the elastic squirrel cage support (11) and the outer ring support of the squeeze oil film damper (12).

6. The identification test device for the dynamic coefficient of a gas turbine squeeze film damper based on the principle of simple harmonic excitation according to claim 4, characterized in that, The outer ring (6) of the extrusion oil film damper is sleeved on the surface of the elastic squirrel cage support (5). The oil supply nozzle (7) is set on the surface of the outer ring (6) of the extrusion oil film damper, and one end is connected to the elastic squirrel cage support (5). The pressure gauge (8) is fixedly set on the surface of the oil supply nozzle (7). The end seal (9) of the extrusion oil film damper is sleeved between the inner arc surface of the outer ring (6) of the extrusion oil film damper and the outer arc surface of the elastic squirrel cage support (5).

7. The identification test device for the dynamic coefficient of a gas turbine squeeze film damper based on the principle of simple harmonic excitation according to claim 4, characterized in that, The oil drain nozzle (10) is fixedly installed below the outer ring (6) of the extrusion oil film damper, and one end of the oil drain nozzle (10) passes through the outer ring (6) of the extrusion oil film damper and communicates with the elastic squirrel cage support (5). The elastic squirrel cage support seat (11) and the outer ring support seat (12) of the extrusion oil film damper are fixedly connected to the elastic squirrel cage support (5) and the outer ring (6) of the extrusion oil film damper, respectively. The elastic squirrel cage support (5) and the outer ring (6) of the extrusion oil film damper are fixedly connected to the base (4).

8. A method for identifying the dynamic coefficient of a gas turbine extrusion film damper based on the principle of harmonic excitation, applied to the identification test device for the dynamic coefficient of a gas turbine extrusion film damper based on the principle of harmonic excitation as described in any one of claims 1-7, characterized in that, The specific steps include the following: S1: Based on the design requirements of the gas turbine, determine the core parameters under different operating conditions, including rotor speed n, target lubricating oil temperature T, target lubricating oil supply pressure P, and calculate the excitation frequency corresponding to the speed. S2: Complete the overall construction of the test bench and the connection of each system, and ensure that the elastic squirrel cage support (5), the extrusion oil film damper, the vibrator (3), and the sensor are installed in place, and that the lubrication system and the control and data acquisition system are connected smoothly. S3: The electric heater LE1 is started by the controller PC1 to heat the lubricating oil in the lubricating oil tank YX1. The oil temperature is monitored in real time by the thermocouple TE1 until the lubricating oil temperature reaches the set value T. After the oil temperature reaches the standard, the controller PC1 first starts the lubricating oil return pump LM2, and then starts the lubricating oil supply pump LM1. The lubricating oil is filtered by the lubricating oil supply filter LQ1 and enters the squeezing oil film damper through the oil supply nozzle (7) to form an effective internal oil film. The output of the lubricating oil supply pump LM1 is adjusted so that the oil supply pressure displayed by the pressure gauge (8) is stabilized at the set value P. S4: The exciter in the X direction is triggered by the controller PC1. The excitation output power is set to P1, the excitation frequency is υ, and the trigger signal is a sine signal. The original data of excitation force OF1x and OF1y in the X and Y directions are collected by the dynamic force sensor (2). The original data of displacement in the X and Y directions OD1x and OD1y are collected by the displacement sensor (15). All the original data are transmitted to the data acquisition system PC2 for storage in real time. The controller PC1 triggers only the Y-direction exciter, sets the excitation output power to P2, the excitation frequency to υ, and the trigger signal to a cosine signal. The data acquisition process is repeated. The original excitation force data OF2x and OF2y are collected by the dynamic force sensor (2), and the original displacement data OD2x and OD2y are collected by the displacement sensor (15). The data is then transmitted to PC2 for storage. S5: The data is filtered, Fourier transformed and parameters are extracted, and unit calibration is performed. Then, the matrix equation is established, the matrix is ​​determined to be invertible, the dynamic coefficients are solved, the dynamic coefficients are identified, and finally the dynamic coefficients of the gas turbine extrusion oil film damper are obtained based on the principle of simple harmonic excitation.

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